[FFmpeg-devel] [PATCH 1/2] lavc/libopenh264: Support full range videos in transcoding

[mypopy at gmail.com]

On Thu, Apr 20, 2023 at 7:27 PM "zhilizhao(赵志立)" <quinkblack at foxmail.com> wrote:
>
>
>
> > On Apr 18, 2023, at 23:33, Jun Zhao <mypopydev at gmail.com> wrote:
> >
> > Support full range videos when transcoding, enabled the
> > YUVJ420P to avoid auto scale from YUVJ420P to YUV420P
>
>
> According to "Towards YUVJ removal"
> http://ffmpeg.org/pipermail/ffmpeg-devel/2022-December/304718.html
>
> > So, as was discussed at the last meeting, we should move towards
> removing YUVJ.
>
> However, it looks like there is no much progress since then.
>
Yes, I know the plan we will remove YUVJ, but now when we transcoding,
ffmpeg auto-inserts swscaler to convert from full range to limited
range when input video with full range, I can't find a full solution
in this case, So until YUVJ is removed, I add the YUVJ format support
for this case.

> >
> > Signed-off-by: Jun Zhao <barryjzhao at tencent.com>
> > ---
> > libavcodec/libopenh264enc.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/libopenh264enc.c b/libavcodec/libopenh264enc.c
> > index 8b4755f5ba..cccc11fbb7 100644
> > --- a/libavcodec/libopenh264enc.c
> > +++ b/libavcodec/libopenh264enc.c
> > @@ -311,10 +311,12 @@ static av_cold int svc_encode_init(AVCodecContext *avctx)
> >
> > #if OPENH264_VER_AT_LEAST(1, 6)
> >     param.sSpatialLayers[0].uiVideoFormat = VF_UNDEF;
> > +
> >     if (avctx->color_range != AVCOL_RANGE_UNSPECIFIED) {
> >         param.sSpatialLayers[0].bVideoSignalTypePresent = true;
> >         param.sSpatialLayers[0].bFullRange = (avctx->color_range == AVCOL_RANGE_JPEG);
> > -    }
> > +    }  else if (avctx->pix_fmt == AV_PIX_FMT_YUVJ420P)
> > +        param.sSpatialLayers[0].bFullRange = 1;
> >
> >     if (avctx->colorspace != AVCOL_SPC_UNSPECIFIED      ||
> >         avctx->color_primaries != AVCOL_PRI_UNSPECIFIED ||
> > @@ -443,6 +445,7 @@ const FFCodec ff_libopenh264_encoder = {
> >     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP |
> >                       FF_CODEC_CAP_AUTO_THREADS,
> >     .p.pix_fmts     = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P,
> > +                                                    AV_PIX_FMT_YUVJ420P,
> >                                                     AV_PIX_FMT_NONE },
> >     .defaults       = svc_enc_defaults,
> >     .p.priv_class   = &class,
> > --
> > 2.25.1
> >