[FFmpeg-devel] [PATCH 7/8] avformat/mpegts: Fix for the DOVI video stream descriptor
lance.lmwang at gmail.com
lance.lmwang at gmail.com
Thu Oct 14 17:30:50 EEST 2021
On Thu, Oct 14, 2021 at 10:12:05AM -0400, quietvoid wrote:
> On Thu, Oct 14, 2021 at 9:52 AM <lance.lmwang at gmail.com> wrote:
>
> > On Thu, Oct 14, 2021 at 09:45:45AM -0400, quietvoid wrote:
> > > On Thu, Oct 14, 2021 at 9:36 AM <lance.lmwang at gmail.com> wrote:
> > >
> > > > On Thu, Oct 14, 2021 at 09:18:16AM -0400, f tcChlisop0 wrote:
> > > > > On Thu, Oct 14, 2021 at 9:10 AM <lance.lmwang at gmail.com> wrote:
> > > > >
> > > > > > From: Limin Wang <lance.lmwang at gmail.com>
> > > > > >
> > > > > > By <<Dolby Vision Streams Within the MPEG-2 Transport Stream Format
> > > > v1.2>>
> > > > > >
> > > > > > Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> > > > > > ---
> > > > > > libavformat/mpegts.c | 11 +++++++++--
> > > > > > 1 file changed, 9 insertions(+), 2 deletions(-)
> > > > > >
> > > > > > diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
> > > > > > index 44d9298..774964d 100644
> > > > > > --- a/libavformat/mpegts.c
> > > > > > +++ b/libavformat/mpegts.c
> > > > > > @@ -2178,6 +2178,8 @@ int ff_parse_mpeg2_descriptor(AVFormatContext
> > > > *fc,
> > > > > > AVStream *st, int stream_type
> > > > > > AVDOVIDecoderConfigurationRecord *dovi;
> > > > > > size_t dovi_size;
> > > > > > int ret;
> > > > > > + int dependency_pid;
> > > > > > +
> > > > > > if (desc_end - *pp < 4) // (8 + 8 + 7 + 6 + 1 + 1 +
> > 1) / 8
> > > > > > return AVERROR_INVALIDDATA;
> > > > > >
> > > > > > @@ -2193,7 +2195,11 @@ int
> > ff_parse_mpeg2_descriptor(AVFormatContext
> > > > *fc,
> > > > > > AVStream *st, int stream_type
> > > > > > dovi->rpu_present_flag = (buf >> 2) & 0x01; // 1
> > bit
> > > > > > dovi->el_present_flag = (buf >> 1) & 0x01; // 1
> > bit
> > > > > > dovi->bl_present_flag = buf & 0x01; // 1
> > bit
> > > > > > - if (desc_end - *pp >= 20) { // 4 + 4 * 4
> > > > > > + if (!dovi->bl_present_flag && desc_end - *pp >= 2) {
> > > > > > + buf = get16(pp, desc_end);
> > > > > > + dependency_pid = buf >> 3; // 13 bits
> > > > > > + }
> > > > > > + if (desc_end - *pp >= 1) { // 8 bits
> > > > > > buf = get8(pp, desc_end);
> > > > > > dovi->dv_bl_signal_compatibility_id = (buf >> 4) &
> > > > 0x0f;
> > > > > > // 4 bits
> > > > > > } else {
> > > > > > @@ -2210,12 +2216,13 @@ int
> > ff_parse_mpeg2_descriptor(AVFormatContext
> > > > *fc,
> > > > > > AVStream *st, int stream_type
> > > > > > }
> > > > > >
> > > > > > av_log(fc, AV_LOG_TRACE, "DOVI, version: %d.%d,
> > profile:
> > > > %d,
> > > > > > level: %d, "
> > > > > > - "rpu flag: %d, el flag: %d, bl flag: %d,
> > > > compatibility
> > > > > > id: %d\n",
> > > > > > + "rpu flag: %d, el flag: %d, bl flag: %d,
> > > > > > dependency_pid: %d, compatibility id: %d\n",
> > > > > > dovi->dv_version_major, dovi->dv_version_minor,
> > > > > > dovi->dv_profile, dovi->dv_level,
> > > > > > dovi->rpu_present_flag,
> > > > > > dovi->el_present_flag,
> > > > > > dovi->bl_present_flag,
> > > > > > + dependency_pid,
> > > > > > dovi->dv_bl_signal_compatibility_id);
> > > > > > }
> > > > > > break;
> > > > > > --
> > > > > > 1.8.3.1
> > > > > >
> > > > > > _______________________________________________
> > > > > > 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".
> > > > > >
> > > > >
> > > > > Hi, this is something I had fixed in this patchset:
> > > > > https://ffmpeg.org/pipermail/ffmpeg-devel/2021-September/286234.html
> > > > > However the dependency_pid is ignored, as it has no use presently.
> > > > >
> > > > > Which patch should take precedence?
> > > >
> > > > Sorry, I have noticed your patch before. By the quick review of your
> > patch,
> > > > it's a lot function change and difficult to merge I think. I prefer to
> > > > fix the issue with existing code first instead of mixed function
> > change.
> > > >
> > >
> > > Okay, that makes sense.
> > > I will wait and rebase before resending for review then.
> > >
> > > However I'm worried my patch will still result in ignoring
> > dependency_pid,
> > > because it is not part of AVDOVIDecoderConfigurationRecord, unless it is
> > > added.
> >
> > I failed to find your patchset in my email archive, so I reply it here for
> > my comments:
> > - if (ret < 0) {
> > - av_free(dovi);
> > + if ((ret = ff_isom_parse_dvcc_dvvc(fc, st, *pp, desc_len, 1))
> > < 0)
> > return ret;
> > - }
> >
> > I think it's wrong to use ff_isom_parse_dvcc_dvvc() here for mpegts
> > use DOVIVideoStreamDescriptor, ISOM use DOVIDecoderConfigurationRecord.
> > they're different syntax if you have checked the two specs. So your
> > parsing isn't
> > follow the specs as dependency_pid is used by DOVIVideoStreamDescriptor.
> >
>
> That's true, however they only differ by dependency_pid.
> This is a concern I've noted here:
> https://ffmpeg.org/pipermail/ffmpeg-devel/2021-September/286159.html
But they're different descriptor anyway, in fact only the first 4 bytes is same,
after that:
DOVI_video_stream_descriptor:
if (!bl_present_flag) {
dependency_pid 13 bits
reserved 3 bits
}
dv_bl_signal_compatibility_id 4 bits
reserved 4 bits
DOVIDecoderConfigurationRecord
dv_bl_signal_compatibility_id 4 bits
reserved 28 bits
reserved 32*4 bits
Now the side data prefer to use DOVIDecoderConfigurationRecord, so mpegts should
parse by the DOVI_video_stream_descriptor syntax and store the result in
DOVIDecoderConfigurationRecord only.
>
> But I still went ahead with it to avoid the duplicated code.
> I've had no response since then, though.
>
> Either way, I'll just wait for your patches to get in.
> Thanks for the review.
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--
Thanks,
Limin Wang
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