[FFmpeg-user] framemd5 for audio?

Peter B. pb at das-werkstatt.com
Wed Aug 8 02:13:51 CEST 2012

On 08/08/2012 01:44 AM, Paul B Mahol wrote:
> On 8/7/12, David Rice <daverice at mac.com> wrote:
>> One issue here is that while there is rawvideo for framemd5 of video
>> streams, there is no equivalent rawaudio format for audio data. The
>> framemd5 of audio will be applied to signed 16 bit raw audio (even if
>> the source is unsigned or >16 bit). So for >16 bit audio the framemd5
>> process wouldn't work for losslessness verification since the bit
>> depth would need to be changed prior to the application of the checksum. 
> AFAIK framemd5 works fine for >16 bits, just user needs to make sure that
> he compares apples to apples: like same sample format (comparing s16p and s16
> is possible because conversion between them is lossless), and same pcm output.
I also would have thought so.
If the compared files did not undergo any format-changes (e.g. s16->s32
or whatever), and the same number of samples is in the right frame,
their checksums should match.

I'll try the "asetnsamples" filter. From what I've read in the docs, it
sounds promising.


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