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<!DOCTYPE html>
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python-ffmpegio
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<!-- Local TOC -->
<div class="local-toc"><ul>
<li><a class="reference internal" href="#">Filtergraph Builder Reference</a><ul>
<li><a class="reference internal" href="#accessing-filter-information-on-ffmpeg">Accessing filter information on FFmpeg</a></li>
<li><a class="reference internal" href="#constructing-filtergraphs">Constructing filtergraphs</a><ul>
<li><a class="reference internal" href="#filtegraph-stacking"><code class="docutils literal notranslate"><span class="pre">|</span></code>: filtegraph stacking</a></li>
<li><a class="reference internal" href="#n-filtergraph-self-stacking"><code class="docutils literal notranslate"><span class="pre">*</span> <span class="pre">n</span></code>: filtergraph self-stacking</a></li>
<li><a class="reference internal" href="#filtergraph-joining"><code class="docutils literal notranslate"><span class="pre">+</span></code>: filtergraph joining</a></li>
<li><a class="reference internal" href="#filtergraph-labeling-filtergraph-p2p-linking"><code class="xref py py-obj docutils literal notranslate"><span class="pre">>></span></code> filtergraph labeling / filtergraph p2p linking</a><ul>
<li><a class="reference internal" href="#filter-pad-labeling">Filter pad labeling</a></li>
<li><a class="reference internal" href="#filtergraph-linking">Filtergraph linking</a></li>
<li><a class="reference internal" href="#filter-pad-indexing">Filter pad indexing</a></li>
</ul>
</li>
<li><a class="reference internal" href="#graph-link-within-filtergraph-linking"><code class="xref py py-func docutils literal notranslate"><span class="pre">Graph.link()</span></code> - within-filtergraph linking</a></li>
<li><a class="reference internal" href="#examples">Examples</a><ul>
<li><a class="reference internal" href="#simple-example">Simple example</a></li>
<li><a class="reference internal" href="#concat-with-preprocessing-stage">Concat with preprocessing stage</a></li>
</ul>
</li>
</ul>
</li>
<li><a class="reference internal" href="#generating-filtergraph-script-for-extremely-long-filtergraph">Generating filtergraph script for extremely long filtergraph</a></li>
<li><a class="reference internal" href="#filtergraph-api-reference">Filtergraph API Reference</a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.as_filter"><code class="docutils literal notranslate"><span class="pre">as_filter()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.as_filterchain"><code class="docutils literal notranslate"><span class="pre">as_filterchain()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.as_filtergraph"><code class="docutils literal notranslate"><span class="pre">as_filtergraph()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.as_filtergraph_object"><code class="docutils literal notranslate"><span class="pre">as_filtergraph_object()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter"><code class="docutils literal notranslate"><span class="pre">Filter</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.Error"><code class="docutils literal notranslate"><span class="pre">Filter.Error</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.Error.add_note"><code class="docutils literal notranslate"><span class="pre">Filter.Error.add_note()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.Error.with_traceback"><code class="docutils literal notranslate"><span class="pre">Filter.Error.with_traceback()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.InvalidName"><code class="docutils literal notranslate"><span class="pre">Filter.InvalidName</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.InvalidName.add_note"><code class="docutils literal notranslate"><span class="pre">Filter.InvalidName.add_note()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.InvalidName.with_traceback"><code class="docutils literal notranslate"><span class="pre">Filter.InvalidName.with_traceback()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.InvalidOption"><code class="docutils literal notranslate"><span class="pre">Filter.InvalidOption</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.InvalidOption.add_note"><code class="docutils literal notranslate"><span class="pre">Filter.InvalidOption.add_note()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.InvalidOption.with_traceback"><code class="docutils literal notranslate"><span class="pre">Filter.InvalidOption.with_traceback()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.Unsupported"><code class="docutils literal notranslate"><span class="pre">Filter.Unsupported</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.Unsupported.add_note"><code class="docutils literal notranslate"><span class="pre">Filter.Unsupported.add_note()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.Unsupported.with_traceback"><code class="docutils literal notranslate"><span class="pre">Filter.Unsupported.with_traceback()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.add_label"><code class="docutils literal notranslate"><span class="pre">Filter.add_label()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.apply"><code class="docutils literal notranslate"><span class="pre">Filter.apply()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.attach"><code class="docutils literal notranslate"><span class="pre">Filter.attach()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.compose"><code class="docutils literal notranslate"><span class="pre">Filter.compose()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.connect"><code class="docutils literal notranslate"><span class="pre">Filter.connect()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.count"><code class="docutils literal notranslate"><span class="pre">Filter.count()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.get_input_pad"><code class="docutils literal notranslate"><span class="pre">Filter.get_input_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.get_label"><code class="docutils literal notranslate"><span class="pre">Filter.get_label()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.get_num_chains"><code class="docutils literal notranslate"><span class="pre">Filter.get_num_chains()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.get_num_filters"><code class="docutils literal notranslate"><span class="pre">Filter.get_num_filters()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.get_num_inputs"><code class="docutils literal notranslate"><span class="pre">Filter.get_num_inputs()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.get_num_outputs"><code class="docutils literal notranslate"><span class="pre">Filter.get_num_outputs()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.get_num_pads"><code class="docutils literal notranslate"><span class="pre">Filter.get_num_pads()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.get_output_pad"><code class="docutils literal notranslate"><span class="pre">Filter.get_output_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.index"><code class="docutils literal notranslate"><span class="pre">Filter.index()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.iter_chains"><code class="docutils literal notranslate"><span class="pre">Filter.iter_chains()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.iter_input_labels"><code class="docutils literal notranslate"><span class="pre">Filter.iter_input_labels()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.iter_input_pads"><code class="docutils literal notranslate"><span class="pre">Filter.iter_input_pads()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.iter_output_labels"><code class="docutils literal notranslate"><span class="pre">Filter.iter_output_labels()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.iter_output_pads"><code class="docutils literal notranslate"><span class="pre">Filter.iter_output_pads()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.join"><code class="docutils literal notranslate"><span class="pre">Filter.join()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.next_input_pad"><code class="docutils literal notranslate"><span class="pre">Filter.next_input_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.next_output_pad"><code class="docutils literal notranslate"><span class="pre">Filter.next_output_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.rattach"><code class="docutils literal notranslate"><span class="pre">Filter.rattach()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.rconnect"><code class="docutils literal notranslate"><span class="pre">Filter.rconnect()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.resolve_pad_index"><code class="docutils literal notranslate"><span class="pre">Filter.resolve_pad_index()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.resolve_pad_indices"><code class="docutils literal notranslate"><span class="pre">Filter.resolve_pad_indices()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.rjoin"><code class="docutils literal notranslate"><span class="pre">Filter.rjoin()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Filter.stack"><code class="docutils literal notranslate"><span class="pre">Filter.stack()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain"><code class="docutils literal notranslate"><span class="pre">Chain</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.Error"><code class="docutils literal notranslate"><span class="pre">Chain.Error</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.Error.add_note"><code class="docutils literal notranslate"><span class="pre">Chain.Error.add_note()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.Error.with_traceback"><code class="docutils literal notranslate"><span class="pre">Chain.Error.with_traceback()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.add_label"><code class="docutils literal notranslate"><span class="pre">Chain.add_label()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.append"><code class="docutils literal notranslate"><span class="pre">Chain.append()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.attach"><code class="docutils literal notranslate"><span class="pre">Chain.attach()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.clear"><code class="docutils literal notranslate"><span class="pre">Chain.clear()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.compose"><code class="docutils literal notranslate"><span class="pre">Chain.compose()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.connect"><code class="docutils literal notranslate"><span class="pre">Chain.connect()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.count"><code class="docutils literal notranslate"><span class="pre">Chain.count()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.extend"><code class="docutils literal notranslate"><span class="pre">Chain.extend()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.get_input_pad"><code class="docutils literal notranslate"><span class="pre">Chain.get_input_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.get_label"><code class="docutils literal notranslate"><span class="pre">Chain.get_label()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.get_num_chains"><code class="docutils literal notranslate"><span class="pre">Chain.get_num_chains()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.get_num_filters"><code class="docutils literal notranslate"><span class="pre">Chain.get_num_filters()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.get_num_inputs"><code class="docutils literal notranslate"><span class="pre">Chain.get_num_inputs()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.get_num_outputs"><code class="docutils literal notranslate"><span class="pre">Chain.get_num_outputs()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.get_num_pads"><code class="docutils literal notranslate"><span class="pre">Chain.get_num_pads()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.get_output_pad"><code class="docutils literal notranslate"><span class="pre">Chain.get_output_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.index"><code class="docutils literal notranslate"><span class="pre">Chain.index()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.insert"><code class="docutils literal notranslate"><span class="pre">Chain.insert()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.is_last_filter"><code class="docutils literal notranslate"><span class="pre">Chain.is_last_filter()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.iter_chains"><code class="docutils literal notranslate"><span class="pre">Chain.iter_chains()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.iter_input_labels"><code class="docutils literal notranslate"><span class="pre">Chain.iter_input_labels()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.iter_input_pads"><code class="docutils literal notranslate"><span class="pre">Chain.iter_input_pads()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.iter_output_labels"><code class="docutils literal notranslate"><span class="pre">Chain.iter_output_labels()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.iter_output_pads"><code class="docutils literal notranslate"><span class="pre">Chain.iter_output_pads()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.join"><code class="docutils literal notranslate"><span class="pre">Chain.join()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.next_input_pad"><code class="docutils literal notranslate"><span class="pre">Chain.next_input_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.next_output_pad"><code class="docutils literal notranslate"><span class="pre">Chain.next_output_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.pop"><code class="docutils literal notranslate"><span class="pre">Chain.pop()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.rattach"><code class="docutils literal notranslate"><span class="pre">Chain.rattach()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.rconnect"><code class="docutils literal notranslate"><span class="pre">Chain.rconnect()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.remove"><code class="docutils literal notranslate"><span class="pre">Chain.remove()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.resolve_pad_index"><code class="docutils literal notranslate"><span class="pre">Chain.resolve_pad_index()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.resolve_pad_indices"><code class="docutils literal notranslate"><span class="pre">Chain.resolve_pad_indices()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.reverse"><code class="docutils literal notranslate"><span class="pre">Chain.reverse()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.rjoin"><code class="docutils literal notranslate"><span class="pre">Chain.rjoin()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Chain.stack"><code class="docutils literal notranslate"><span class="pre">Chain.stack()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph"><code class="docutils literal notranslate"><span class="pre">Graph</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.Error"><code class="docutils literal notranslate"><span class="pre">Graph.Error</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.Error.add_note"><code class="docutils literal notranslate"><span class="pre">Graph.Error.add_note()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.Error.with_traceback"><code class="docutils literal notranslate"><span class="pre">Graph.Error.with_traceback()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.FilterPadMediaTypeMismatch"><code class="docutils literal notranslate"><span class="pre">Graph.FilterPadMediaTypeMismatch</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.FilterPadMediaTypeMismatch.add_note"><code class="docutils literal notranslate"><span class="pre">Graph.FilterPadMediaTypeMismatch.add_note()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.FilterPadMediaTypeMismatch.with_traceback"><code class="docutils literal notranslate"><span class="pre">Graph.FilterPadMediaTypeMismatch.with_traceback()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.InvalidFilterPadId"><code class="docutils literal notranslate"><span class="pre">Graph.InvalidFilterPadId</span></code></a><ul>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.InvalidFilterPadId.add_note"><code class="docutils literal notranslate"><span class="pre">Graph.InvalidFilterPadId.add_note()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.InvalidFilterPadId.with_traceback"><code class="docutils literal notranslate"><span class="pre">Graph.InvalidFilterPadId.with_traceback()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.add_label"><code class="docutils literal notranslate"><span class="pre">Graph.add_label()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.append"><code class="docutils literal notranslate"><span class="pre">Graph.append()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.are_linked"><code class="docutils literal notranslate"><span class="pre">Graph.are_linked()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.as_script_file"><code class="docutils literal notranslate"><span class="pre">Graph.as_script_file()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.attach"><code class="docutils literal notranslate"><span class="pre">Graph.attach()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.clear"><code class="docutils literal notranslate"><span class="pre">Graph.clear()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.compose"><code class="docutils literal notranslate"><span class="pre">Graph.compose()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.connect"><code class="docutils literal notranslate"><span class="pre">Graph.connect()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.count"><code class="docutils literal notranslate"><span class="pre">Graph.count()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.extend"><code class="docutils literal notranslate"><span class="pre">Graph.extend()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.get_input_pad"><code class="docutils literal notranslate"><span class="pre">Graph.get_input_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.get_label"><code class="docutils literal notranslate"><span class="pre">Graph.get_label()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.get_num_chains"><code class="docutils literal notranslate"><span class="pre">Graph.get_num_chains()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.get_num_filters"><code class="docutils literal notranslate"><span class="pre">Graph.get_num_filters()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.get_num_inputs"><code class="docutils literal notranslate"><span class="pre">Graph.get_num_inputs()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.get_num_outputs"><code class="docutils literal notranslate"><span class="pre">Graph.get_num_outputs()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.get_num_pads"><code class="docutils literal notranslate"><span class="pre">Graph.get_num_pads()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.get_output_pad"><code class="docutils literal notranslate"><span class="pre">Graph.get_output_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.index"><code class="docutils literal notranslate"><span class="pre">Graph.index()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.insert"><code class="docutils literal notranslate"><span class="pre">Graph.insert()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.is_chain_siso"><code class="docutils literal notranslate"><span class="pre">Graph.is_chain_siso()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.iter_chains"><code class="docutils literal notranslate"><span class="pre">Graph.iter_chains()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.iter_input_labels"><code class="docutils literal notranslate"><span class="pre">Graph.iter_input_labels()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.iter_input_pads"><code class="docutils literal notranslate"><span class="pre">Graph.iter_input_pads()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.iter_output_labels"><code class="docutils literal notranslate"><span class="pre">Graph.iter_output_labels()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.iter_output_pads"><code class="docutils literal notranslate"><span class="pre">Graph.iter_output_pads()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.join"><code class="docutils literal notranslate"><span class="pre">Graph.join()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.link"><code class="docutils literal notranslate"><span class="pre">Graph.link()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.next_input_pad"><code class="docutils literal notranslate"><span class="pre">Graph.next_input_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.next_output_pad"><code class="docutils literal notranslate"><span class="pre">Graph.next_output_pad()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.pop"><code class="docutils literal notranslate"><span class="pre">Graph.pop()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.rattach"><code class="docutils literal notranslate"><span class="pre">Graph.rattach()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.rconnect"><code class="docutils literal notranslate"><span class="pre">Graph.rconnect()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.remove"><code class="docutils literal notranslate"><span class="pre">Graph.remove()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.remove_label"><code class="docutils literal notranslate"><span class="pre">Graph.remove_label()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.rename_label"><code class="docutils literal notranslate"><span class="pre">Graph.rename_label()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.resolve_pad_index"><code class="docutils literal notranslate"><span class="pre">Graph.resolve_pad_index()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.resolve_pad_indices"><code class="docutils literal notranslate"><span class="pre">Graph.resolve_pad_indices()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.reverse"><code class="docutils literal notranslate"><span class="pre">Graph.reverse()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.rjoin"><code class="docutils literal notranslate"><span class="pre">Graph.rjoin()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.stack"><code class="docutils literal notranslate"><span class="pre">Graph.stack()</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.sws_flags"><code class="docutils literal notranslate"><span class="pre">Graph.sws_flags</span></code></a></li>
<li><a class="reference internal" href="#ffmpegio.filtergraph.Graph.unlink"><code class="docutils literal notranslate"><span class="pre">Graph.unlink()</span></code></a></li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>
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<section id="filtergraph-builder-reference">
<span id="filtergraph"></span><h1>Filtergraph Builder Reference<a class="headerlink" href="#filtergraph-builder-reference" title="Link to this heading"></a></h1>
<p>One of the great feature of FFmpeg is the plethora of filters to manipulate video and audio data.
See <a class="reference external" href="https://ffmpeg.org/ffmpeg-filters.html">the official FFmpeg Filters Documentation</a> and
<a class="reference external" href="https://trac.ffmpeg.org/#Filtering">FFmpeg Wiki articles on Filtering</a>.</p>
<p>All the media I/O operations in <code class="xref py py-mod docutils literal notranslate"><span class="pre">ffmpegio</span></code> support FFmpeg filtering via per-stream
<code class="docutils literal notranslate"><span class="pre">filter</span></code>, <code class="docutils literal notranslate"><span class="pre">vf</span></code>, <code class="docutils literal notranslate"><span class="pre">af</span></code>, and <code class="docutils literal notranslate"><span class="pre">filter_script</span></code> output options as well as the <code class="docutils literal notranslate"><span class="pre">filter_complex</span></code> and
<code class="docutils literal notranslate"><span class="pre">filter_complex_script</span></code> global option. These options are typically specified by filtergraph
expression strings. For example, <code class="docutils literal notranslate"><span class="pre">'scale=iw/2:-1'</span></code> to reduce the video frame size by half. Multiple
operations can be performed in sequence by chaining the filters, e.g., <code class="docutils literal notranslate"><span class="pre">'afade=t=in:d=1,afade=t=out:st=9:d=1'</span></code>
adds fade-in and fade-out effect to an audio stream. More complex filtergraph with multiple chains
can also be specified, but as the complexity increases the expression length also increases.
The <code class="xref py py-mod docutils literal notranslate"><span class="pre">ffmpegio.filtergraph</span></code> submodule is designed to assist building complex filtergraphs. The
module serves 3 primary functions:</p>
<ul class="simple">
<li><p><a class="reference internal" href="#access"><span class="std std-ref">Accessing filter information on FFmpeg</span></a></p></li>
<li><p><a class="reference internal" href="#build"><span class="std std-ref">Constructing filtergraphs</span></a></p></li>
<li><p><a class="reference internal" href="#script"><span class="std std-ref">Generating filtergraph script for extremely long filtergraph</span></a></p></li>
</ul>
<p>These functions are served by three classes:</p>
<table class="autosummary longtable docutils align-default">
<tbody>
<tr class="row-odd"><td><p><a class="reference internal" href="#ffmpegio.filtergraph.Filter" title="ffmpegio.filtergraph.Filter"><code class="xref py py-obj docutils literal notranslate"><span class="pre">ffmpegio.filtergraph.Filter</span></code></a></p></td>
<td><p>FFmpeg filter definition immutable class</p></td>
</tr>
<tr class="row-even"><td><p><a class="reference internal" href="#ffmpegio.filtergraph.Chain" title="ffmpegio.filtergraph.Chain"><code class="xref py py-obj docutils literal notranslate"><span class="pre">ffmpegio.filtergraph.Chain</span></code></a></p></td>
<td><p>List of FFmpeg filters, connected in series</p></td>
</tr>
<tr class="row-odd"><td><p><a class="reference internal" href="#ffmpegio.filtergraph.Graph" title="ffmpegio.filtergraph.Graph"><code class="xref py py-obj docutils literal notranslate"><span class="pre">ffmpegio.filtergraph.Graph</span></code></a></p></td>
<td><p>List of FFmpeg filterchains in parallel with interchain link specifications</p></td>
</tr>
</tbody>
</table>
<p>See <a class="reference internal" href="#api"><span class="std std-ref">Filtergraph API Reference</span></a> section below for the full documentation of these classes
and other helper functions.</p>
<p>All filtergraph classes can be instantiated with a valid filtergraph description string and yield
filtergraph descriptions when converted to <code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code>.</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">ffmpegio.filtergraph</span> <span class="k">as</span> <span class="nn">fgb</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># for a simple chain, use either Chain or Graph</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">(</span><span class="s1">'afade=t=in:d=1,afade=t=out:st=9:d=1'</span><span class="p">)</span>
<span class="go"><ffmpegio.filtergraph.Chain.Chain object at 0x7f95df033110></span>
<span class="go"> FFmpeg expression: "[UNC0]afade=t=in:d=1[UNC2];[UNC1]afade=t=out:st=9:d=1[UNC3]"</span>
<span class="go"> Number of filters: 2</span>
<span class="go"> Input pads (1): (0, 0)</span>
<span class="go"> Output pads: (1): (1, 0)</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'afade=t=in:d=1,afade=t=out:st=9:d=1'</span><span class="p">)</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95df031970></span>
<span class="go"> FFmpeg expression: "afade=t=in:d=1,afade=t=out:st=9:d=1"</span>
<span class="go"> Number of chains: 1</span>
<span class="go"> chain[0]: [UNC0]afade=t=in:d=1,afade=t=out:st=9:d=1[UNC1] </span>
<span class="go"> Available input pads (1): (0, 0, 0)</span>
<span class="go"> Available output pads: (1): (0, 1, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># construct the chain from filters</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Filter</span><span class="p">(</span><span class="s1">'afade=t=in:d=1'</span><span class="p">)</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Filter</span><span class="p">(</span><span class="s1">'afade=t=out:st=9:d=1'</span><span class="p">)</span>
<span class="go"><ffmpegio.filtergraph.Chain.Chain object at 0x7f95cfe9e3f0></span>
<span class="go"> FFmpeg expression: "[UNC0]afade=t=in:d=1[UNC2];[UNC1]afade=t=out:st=9:d=1[UNC3]"</span>
<span class="go"> Number of filters: 2</span>
<span class="go"> Input pads (1): (0, 0)</span>
<span class="go"> Output pads: (1): (1, 0)</span>
</pre></div>
</div>
<p>All <code class="xref py py-mod docutils literal notranslate"><span class="pre">ffmpegio</span></code> functions that take filter options accept these objects as input arguments
and convert to <code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code> internally:</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">fs</span><span class="p">,</span> <span class="n">x</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">audio</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'input.mp3'</span><span class="p">,</span> <span class="n">af</span><span class="o">=</span><span class="n">fg</span><span class="p">)</span>
<span class="gp">>>> </span><span class="c1"># x contains the audio samples with the fading effects</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>The simplified examples on this pages are for illustration purpose only. If a filtergraph is
simple and does not require programmatic construction, use plain :py:class`str` expressions to
improve the runtime speed.</p>
</div>
<section id="accessing-filter-information-on-ffmpeg">
<span id="access"></span><h2>Accessing filter information on FFmpeg<a class="headerlink" href="#accessing-filter-information-on-ffmpeg" title="Link to this heading"></a></h2>
<p>Filters can be instantiated in a several different ways:</p>
<ul class="simple">
<li><p><code class="xref py py-class docutils literal notranslate"><span class="pre">fgb.Filter</span></code> constructor with option values as arguments</p></li>
<li><p><code class="xref py py-class docutils literal notranslate"><span class="pre">fgb.Filter</span></code> constructor with a single-filter filtergraph description</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">fgb.<filter_name></span></code> dynamic function (where <code class="docutils literal notranslate"><span class="pre"><filter_name>></span></code> is the
name of a FFmpeg filter)</p></li>
</ul>
<p>For example, a crop filter <code class="docutils literal notranslate"><span class="pre">crop=in_w-100:in_h-100:x=100:y=100</span></code> can be created
by any of the following 3 lines:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Filter</span><span class="p">(</span><span class="s1">'crop'</span><span class="p">,</span> <span class="s1">'in_w-100'</span><span class="p">,</span> <span class="s1">'in_h-100'</span><span class="p">,</span> <span class="n">x</span><span class="o">=</span><span class="mi">100</span><span class="p">,</span> <span class="n">y</span><span class="o">=</span><span class="mi">100</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Filter.py"</span>, line <span class="m">164</span>, in <span class="n">__repr__</span>
<span class="w"> </span><span class="n">FFmpeg</span> <span class="n">expression</span><span class="p">:</span> \<span class="s2">"{self.compose(True,True)}</span><span class="se">\"</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Filter.py"</span>, line <span class="m">154</span>, in <span class="n">compose</span>
<span class="w"> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">data</span><span class="p">)</span><span class="o">.</span><span class="n">compose</span><span class="p">(</span>
<span class="w"> </span><span class="pm">^^^^^^^^^</span>
<span class="gr">AttributeError</span>: <span class="n">'Filter' object has no attribute 'data'</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Filter</span><span class="p">(</span><span class="s1">'crop=in_w-100:in_h-100:x=100:y=100'</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Filter.py"</span>, line <span class="m">164</span>, in <span class="n">__repr__</span>
<span class="w"> </span><span class="n">FFmpeg</span> <span class="n">expression</span><span class="p">:</span> \<span class="s2">"{self.compose(True,True)}</span><span class="se">\"</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Filter.py"</span>, line <span class="m">154</span>, in <span class="n">compose</span>
<span class="w"> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">data</span><span class="p">)</span><span class="o">.</span><span class="n">compose</span><span class="p">(</span>
<span class="w"> </span><span class="pm">^^^^^^^^^</span>
<span class="gr">AttributeError</span>: <span class="n">'Filter' object has no attribute 'data'</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">crop</span><span class="p">(</span><span class="s1">'in_w-100'</span><span class="p">,</span> <span class="s1">'in_h-100'</span><span class="p">,</span> <span class="n">x</span><span class="o">=</span><span class="mi">100</span><span class="p">,</span> <span class="n">y</span><span class="o">=</span><span class="mi">100</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Filter.py"</span>, line <span class="m">164</span>, in <span class="n">__repr__</span>
<span class="w"> </span><span class="n">FFmpeg</span> <span class="n">expression</span><span class="p">:</span> \<span class="s2">"{self.compose(True,True)}</span><span class="se">\"</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Filter.py"</span>, line <span class="m">154</span>, in <span class="n">compose</span>
<span class="w"> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">data</span><span class="p">)</span><span class="o">.</span><span class="n">compose</span><span class="p">(</span>
<span class="w"> </span><span class="pm">^^^^^^^^^</span>
<span class="gr">AttributeError</span>: <span class="n">'Filter' object has no attribute 'data'</span>
</pre></div>
</div>
<p>The :py:func`fgb.crop` function is dynamically created when user call it for the
first time. If the function name fails to resolve an FFmpeg filter, an
<code class="xref py py-exc docutils literal notranslate"><span class="pre">AttributeError</span></code> will be raised.</p>
<p>In addition, these dynamic functions get FFmpeg filter help text as their docstrings:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">help</span><span class="p">(</span><span class="n">fgb</span><span class="o">.</span><span class="n">crop</span><span class="p">)</span>
<span class="go">Help on function crop in module ffmpegio.filtergraph:</span>
<span class="go">crop(*args, filter_id=None, **kwargs)</span>
<span class="go"> Filter crop</span>
<span class="go"> Crop the input video.</span>
<span class="go"> Inputs:</span>
<span class="go"> #0: default (video)</span>
<span class="go"> Outputs:</span>
<span class="go"> #0: default (video)</span>
<span class="go"> crop AVOptions:</span>
<span class="go"> out_w <string> ..FV.....T. set the width crop area expression (default "iw")</span>
<span class="go"> w <string> ..FV.....T. set the width crop area expression (default "iw")</span>
<span class="go"> out_h <string> ..FV.....T. set the height crop area expression (default "ih")</span>
<span class="go"> h <string> ..FV.....T. set the height crop area expression (default "ih")</span>
<span class="go"> x <string> ..FV.....T. set the x crop area expression (default "(in_w-out_w)/2")</span>
<span class="go"> y <string> ..FV.....T. set the y crop area expression (default "(in_h-out_h)/2")</span>
<span class="go"> keep_aspect <boolean> ..FV....... keep aspect ratio (default false)</span>
<span class="go"> exact <boolean> ..FV....... do exact cropping (default false)</span>
</pre></div>
</div>
<p>Use <a class="reference internal" href="caps.html#ffmpegio.caps.filters" title="ffmpegio.caps.filters"><code class="xref py py-func docutils literal notranslate"><span class="pre">ffmpegio.caps.filters()</span></code></a> to get the full list of filters supported by the installed
FFmpeg and <a class="reference internal" href="caps.html#ffmpegio.caps.filter_info" title="ffmpegio.caps.filter_info"><code class="xref py py-func docutils literal notranslate"><span class="pre">ffmpegio.caps.filter_info()</span></code></a> to get a parsed version of the filter help text.</p>
</section>
<section id="constructing-filtergraphs">
<span id="build"></span><h2>Constructing filtergraphs<a class="headerlink" href="#constructing-filtergraphs" title="Link to this heading"></a></h2>
<p>A complex filtergraph can be authored using a combination of <a class="reference internal" href="#ffmpegio.filtergraph.Filter" title="ffmpegio.filtergraph.Filter"><code class="xref py py-class docutils literal notranslate"><span class="pre">Filter</span></code></a>, <a class="reference internal" href="#ffmpegio.filtergraph.Chain" title="ffmpegio.filtergraph.Chain"><code class="xref py py-class docutils literal notranslate"><span class="pre">Chain</span></code></a>,
and <a class="reference internal" href="#ffmpegio.filtergraph.Graph" title="ffmpegio.filtergraph.Graph"><code class="xref py py-class docutils literal notranslate"><span class="pre">Graph</span></code></a>. The following 4 operators are defined:</p>
<table class="docutils align-default">
<thead>
<tr class="row-odd"><th class="head"><p>Operator</p></th>
<th class="head"><p>Description</p></th>
</tr>
</thead>
<tbody>
<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">|</span></code></p></td>
<td><p>Stack sections (no linking)</p></td>
</tr>
<tr class="row-odd"><td><p><code class="docutils literal notranslate"><span class="pre">*</span> <span class="pre">n</span></code></p></td>
<td><p>Create <code class="docutils literal notranslate"><span class="pre">n</span></code> copies of itself and stack them</p></td>
</tr>
<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">+</span></code></p></td>
<td><p>Join filtergraph sections</p></td>
</tr>
<tr class="row-odd"><td><p><code class="docutils literal notranslate"><span class="pre">>></span></code></p></td>
<td><p>Point-to-point connection and pad labeling</p></td>
</tr>
</tbody>
</table>
<p>Other useful filtergraph manipulation class methods are:</p>
<table class="autosummary longtable docutils align-default">
<tbody>
</tbody>
</table>
<p>This section mainly describes the operators, leaving the details of the class methods to the API
reference section later on this page.</p>
<section id="filtegraph-stacking">
<h3><code class="docutils literal notranslate"><span class="pre">|</span></code>: filtegraph stacking<a class="headerlink" href="#filtegraph-stacking" title="Link to this heading"></a></h3>
<p>Stacking operation creates a new <a class="reference internal" href="#ffmpegio.filtergraph.Graph" title="ffmpegio.filtergraph.Graph"><code class="xref py py-class docutils literal notranslate"><span class="pre">Graph</span></code></a> object from two filtergraph objects, orienting
them in parallel without making any connections. The left and right sides do not need to be of the
same class, and they can be mixed and matched.</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># 1. given 2 filters</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">trim</span><span class="p">(</span><span class="mi">30</span><span class="p">,</span> <span class="mi">60</span><span class="p">)</span> <span class="o">|</span> <span class="n">fgb</span><span class="o">.</span><span class="n">trim</span><span class="p">(</span><span class="mi">90</span><span class="p">,</span> <span class="mi">120</span><span class="p">)</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd2060></span>
<span class="go"> FFmpeg expression: "trim=30:60;trim=90:120"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [UNC0]trim=30:60[UNC2];</span>
<span class="go"> chain[1]: [UNC1]trim=90:120[UNC3] </span>
<span class="go"> Available input pads (2): (0, 0, 0), (1, 0, 0)</span>
<span class="go"> Available output pads: (2): (0, 0, 0), (1, 0, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># 2. given 2 chains</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">(</span><span class="s1">'trim=30:60,scale=200:-1'</span><span class="p">)</span> <span class="o">|</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">(</span><span class="s1">'atrim=30:60,afade=t=in'</span><span class="p">)</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95df0319a0></span>
<span class="go"> FFmpeg expression: "trim=30:60,scale=200:-1;atrim=30:60,afade=t=in"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [UNC0]trim=30:60,scale=200:-1[UNC2];</span>
<span class="go"> chain[1]: [UNC1]atrim=30:60,afade=t=in[UNC3] </span>
<span class="go"> Available input pads (2): (0, 0, 0), (1, 0, 0)</span>
<span class="go"> Available output pads: (2): (0, 1, 0), (1, 1, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># 3. given 2 graphs</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'[0:v]trim=30:60,scale=200:-1[out]'</span><span class="p">)</span> <span class="o">|</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'[0:a]atrim=30:60,afade=t=in[out]'</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Graph.py"</span>, line <span class="m">835</span>, in <span class="n">_stack</span>
<span class="w"> </span><span class="n">fg</span><span class="o">.</span><span class="n">_links</span><span class="o">.</span><span class="n">update</span><span class="p">(</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">820</span>, in <span class="n">update</span>
<span class="w"> </span><span class="n">fglinks</span><span class="o">.</span><span class="n">create_label</span><span class="p">(</span><span class="n">l</span><span class="p">,</span> <span class="n">i</span><span class="p">,</span> <span class="n">o</span><span class="p">,</span> <span class="n">force</span><span class="p">)</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">656</span>, in <span class="n">create_label</span>
<span class="w"> </span><span class="n">label</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_resolve_label</span><span class="p">(</span><span class="n">label</span><span class="p">,</span> <span class="n">force</span><span class="o">=</span><span class="n">force</span><span class="p">,</span> <span class="n">check_stream_spec</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">337</span>, in <span class="n">_resolve_label</span>
<span class="w"> </span><span class="k">raise</span> <span class="n">GraphLinks</span><span class="o">.</span><span class="n">Error</span><span class="p">(</span><span class="sa">f</span><span class="s2">"</span><span class="si">{</span><span class="n">label</span><span class="si">=}</span><span class="s2"> is already in use."</span><span class="p">)</span>
<span class="gr">ffmpegio.filtergraph.GraphLinks.GraphLinks.Error</span>: <span class="n">label='out' is already in use.</span>
<span class="gt">The above exception was the direct cause of the following exception:</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">653</span>, in <span class="n">__or__</span>
<span class="w"> </span><span class="k">return</span> <span class="n">fgb</span><span class="o">.</span><span class="n">stack</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">other</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/build.py"</span>, line <span class="m">347</span>, in <span class="n">stack</span>
<span class="w"> </span><span class="n">fg</span> <span class="o">=</span> <span class="n">fg</span><span class="o">.</span><span class="n">_stack</span><span class="p">(</span><span class="n">fgb</span><span class="o">.</span><span class="n">as_filtergraph_object</span><span class="p">(</span><span class="n">other</span><span class="p">),</span> <span class="n">auto_link</span><span class="p">,</span> <span class="n">replace_sws_flags</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Graph.py"</span>, line <span class="m">842</span>, in <span class="n">_stack</span>
<span class="w"> </span><span class="k">raise</span> <span class="n">Graph</span><span class="o">.</span><span class="n">Error</span><span class="p">(</span><span class="n">e</span><span class="p">)</span> <span class="kn">from</span> <span class="nn">e</span>
<span class="gr">ffmpegio.filtergraph.Graph.Graph.Error</span>: <span class="n">label='out' is already in use.</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Duplicate link labels are automatically renamed with a trailing counter.</p>
</div>
</section>
<section id="n-filtergraph-self-stacking">
<h3><code class="docutils literal notranslate"><span class="pre">*</span> <span class="pre">n</span></code>: filtergraph self-stacking<a class="headerlink" href="#n-filtergraph-self-stacking" title="Link to this heading"></a></h3>
<p>Like Python lists and tuples, multipling any <code class="xref py py-mod docutils literal notranslate"><span class="pre">filtergraph</span></code> object by an integer creates a
<a class="reference internal" href="#ffmpegio.filtergraph.Graph" title="ffmpegio.filtergraph.Graph"><code class="xref py py-class docutils literal notranslate"><span class="pre">Graph</span></code></a> object containing <code class="docutils literal notranslate"><span class="pre">n</span></code> copies of the object and stack them (i.e., create parallel
chains).</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># multiplying filters</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">crop</span><span class="p">(</span><span class="mi">100</span><span class="p">,</span><span class="mi">100</span><span class="p">)</span> <span class="o">*</span> <span class="mi">3</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd2360></span>
<span class="go"> FFmpeg expression: "crop=100:100;crop=100:100;crop=100:100"</span>
<span class="go"> Number of chains: 3</span>
<span class="go"> chain[0]: [UNC0]crop=100:100[UNC3];</span>
<span class="go"> chain[1]: [UNC1]crop=100:100[UNC4];</span>
<span class="go"> chain[2]: [UNC2]crop=100:100[UNC5] </span>
<span class="go"> Available input pads (3): (0, 0, 0), (1, 0, 0), (2, 0, 0)</span>
<span class="go"> Available output pads: (3): (0, 0, 0), (1, 0, 0), (2, 0, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># multiplying chains</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">(</span><span class="s1">'fps=30,format=yuv420p'</span><span class="p">)</span> <span class="o">*</span> <span class="mi">2</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd25a0></span>
<span class="go"> FFmpeg expression: "fps=30,format=yuv420p;fps=30,format=yuv420p"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [UNC0]fps=30,format=yuv420p[UNC2];</span>
<span class="go"> chain[1]: [UNC1]fps=30,format=yuv420p[UNC3] </span>
<span class="go"> Available input pads (2): (0, 0, 0), (1, 0, 0)</span>
<span class="go"> Available output pads: (2): (0, 1, 0), (1, 1, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># multiplying graphs</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'color,[0]overlay[vout]'</span><span class="p">)</span> <span class="o">*</span> <span class="mi">2</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Graph.py"</span>, line <span class="m">835</span>, in <span class="n">_stack</span>
<span class="w"> </span><span class="n">fg</span><span class="o">.</span><span class="n">_links</span><span class="o">.</span><span class="n">update</span><span class="p">(</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">820</span>, in <span class="n">update</span>
<span class="w"> </span><span class="n">fglinks</span><span class="o">.</span><span class="n">create_label</span><span class="p">(</span><span class="n">l</span><span class="p">,</span> <span class="n">i</span><span class="p">,</span> <span class="n">o</span><span class="p">,</span> <span class="n">force</span><span class="p">)</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">656</span>, in <span class="n">create_label</span>
<span class="w"> </span><span class="n">label</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">_resolve_label</span><span class="p">(</span><span class="n">label</span><span class="p">,</span> <span class="n">force</span><span class="o">=</span><span class="n">force</span><span class="p">,</span> <span class="n">check_stream_spec</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">337</span>, in <span class="n">_resolve_label</span>
<span class="w"> </span><span class="k">raise</span> <span class="n">GraphLinks</span><span class="o">.</span><span class="n">Error</span><span class="p">(</span><span class="sa">f</span><span class="s2">"</span><span class="si">{</span><span class="n">label</span><span class="si">=}</span><span class="s2"> is already in use."</span><span class="p">)</span>
<span class="gr">ffmpegio.filtergraph.GraphLinks.GraphLinks.Error</span>: <span class="n">label='vout' is already in use.</span>
<span class="gt">The above exception was the direct cause of the following exception:</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">643</span>, in <span class="n">__mul__</span>
<span class="w"> </span><span class="k">return</span> <span class="n">fgb</span><span class="o">.</span><span class="n">stack</span><span class="p">(</span><span class="o">*</span><span class="p">((</span><span class="bp">self</span><span class="p">,)</span> <span class="o">*</span> <span class="n">__n</span><span class="p">))</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/build.py"</span>, line <span class="m">347</span>, in <span class="n">stack</span>
<span class="w"> </span><span class="n">fg</span> <span class="o">=</span> <span class="n">fg</span><span class="o">.</span><span class="n">_stack</span><span class="p">(</span><span class="n">fgb</span><span class="o">.</span><span class="n">as_filtergraph_object</span><span class="p">(</span><span class="n">other</span><span class="p">),</span> <span class="n">auto_link</span><span class="p">,</span> <span class="n">replace_sws_flags</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Graph.py"</span>, line <span class="m">842</span>, in <span class="n">_stack</span>
<span class="w"> </span><span class="k">raise</span> <span class="n">Graph</span><span class="o">.</span><span class="n">Error</span><span class="p">(</span><span class="n">e</span><span class="p">)</span> <span class="kn">from</span> <span class="nn">e</span>
<span class="gr">ffmpegio.filtergraph.Graph.Graph.Error</span>: <span class="n">label='vout' is already in use.</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Multiplied link labels receive unique labels with trailing counter.</p>
</div>
</section>
<section id="filtergraph-joining">
<h3><code class="docutils literal notranslate"><span class="pre">+</span></code>: filtergraph joining<a class="headerlink" href="#filtergraph-joining" title="Link to this heading"></a></h3>
<p>Join operation connects two <code class="xref py py-mod docutils literal notranslate"><span class="pre">filtergraph</span></code> objects by auto-linking the available output
pads of the left side and the available input pads of the right side. The output object type depends
on the input types.</p>
<p>Joining a single-output object to a single-input object connection is trivial. If both are of either
<a class="reference internal" href="#ffmpegio.filtergraph.Filter" title="ffmpegio.filtergraph.Filter"><code class="xref py py-class docutils literal notranslate"><span class="pre">Filter</span></code></a> or <a class="reference internal" href="#ffmpegio.filtergraph.Chain" title="ffmpegio.filtergraph.Chain"><code class="xref py py-class docutils literal notranslate"><span class="pre">Chain</span></code></a> classes, they are joined in series, resulting in
<a class="reference internal" href="#ffmpegio.filtergraph.Chain" title="ffmpegio.filtergraph.Chain"><code class="xref py py-class docutils literal notranslate"><span class="pre">Chain</span></code></a> object. If <a class="reference internal" href="#ffmpegio.filtergraph.Graph" title="ffmpegio.filtergraph.Graph"><code class="xref py py-class docutils literal notranslate"><span class="pre">Graph</span></code></a> is involved, the joining chain is extended with the
other object.</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># 1. joining 2 filters:</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">trim</span><span class="p">(</span><span class="mi">60</span><span class="p">,</span><span class="mi">120</span><span class="p">)</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">(</span><span class="s1">'crop=100:100:12:34,fps=30'</span><span class="p">)</span>
<span class="go"><ffmpegio.filtergraph.Chain.Chain object at 0x7f95cfcd20f0></span>
<span class="go"> FFmpeg expression: "[UNC0]trim=60:120[UNC3];[UNC1]crop=100:100:12:34[UNC4];[UNC2]fps=30[UNC5]"</span>
<span class="go"> Number of filters: 3</span>
<span class="go"> Input pads (1): (0, 0)</span>
<span class="go"> Output pads: (1): (2, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># 2. joining 2 graphs:</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'[0]fps=30[v0];[v0]overlay'</span><span class="p">)</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'split[v0][v1];[v1]hflip'</span><span class="p">)</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd2270></span>
<span class="go"> FFmpeg expression: "[0]fps=30[v0];[v0]overlay[L0];[L0]split[v1];[v1]hflip"</span>
<span class="go"> Number of chains: 4</span>
<span class="go"> chain[0]: [0]fps=30[v0];</span>
<span class="go"> chain[1]: [v0][UNC0]overlay[L0];</span>
<span class="go"> chain[2]: [L0]split[UNC1][v1];</span>
<span class="go"> chain[3]: [v1]hflip[UNC2] </span>
<span class="go"> Available input pads (1): (1, 0, 1)</span>
<span class="go"> Available output pads: (2): (2, 0, 0), (3, 0, 0)</span>
</pre></div>
</div>
<p>Joining multiple-output <a class="reference internal" href="#ffmpegio.filtergraph.Graph" title="ffmpegio.filtergraph.Graph"><code class="xref py py-class docutils literal notranslate"><span class="pre">Graph</span></code></a> object with multiple-input <a class="reference internal" href="#ffmpegio.filtergraph.Graph" title="ffmpegio.filtergraph.Graph"><code class="xref py py-class docutils literal notranslate"><span class="pre">Graph</span></code></a> object yields
a <a class="reference internal" href="#ffmpegio.filtergraph.Graph" title="ffmpegio.filtergraph.Graph"><code class="xref py py-class docutils literal notranslate"><span class="pre">Graph</span></code></a> object. The number of exposed filter pads must match on both sides. The pad
pairing is automatically performed in one of the two possible ways:</p>
<ol class="arabic simple">
<li><dl class="simple">
<dt>pairs the first unused output filter pad of each chain of the left filtergraph and the</dt><dd><p>first unused input filter pad of each chain of the right filtergraph (per-chain)</p>
</dd>
</dl>
</li>
<li><p>pairs all the unused filter pads of the left and right filtergraphs (all)</p></li>
</ol>
<p>Both pairing types require the two sides to have the matching number of unused pads. If no match is
attained per chain, then the all unused pads are paired. This mechanism allows the <code class="docutils literal notranslate"><span class="pre">+</span></code> operator to
support two important usecases involving branching and merging filters such as <code class="docutils literal notranslate"><span class="pre">overlay</span></code>,
<code class="docutils literal notranslate"><span class="pre">concat</span></code>, <code class="docutils literal notranslate"><span class="pre">split</span></code>, and <code class="docutils literal notranslate"><span class="pre">asplit</span></code>. The following examples demonstrate these cases:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># case 1: attaching a chain of one side to one of the multiple pads of the other</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">hflip</span><span class="p">()</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">hstack</span><span class="p">()</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd27b0></span>
<span class="go"> FFmpeg expression: "hflip[L0];[L0]hstack"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [UNC0]hflip[L0];</span>
<span class="go"> chain[1]: [L0][UNC1]hstack[UNC2] </span>
<span class="go"> Available input pads (2): (0, 0, 0), (1, 0, 1)</span>
<span class="go"> Available output pads: (1): (1, 0, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># case 2: connecting all the chains (one unused pad each) of one side to a filter with</span>
<span class="gp">>>> </span><span class="c1"># matching number of pads on the other side</span>
<span class="gp">>>> </span><span class="p">(</span><span class="n">fgb</span><span class="o">.</span><span class="n">hflip</span><span class="p">()</span> <span class="o">|</span> <span class="n">fgb</span><span class="o">.</span><span class="n">vflip</span><span class="p">())</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">hstack</span><span class="p">()</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd2960></span>
<span class="go"> FFmpeg expression: "hflip[L0];vflip[L1];[L0][L1]hstack"</span>
<span class="go"> Number of chains: 3</span>
<span class="go"> chain[0]: [UNC0]hflip[L0];</span>
<span class="go"> chain[1]: [UNC1]vflip[L1];</span>
<span class="go"> chain[2]: [L0][L1]hstack[UNC2] </span>
<span class="go"> Available input pads (2): (0, 0, 0), (1, 0, 0)</span>
<span class="go"> Available output pads: (1): (2, 0, 0)</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>If joining results in a multi-chain filtergraph, inter-chain links are <em>unnamed</em>, and when
converted to :py:class:<code class="docutils literal notranslate"><span class="pre">str</span></code> the unnamed links uses <code class="docutils literal notranslate"><span class="pre">L#</span></code> link names.</p>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Be aware of <a class="reference external" href="https://docs.python.org/3/reference/expressions.html#operator-precedence">the operator precedence</a>.
That is, <code class="docutils literal notranslate"><span class="pre">*</span></code> precedes <code class="docutils literal notranslate"><span class="pre">+</span></code>, and <code class="docutils literal notranslate"><span class="pre">+</span></code> precedes <code class="docutils literal notranslate"><span class="pre">|</span></code>.</p>
</div>
<p>When joining filtergraph objects with multiple inputs and outputs, <code class="docutils literal notranslate"><span class="pre">+</span></code></p>
</section>
<section id="filtergraph-labeling-filtergraph-p2p-linking">
<h3><code class="xref py py-obj docutils literal notranslate"><span class="pre">>></span></code> filtergraph labeling / filtergraph p2p linking<a class="headerlink" href="#filtergraph-labeling-filtergraph-p2p-linking" title="Link to this heading"></a></h3>
<p>The <code class="xref py py-obj docutils literal notranslate"><span class="pre">>></span></code> is a multi-purpose operator to label a filter pad and to stack two filtergraphs
with a single link between them. It also accepts optionally explicit filter pad id’s to override the
default selection policty of the first unused filter pad.</p>
<p>Simple usecases are:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># label input and output pads to a SISO filtergraph</span>
<span class="gp">>>> </span><span class="s1">'[in]'</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">scale</span><span class="p">(</span><span class="mi">100</span><span class="p">,</span><span class="o">-</span><span class="mi">2</span><span class="p">)</span> <span class="o">>></span> <span class="s1">'[out]'</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd23f0></span>
<span class="go"> FFmpeg expression: "[in]scale=100:-2[out]"</span>
<span class="go"> Number of chains: 1</span>
<span class="go"> chain[0]: [in]scale=100:-2[out] </span>
<span class="go"> Available input pads (1): (0, 0, 0)</span>
<span class="go"> Available output pads: (1): (0, 0, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># connect 2 filtergraphs with the first available filter pads</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">hflip</span><span class="p">()</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">concat</span><span class="p">()</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd21b0></span>
<span class="go"> FFmpeg expression: "hflip[L0];[L0]concat"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [UNC0]hflip[L0];</span>
<span class="go"> chain[1]: [L0][UNC1]concat[UNC2] </span>
<span class="go"> Available input pads (2): (0, 0, 0), (1, 0, 1)</span>
<span class="go"> Available output pads: (1): (1, 0, 0)</span>
</pre></div>
</div>
<section id="filter-pad-labeling">
<h4>Filter pad labeling<a class="headerlink" href="#filter-pad-labeling" title="Link to this heading"></a></h4>
<p>To label a filter pad, the label string must be fully specified with the square brackets:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="c1"># valid label strings</span>
<span class="s1">'[in]'</span> <span class="o">>></span> <span class="n">fg</span> <span class="c1"># valid FFmpeg link label (alphanumeric characters + '_' inside '[]')</span>
<span class="s1">'[0:v]'</span> <span class="o">>></span> <span class="n">fg</span> <span class="c1"># valid FFmpeg stream specifier (the first video stream of the first input url)</span>
<span class="c1"># incorrect label strings</span>
<span class="s1">'in'</span> <span class="o">>></span> <span class="n">fg</span> <span class="c1"># create an "in" Filter object (not a valid FFmpeg filter)</span>
<span class="s1">'0:v'</span> <span class="o">>></span> <span class="n">fg</span> <span class="c1"># fails to parse the string as a filtergraph</span>
</pre></div>
</div>
<p>To label multiple pads at once, provide a sequence of labels:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="p">[</span><span class="s1">'[0:v]'</span><span class="p">,</span><span class="s1">'[1:v]'</span><span class="p">]</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">(</span><span class="s1">'overlay,split'</span><span class="p">)</span> <span class="o">>></span> <span class="p">[</span><span class="s1">'[vout1]'</span><span class="p">,</span><span class="s1">'[vout2]'</span><span class="p">]</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd2ea0></span>
<span class="go"> FFmpeg expression: "[0:v][1:v]overlay,split[vout1][vout2]"</span>
<span class="go"> Number of chains: 1</span>
<span class="go"> chain[0]: [0:v][1:v]overlay,split[vout1][vout2] </span>
<span class="go"> Available input pads (0): </span>
<span class="go"> Available output pads: (2): (0, 1, 0), (0, 1, 1)</span>
</pre></div>
</div>
<p>The pads do not need to be of the same filter:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="p">[</span><span class="s1">'[0:v]'</span><span class="p">,</span><span class="s1">'[1:v]'</span><span class="p">]</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'pad=640:480[v1];scale=100:100[v2];[v1][v2]overlay'</span><span class="p">)</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd30b0></span>
<span class="go"> FFmpeg expression: "[0:v]pad=640:480[v1];[1:v]scale=100:100[v2];[v1][v2]overlay"</span>
<span class="go"> Number of chains: 3</span>
<span class="go"> chain[0]: [0:v]pad=640:480[v1];</span>
<span class="go"> chain[1]: [1:v]scale=100:100[v2];</span>
<span class="go"> chain[2]: [v1][v2]overlay[UNC0] </span>
<span class="go"> Available input pads (0): </span>
<span class="go"> Available output pads: (1): (2, 0, 0)</span>
</pre></div>
</div>
</section>
<section id="filtergraph-linking">
<h4>Filtergraph linking<a class="headerlink" href="#filtergraph-linking" title="Link to this heading"></a></h4>
<p>Functionally, <code class="xref py py-obj docutils literal notranslate"><span class="pre">>></span></code> and <code class="xref py py-obj docutils literal notranslate"><span class="pre">+</span></code> are the same if both sides of the operator expose only
one pad. So, they can be used interchangeably.</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># following two operations produce the same filtergraph</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">hflip</span><span class="p">()</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">vflip</span><span class="p">()</span>
<span class="go"><ffmpegio.filtergraph.Chain.Chain object at 0x7f95cfcd2fc0></span>
<span class="go"> FFmpeg expression: "[UNC0]hflip[UNC2];[UNC1]vflip[UNC3]"</span>
<span class="go"> Number of filters: 2</span>
<span class="go"> Input pads (1): (0, 0)</span>
<span class="go"> Output pads: (1): (1, 0)</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">hflip</span><span class="p">()</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">vflip</span><span class="p">()</span>
<span class="go"><ffmpegio.filtergraph.Chain.Chain object at 0x7f95cfcd30b0></span>
<span class="go"> FFmpeg expression: "[UNC0]hflip[UNC2];[UNC1]vflip[UNC3]"</span>
<span class="go"> Number of filters: 2</span>
<span class="go"> Input pads (1): (0, 0)</span>
<span class="go"> Output pads: (1): (1, 0)</span>
</pre></div>
</div>
<p>The <code class="xref py py-obj docutils literal notranslate"><span class="pre">>></span></code> operator is primarily designed to attach a filter or a filterchain to a larger
filtergraph with multiple pads.</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># a 4-input graph with the first one connected to an input stream</span>
<span class="gp">>>> </span><span class="n">fg</span> <span class="o">=</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'[0:v]hstack[h1];hstack[h2];[h1][h2]vstack'</span><span class="p">)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1"># add the zoomed version as the second input</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'[0:v]crop,scale'</span><span class="p">)</span> <span class="o">>></span> <span class="n">fg</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">708</span>, in <span class="n">__rshift__</span>
<span class="w"> </span><span class="k">return</span> <span class="n">fgb</span><span class="o">.</span><span class="n">attach</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">right</span><span class="p">,</span> <span class="n">left_on</span><span class="p">,</span> <span class="n">right_on</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/build.py"</span>, line <span class="m">252</span>, in <span class="n">attach</span>
<span class="w"> </span><span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span>
<span class="gr">ValueError</span>: <span class="n">Cannot determine which side is attaching. One of left or right argument must be a Filter or Chain object.</span>
<span class="gp">>>> </span><span class="c1"># -> [0:v]crop,scale[L1];[0:v][L1]hstack[h1];hstack[h2];[h1][h2]vstack</span>
</pre></div>
</div>
</section>
<section id="filter-pad-indexing">
<h4>Filter pad indexing<a class="headerlink" href="#filter-pad-indexing" title="Link to this heading"></a></h4>
<p>In some cases linking of the filter pads may not happen in a top-down order. It is also possible to
specify which filter pad to label or to connect.</p>
<p>First, here is the the automatic pad selection rules:</p>
<ul class="simple">
<li><p>Unused filter pad is searched on filterchains in sequence</p></li>
<li><p>On the selected filterchain on the left side of <code class="xref py py-obj docutils literal notranslate"><span class="pre">>></span></code></p>
<ul>
<li><p>The first filter with an unused input pad is selected</p></li>
<li><p>The first unused input pad on the selected filter is selected</p></li>
</ul>
</li>
<li><p>On the selected filterchain on the right side of <code class="xref py py-obj docutils literal notranslate"><span class="pre">>></span></code></p>
<ul>
<li><p>The last filter with an unused output pad is selected</p></li>
<li><p>The first unused output pad on the selected filter is selected</p></li>
</ul>
</li>
</ul>
<p>These rules apply to both labeling and linking. Here are a couple examples to illustrate
the order of pad selection:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="p">[</span><span class="s2">"[in1]"</span><span class="p">,</span> <span class="s2">"[in2]"</span><span class="p">,</span> <span class="s2">"[in3]"</span><span class="p">,</span> <span class="s2">"[in4]"</span><span class="p">]</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s2">"overlay,overlay;hflip"</span><span class="p">)</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd3110></span>
<span class="go"> FFmpeg expression: "[in1][in2]overlay,[in3]overlay;[in4]hflip"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [in1][in2]overlay,[in3]overlay[UNC0];</span>
<span class="go"> chain[1]: [in4]hflip[UNC1] </span>
<span class="go"> Available input pads (4): (0, 0, 0), (0, 0, 1), (0, 1, 0), (1, 0, 0)</span>
<span class="go"> Available output pads: (2): (0, 1, 0), (1, 0, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">(</span><span class="s2">"split,split"</span><span class="p">)</span> <span class="o">>></span> <span class="s2">"[label1]"</span> <span class="o">>></span> <span class="s2">"[label2]"</span> <span class="o">>></span> <span class="s2">"[label3]"</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">708</span>, in <span class="n">__rshift__</span>
<span class="w"> </span><span class="k">return</span> <span class="n">fgb</span><span class="o">.</span><span class="n">attach</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">right</span><span class="p">,</span> <span class="n">left_on</span><span class="p">,</span> <span class="n">right_on</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/build.py"</span>, line <span class="m">302</span>, in <span class="n">attach</span>
<span class="w"> </span><span class="k">return</span> <span class="n">left_objs_labels</span><span class="o">.</span><span class="n">_attach</span><span class="p">(</span><span class="n">right_objs_labels</span><span class="p">,</span> <span class="n">left_on</span><span class="p">,</span> <span class="n">right_on</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">1020</span>, in <span class="n">_attach</span>
<span class="w"> </span><span class="n">fg</span><span class="o">.</span><span class="n">add_label</span><span class="p">(</span><span class="n">r</span><span class="p">,</span> <span class="n">outpad</span><span class="o">=</span><span class="n">l_idx</span><span class="p">)</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Graph.py"</span>, line <span class="m">729</span>, in <span class="n">add_label</span>
<span class="w"> </span><span class="bp">self</span><span class="o">.</span><span class="n">_links</span><span class="o">.</span><span class="n">create_label</span><span class="p">(</span><span class="n">label</span><span class="p">,</span> <span class="n">inpad</span><span class="p">,</span> <span class="n">outpad</span><span class="p">,</span> <span class="n">force</span><span class="p">)</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">699</span>, in <span class="n">create_label</span>
<span class="w"> </span><span class="k">raise</span> <span class="n">GraphLinks</span><span class="o">.</span><span class="n">Error</span><span class="p">(</span>
<span class="gr">ffmpegio.filtergraph.GraphLinks.GraphLinks.Error</span>: <span class="n">pad_in_use='label1' is already using the specified pad: (0, 0, 0)</span>
</pre></div>
</div>
<p>To specify the connecting pads, accompany the label or attaching filtergraph with
the filter pad index:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="p">(</span><span class="s2">"[in]"</span><span class="p">,</span> <span class="p">(</span><span class="mi">0</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">1</span><span class="p">))</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s2">"overlay,overlay;hflip"</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">758</span>, in <span class="n">__rrshift__</span>
<span class="w"> </span><span class="k">return</span> <span class="n">fgb</span><span class="o">.</span><span class="n">attach</span><span class="p">(</span><span class="n">left</span><span class="p">,</span> <span class="bp">self</span><span class="p">,</span> <span class="n">left_on</span><span class="p">,</span> <span class="n">right_on</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/build.py"</span>, line <span class="m">297</span>, in <span class="n">attach</span>
<span class="w"> </span><span class="n">right_on</span><span class="p">,</span> <span class="n">left_on</span> <span class="o">=</span> <span class="n">resolve_indices</span><span class="p">(</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/build.py"</span>, line <span class="m">271</span>, in <span class="n">resolve_indices</span>
<span class="w"> </span><span class="n">base_indices</span> <span class="o">=</span> <span class="n">base</span><span class="o">.</span><span class="n">resolve_pad_indices</span><span class="p">(</span><span class="n">base_indices</span><span class="p">,</span> <span class="n">is_input</span><span class="o">=</span><span class="n">base_is_input</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">914</span>, in <span class="n">resolve_pad_indices</span>
<span class="w"> </span><span class="bp">self</span><span class="o">.</span><span class="n">resolve_pad_index</span><span class="p">(</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Graph.py"</span>, line <span class="m">200</span>, in <span class="n">resolve_pad_index</span>
<span class="w"> </span><span class="k">return</span> <span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="n">resolve_pad_index</span><span class="p">(</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">882</span>, in <span class="n">resolve_pad_index</span>
<span class="w"> </span><span class="k">raise</span> <span class="n">FiltergraphPadNotFoundError</span><span class="p">(</span>
<span class="gr">ffmpegio.filtergraph.exceptions.FiltergraphPadNotFoundError</span>: <span class="n">index_or_label=(0, 1, 1) is either already connected or invalid input pad.</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">(</span><span class="s2">"split,split"</span><span class="p">)</span> <span class="o">>></span> <span class="p">((</span><span class="mi">0</span><span class="p">,</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span><span class="mi">1</span><span class="p">),</span> <span class="s2">"[label]"</span><span class="p">)</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">708</span>, in <span class="n">__rshift__</span>
<span class="w"> </span><span class="k">return</span> <span class="n">fgb</span><span class="o">.</span><span class="n">attach</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">right</span><span class="p">,</span> <span class="n">left_on</span><span class="p">,</span> <span class="n">right_on</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/build.py"</span>, line <span class="m">293</span>, in <span class="n">attach</span>
<span class="w"> </span><span class="n">left_on</span><span class="p">,</span> <span class="n">right_on</span> <span class="o">=</span> <span class="n">resolve_indices</span><span class="p">(</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/build.py"</span>, line <span class="m">271</span>, in <span class="n">resolve_indices</span>
<span class="w"> </span><span class="n">base_indices</span> <span class="o">=</span> <span class="n">base</span><span class="o">.</span><span class="n">resolve_pad_indices</span><span class="p">(</span><span class="n">base_indices</span><span class="p">,</span> <span class="n">is_input</span><span class="o">=</span><span class="n">base_is_input</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">914</span>, in <span class="n">resolve_pad_indices</span>
<span class="w"> </span><span class="bp">self</span><span class="o">.</span><span class="n">resolve_pad_index</span><span class="p">(</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/abc.py"</span>, line <span class="m">882</span>, in <span class="n">resolve_pad_index</span>
<span class="w"> </span><span class="k">raise</span> <span class="n">FiltergraphPadNotFoundError</span><span class="p">(</span>
<span class="gr">ffmpegio.filtergraph.exceptions.FiltergraphPadNotFoundError</span>: <span class="n">index_or_label=(0, -1, 1) is either already connected or invalid output pad.</span>
</pre></div>
</div>
<p>The filter pad index is given by a three-element <code class="xref py py-obj docutils literal notranslate"><span class="pre">tuple</span></code>:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="c1"># filter pad index (tuple of 3 ints)</span>
<span class="p">(</span><span class="n">i</span><span class="p">,</span> <span class="n">j</span><span class="p">,</span> <span class="n">k</span><span class="p">)</span>
<span class="c1"># i -> chain index, selecting the (i+1)st chain</span>
<span class="c1"># j -> filter index on the (i+1)st chain</span>
<span class="c1"># k -> (input or output) pad index of the (j+1)st filter</span>
</pre></div>
</div>
<p>So, the first example <code class="docutils literal notranslate"><span class="pre">(0,1,1)</span></code> selects the 1st chain’s 2nd filter (<code class="docutils literal notranslate"><span class="pre">overlay</span></code>)
and label its 2nd input pad <code class="docutils literal notranslate"><span class="pre">[in3]</span></code>. Negative indices (as used for Python
sequences) are supported. The second example <code class="docutils literal notranslate"><span class="pre">(0,-1,1)</span></code> selects
the 1st chain’s last filter and labels its 2nd output as <code class="docutils literal notranslate"><span class="pre">[label3]</span></code>.</p>
<p>Alternatively, an existing label could be used to specify the connecting pad:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">fg_overlay</span> <span class="o">=</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">(</span><span class="s2">"scale=240:-2,format=gray"</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">fg1</span> <span class="o">=</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s2">"[in1][in2]overlay,[in3]overlay;[in4]hflip"</span><span class="p">)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="p">(</span><span class="n">fg_overlay</span><span class="p">,</span><span class="s1">'in2'</span><span class="p">)</span> <span class="o">>></span> <span class="n">fg1</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd33e0></span>
<span class="go"> FFmpeg expression: "scale=240:-2,format=gray[L0];[in1][L0]overlay,[in3]overlay;[in4]hflip"</span>
<span class="go"> Number of chains: 3</span>
<span class="go"> chain[0]: [UNC0]scale=240:-2,format=gray[L0];</span>
<span class="go"> chain[1]: [in1][L0]overlay,[in3]overlay[UNC1];</span>
<span class="go"> chain[2]: [in4]hflip[UNC2] </span>
<span class="go"> Available input pads (4): (0, 0, 0), (1, 0, 0), (1, 1, 0), (2, 0, 0)</span>
<span class="go"> Available output pads: (2): (1, 1, 0), (2, 0, 0)</span>
</pre></div>
</div>
<p>The label name for indexing may optionally omit the square brackets as done in this example.</p>
</section>
</section>
<section id="graph-link-within-filtergraph-linking">
<h3><a class="reference internal" href="#ffmpegio.filtergraph.Graph.link" title="ffmpegio.filtergraph.Graph.link"><code class="xref py py-func docutils literal notranslate"><span class="pre">Graph.link()</span></code></a> - within-filtergraph linking<a class="headerlink" href="#graph-link-within-filtergraph-linking" title="Link to this heading"></a></h3>
<p>To create a link within a filtergraph, use :py:func`link`. An example in which an intra-graph linking
is with <code class="docutils literal notranslate"><span class="pre">scale2ref</span></code>. Its 2 outputs (scaled and passthrough reference streams) may not be used in
the output pad order. Suppose we want the output video to show the first input on top of the scaled
version of the second input, the desired filtergraph expression is</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="p">[</span><span class="mi">1</span><span class="p">:</span><span class="n">v</span><span class="p">][</span><span class="mi">0</span><span class="p">:</span><span class="n">v</span><span class="p">]</span><span class="n">scale2ref</span><span class="p">[</span><span class="n">v1_scaled</span><span class="p">][</span><span class="n">v0</span><span class="p">];[</span><span class="n">v0</span><span class="p">][</span><span class="n">v1_scaled</span><span class="p">]</span><span class="n">vstack</span>
</pre></div>
</div>
<p>Neither joining nor linking operation cannot produce the desired outcome:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1">#INCORRECT: only one link which is incorrect</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'[1:v][0:v]scale2ref[v1_scaled][v0]'</span><span class="p">)</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">vstack</span><span class="p">()</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd3350></span>
<span class="go"> FFmpeg expression: "[1:v][0:v]scale2ref[L0][L1];[L0][L1]vstack"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [1:v][0:v]scale2ref[L0][L1];</span>
<span class="go"> chain[1]: [L0][L1]vstack[UNC0] </span>
<span class="go"> Available input pads (0): </span>
<span class="go"> Available output pads: (1): (1, 0, 0)</span>
<span class="gp">>>> </span>
<span class="gp">>>> </span><span class="c1">#INCORRECT: correct first link but only one link</span>
<span class="gp">>>> </span><span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s1">'[1:v][0:v]scale2ref[v1_scaled][v0]'</span><span class="p">)</span> <span class="o">>></span> <span class="p">(</span><span class="s1">'v0'</span><span class="p">,</span> <span class="n">fgb</span><span class="o">.</span><span class="n">vstack</span><span class="p">())</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd32f0></span>
<span class="go"> FFmpeg expression: "[1:v][0:v]scale2ref[v1_scaled][L0];[L0]vstack"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [1:v][0:v]scale2ref[v1_scaled][L0];</span>
<span class="go"> chain[1]: [L0][UNC0]vstack[UNC1] </span>
<span class="go"> Available input pads (1): (1, 0, 1)</span>
<span class="go"> Available output pads: (2): (0, 0, 0), (1, 0, 0)</span>
</pre></div>
</div>
<p>To make the explicit link. Use the <a class="reference internal" href="#ffmpegio.filtergraph.Graph.link" title="ffmpegio.filtergraph.Graph.link"><code class="xref py py-func docutils literal notranslate"><span class="pre">Graph.link()</span></code></a> method to create out-of-order links:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># first stack 2 filters</span>
<span class="gp">>>> </span><span class="n">fg</span> <span class="o">=</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Graph</span><span class="p">(</span><span class="s2">"[1:v][0:v]scale2ref[v1_scaled][v0]"</span><span class="p">)</span> <span class="o">|</span> <span class="n">fgb</span><span class="o">.</span><span class="n">vstack</span><span class="p">()</span>
<span class="gp">>>> </span><span class="c1"># then make the connections (returns the link label)</span>
<span class="gp">>>> </span><span class="n">fg</span><span class="o">.</span><span class="n">link</span><span class="p">((</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">),</span> <span class="s2">"v0"</span><span class="p">)</span> <span class="c1"># (-1, 0, 0) <- [v0]</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Graph.py"</span>, line <span class="m">673</span>, in <span class="n">link</span>
<span class="w"> </span><span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_links</span><span class="o">.</span><span class="n">link</span><span class="p">(</span><span class="n">inpad</span><span class="p">,</span> <span class="n">outpad</span><span class="p">,</span> <span class="n">label</span><span class="p">,</span> <span class="n">preserve_label</span><span class="p">,</span> <span class="n">force</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">228</span>, in <span class="n">link</span>
<span class="w"> </span><span class="bp">self</span><span class="o">.</span><span class="n">validate_pad_idx</span><span class="p">(</span><span class="n">inpad</span><span class="p">,</span> <span class="n">none_ok</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">93</span>, in <span class="n">validate_pad_idx</span>
<span class="w"> </span><span class="k">raise</span> <span class="n">GraphLinks</span><span class="o">.</span><span class="n">Error</span><span class="p">(</span>
<span class="gr">ffmpegio.filtergraph.GraphLinks.GraphLinks.Error</span>: <span class="n">id=(-1, 0, 0) is not a valid filter pad ID. Filter pad ID must be a 3-element tuple: (chain id, filter id, pad id)</span>
<span class="gp">>>> </span><span class="n">fg</span><span class="o">.</span><span class="n">link</span><span class="p">((</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">),</span> <span class="s2">"v1_scaled"</span><span class="p">)</span> <span class="c1"># (-1, 0, 1) <- [v1_scaled]</span>
<span class="gt">Traceback (most recent call last):</span>
File <span class="nb">"<stdin>"</span>, line <span class="m">1</span>, in <span class="n"><module></span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/Graph.py"</span>, line <span class="m">673</span>, in <span class="n">link</span>
<span class="w"> </span><span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">_links</span><span class="o">.</span><span class="n">link</span><span class="p">(</span><span class="n">inpad</span><span class="p">,</span> <span class="n">outpad</span><span class="p">,</span> <span class="n">label</span><span class="p">,</span> <span class="n">preserve_label</span><span class="p">,</span> <span class="n">force</span><span class="p">)</span>
<span class="w"> </span><span class="pm">^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">228</span>, in <span class="n">link</span>
<span class="w"> </span><span class="bp">self</span><span class="o">.</span><span class="n">validate_pad_idx</span><span class="p">(</span><span class="n">inpad</span><span class="p">,</span> <span class="n">none_ok</span><span class="o">=</span><span class="kc">False</span><span class="p">)</span>
File <span class="nb">"/home/runner/work/python-ffmpegio/python-ffmpegio/src/ffmpegio/filtergraph/GraphLinks.py"</span>, line <span class="m">93</span>, in <span class="n">validate_pad_idx</span>
<span class="w"> </span><span class="k">raise</span> <span class="n">GraphLinks</span><span class="o">.</span><span class="n">Error</span><span class="p">(</span>
<span class="gr">ffmpegio.filtergraph.GraphLinks.GraphLinks.Error</span>: <span class="n">id=(-1, 0, 1) is not a valid filter pad ID. Filter pad ID must be a 3-element tuple: (chain id, filter id, pad id)</span>
<span class="gp">>>> </span><span class="n">fg</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd2ba0></span>
<span class="go"> FFmpeg expression: "[1:v][0:v]scale2ref[v1_scaled][v0];vstack"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [1:v][0:v]scale2ref[v1_scaled][v0];</span>
<span class="go"> chain[1]: [UNC0][UNC1]vstack[UNC2] </span>
<span class="go"> Available input pads (2): (1, 0, 0), (1, 0, 1)</span>
<span class="go"> Available output pads: (3): (0, 0, 0), (0, 0, 1), (1, 0, 0)</span>
</pre></div>
</div>
<p>This method modifies the filtergraph.</p>
</section>
<section id="examples">
<h3>Examples<a class="headerlink" href="#examples" title="Link to this heading"></a></h3>
<section id="simple-example">
<h4>Simple example<a class="headerlink" href="#simple-example" title="Link to this heading"></a></h4>
<p>Borrowing <a class="reference external" href="https://github.com/kkroening/ffmpeg-python#complex-filter-graphs">the example from ffmpeg-python package</a>:</p>
<div class="highlight-bash notranslate"><div class="highlight"><pre><span></span><span class="o">[</span><span class="m">0</span><span class="o">]</span><span class="nv">trim</span><span class="o">=</span><span class="nv">start_frame</span><span class="o">=</span><span class="m">10</span>:end_frame<span class="o">=</span><span class="m">20</span><span class="o">[</span>v0<span class="o">]</span><span class="p">;</span><span class="w"> </span><span class="se">\</span>
<span class="o">[</span><span class="m">0</span><span class="o">]</span><span class="nv">trim</span><span class="o">=</span><span class="nv">start_frame</span><span class="o">=</span><span class="m">30</span>:end_frame<span class="o">=</span><span class="m">40</span><span class="o">[</span>v1<span class="o">]</span><span class="p">;</span><span class="w"> </span><span class="se">\</span>
<span class="o">[</span><span class="m">1</span><span class="o">]</span>hflip<span class="o">[</span>v2<span class="o">]</span><span class="p">;</span><span class="w"> </span><span class="se">\</span>
<span class="o">[</span>v0<span class="o">][</span>v1<span class="o">]</span><span class="nv">concat</span><span class="o">=</span><span class="nv">n</span><span class="o">=</span><span class="m">2</span><span class="o">[</span>v3<span class="o">]</span><span class="p">;</span><span class="w"> </span><span class="se">\</span>
<span class="o">[</span>v3<span class="o">][</span>v2<span class="o">]</span><span class="nv">overlay</span><span class="o">=</span><span class="nv">eof_action</span><span class="o">=</span>repeat,<span class="w"> </span><span class="nv">drawbox</span><span class="o">=</span><span class="m">50</span>:50:120:120:red:t<span class="o">=</span><span class="m">5</span><span class="o">[</span>v5<span class="o">]</span>
</pre></div>
</div>
<p>This filtergraph can be built in the following steps:</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">v0</span> <span class="o">=</span> <span class="s2">"[0]"</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">trim</span><span class="p">(</span><span class="n">start_frame</span><span class="o">=</span><span class="mi">10</span><span class="p">,</span> <span class="n">end_frame</span><span class="o">=</span><span class="mi">20</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">v1</span> <span class="o">=</span> <span class="s2">"[0]"</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">trim</span><span class="p">(</span><span class="n">start_frame</span><span class="o">=</span><span class="mi">30</span><span class="p">,</span> <span class="n">end_frame</span><span class="o">=</span><span class="mi">40</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">v3</span> <span class="o">=</span> <span class="s2">"[1]"</span> <span class="o">>></span> <span class="n">fgb</span><span class="o">.</span><span class="n">hflip</span><span class="p">()</span>
<span class="gp">>>> </span><span class="n">v2</span> <span class="o">=</span> <span class="p">(</span><span class="n">v0</span> <span class="o">|</span> <span class="n">v1</span><span class="p">)</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">concat</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">v5</span> <span class="o">=</span> <span class="p">(</span><span class="n">v2</span><span class="o">|</span><span class="n">v3</span><span class="p">)</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">overlay</span><span class="p">(</span><span class="n">eof_action</span><span class="o">=</span><span class="s1">'repeat'</span><span class="p">)</span> <span class="o">+</span> <span class="n">fgb</span><span class="o">.</span><span class="n">drawbox</span><span class="p">(</span><span class="mi">50</span><span class="p">,</span> <span class="mi">50</span><span class="p">,</span> <span class="mi">120</span><span class="p">,</span> <span class="mi">120</span><span class="p">,</span> <span class="s1">'red'</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mi">5</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">v5</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd3920></span>
<span class="go"> FFmpeg expression: "[0]trim=start_frame=10:end_frame=20[L0];[0]trim=start_frame=30:end_frame=40[L1];[L0][L1]concat=2[L2];[1]hflip[L3];[L2][L3]overlay=eof_action=repeat,drawbox=50:50:120:120:red:t=5"</span>
<span class="go"> Number of chains: 5</span>
<span class="go"> chain[0]: [0]trim=start_frame=10:end_frame=20[L0];</span>
<span class="go"> chain[1]: [0]trim=start_frame=30:end_frame=40[L1];</span>
<span class="go"> chain[2]: [L0][L1]concat=2[L2];</span>
<span class="go"> chain[3]: [1]hflip[L3];</span>
<span class="go"> chain[4]: [L2][L3]overlay=eof_action=repeat,drawbox=50:50:120:120:red:t=5[UNC0] </span>
<span class="go"> Available input pads (0): </span>
<span class="go"> Available output pads: (1): (4, 1, 0)</span>
</pre></div>
</div>
</section>
<section id="concat-with-preprocessing-stage">
<h4>Concat with preprocessing stage<a class="headerlink" href="#concat-with-preprocessing-stage" title="Link to this heading"></a></h4>
<p>The <code class="docutils literal notranslate"><span class="pre">concat</span></code> filter can be finicky, requiring all the streams to have the same attributes. To combine
mismatched streams, they need to be preprocessed by other filters. Video streams must have the same
frame size, frame rate, and pixel format. Meanwhile, the audio streams need to have the same sampling
rate, channel format, and sample format.</p>
<p>To build the filtergraph to concatenate mismatched video files, we start by defining the filters</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">audio_filter</span> <span class="o">=</span> <span class="n">fgb</span><span class="o">.</span><span class="n">aformat</span><span class="p">(</span><span class="n">sample_fmts</span><span class="o">=</span><span class="s1">'flt'</span><span class="p">,</span> <span class="c1"># 32-bit floating point format</span>
<span class="gp">... </span> <span class="n">sample_rates</span><span class="o">=</span><span class="mi">48000</span><span class="p">,</span> <span class="c1"># 48 kS/s sampling rate</span>
<span class="gp">... </span> <span class="n">channel_layouts</span><span class="o">=</span><span class="s1">'stereo'</span><span class="p">)</span> <span class="c1"># 2 channels in stereo layout</span>
<span class="gp">>>> </span><span class="n">video_filters</span> <span class="o">=</span> <span class="p">[</span>
<span class="gp">... </span> <span class="n">fgb</span><span class="o">.</span><span class="n">scale</span><span class="p">(</span><span class="mi">1280</span><span class="p">,</span> <span class="mi">720</span><span class="p">,</span>
<span class="gp">... </span> <span class="n">force_original_aspect_ratio</span><span class="o">=</span><span class="s1">'decrease'</span><span class="p">),</span> <span class="c1"># scale at least one dimension to 720p</span>
<span class="gp">... </span> <span class="n">fgb</span><span class="o">.</span><span class="n">pad</span><span class="p">(</span><span class="mi">1280</span><span class="p">,</span> <span class="mi">720</span><span class="p">,</span> <span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="o">-</span><span class="mi">1</span><span class="p">),</span> <span class="c1"># if not 16:9, pad to fill the frame</span>
<span class="gp">... </span> <span class="n">fgb</span><span class="o">.</span><span class="n">setsar</span><span class="p">(</span><span class="mi">1</span><span class="p">),</span> <span class="c1"># make sure pixels are square</span>
<span class="gp">... </span> <span class="n">fgb</span><span class="o">.</span><span class="n">fps</span><span class="p">(</span><span class="mi">30</span><span class="p">),</span> <span class="c1"># set framerate to 30 (dupe or drop frames)</span>
<span class="gp">... </span> <span class="n">fgb</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="s1">'yuv420p'</span><span class="p">)</span> <span class="c1"># use yuv420p pixel format</span>
<span class="gp">... </span><span class="p">]</span>
</pre></div>
</div>
<p>We need multiple video filters while the <code class="docutils literal notranslate"><span class="pre">aformat</span></code> filter takes care of the audio stream format.
To combine the video filters, we can use the built-in <code class="xref py py-func docutils literal notranslate"><span class="pre">sum()</span></code> with an empty :py:class:<code class="docutils literal notranslate"><span class="pre">Filter</span></code>.
as the initial value. Then, stack video and audio filters to finalize the preprocessor filtergraph
for an input file.</p>
<div class="doctest highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">preproc</span> <span class="o">=</span> <span class="nb">sum</span><span class="p">(</span><span class="n">video_filters</span><span class="p">,</span> <span class="n">fgb</span><span class="o">.</span><span class="n">Chain</span><span class="p">())</span> <span class="o">|</span> <span class="n">audio_filter</span>
<span class="gp">>>> </span><span class="n">preproc</span>
<span class="go"><ffmpegio.filtergraph.Graph.Graph object at 0x7f95cfcd3740></span>
<span class="go"> FFmpeg expression: "scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p;aformat=sample_fmts=flt:sample_rates=48000:channel_layouts=stereo"</span>
<span class="go"> Number of chains: 2</span>
<span class="go"> chain[0]: [UNC0]scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:-1:-1,setsar=1,fps=30,format=yuv420p[UNC2];</span>