[FFmpeg-devel] [PATCH 2/2] avcodec: add an AVCodecContext flag to export A53/SCTE20/DVD CC side data on demand

[lance.lmwang at gmail.com]

On Thu, May 19, 2022 at 11:12:58AM +0200, Anton Khirnov wrote:
> Quoting lance.lmwang at gmail.com (2022-05-11 15:30:37)
> > On Wed, May 11, 2022 at 02:00:10PM +0200, Anton Khirnov wrote:
> > > Quoting lance.lmwang at gmail.com (2022-05-08 09:17:01)
> > > > From: Limin Wang <lance.lmwang at gmail.com>
> > > > 
> > > > some samples include both A53 and SCTE20 data. Before the commit, both
> > > > of the will be exported, so the CC data will be repeated or garbarge
> > > 
> > > Why would it be garbage? That sounds like a bug.
> > > Why can't we just export both?
> > for A53/SCTE20/DVDCC are exprted by A53_CC side data and they're sharing
> > the same a53_buf_ref to store the data, so if stream contains CC wrapped
> > as ATSC A53 packets + the same data wrapped as SCTE-20 packets, the CC
> > data will repeated. We can consider to add a new side data type if necessary,
> > but it's preferable to export A53_CC even it's SCTE20, so we can't export
> > both by A53_CC still.
> 
> Does this apply to anything other than mpeg2? If not, it should be a
> codec-private option rather than a new global flag.

Yes, it's for mpeg2 only. At first, I think export_side_data option is 
proper place to use. But if export_side_data are considered to use for
global, then I'll consider to add a mpeg2-private option for it.

> 
> -- 
> Anton Khirnov
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".

-- 
Thanks,
Limin Wang