[FFmpeg-devel] [PATCH] avformat/framecrcenc: compute the checksum for side data

[James Almer]

On 5/27/2024 3:11 PM, Michael Niedermayer wrote:
> On Mon, May 27, 2024 at 10:15:43AM +0200, Anton Khirnov wrote:
>> Quoting Michael Niedermayer (2024-04-27 02:36:23)
>>> This allows detecting issues in side data related code, same as what
>>> framecrc does for before already for packet data itself.
>>>
>>> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
>>> ---
>>
>> I am against this patch. Checksumming side data is a fundamentally wrong
>> thing to do.
> 
> It, or something equivalent is neccessary for regression testing.
> (and it was you who asked also for the tests i run to be part of
>   fate. But here you object to it)
> 
> You know, not checking side data is not checking it so differences would then not be
> detected allowing for unintended changes to be introduced (aka bugs)

You have seen how much code is needed to get hashing to work for all 
targets with some types, so it does feel like it's not the right thing 
to do. ffprobe (and f_sidedata) are what should be used for actual 
integrity checks.

And i insist that disabling printing the size (or any information about 
side data) from framecrc is needed for FATE tests, as we can't even use 
it to hash actual packet data otherwise.