[FFmpeg-devel] [PATCH] ffmpeg: fix order between field order autodetection and override

[Jan Ekström]

On Sun, Jul 25, 2021 at 10:38 PM Paul B Mahol <onemda at gmail.com> wrote:
>
> On Wed, Jul 21, 2021 at 7:29 PM Jan Ekström <jeebjp at gmail.com> wrote:
>
> > Somehow I missed this in fbb44bc51a647862eb05ae3f9d7d49a0be9bed57 ,
> > even though the lines were within the context. Probably the code
> > originally being after the this logic had something to do with it,
> > but previously it only touched the avformat context's codecpar,
> > which did not affect the encoder codec context whatsoever.
> >
> > Fixes #9320
> > Fixes #9339
> > ---
> >  fftools/ffmpeg.c | 14 ++++++++------
> >  1 file changed, 8 insertions(+), 6 deletions(-)
> >
> > diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
> > index 40e8010096..b0ce7c7c32 100644
> > --- a/fftools/ffmpeg.c
> > +++ b/fftools/ffmpeg.c
> > @@ -3483,12 +3483,7 @@ static int init_output_stream_encode(OutputStream
> > *ost, AVFrame *frame)
> >              enc_ctx->bits_per_raw_sample = frame_bits_per_raw_sample;
> >          }
> >
> > -        if (ost->top_field_first == 0) {
> > -            enc_ctx->field_order = AV_FIELD_BB;
> > -        } else if (ost->top_field_first == 1) {
> > -            enc_ctx->field_order = AV_FIELD_TT;
> > -        }
> > -
> > +        // Field order: autodetection
> >          if (frame) {
> >              if (enc_ctx->flags & (AV_CODEC_FLAG_INTERLACED_DCT |
> > AV_CODEC_FLAG_INTERLACED_ME) &&
> >                  ost->top_field_first >= 0)
> > @@ -3503,6 +3498,13 @@ static int init_output_stream_encode(OutputStream
> > *ost, AVFrame *frame)
> >                  enc_ctx->field_order = AV_FIELD_PROGRESSIVE;
> >          }
> >
> > +        // Field order: override
> > +        if (ost->top_field_first == 0) {
> > +            enc_ctx->field_order = AV_FIELD_BB;
> > +        } else if (ost->top_field_first == 1) {
> > +            enc_ctx->field_order = AV_FIELD_TT;
> > +        }
> > +
> >          if (ost->forced_keyframes) {
> >              if (!strncmp(ost->forced_keyframes, "expr:", 5)) {
> >                  ret = av_expr_parse(&ost->forced_keyframes_pexpr,
> > ost->forced_keyframes+5,
> > --
> > 2.31.1
> >
> >
> LGTM
>

Thanks, applied with the recommendations you made for the commit
message, as well as fixing a case of "the this logic".

Jan