[FFmpeg-devel] [PATCH 1/2] avformat/mxfdec: fix opAtom audio demuxing

[Tomas Härdin]

tor 2018-03-01 klockan 22:41 +0100 skrev Marton Balint:
> Consider edit rate when determining edit_units_per_packet and also make sure
> that checks are done in edit rate time base and not in stream time base.
> 
> Fixes some errors reported with the sample in ticket #5863.
> 
> > Signed-off-by: Marton Balint <cus at passwd.hu>
> ---
>  libavformat/mxfdec.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> @@ -2786,6 +2786,7 @@ static AVStream* mxf_get_opatom_stream(MXFContext *mxf)
>  static void mxf_handle_small_eubc(AVFormatContext *s)
>  {
>      MXFContext *mxf = s->priv_data;
> +    MXFTrack *track;
>  
>      /* assuming non-OPAtom == frame wrapped
>       * no sane writer would wrap 2 byte PCM packets with 20 byte headers.. */
> @@ -2805,7 +2806,8 @@ static void mxf_handle_small_eubc(AVFormatContext *s)
>      /* TODO: We could compute this from the ratio between the audio
>       *       and video edit rates for 48 kHz NTSC we could use the
>       *       1802-1802-1802-1802-1801 pattern. */
> -    mxf->edit_units_per_packet = 1920;
> +    track = st->priv_data;
> +    mxf->edit_units_per_packet = FFMAX(1, track->edit_rate.num / track->edit_rate.den / 25);
>  }

That 25 looks a bit arbitrary. But I guess with OPAtom we don't have a
video edit rate to make use of

Other than that, patch looks OK

/Tomas