Как преобразовать формат аудиопотока?

Это должно быть примерно так:

$ ffmpeg -i input-file.wav -acodec pcm_f32le -ar 96000 output-file.wav

И у вас есть много вариантов, если вы используете PCM, другие кодеки могут быть ограничены определенными профилями.

$ ffmpeg -formats 2>/dev/null | grep endian
 DE f32be           PCM 32 bit floating-point big-endian format
 DE f32le           PCM 32 bit floating-point little-endian format
 DE f64be           PCM 64 bit floating-point big-endian format
 DE f64le           PCM 64 bit floating-point little-endian format
 DE s16be           PCM signed 16 bit big-endian format
 DE s16le           PCM signed 16 bit little-endian format
 DE s24be           PCM signed 24 bit big-endian format
 DE s24le           PCM signed 24 bit little-endian format
 DE s32be           PCM signed 32 bit big-endian format
 DE s32le           PCM signed 32 bit little-endian format
 DE u16be           PCM unsigned 16 bit big-endian format
 DE u16le           PCM unsigned 16 bit little-endian format
 DE u24be           PCM unsigned 24 bit big-endian format
 DE u24le           PCM unsigned 24 bit little-endian format
 DE u32be           PCM unsigned 32 bit big-endian format
 DE u32le           PCM unsigned 32 bit little-endian format

$ ffmpeg -codecs 2>/dev/null | grep endian
 D A D  pcm_bluray      PCM signed 16|20|24-bit big-endian for Blu-ray media
 D A D  pcm_dvd         PCM signed 20|24-bit big-endian
 D A D  pcm_f32be       PCM 32-bit floating point big-endian
 D A D  pcm_f32le       PCM 32-bit floating point little-endian
 D A D  pcm_f64be       PCM 64-bit floating point big-endian
 D A D  pcm_f64le       PCM 64-bit floating point little-endian
 D A D  pcm_lxf         PCM signed 20-bit little-endian planar
 D A D  pcm_s16be       PCM signed 16-bit big-endian
 D A D  pcm_s16le       PCM signed 16-bit little-endian
 D A D  pcm_s16le_planar PCM 16-bit little-endian planar
 D A D  pcm_s24be       PCM signed 24-bit big-endian
 D A D  pcm_s24le       PCM signed 24-bit little-endian
 D A D  pcm_s32be       PCM signed 32-bit big-endian
 D A D  pcm_s32le       PCM signed 32-bit little-endian
 D A D  pcm_u16be       PCM unsigned 16-bit big-endian
 D A D  pcm_u16le       PCM unsigned 16-bit little-endian
 D A D  pcm_u24be       PCM unsigned 24-bit big-endian
 D A D  pcm_u24le       PCM unsigned 24-bit little-endian
 D A D  pcm_u32be       PCM unsigned 32-bit big-endian
 D A D  pcm_u32le       PCM unsigned 32-bit little-endian