[FFmpeg-devel] Major bump

[James Almer]

On 4/5/2021 8:09 AM, Anton Khirnov wrote:
> Hi,
> this patchset bumps major version of all the libraries and removes many
> deprecated APIs, as discussed at length during past months. Patches
> 11-16 will be squashed together on push, but are sent separately for
> ease of review. FATE passes (here at least).
> 
> As agreed during the last developer call, I am disabling the
> uspp/mcdeint filters that depend on removed libavcodec APIs. They should
> be easy to re-enable if anyone finds the motivation to update them.
> 
> I am postponing the removal of compute_muxer_pkt_fields() in lavf, along
> with usage of AVCodecContext.time_base for decoding, since removing them
> without breakage requires a fair bit of additional infrastructure that
> is not yet there. I have plans for all these and hopefully I'll get to
> it before the next bump.
> 
> Carl asked during the last meeting for some reasoning for the bump. The
> general reasons are that
> - old APIs are unable to provide all the features of the new ones
>    (that's usually why new APIs are added)
> - old APIs tend to be harder to use correctly, they often have obscure
>    quirks or corner cases
> - maintaining compatibility wrappers for them is a major obstacle to
>    further development
> I'm appending some notes for the specific changes further down, they
> could be added to the wiki or the website news entry.
> 
> Please comment,

The deprecated APIs should be removed one by one before the commit that 
bumps the versions, so any potential issues or regressions can be 
bisected to the culprit instead of the "Bump and disable everything" 
commit. The latter was done last bump and it was a bit hectic.
This means that the changes from 12 to 16 should be in the respective 
API removal commit to not break FATE, of course.

Andreas also found out that some crypto modules that are being switch 
from int to size_t apparently need more changes than just the switch 
flip. See 
https://github.com/mkver/FFmpeg/commit/1d830b0495399bb59a296d7bb3e2b2ab88a32fc1