[FFmpeg-devel] [PATCH 3/6] avcodec/h264_slice: export S12M timecode side data

[Kieran Kunhya]

On Wed, 15 Jul 2020 at 02:19, <lance.lmwang at gmail.com> wrote:

> On Wed, Jul 15, 2020 at 12:54:35AM +0100, Kieran Kunhya wrote:
> > On Wed, 15 Jul 2020 at 00:36, <lance.lmwang at gmail.com> wrote:
> >
> > > From: Limin Wang <lance.lmwang at gmail.com>
> > >
> > > Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
> > > ---
> > >  libavcodec/h264_slice.c | 10 ++++++++++
> > >  1 file changed, 10 insertions(+)
> > >
> > > diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
> > > index c7b2764..db720de 100644
> > > --- a/libavcodec/h264_slice.c
> > > +++ b/libavcodec/h264_slice.c
> > > @@ -1307,6 +1307,7 @@ static int h264_export_frame_props(H264Context
> *h)
> > >      if (h->sei.picture_timing.timecode_cnt > 0) {
> > >          uint32_t *tc_sd;
> > >          char tcbuf[AV_TIMECODE_STR_SIZE];
> > > +        uint32_t *s12m_sd;
> > >
> > >          AVFrameSideData *tcside = av_frame_new_side_data(out,
> > >
> > > AV_FRAME_DATA_S12M_TIMECODE,
> > > @@ -1316,6 +1317,12 @@ static int h264_export_frame_props(H264Context
> *h)
> > >
> > >          tc_sd = (uint32_t*)tcside->data;
> > >          tc_sd[0] = h->sei.picture_timing.timecode_cnt;
> > > +        if (h->avctx->export_side_data &
> AV_CODEC_EXPORT_DATA_S12M_TC) {
> > > +            s12m_sd = ff_add_s12m_timecode_side_data(h->avctx);
> > > +            if (!s12m_sd)
> > > +                return AVERROR(ENOMEM);
> > > +            s12m_sd[0] = tc_sd[0];
> > > +        }
> > >
> > >          for (int i = 0; i < tc_sd[0]; i++) {
> > >              int drop = h->sei.picture_timing.timecode[i].dropframe;
> > > @@ -1325,6 +1332,9 @@ static int h264_export_frame_props(H264Context
> *h)
> > >              int   ff = h->sei.picture_timing.timecode[i].frame;
> > >
> > >              tc_sd[i + 1] = av_timecode_get_smpte(h->avctx->framerate,
> > > drop, hh, mm, ss, ff);
> > > +            if (h->avctx->export_side_data &
> > > AV_CODEC_EXPORT_DATA_S12M_TC) {
> > > +                s12m_sd[i + 1] = tc_sd[i + 1];
> > > +            }
> > >              av_timecode_make_smpte_tc_string(tcbuf, tc_sd[i + 1], 0);
> > >              av_dict_set(&out->metadata, "timecode", tcbuf, 0);
> > >          }
> > > --
> >
> >
> > Does this not duplicate the existing logic?
>
> It's export packet timecode sidedata, so that you can export the TC side
> data to stream
> level. patch#5 show the command how to use it, before the patch, you had
> to input timecode
> to export the TC to tmcd track for mp4. Please give advise if you have
> better way to get it,
> thanks.
>

I don't understand, timecode side data is already exported from H.264.
Why do you need to create two side datas?

Kieran