This directory contains the Finite Impulse Response (FIR) EQ component.

FIR equalizers implement linear-phase (or minimal-phase) audio frequency shaping over a specified set of taps.

graph LR
  In[Input Frame] --> FIR[FIR Filter Engine]
  Coeffs[(Filter Coefficients)] --> FIR
  FIR --> Out[Output Frame]

• Kconfig: Enables the FIR component (COMP_FIR), which automatically imports MATH_FIR and COMP_BLOB. Relies on compiler capabilities to leverage DSP MAC instructions for optimal performance.
• CMakeLists.txt: Integrates generic and architecture-specific (eq_fir_hifi2ep.c, eq_fir_hifi3.c) files into the build, picking the correct IPC wrapper (ipc3 or ipc4), and supports llext.
• eq_fir.toml: Topology parameters for the EQFIR module, defining UUIDs, memory parameters (like 4096 bytes limits) and pin layouts.
• Topology (.conf): Constrained by tools/topology/topology2/include/components/eqfir.conf, assigning it widget type effect and UUID e7:0c:a9:43:a5:f3:df:41:ac:06:ba:98:65:1a:e6:a3.
• MATLAB Tuning (tune/): sof_example_fir_eq.m utilizes the Parks-McClellan (or related) algorithms to model loudness or mid-boost curves, iterating length variables to determine optimal FIR phase behaviors. It outputs quantized binary arrays containing the calculated taps necessary for topology population.