[FFmpeg-devel] [PATCH v3] avformat/framecrcenc: compute the checksum for side data

[Marton Balint]

On Sat, 4 May 2024, James Almer wrote:

> On 5/4/2024 5:34 AM, Marton Balint wrote:
>>
>>
>>  On Thu, 2 May 2024, James Almer wrote:
>>
>>>  On 5/2/2024 6:23 PM, Marton Balint wrote:
>>>> 
>>>>
>>>>   On Wed, 1 May 2024, Michael Niedermayer wrote:
>>>>
>>>>>   This allows detecting issues in side data related code, same as what
>>>>>   framecrc does for before already for packet data itself.
>>>>>
>>>>>   This basically reverts c6ae560a18d67b9ddaa25a0338b7fb55e3312e57.
>>>>
>>>>   Can you at least add an option which allows disabling dumping the side
>>>>   data? Changing the format of framecrc output again and again is not
>>>>  very 
>>>
>>>  The framehash/framemd5 muxer is versioned, which is what you should use
>>>  if you want parseable output.
>>
>>  Okay, but then the question is that why framecrc is using different code
>>  and options?
>
> Originally it was framecrc (using AVAdler) and framemd5 (using AVMD5). The 
> latter was renamed/aliased to framehash and made to use the AVHash API, which 
> supports all lavu hashing algorithms, and is versioned.
> If anyone cared, framecrc could be also made into an alias of framehash that 
> defaults to adler32 output, but it would result in a massive change to 
> reference files, if anything because AVHash initializes adler32 with a 1 
> whereas framecrc does it with a 0.

If we are changing the output format, we might as well change this as 
well...

Framehash also has side data hashing, so making framecrc output 
arch-indenpendent but not framehash would be a bit inconsistent.

Regards,
Marton