> On Mar 30, 2025, at 23:33, Kieran Kunhya via ffmpeg-devel > <ffmpeg-devel@ffmpeg.org> wrote: > > On Sun, Mar 30, 2025 at 12:04 AM Cameron Gutman <aicomman...@gmail.com > <mailto:aicomman...@gmail.com>> wrote: >> >> Previously, AV1 used filler data with CBR by default while H.264 >> and HEVC did not. Make this consistent by using filler data in >> CBR mode across all codecs. >> >> Since there are valid reasons to use CBR with or without filler, >> also add a cbr_padding option to allow users to opt out. >> >> Signed-off-by: Cameron Gutman <aicomman...@gmail.com> >> --- >> libavcodec/nvenc.c | 16 +++++++++++++--- >> libavcodec/nvenc.h | 2 ++ >> libavcodec/nvenc_av1.c | 2 ++ >> libavcodec/nvenc_h264.c | 4 ++++ >> libavcodec/nvenc_hevc.c | 4 ++++ >> 5 files changed, 25 insertions(+), 3 deletions(-) >> >> diff --git a/libavcodec/nvenc.c b/libavcodec/nvenc.c >> index 0f5e772b3e..41a4dc55f4 100644 >> --- a/libavcodec/nvenc.c >> +++ b/libavcodec/nvenc.c >> @@ -1304,7 +1304,12 @@ static av_cold int >> nvenc_setup_h264_config(AVCodecContext *avctx) >> h264->idrPeriod = cc->gopLength; >> >> if (IS_CBR(cc->rcParams.rateControlMode)) { >> - h264->outputBufferingPeriodSEI = 1; >> + /* Older SDKs use outputBufferingPeriodSEI to control filler data */ >> + h264->outputBufferingPeriodSEI = ctx->cbr_padding; >> + >> +#ifdef NVENC_HAVE_FILLER_DATA >> + h264->enableFillerDataInsertion = ctx->cbr_padding; >> +#endif >> } >> >> h264->outputPictureTimingSEI = 1; >> @@ -1503,7 +1508,12 @@ static av_cold int >> nvenc_setup_hevc_config(AVCodecContext *avctx) >> hevc->idrPeriod = cc->gopLength; >> >> if (IS_CBR(cc->rcParams.rateControlMode)) { >> - hevc->outputBufferingPeriodSEI = 1; >> + /* Older SDKs use outputBufferingPeriodSEI to control filler data */ >> + hevc->outputBufferingPeriodSEI = ctx->cbr_padding; >> + >> +#ifdef NVENC_HAVE_FILLER_DATA >> + hevc->enableFillerDataInsertion = ctx->cbr_padding; >> +#endif >> } >> >> hevc->outputPictureTimingSEI = 1; >> @@ -1625,7 +1635,7 @@ static av_cold int >> nvenc_setup_av1_config(AVCodecContext *avctx) >> av1->idrPeriod = cc->gopLength; >> >> if (IS_CBR(cc->rcParams.rateControlMode)) { >> - av1->enableBitstreamPadding = 1; >> + av1->enableBitstreamPadding = ctx->cbr_padding; >> } >> >> if (ctx->tile_cols >= 0) >> diff --git a/libavcodec/nvenc.h b/libavcodec/nvenc.h >> index e035e123c6..4b12846ed7 100644 >> --- a/libavcodec/nvenc.h >> +++ b/libavcodec/nvenc.h >> @@ -61,6 +61,7 @@ typedef void ID3D11Device; >> #define NVENC_HAVE_MULTIPLE_REF_FRAMES >> #define NVENC_HAVE_CUSTREAM_PTR >> #define NVENC_HAVE_GETLASTERRORSTRING >> +#define NVENC_HAVE_FILLER_DATA >> #endif >> >> // SDK 10.0 compile time feature checks >> @@ -309,6 +310,7 @@ typedef struct NvencContext >> int unidir_b; >> int split_encode_mode; >> int mdm, cll; >> + int cbr_padding; >> } NvencContext; >> >> int ff_nvenc_encode_init(AVCodecContext *avctx); >> diff --git a/libavcodec/nvenc_av1.c b/libavcodec/nvenc_av1.c >> index 01626113ab..b1b95672f2 100644 >> --- a/libavcodec/nvenc_av1.c >> +++ b/libavcodec/nvenc_av1.c >> @@ -156,6 +156,8 @@ static const AVOption options[] = { >> >> OFFSET(extra_sei), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, VE }, >> { "a53cc", "Use A53 Closed Captions (if available)", >> OFFSET(a53_cc), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, VE }, >> { "s12m_tc", "Use timecode (if available)", OFFSET(s12m_tc), >> AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, VE }, >> + { "cbr_padding", "Pad the bitstream to ensure bitrate does not drop >> below the target in CBR mode", >> + >> OFFSET(cbr_padding), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, VE }, >> #ifdef NVENC_HAVE_H264_AND_AV1_TEMPORAL_FILTER >> { "tf_level", "Specifies the strength of the temporal filtering", >> >> OFFSET(tf_level), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, VE, >> .unit = "tf_level" }, >> diff --git a/libavcodec/nvenc_h264.c b/libavcodec/nvenc_h264.c >> index 21d25d643a..4845d0422d 100644 >> --- a/libavcodec/nvenc_h264.c >> +++ b/libavcodec/nvenc_h264.c >> @@ -231,6 +231,10 @@ static const AVOption options[] = { >> >> OFFSET(max_slice_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, VE }, >> { "constrained-encoding", "Enable constrainedFrame encoding where each >> slice in the constrained picture is independent of other slices", >> >> OFFSET(constrained_encoding), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE }, >> +#ifdef NVENC_HAVE_FILLER_DATA >> + { "cbr_padding", "Pad the bitstream to ensure bitrate does not drop >> below the target in CBR mode", >> + >> OFFSET(cbr_padding), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, VE }, >> +#endif >> #ifdef NVENC_HAVE_H264_AND_AV1_TEMPORAL_FILTER >> { "tf_level", "Specifies the strength of the temporal filtering", >> >> OFFSET(tf_level), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, VE, >> .unit = "tf_level" }, >> diff --git a/libavcodec/nvenc_hevc.c b/libavcodec/nvenc_hevc.c >> index c74eca9bb3..8648f4f3a9 100644 >> --- a/libavcodec/nvenc_hevc.c >> +++ b/libavcodec/nvenc_hevc.c >> @@ -206,6 +206,10 @@ static const AVOption options[] = { >> >> OFFSET(max_slice_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, VE }, >> { "constrained-encoding", "Enable constrainedFrame encoding where each >> slice in the constrained picture is independent of other slices", >> >> OFFSET(constrained_encoding), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE }, >> +#ifdef NVENC_HAVE_FILLER_DATA >> + { "cbr_padding", "Pad the bitstream to ensure bitrate does not drop >> below the target in CBR mode", >> + >> OFFSET(cbr_padding), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, VE }, >> +#endif >> #ifdef NVENC_HAVE_TEMPORAL_FILTER >> { "tf_level", "Specifies the strength of the temporal filtering", >> >> OFFSET(tf_level), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, VE, >> .unit = "tf_level" }, >> -- >> 2.49.0 > > > This should be off by default in FFmpeg. We don't do this in any other > encoder.
I agree. > > Kieran > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org <mailto:ffmpeg-devel@ffmpeg.org> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org <mailto:ffmpeg-devel-requ...@ffmpeg.org> with > subject "unsubscribe". _______________________________________________ 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".
