asr
Automatic Speech Recognition
This filter uses PocketSphinx for speech recognition. To enable
compilation of this filter, you need to configure FFmpeg with
--enable-pocketsphinx.
It accepts the following options:
- rate
- Set sampling rate of input audio. Defaults is - 16000. This need to match speech models, otherwise one will get poor results.
- hmm
- Set dictionary containing acoustic model files. 
- dict
- Set pronunciation dictionary. 
- lm
- Set language model file. 
- lmctl
- Set language model set. 
- lmname
- Set which language model to use. 
- logfn
- Set output for log messages. 
The filter exports recognized speech as the frame metadata lavfi.asr.text.