On Sat, Jul 25, 2015 at 04:41:46PM +0300, Ivan Uskov wrote: > Hello Hendrik, > > Saturday, July 25, 2015, 3:13:38 PM, you wrote: > > HL> I'm slightly confused by the entire concept here. > > HL> - Why does the decoder need to re-init anyway? > Each time when I launch a command line like: > ./ffmpeg -c:v h264_qsv -i hd.mp4 -y result.yuv > I can see that: > 1. decoder opens, > 2. decoding until stream detect performs, > 3. decoder closes, > 4. decoder opens, > 5. normal decoding begins. > I still not big ffmpeg expert but I suspecting this behavior is by design.
the first opening comes from avformat_find_stream_info() > > HL> - You want the bsf to convert the bitstream to annexb, but not the > HL> extradata? Why not? > qsv* modules does not touch extradata at all. > But at step #5 above the bsf bumped to converted extradata which product of > bsf by itself at step #2. So at step #5 bsf confuses and fails. > So no mkv and mp4 decoding by h264_qsv at all currently. > > HL> - Ideally, a decoder should support both bitstream syntax without the > HL> bsf, since the bsf is a hack for re-muxing, and many playback > HL> applications do not use the bsf since practically no decoder otherwise > HL> needs them. > Intel's QSV decoder does require annex-b stream, it is documented in > SDK reference. > I can implement necessary functions to generate annex-b prefixes just into > libavcodec/qsvdec_h264.c if Michael will agree this way. would this be faster ? avoid a copy/malloc ? [...] -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB Frequently ignored answer#1 FFmpeg bugs should be sent to our bugtracker. User questions about the command line tools should be sent to the ffmpeg-user ML. And questions about how to use libav* should be sent to the libav-user ML.
signature.asc
Description: Digital signature
_______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
