[FFmpeg-devel] [PATCH] avformat/avidec: add support for recognizing HEVC fourcc when demuxing

[Marton Balint]

On Thu, 29 Aug 2019, Marton Balint wrote:

>
>
> On Sat, 24 Aug 2019, James Almer wrote:
>
>> On Sat, Aug 24, 2019 at 5:48 AM Marton Balint <cus at passwd.hu> wrote:
>>
>>>
>>>
>>> On Sat, 24 Aug 2019, Carl Eugen Hoyos wrote:
>>>
>>> > Am Sa., 24. Aug. 2019 um 01:47 Uhr schrieb Marton Balint <cus at passwd.hu
>>> >:
>>> >>
>>> >> Some security cams generate this, as well as some versions of
>>> VirtualDub so
>>> >> support for _reading_ such files is justified.
>>> >
>>> > Please also mention vlc.
>>>
>>> Ok.
>>>
>>> >
>>> >>
>>> >> Fixes ticket #7110.
>>> >>
>>> >> See also this discussion: https://patchwork.ffmpeg.org/patch/8744/
>>> >>
>>> >> Signed-off-by: Marton Balint <cus at passwd.hu>
>>> >> ---
>>> >>  libavformat/avidec.c | 4 ++++
>>> >>  libavformat/riff.c   | 5 +++++
>>> >>  libavformat/riff.h   | 2 ++
>>> >>  3 files changed, 11 insertions(+)
>>> >>
>>> >> diff --git a/libavformat/avidec.c b/libavformat/avidec.c
>>> >> index 1d887b1cc9..7946791fe4 100644
>>> >> --- a/libavformat/avidec.c
>>> >> +++ b/libavformat/avidec.c
>>> >> @@ -815,6 +815,10 @@ FF_ENABLE_DEPRECATION_WARNINGS
>>> >>                                    "mov tag found in avi (fourcc 
> %s)\n",
>>> >>                                    av_fourcc2str(tag1));
>>> >>                      }
>>> >
>>> >> +                    /* Finally try unofficial codec tags to support
>>> non-standard files. */
>>> >
>>> > The comment does not look useful.
>>>
>>> Ok, removed locally.
>>>
>>> >
>>> >> +                    if (!st->codecpar->codec_id)
>>> >> +                        st->codecpar->codec_id =
>>> ff_codec_get_id(ff_codec_bmp_tags_unofficial, tag1);
>>> >> +
>>> >>                      /* This is needed to get the pict type which is
>>> necessary
>>> >>                       * for generating correct pts. */
>>> >>                      st->need_parsing = AVSTREAM_PARSE_HEADERS;
>>> >> diff --git a/libavformat/riff.c b/libavformat/riff.c
>>> >> index e755ad8d5f..52b0bf8f03 100644
>>> >> --- a/libavformat/riff.c
>>> >> +++ b/libavformat/riff.c
>>> >> @@ -491,6 +491,11 @@ const AVCodecTag ff_codec_bmp_tags[] = {
>>> >>      { AV_CODEC_ID_NONE,         0 }
>>> >>  };
>>> >>
>>> >> +const AVCodecTag ff_codec_bmp_tags_unofficial[] = {
>>> >> +    { AV_CODEC_ID_HEVC,         MKTAG('H', 'E', 'V', 'C') },
>>> >> +    { AV_CODEC_ID_NONE,         0 }
>>> >> +};
>>> >> +
>>> >>  const AVCodecTag ff_codec_wav_tags[] = {
>>> >>      { AV_CODEC_ID_PCM_S16LE,       0x0001 },
>>> >>      /* must come after s16le in this list */
>>> >> diff --git a/libavformat/riff.h b/libavformat/riff.h
>>> >> index 323aa38b4d..21078b77c8 100644
>>> >> --- a/libavformat/riff.h
>>> >> +++ b/libavformat/riff.h
>>> >> @@ -73,6 +73,8 @@ int ff_get_wav_header(AVFormatContext *s, AVIOContext
>>> *pb, AVCodecParameters *pa
>>> >>  extern const AVCodecTag ff_codec_bmp_tags[]; // exposed through
>>> avformat_get_riff_video_tags()
>>> >>  extern const AVCodecTag ff_codec_wav_tags[];
>>> >>
>>> >> +extern const AVCodecTag ff_codec_bmp_tags_unofficial[];
>>> >
>>> > Imo, this is far too complicated to avoid writing files
>>> > that all other relevant applications write happily.
>>>
>>> I am personally OK if we simply add the tag to ff_codec_bmp_tags but there
>>> was an uproar against supporting writing such files.
>>>
>>> IMHO the cleanest way of doing things is allowing writing files _if_
>>> std_complience is ALLOW_UNOFFICIAL, and otherwise rejecting it, but I am
>>> not intereseted in implementing this, but if you are then you can, and in
>>> order to separate the standard list and the unofficial list, you must have
>>> two...
>>>
>>> Regards,
>>> Marton
>>>
>>
>> That was my suggestion as well. It's what we do in movenc when dealing with
>> codecs that have non-finished encapsulation specs (VP9/AV1 at some point,
>> FLAC currently, etc).
>
> Will apply soon.

Applied.

Regards,
Marton