On Mon, Aug 12, 2019 at 11:50 PM sharpbai <sharp...@gmail.com> wrote:
> On iOS 11, encoding a frame may return error with log > "Error encoding frame 0", which means vtenc_output_callback > is called with status=0 and sample_buffer=NULL. Then the > encoding session will be crashed on next callback wether or not > closing the codec context. > > Let us look through the link below introducing VTCompressionOutputCallback, > > > https://developer.apple.com/documentation/videotoolbox/vtcompressionoutputcallback?language=objc > > "status=0" (noErr) means compression was successful. > "sampleBuffer=NULL" means the frame was dropped when compression > was successful (status=0) or compression was not successful (status!=0). > > So we should not set AVERROR_EXTERNAL on "status=0" and > "sample_buffer=NULL" > as it is not a error. > > The fix is that we only set AVERROR_EXTERNAL with status value non zero. > When sample_buffer is NULL and status value is zero, we simply return > with no other operation. > > This crash often occurs on iOS 11 for example encoding 720p@25fps. > Is it fixed in iOS 12, or untested there? > > Signed-off-by: sharpbai <sharp...@gmail.com> > --- > libavcodec/videotoolboxenc.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c > index d76bb7f646..8afdd125d2 100644 > --- a/libavcodec/videotoolboxenc.c > +++ b/libavcodec/videotoolboxenc.c > @@ -569,12 +569,16 @@ static void vtenc_output_callback( > return; > } > > - if (status || !sample_buffer) { > + if (status) { > av_log(avctx, AV_LOG_ERROR, "Error encoding frame: %d\n", > (int)status); > set_async_error(vtctx, AVERROR_EXTERNAL); > return; > } > > + if (!sample_buffer) { > + return; > + } > + > if (!avctx->extradata && (avctx->flags & > AV_CODEC_FLAG_GLOBAL_HEADER)) { > int set_status = set_extradata(avctx, sample_buffer); > if (set_status) { > -- > 2.21.0 > > _______________________________________________ > 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". _______________________________________________ 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".
