On Fri, Sep 1, 2023 at 11:50 AM "zhilizhao(赵志立)" <quinkbl...@foxmail.com> wrote: > > > > > On Sep 1, 2023, at 09:13, myp...@gmail.com wrote: > > > > On Fri, Sep 1, 2023 at 2:13 AM Zhao Zhili <quinkbl...@foxmail.com> wrote: > >> > >> > >>> From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of Jun Zhao > >>> Sent: 2023年8月31日 22:50 > >>> To: ffmpeg-devel@ffmpeg.org > >>> Cc: Jun Zhao <barryjz...@tencent.com>; Jun Zhao <mypopy...@gmail.com> > >>> Subject: [FFmpeg-devel] [PATCH 2/2] lavc/videotoolboxenc: enable > >>> low-latency mode for HEVC > >>> > >>> Enable the HEVC encoder that supports low-latency mode. > >>> > >>> Signed-off-by: Jun Zhao <barryjz...@tencent.com> > >>> --- > >>> libavcodec/videotoolboxenc.c | 3 ++- > >>> 1 file changed, 2 insertions(+), 1 deletion(-) > >>> > >>> diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c > >>> index 8e493c4f7a..bfc03787a0 100644 > >>> --- a/libavcodec/videotoolboxenc.c > >>> +++ b/libavcodec/videotoolboxenc.c > >>> @@ -1568,7 +1568,8 @@ static int vtenc_configure_encoder(AVCodecContext > >>> *avctx) > >>> #endif > >>> > >>> // low-latency mode: eliminate frame reordering, follow a > >>> one-in-one-out encoding mode > >>> - if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && avctx->codec_id == > >>> AV_CODEC_ID_H264) { > >>> + if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && > >>> + (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == > >>> AV_CODEC_ID_HEVC)) { > >> > >> How about just remove the codec_id check? > >> Is there any unwelcome side effects for encoders other than H264/HEVC? > > > > 1. One reason is that there are now other encoders available, such as > > prores_videotoolbox. > > > > 2. It may be more appropriate to use a strictly qualified check > > instead of an open condition. > > Both HEVC and ProRes failed with low_latency on my machine (with or without > -allow_sw 1) > > [hevc_videotoolbox @ 0x61900002a380] Error: cannot create compression > session: -12902 > [prores_videotoolbox @ 0x61900002a380] Error: cannot create compression > session: -12902 > > kVTParameterErr = > -12902, > I think you missed the other options, low delay in VT encoder need to co-work with some other options
> 1. FFmpeg users should have an idea whether or not to set > AV_CODEC_FLAG_LOW_DELAY. > AV_CODEC_FLAG_LOW_DELAY doesn’t make sense for ProRes, but if user wants to > try, let he/she > do. > > 2. I can’t find API to query the capability. Only VideoToolBox framework > itself know how > to handle the argument. There isn’t much protect to provide for users. > Yes, now FFmpeg VT encoder didn't used the capability query, I think need to used the some API VTCopySupportedPropertyDictionaryForEncoder for capability query, this my next step > Even with H.264, the results is unexpected: the input framerate is 25 but the > output > framerate is 5, it dropped 80 percent frames silently. > _______________________________________________ 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".