[FFmpeg-devel] [PATCH] avformat/ac3dec: detect fairplay encryption

[Carl Eugen Hoyos]

Am Mi., 4. März 2020 um 18:57 Uhr schrieb James Almer <jamrial at gmail.com>:
>
> On 3/4/2020 1:56 PM, Carl Eugen Hoyos wrote:
> > Am Mi., 4. März 2020 um 17:53 Uhr schrieb Sebastian Hubbard
> > <sebh-at-google.com at ffmpeg.org>:
> >>
> >> I knew this was an ABI change and probably wasn't going to be
> >> acceptable, but I decided to share it for consideration anyway.
> >> There's special code in av_probe_input_format3 to skip over id3 tags
> >> for the purposes of format detection, but Apple uses id3 tags to
> >> signal information for HLS audio only tracks. Maybe this change
> >> shouldn't be made, but if it could ever be helpful for another format
> >> prober to know about leading id3 tags this is the only way I could
> >> imagine it.
> >
> > If the additional fields are necessary (I don't know), they could be
> > added to the end of the struct where they do not break abi.
> >
> > Carl Eugen
>
> sizeof(AVProbeData) is part of the ABI because its doxy doesn't strictly
> state otherwise. This means we can't add new fields to it, even at the
> end, until a major bump. Else we'll be breaking ABI.

Thank you both for the explanation!

Carl Eugen