-
Notifications
You must be signed in to change notification settings - Fork 9
Expand file tree
/
Copy pathquick.html
More file actions
524 lines (492 loc) · 49.2 KB
/
quick.html
File metadata and controls
524 lines (492 loc) · 49.2 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
<!DOCTYPE html>
<html class="writer-html5" lang="en" data-content_root="./">
<head>
<meta charset="utf-8" /><meta name="viewport" content="width=device-width, initial-scale=1" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Quick Start Guide — python-ffmpegio 0.11.0 documentation</title>
<link rel="stylesheet" type="text/css" href="_static/pygments.css?v=80d5e7a1" />
<link rel="stylesheet" type="text/css" href="_static/css/theme.css?v=e59714d7" />
<link rel="stylesheet" type="text/css" href="_static/plot_directive.css" />
<link rel="stylesheet" type="text/css" href="_static/css/custom.css?v=048f17f8" />
<script src="_static/jquery.js?v=5d32c60e"></script>
<script src="_static/_sphinx_javascript_frameworks_compat.js?v=2cd50e6c"></script>
<script src="_static/documentation_options.js?v=f3b36f1a"></script>
<script src="_static/doctools.js?v=9bcbadda"></script>
<script src="_static/sphinx_highlight.js?v=dc90522c"></script>
<script src="_static/js/theme.js"></script>
<link rel="index" title="Index" href="genindex.html" />
<link rel="search" title="Search" href="search.html" />
</head>
<body class="wy-body-for-nav">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-scroll">
<div class="wy-side-nav-search" >
<a href="index.html" class="icon icon-home">
python-ffmpegio
</a>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
<input type="text" name="q" placeholder="Search docs" aria-label="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div><div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="Navigation menu">
<!-- Local TOC -->
<div class="local-toc"><ul>
<li><a class="reference internal" href="#">Quick Start Guide</a><ul>
<li><a class="reference internal" href="#install">Install</a></li>
<li><a class="reference internal" href="#features">Features</a></li>
<li><a class="reference internal" href="#media-probe">Media Probe</a></li>
<li><a class="reference internal" href="#block-read-write">Block Read/Write</a></li>
<li><a class="reference internal" href="#stream-read-write">Stream Read/Write</a></li>
<li><a class="reference internal" href="#specify-read-time-range">Specify Read Time Range</a></li>
<li><a class="reference internal" href="#specify-output-frame-sample-size">Specify Output Frame/Sample Size</a></li>
<li><a class="reference internal" href="#specify-sample-formats">Specify Sample Formats</a></li>
<li><a class="reference internal" href="#progress-callback">Progress Callback</a></li>
</ul>
</li>
</ul>
</div>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap"><nav class="wy-nav-top" aria-label="Mobile navigation menu" >
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="index.html">python-ffmpegio</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="Page navigation">
<ul class="wy-breadcrumbs">
<li><a href="index.html" class="icon icon-home" aria-label="Home"></a></li>
<li class="breadcrumb-item active">Quick Start Guide</li>
<li class="wy-breadcrumbs-aside">
<a href="_sources/quick.rst.txt" rel="nofollow"> View page source</a>
</li>
</ul>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<section id="quick-start-guide">
<span id="quick"></span><h1>Quick Start Guide<a class="headerlink" href="#quick-start-guide" title="Link to this heading"></a></h1>
<section id="install">
<h2>Install<a class="headerlink" href="#install" title="Link to this heading"></a></h2>
<p>To use <code class="xref py py-mod docutils literal notranslate"><span class="pre">ffmpegio</span></code>, the package must be installed on Python as well as
having the FFmpeg binary files at a location <code class="xref py py-mod docutils literal notranslate"><span class="pre">ffmpegio</span></code> can find.</p>
<p>Install the full <code class="xref py py-mod docutils literal notranslate"><span class="pre">ffmpegio</span></code> package via <code class="docutils literal notranslate"><span class="pre">pip</span></code>:</p>
<div class="highlight-bash notranslate"><div class="highlight"><pre><span></span>pip<span class="w"> </span>install<span class="w"> </span>ffmpegio
</pre></div>
</div>
<p>If <cite>numpy.ndarray</cite> data I/O is not needed, instead use</p>
<div class="highlight-bash notranslate"><div class="highlight"><pre><span></span>pip<span class="w"> </span>install<span class="w"> </span>ffmpegio-core
</pre></div>
</div>
<p>If FFmpeg is not installed on your system, please follow the instructions on
<a class="reference internal" href="install.html#install"><span class="std std-ref">Installation page</span></a></p>
</section>
<section id="features">
<h2>Features<a class="headerlink" href="#features" title="Link to this heading"></a></h2>
<p>FFmpeg can read/write virtually any multimedia file out there, and <code class="code docutils literal notranslate"><span class="pre">ffmpegio</span></code> uses
the FFmpeg’s prowess to perform media I/O (and other) operations in Python. It offers two
basic modes of operation: block read/write and stream read/write. For the read operations,
it can output data either in a Numpy array or in a plain <code class="code docutils literal notranslate"><span class="pre">bytes</span></code>. The Numpy mode is
enabled by default if Numpy is available in the system. Another feature of
<code class="code docutils literal notranslate"><span class="pre">ffmpegio</span></code> is to report the properties of the media files, using FFprobe.</p>
</section>
<section id="media-probe">
<h2>Media Probe<a class="headerlink" href="#media-probe" title="Link to this heading"></a></h2>
<p>To process a media file, you first need to know what’s in it. Within FFmpeg
ecosystem, this task is handled by <a class="reference external" href="https://ffmpeg.org/ffprobe.html">ffprobe</a>.
<code class="code docutils literal notranslate"><span class="pre">ffmpegio</span></code>’s <a class="reference internal" href="probe.html#probe"><span class="std std-ref">ffmpegio:probe</span></a> module wraps ffprobe with 5
basic functions:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">ffmpegio</span>
<span class="gp">>>> </span><span class="kn">from</span> <span class="nn">pprint</span> <span class="kn">import</span> <span class="n">pprint</span>
<span class="gp">>>> </span><span class="n">url</span> <span class="o">=</span> <span class="s1">'mytestvideo.mpg'</span>
<span class="gp">>>> </span><span class="n">format_info</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">probe</span><span class="o">.</span><span class="n">format_basic</span><span class="p">(</span><span class="n">url</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">pprint</span><span class="p">(</span><span class="n">format_info</span><span class="p">)</span>
<span class="go">{'duration': 66.403256,</span>
<span class="go">'filename': 'mytestvideo.mpg',</span>
<span class="go">'format_name': 'mpegts',</span>
<span class="go">'nb_streams': 2,</span>
<span class="go">'start_time': 0.0}</span>
<span class="gp">>>> </span><span class="n">stream_info</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">probe</span><span class="o">.</span><span class="n">streams_basic</span><span class="p">(</span><span class="n">url</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">pprint</span><span class="p">(</span><span class="n">stream_info</span><span class="p">)</span>
<span class="go">[{'codec_name': 'mp2', 'codec_type': 'audio', 'index': 0},</span>
<span class="go">{'codec_name': 'h264', 'codec_type': 'video', 'index': 1}]</span>
<span class="gp">>>> </span><span class="n">vst_info</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">probe</span><span class="o">.</span><span class="n">video_streams_basic</span><span class="p">(</span><span class="n">url</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">pprint</span><span class="p">(</span><span class="n">vst_info</span><span class="p">)</span>
<span class="go">[{'codec_name': 'h264',</span>
<span class="go">'display_aspect_ratio': Fraction(22, 15),</span>
<span class="go">'duration': 66.39972222222222,</span>
<span class="go">'frame_rate': Fraction(15000, 1001),</span>
<span class="go">'height': 240,</span>
<span class="go">'index': 1,</span>
<span class="go">'pix_fmt': 'yuv420p',</span>
<span class="go">'sample_aspect_ratio': Fraction(1, 1),</span>
<span class="go">'start_time': 0.0,</span>
<span class="go">'width': 352}]</span>
<span class="gp">>>> </span><span class="n">ast_info</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">probe</span><span class="o">.</span><span class="n">audio_streams_basic</span><span class="p">(</span><span class="n">url</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">pprint</span><span class="p">(</span><span class="n">ast_info</span><span class="p">)</span>
<span class="go">[{'channel_layout': 'stereo',</span>
<span class="go">'channels': 2,</span>
<span class="go">'codec_name': 'mp2',</span>
<span class="go">'duration': 66.40325555555556,</span>
<span class="go">'index': 0,</span>
<span class="go">'nb_samples': 2928384,</span>
<span class="go">'sample_fmt': 'fltp',</span>
<span class="go">'sample_rate': 44100,</span>
<span class="go">'start_time': 0.0}]</span>
</pre></div>
</div>
<p>To obtain the complete ffprobe output, use <a class="reference internal" href="probe.html#ffmpegio.probe.full_details" title="ffmpegio.probe.full_details"><code class="xref py py-func docutils literal notranslate"><span class="pre">ffmpegio.probe.full_details()</span></code></a>,
and to obtain specific format or stream fields, use <a class="reference internal" href="probe.html#ffmpegio.probe.query" title="ffmpegio.probe.query"><code class="xref py py-func docutils literal notranslate"><span class="pre">ffmpegio.probe.query()</span></code></a>.
For more information on <code class="xref py py-mod docutils literal notranslate"><span class="pre">probe</span></code>, see <a class="reference internal" href="probe.html#probe"><span class="std std-ref">Media Probe Function References</span></a>.</p>
</section>
<section id="block-read-write">
<h2>Block Read/Write<a class="headerlink" href="#block-read-write" title="Link to this heading"></a></h2>
<p>Suppose you need to analyze short audio data in <code class="code docutils literal notranslate"><span class="pre">mytestfile.mp3</span></code>, you can
read all its samples by</p>
<div class="highlight-python 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">'mytestfile.wav'</span><span class="p">)</span>
</pre></div>
</div>
<p>It returns the sampling rate <code class="code docutils literal notranslate"><span class="pre">fs</span></code> and <a class="reference external" href="https://numpy.org/doc/stable/reference/generated/numpy.ndarray.html#numpy.ndarray" title="(in NumPy v2.2)"><code class="xref py py-class docutils literal notranslate"><span class="pre">numpy.ndarray</span></code></a> <code class="code docutils literal notranslate"><span class="pre">x</span></code>.
The audio data is always represetned by a 2-D array, each of which column represents
an audio channel. So, a 2-second stereo recording at 8000 samples/second yields
<code class="code docutils literal notranslate"><span class="pre">x.shape</span></code> to be <code class="code docutils literal notranslate"><span class="pre">(16000,2)</span></code>. Also, the sample format is preserved: If
the samples in the wav file is 16-bit, <code class="code docutils literal notranslate"><span class="pre">x</span></code> is of <code class="code docutils literal notranslate"><span class="pre">numpy.int16</span></code> dtype.</p>
<p>Now, you’ve processed this audio data and produced the 8000-sample 1-D array <code class="code docutils literal notranslate"><span class="pre">y</span></code>
at reduced sampling rate at 4000-samples/second. You want to save this new audio
data as FLAC file. To do so, you run:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">ffmpegio</span><span class="o">.</span><span class="n">audio</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">'myoutput.flac'</span><span class="p">,</span> <span class="mi">4000</span><span class="p">,</span> <span class="n">y</span><span class="p">)</span>
</pre></div>
</div>
<p>There are video counterparts to these two functions:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">fs</span><span class="p">,</span> <span class="n">F</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">video</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'mytestvideo.mp4'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">ffmpegio</span><span class="o">.</span><span class="n">video</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">'myoutput.avi'</span><span class="p">,</span> <span class="n">fs</span><span class="p">,</span> <span class="n">F</span><span class="p">)</span>
</pre></div>
</div>
<p>Let’s suppose <code class="code docutils literal notranslate"><span class="pre">mytestvideo.mp4</span></code> is 10 seconds long, containing a
<code class="code docutils literal notranslate"><span class="pre">yuv420p</span></code>-encoded color video stream with the frame size of 640x480 pixels,
and the frame rate of 29.97 (30000/1001) frames/second. Then, the <code class="xref py py-func docutils literal notranslate"><span class="pre">video.read()</span></code>
returns a 2-element tuple: the first element <code class="code docutils literal notranslate"><span class="pre">fs</span></code> is the frame rate in
<code class="xref py py-class docutils literal notranslate"><span class="pre">fractions.Fraction</span></code> and the second element <code class="code docutils literal notranslate"><span class="pre">F</span></code> contains all the frames
of the video in <a class="reference external" href="https://numpy.org/doc/stable/reference/generated/numpy.ndarray.html#numpy.ndarray" title="(in NumPy v2.2)"><code class="xref py py-class docutils literal notranslate"><span class="pre">numpy.ndarray</span></code></a> with shape <code class="code docutils literal notranslate"><span class="pre">(299,</span> <span class="pre">480,</span> <span class="pre">640,</span> <span class="pre">3)</span></code>.
Because the video is in color, each pixel is represented in 24-bit RGB, thus
<code class="code docutils literal notranslate"><span class="pre">F.dtype</span></code> is <code class="code docutils literal notranslate"><span class="pre">numpy.uint8</span></code>. The video write is the reciprocal of
the read operation.</p>
<p>For image (or single video frame) I/O, there is a pair of functions as well:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">I</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">image</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'myimage.png'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">ffmpegio</span><span class="o">.</span><span class="n">image</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="s1">'myoutput.bmp'</span><span class="p">,</span> <span class="n">I</span><span class="p">)</span>
</pre></div>
</div>
<p>The image data <code class="code docutils literal notranslate"><span class="pre">I</span></code> is like the video frame data, but without the leading
dimension.</p>
</section>
<section id="stream-read-write">
<span id="quick-streamio"></span><h2>Stream Read/Write<a class="headerlink" href="#stream-read-write" title="Link to this heading"></a></h2>
<p>Block read/write is simple and convenient for a short file, but it quickly
becomes slow and inefficient as the data size grows; this is especially true
for video. To enable on-demand data retrieval, <code class="code docutils literal notranslate"><span class="pre">ffmpegio</span></code> offers stream
read/write operation. It mimics the familiar Python’s file I/O with
<a class="reference internal" href="basicio.html#ffmpegio.open" title="ffmpegio.open"><code class="xref py py-func docutils literal notranslate"><span class="pre">ffmpegio.open()</span></code></a>:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="k">with</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s1">'mytestvideo.mp4'</span><span class="p">,</span> <span class="s1">'rv'</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span> <span class="c1"># opens the first video stream</span>
<span class="gp">>>> </span> <span class="nb">print</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">rate</span><span class="p">)</span> <span class="c1"># frame rate fraction in frames/second</span>
<span class="gp">>>> </span> <span class="n">F</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span> <span class="c1"># read the first frame</span>
<span class="gp">>>> </span> <span class="n">F</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="mi">5</span><span class="p">)</span> <span class="c1"># read the next 5 frames at once</span>
</pre></div>
</div>
<p>Another example, which uses read and write streams simultaneously:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="k">with</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s1">'mytestvideo.mp4'</span><span class="p">,</span> <span class="s1">'rv'</span><span class="p">,</span> <span class="n">blocksize</span><span class="o">=</span><span class="mi">100</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">,</span>
<span class="gp">>>> </span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s1">'myoutput.avi'</span><span class="p">,</span> <span class="s1">'wv'</span><span class="p">,</span> <span class="n">f</span><span class="o">.</span><span class="n">rate</span><span class="p">)</span> <span class="k">as</span> <span class="n">g</span><span class="p">:</span>
<span class="gp">>>> </span> <span class="k">for</span> <span class="n">frames</span> <span class="ow">in</span> <span class="n">f</span><span class="p">:</span> <span class="c1"># iterates over all frames, 100 frames at a time</span>
<span class="gp">>>> </span> <span class="n">output</span> <span class="o">=</span> <span class="n">my_processor</span><span class="p">(</span><span class="n">frames</span><span class="p">)</span> <span class="c1"># function to process data</span>
<span class="gp">>>> </span> <span class="n">g</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">output</span><span class="p">)</span> <span class="c1"># send the processed frames to 'myoutput.avi'</span>
</pre></div>
</div>
<p>By default, <code class="code docutils literal notranslate"><span class="pre">ffmpegio.open()</span></code> opens the first media stream available to read.
However, the operation mode can be specified via the <code class="code docutils literal notranslate"><span class="pre">mode</span></code> second argument.
The above example, opens <code class="code docutils literal notranslate"><span class="pre">mytestvideo.mp4</span></code> file in <code class="code docutils literal notranslate"><span class="pre">'rv'</span></code> or “read
video” mode and <code class="code docutils literal notranslate"><span class="pre">myoutput.avi</span></code> in <code class="code docutils literal notranslate"><span class="pre">'wv'</span></code> or “write video” mode. The
file reader object <code class="code docutils literal notranslate"><span class="pre">f</span></code> is an Iterable object, which returns the next set of
frames (the number set by the <code class="code docutils literal notranslate"><span class="pre">blocksize</span></code> argument). For more,
see <a class="reference internal" href="basicio.html#ffmpegio.open" title="ffmpegio.open"><code class="xref py py-func docutils literal notranslate"><span class="pre">ffmpegio.open()</span></code></a>.</p>
</section>
<section id="specify-read-time-range">
<h2>Specify Read Time Range<a class="headerlink" href="#specify-read-time-range" title="Link to this heading"></a></h2>
<p>For both block and stream read operations, you can specify the time range to read
data from. There are four options available:</p>
<table class="tight-table docutils align-default" id="id1">
<caption><span class="caption-text">Read Timing Options</span><a class="headerlink" href="#id1" title="Link to this table"></a></caption>
<thead>
<tr class="row-odd"><th class="head"><p>Name</p></th>
<th class="head"><p>Description</p></th>
</tr>
</thead>
<tbody>
<tr class="row-even"><td><p><code class="code docutils literal notranslate"><span class="pre">ss</span></code></p></td>
<td><p>Start time in seconds</p></td>
</tr>
<tr class="row-odd"><td><p><code class="code docutils literal notranslate"><span class="pre">t</span></code></p></td>
<td><p>Duration in seconds</p></td>
</tr>
<tr class="row-even"><td><p><code class="code docutils literal notranslate"><span class="pre">to</span></code></p></td>
<td><p>End time in seconds (ignored if <code class="code docutils literal notranslate"><span class="pre">t_in</span></code> is also specified)</p></td>
</tr>
</tbody>
</table>
<p>Note it is also possible to specify these timing options for the input (i.e., using the
options <code class="code docutils literal notranslate"><span class="pre">ss_in</span></code>, <code class="code docutils literal notranslate"><span class="pre">t_in</span></code>, and <code class="code docutils literal notranslate"><span class="pre">to_in</span></code>). The input options, especially
<code class="code docutils literal notranslate"><span class="pre">ss_in</span></code>, may run faster but potentially less accurate. See <a class="reference external" href="https://ffmpeg.org/ffmpeg.html#Options">FFmpeg documentation</a> for the explanation.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">url</span> <span class="o">=</span> <span class="s1">'myvideo.mp4'</span>
<span class="gp">>>> </span><span class="c1">#read only the first 1 seconds</span>
<span class="gp">>>> </span><span class="n">fs</span><span class="p">,</span> <span class="n">F</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">video</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="n">url</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mf">1.0</span><span class="p">)</span>
<span class="gp">>>> </span><span class="c1">#read from 1.2 second mark to 2.5 second mark</span>
<span class="gp">>>> </span><span class="n">fs</span><span class="p">,</span> <span class="n">F</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">video</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="n">url</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mf">1.2</span><span class="p">,</span> <span class="n">to</span><span class="o">=</span><span class="mf">2.5</span><span class="p">)</span>
</pre></div>
</div>
<p>To specify by the frame numbers for video and sample numbers for audio, user must
convert the units to seconds using <code class="xref py py-func docutils literal notranslate"><span class="pre">probe()</span></code>. For example:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># get frame rate of the (first) video stream</span>
<span class="gp">>>> </span><span class="n">info</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">probe</span><span class="o">.</span><span class="n">video_streams_basic</span><span class="p">(</span><span class="s1">'myvideo.mp4'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">fs</span> <span class="o">=</span> <span class="n">info</span><span class="p">[</span><span class="mi">0</span><span class="p">][</span><span class="s1">'frame_rate'</span><span class="p">]</span>
<span class="gp">>>> </span><span class="c1">#read 30 frame from the 11th frame (remember Python uses 0-based index)</span>
<span class="gp">>>> </span><span class="k">with</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">open</span><span class="p">(</span><span class="s1">'myvideo.mp4'</span><span class="p">,</span> <span class="s1">'rv'</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mi">10</span><span class="o">/</span><span class="n">fs</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mi">30</span><span class="o">/</span><span class="n">fs</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>
<span class="gp">>>> </span> <span class="n">frame</span> <span class="o">=</span> <span class="n">f</span><span class="o">.</span><span class="n">read</span><span class="p">()</span>
<span class="gp">>>> </span> <span class="c1"># do your thing with the frame data</span>
</pre></div>
</div>
<p>Likewise, for an audio input stream:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># get sampling rate of the (first) audio stream</span>
<span class="gp">>>> </span><span class="n">info</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">probe</span><span class="o">.</span><span class="n">audio_streams_basic</span><span class="p">(</span><span class="s1">'myaudio.wav'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">fs</span> <span class="o">=</span> <span class="n">info</span><span class="p">[</span><span class="mi">0</span><span class="p">][</span><span class="s1">'sample_rate'</span><span class="p">]</span>
<span class="gp">>>> </span><span class="c1">#read first 10000 audio samples</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">'myaudio.wav'</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mi">10000</span><span class="o">/</span><span class="n">fs</span><span class="p">)</span>
</pre></div>
</div>
</section>
<section id="specify-output-frame-sample-size">
<h2>Specify Output Frame/Sample Size<a class="headerlink" href="#specify-output-frame-sample-size" title="Link to this heading"></a></h2>
<p>FFmpeg let you change video size or the number of audio channels via output
options <code class="code docutils literal notranslate"><span class="pre">s</span></code> and <code class="code docutils literal notranslate"><span class="pre">ac</span></code>, respectively, without setting up a
filtergraph. For example,</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># auto-scale video frame</span>
<span class="gp">>>> </span><span class="n">fs</span><span class="p">,</span> <span class="n">F</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">video</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'myvideo.mp4'</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mf">1.0</span><span class="p">)</span> <span class="c1"># natively 320x240</span>
<span class="gp">>>> </span><span class="n">F</span><span class="o">.</span><span class="n">shape</span>
<span class="go">(30, 240, 320, 3)</span>
<span class="gp">>>> </span><span class="c1"># halve the size</span>
<span class="gp">>>> </span><span class="n">width</span> <span class="o">=</span> <span class="mi">160</span>
<span class="gp">>>> </span><span class="n">height</span> <span class="o">=</span> <span class="mi">120</span>
<span class="gp">>>> </span><span class="n">_</span><span class="p">,</span> <span class="n">G</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">video</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'myvideo.mp4'</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mf">1.0</span><span class="p">,</span> <span class="n">s</span><span class="o">=</span><span class="p">(</span><span class="n">width</span><span class="p">,</span><span class="n">height</span><span class="p">))</span>
<span class="gp">>>> </span><span class="n">G</span><span class="o">.</span><span class="n">shape</span>
<span class="go">(29, 120, 160, 3)</span>
<span class="gp">>>> </span><span class="c1"># auto-convert to mono</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">'myaudio.wav'</span><span class="p">)</span> <span class="c1"># natively stereo</span>
<span class="gp">>>> </span><span class="n">_</span><span class="p">,</span> <span class="n">y</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">'myaudio.wav'</span><span class="p">,</span> <span class="n">ac</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span> <span class="c1"># to mono</span>
<span class="gp">>>> </span><span class="n">x</span><span class="o">.</span><span class="n">shape</span>
<span class="go">(44100, 2)</span>
<span class="gp">>>> </span><span class="n">y</span><span class="o">.</span><span class="n">shape</span>
<span class="go">(44100, 1)</span>
</pre></div>
</div>
<p>To customize the conversion configuration, use <code class="code docutils literal notranslate"><span class="pre">vf</span></code> output option
with with <code class="code docutils literal notranslate"><span class="pre">scale</span></code> filter or <code class="code docutils literal notranslate"><span class="pre">af</span></code> output option with
<code class="code docutils literal notranslate"><span class="pre">channelmap</span></code> or <code class="code docutils literal notranslate"><span class="pre">pan</span></code> or other channel mixing filter</p>
</section>
<section id="specify-sample-formats">
<h2>Specify Sample Formats<a class="headerlink" href="#specify-sample-formats" title="Link to this heading"></a></h2>
<p>FFmpeg can also convert the formats of video pixels and sound samples on the fly.
This feature is enabled in <code class="xref py py-mod docutils literal notranslate"><span class="pre">ffmpegio</span></code> via output options <code class="code docutils literal notranslate"><span class="pre">pix_fmt</span></code>
for video and <code class="code docutils literal notranslate"><span class="pre">sample_fmt</span></code> for audio.</p>
<blockquote>
<div><table class="tight-table docutils align-default" id="id2">
<caption><span class="caption-text">Video <code class="code docutils literal notranslate"><span class="pre">pix_fmt</span></code> Option Values</span><a class="headerlink" href="#id2" title="Link to this table"></a></caption>
<thead>
<tr class="row-odd"><th class="head"><p><code class="code docutils literal notranslate"><span class="pre">pix_fmt</span></code></p></th>
<th class="head"><p>Description</p></th>
</tr>
</thead>
<tbody>
<tr class="row-even"><td><p><code class="code docutils literal notranslate"><span class="pre">gray</span></code></p></td>
<td><p>grayscale</p></td>
</tr>
<tr class="row-odd"><td><p><code class="code docutils literal notranslate"><span class="pre">ya8</span></code></p></td>
<td><p>grayscale with transparent alpha channel</p></td>
</tr>
<tr class="row-even"><td><p><code class="code docutils literal notranslate"><span class="pre">rgb24</span></code></p></td>
<td><p>RGB</p></td>
</tr>
<tr class="row-odd"><td><p><code class="code docutils literal notranslate"><span class="pre">rgba</span></code></p></td>
<td><p>RGB with alpha transparent alpha channel</p></td>
</tr>
</tbody>
</table>
<table class="tight-table docutils align-default" id="id3">
<caption><span class="caption-text">Audio <code class="code docutils literal notranslate"><span class="pre">sample_fmt</span></code> Option Values</span><a class="headerlink" href="#id3" title="Link to this table"></a></caption>
<thead>
<tr class="row-odd"><th class="head"><p><code class="code docutils literal notranslate"><span class="pre">sample_fmt</span></code></p></th>
<th class="head"><p>Description</p></th>
<th class="head"><p>min</p></th>
<th class="head"><p>max</p></th>
</tr>
</thead>
<tbody>
<tr class="row-even"><td><p><code class="code docutils literal notranslate"><span class="pre">u8</span></code></p></td>
<td><p>unsigned 8-bit integer</p></td>
<td><p>0</p></td>
<td><p>255</p></td>
</tr>
<tr class="row-odd"><td><p><code class="code docutils literal notranslate"><span class="pre">s16</span></code></p></td>
<td><p>signed 16-bit integer</p></td>
<td><p>-32768</p></td>
<td><p>32767</p></td>
</tr>
<tr class="row-even"><td><p><code class="code docutils literal notranslate"><span class="pre">s32</span></code></p></td>
<td><p>signed 32-bit integer</p></td>
<td><p>-2147483648</p></td>
<td><p>2147483647</p></td>
</tr>
<tr class="row-odd"><td><p><code class="code docutils literal notranslate"><span class="pre">flt</span></code></p></td>
<td><p>single-precision floating point</p></td>
<td><p>-1.0</p></td>
<td><p>1.0</p></td>
</tr>
<tr class="row-even"><td><p><code class="code docutils literal notranslate"><span class="pre">dbl</span></code></p></td>
<td><p>double-precision floating point</p></td>
<td><p>-1.0</p></td>
<td><p>1.0</p></td>
</tr>
</tbody>
</table>
</div></blockquote>
<p>For example,</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># auto-convert video frames to grayscale</span>
<span class="gp">>>> </span><span class="n">fs</span><span class="p">,</span> <span class="n">RGB</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">video</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'myvideo.mp4'</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mf">1.0</span><span class="p">)</span> <span class="c1"># natively rgb24</span>
<span class="gp">>>> </span><span class="n">_</span><span class="p">,</span> <span class="n">GRAY</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">video</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'myvideo.mp4'</span><span class="p">,</span> <span class="n">t</span><span class="o">=</span><span class="mf">1.0</span><span class="p">,</span> <span class="n">pix_fmt</span><span class="o">=</span><span class="s1">'gray'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">RGB</span><span class="o">.</span><span class="n">shape</span>
<span class="go">(29, 640, 480, 3)</span>
<span class="gp">>>> </span><span class="n">GRAY</span><span class="o">.</span><span class="n">shape</span>
<span class="go">(29, 640, 480, 1)</span>
<span class="gp">>>> </span><span class="c1"># auto-convert PNG image to remove transparency with white background</span>
<span class="gp">>>> </span><span class="n">RGBA</span> <span class="o">=</span> <span class="n">ffmpegio</span><span class="o">.</span><span class="n">image</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'myimage.png'</span><span class="p">)</span> <span class="c1"># natively rgba with transparency</span>
<span class="go">.. >>> RGB = ffmpegio.image.read('myimage.png', pix_fmt='rgb24', fill_color='white')</span>
<span class="gp">>>> </span><span class="n">RGB</span><span class="o">.</span><span class="n">shape</span>
<span class="go">(100, 396, 4)</span>
<span class="gp">>>> </span><span class="n">RGB</span><span class="o">.</span><span class="n">shape</span>
<span class="go">(100, 396, 3)</span>
<span class="gp">>>> </span><span class="c1"># auto-convert to audio samples to double precision</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">'myaudio.wav'</span><span class="p">)</span> <span class="c1"># natively s16</span>
<span class="gp">>>> </span><span class="n">_</span><span class="p">,</span> <span class="n">y</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">'myaudio.wav'</span><span class="p">,</span> <span class="n">sample_fmt</span><span class="o">=</span><span class="s1">'dbl'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">x</span><span class="o">.</span><span class="n">max</span><span class="p">()</span>
<span class="go">2324</span>
<span class="gp">>>> </span><span class="n">y</span><span class="o">.</span><span class="n">max</span><span class="p">()</span>
<span class="go">0.0709228515625</span>
</pre></div>
</div>
<p>Note when converting from an image with alpha channel (FFmpeg does not support
alpha channel in video input) the background color may be specified with
<code class="code docutils literal notranslate"><span class="pre">fill_color</span></code> option (which defaults to <code class="docutils literal notranslate"><span class="pre">'white'</span></code>).
See <a class="reference external" href="https://ffmpeg.org/ffmpeg-utils.html#Color">the FFmpeg color specification</a>
for the list of predefined color names.</p>
<table class="tight-table docutils align-default" id="id4">
<caption><span class="caption-text">Examples of changing image format</span><a class="headerlink" href="#id4" title="Link to this table"></a></caption>
<tbody>
<tr class="row-odd"><td><p><code class="code docutils literal notranslate"><span class="pre">'rgba'</span></code> (original)</p></td>
<td><figure class="align-default">
<img alt="_images/quick-1.png" class="plot-directive" src="_images/quick-1.png" />
</figure>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">ffmpegio</span><span class="o">.</span><span class="n">image</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'ffmpeg-logo.png'</span><span class="p">)</span>
</pre></div>
</div>
</td>
</tr>
<tr class="row-even"><td><p><code class="code docutils literal notranslate"><span class="pre">'rgb24'</span></code> with ‘Linen’ background</p></td>
<td><figure class="align-default">
<img alt="_images/quick-2.png" class="plot-directive" src="_images/quick-2.png" />
</figure>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">ffmpegio</span><span class="o">.</span><span class="n">image</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'ffmpeg-logo.png'</span><span class="p">,</span> <span class="n">pix_fmt</span><span class="o">=</span><span class="s1">'rgb24'</span><span class="p">,</span> <span class="n">fill_color</span><span class="o">=</span><span class="s1">'linen'</span><span class="p">)</span>
</pre></div>
</div>
</td>
</tr>
<tr class="row-odd"><td><p><code class="code docutils literal notranslate"><span class="pre">'ya8'</span></code></p></td>
<td><figure class="align-default">
<img alt="_images/quick-3.png" class="plot-directive" src="_images/quick-3.png" />
</figure>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">ffmpegio</span><span class="o">.</span><span class="n">image</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'ffmpeg-logo.png'</span><span class="p">,</span> <span class="n">pix_fmt</span><span class="o">=</span><span class="s1">'ya8'</span><span class="p">)</span>
</pre></div>
</div>
</td>
</tr>
<tr class="row-even"><td><p><code class="code docutils literal notranslate"><span class="pre">'gray'</span></code> with light gray background</p></td>
<td><figure class="align-default">
<img alt="_images/quick-4.png" class="plot-directive" src="_images/quick-4.png" />
</figure>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">ffmpegio</span><span class="o">.</span><span class="n">image</span><span class="o">.</span><span class="n">read</span><span class="p">(</span><span class="s1">'ffmpeg-logo.png'</span><span class="p">,</span> <span class="n">pix_fmt</span><span class="o">=</span><span class="s1">'gray'</span><span class="p">,</span>
<span class="n">fill_color</span><span class="o">=</span><span class="s1">'#F0F0F0'</span><span class="p">)</span>
</pre></div>
</div>
</td>
</tr>
</tbody>
</table>
</section>
<section id="progress-callback">
<span id="quick-callback"></span><h2>Progress Callback<a class="headerlink" href="#progress-callback" title="Link to this heading"></a></h2>
<p>FFmpeg has <code class="code docutils literal notranslate"><span class="pre">-progress</span></code> option, which sends program-friendly progress
information to url. <code class="xref py py-mod docutils literal notranslate"><span class="pre">ffmpegio</span></code> takes advantage of this option to
let user monitor the transcoding progress with a callback, which could be
set with <code class="code docutils literal notranslate"><span class="pre">progress</span></code> argument of all media operations. The callback
function must have the following signature:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="n">progress_callback</span><span class="p">(</span><span class="n">status</span><span class="p">:</span><span class="nb">dict</span><span class="p">,</span> <span class="n">done</span><span class="p">:</span><span class="nb">bool</span><span class="p">)</span> <span class="o">-></span> <span class="kc">None</span><span class="o">|</span><span class="nb">bool</span>
</pre></div>
</div>
<p>The <code class="code docutils literal notranslate"><span class="pre">status</span></code> dict containing the information similar to what FFmpeg
displays on console. The second argument <code class="code docutils literal notranslate"><span class="pre">done</span></code> is only <code class="code docutils literal notranslate"><span class="pre">True</span></code>
on the last progress call. Here is an example of <code class="code docutils literal notranslate"><span class="pre">status</span></code> dict:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="p">{</span><span class="s1">'bitrate'</span><span class="p">:</span> <span class="s1">'61.9kbits/s'</span><span class="p">,</span>
<span class="s1">'drop_frames'</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span>
<span class="s1">'dup_frames'</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span>
<span class="s1">'fps'</span><span class="p">:</span> <span class="mf">336.18</span><span class="p">,</span>
<span class="s1">'frame'</span><span class="p">:</span> <span class="mi">1014</span><span class="p">,</span>
<span class="s1">'out_time'</span><span class="p">:</span> <span class="s1">'00:00:33.877914'</span><span class="p">,</span>
<span class="s1">'out_time_ms'</span><span class="p">:</span> <span class="mi">33877914</span><span class="p">,</span>
<span class="s1">'out_time_us'</span><span class="p">:</span> <span class="mi">33877914</span><span class="p">,</span>
<span class="s1">'speed'</span><span class="p">:</span> <span class="s1">'11.2x'</span><span class="p">,</span>
<span class="s1">'stream_0_0_q'</span><span class="p">:</span> <span class="mf">29.0</span><span class="p">,</span>
<span class="s1">'total_size'</span><span class="p">:</span> <span class="mi">262192</span><span class="p">}</span>
</pre></div>
</div>
<p>While FFmpeg does not report percent progress, it is possible to compute it from
<code class="code docutils literal notranslate"><span class="pre">frame</span></code> or <code class="code docutils literal notranslate"><span class="pre">out_time</span></code> if you know the total number of output frames
or the output duration, respectively.</p>
<p>If an FFmpeg media stream object is invoked by <a class="reference internal" href="basicio.html#ffmpegio.open" title="ffmpegio.open"><code class="xref py py-func docutils literal notranslate"><span class="pre">ffmpegio.open()</span></code></a>
with <code class="code docutils literal notranslate"><span class="pre">progress</span></code> callback argument, the callback function can terminate
the FFmpeg execution by returning <code class="code docutils literal notranslate"><span class="pre">True</span></code>. This feature is useful for GUI
programming.</p>
</section>
</section>
</div>
</div>
<footer>
<hr/>
<div role="contentinfo">
<p>© Copyright 2021-2022, Takeshi (Kesh) Ikuma, Louisiana State University Health Sciences Center.</p>
</div>
Built with <a href="https://www.sphinx-doc.org/">Sphinx</a> using a
<a href="https://github.com/readthedocs/sphinx_rtd_theme">theme</a>
provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<script>
jQuery(function () {
SphinxRtdTheme.Navigation.enable(true);
});
</script>
</body>
</html>