[FFmpeg-user] audio frequency frame by frame

[Fernanda Rebelatto]

Em 9 de fevereiro de 2012 21:10, Stefano Sabatini <stefasab at gmail.com> escreveu:
> You may write an audio filter and perform audio data analysis (hint:
> you can find many high quality DSP routines in libavcodec in case you
> want to do some coding).

Which filter could I use? I tried using ashowinfo, but it failed. I
don't know to use the audio filter in the right way. could it be like
this: ffmpeg-i input.mp4-filter: a ashowinfo?