[FFmpeg-devel] [PATCH] deprecate SAMPLE_FMT_S24

Aurelien Jacobs aurel
Sun Aug 17 15:32:30 CEST 2008

Peter Ross wrote:

> This patch flags SAMPLE_FMT_S24 as deprecated.

So what will happen if a user suply a 32-bits pcm sample and re-encode
it with a supposedly lossless encoder which only support 24-bits ?
There is no way to tell the user that the encoding won't be lossless.
There is also no way for the 24-bits encoder to apply dithering to
32-bits samples (it would mess-up the real 24-bits samples stored in
Also, what happens if you transcode a 24-bits sample to wav (pcm) ?
The "encoder" will have no way to know that it's a 24-bits sample
and will store it as 32-bits. This is a huge waste of bytes.

IMO, SAMPLE_FMT_S24 is useful, even if it's treated internally the
exact same way as SAMPLE_FMT_S32. This allows encoders to behave
more sensibly if desired.


More information about the ffmpeg-devel mailing list