James Almer <jamr...@gmail.com> 于2019年12月13日周五 上午12:14写道： > > On 12/4/2019 11:24 AM, Zhong Li wrote: > > "HEVC HDR UHDTV Bitstreams using HLG10 shall also contain the > > alternative_transfer_characteristics SEI message. The > > alternative_transfer_characteristics SEI message shall be inserted on > > the HEVC DVB_RAP, and preferred_transfer_characteristics shall be set > > equal to "18", indicating Recommendation ITU-R BT. 2100 [45] HLG > > system." > > > > Signed-off-by: Zhong Li <zhongli_...@126.com> > > --- > > libavcodec/libx265.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/libavcodec/libx265.c b/libavcodec/libx265.c > > index 4e75077..963c28f 100644 > > --- a/libavcodec/libx265.c > > +++ b/libavcodec/libx265.c > > @@ -159,6 +159,10 @@ static av_cold int libx265_encode_init(AVCodecContext > > *avctx) > > // x265 validates the parameters internally > > ctx->params->vui.colorPrimaries = avctx->color_primaries; > > ctx->params->vui.transferCharacteristics = avctx->color_trc; > > +#if X265_BUILD >= 159 > > + if (avctx->color_trc == AVCOL_TRC_ARIB_STD_B67) > > + ctx->params->preferredTransferCharacteristics = > > ctx->params->vui.transferCharacteristics; > > +#endif > > isn't the point of preferred_transfer_characteristics to have the Arib > value at the same time the standard VUI trc field contains a value like > BT2020 instead, for device backwards compat purposes? > > If both have the Arib value, then it seems redundant.
It is also for robustness，if preferred_transfer_characteristics is existed but not set, decoder may use preferred_transfer_characteristics instead of vui transfer_characteristics. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
