> From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of > James Almer > Sent: Tuesday, March 31, 2020 23:44 > To: ffmpeg-devel@ffmpeg.org > Subject: Re: [FFmpeg-devel] [PATCH 1/7] lavc/libopenh264enc: Add default > qmin/qmax support > > On 3/31/2020 12:31 PM, Linjie Fu wrote: > > Set default QP range to (1, 51) instead of (2, 32). > > > > QP = 0 is not well supported currently in libopenh264. If iMaxQp/iMinQp > > equals 0, the QP range would be changed unexpectedly inside libopenh264 > > with a warning: > > > > Warning:Change QP Range from(0,51) to (12,42) > > > > Signed-off-by: Linjie Fu <linjie...@intel.com> > > --- > > [1] > <https://github.com/cisco/openh264/blob/master/codec/encoder/core/src/ > encoder_ext.cpp#L375> > > [2] <https://github.com/cisco/openh264/issues/3259> > > > > libavcodec/libopenh264enc.c | 10 ++++++++++ > > 1 file changed, 10 insertions(+) > > > > diff --git a/libavcodec/libopenh264enc.c b/libavcodec/libopenh264enc.c > > index ae6d17c..7cd1efe 100644 > > --- a/libavcodec/libopenh264enc.c > > +++ b/libavcodec/libopenh264enc.c > > @@ -135,6 +135,9 @@ FF_ENABLE_DEPRECATION_WARNINGS > > param.iTargetBitrate = avctx->bit_rate; > > param.iMaxBitrate = FFMAX(avctx->rc_max_rate, avctx- > >bit_rate); > > param.iRCMode = RC_QUALITY_MODE; > > + // QP = 0 is not well supported, so default to (1, 51) > > + param.iMaxQp = avctx->qmax >= 0 ? > > av_clip(avctx->qmax, 1, > 51) : 51; > > + param.iMinQp = avctx->qmin >= 0 ? > > av_clip(avctx->qmin, 1, > avctx->qmax) : 1; > > Should be param.iMaxQp. avctx->qmax may be <= 0. > Fixed locally, thanks for pointing this out and the elaborations in IRC.
- Linjie _______________________________________________ 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".