On Tue, 4 Oct 2016 14:15:03 +0200 Michael Niedermayer <mich...@niedermayer.cc> wrote:
> On Tue, Oct 04, 2016 at 01:52:02PM +0200, Hendrik Leppkes wrote: > > On Tue, Oct 4, 2016 at 1:44 PM, Hendrik Leppkes <h.lepp...@gmail.com> > > wrote: > > > On Tue, Oct 4, 2016 at 1:23 PM, Michael Niedermayer > > > <mich...@niedermayer.cc> wrote: > > >> On Tue, Oct 04, 2016 at 08:41:42AM +0200, Hendrik Leppkes wrote: > > >>> On Tue, Oct 4, 2016 at 4:05 AM, Michael Niedermayer > > >>> <mich...@niedermayer.cc> wrote: > > >>> > On Sat, Oct 01, 2016 at 04:15:45PM +0200, Hendrik Leppkes wrote: > > >>> >> Decoders have previously not used AVFrame.pts, and with the upcoming > > >>> >> deprecation of pkt_pts (in favor of pts), this would lead to an > > >>> >> errorneous > > >>> >> interpration of timestamps. > > >>> > > > >>> > I probably misunderstand the commit message but > > >>> > If code is changed in a user application that cannot really lift > > >>> > some blockage from changing a lib. > > >>> > a lib can only change in an incompaible way with (deprecation and) > > >>> > major version bump. > > >>> > > > >>> > > >>> The lib never did what this code suggests it did, not that I remember > > >>> (so at least not for a long long time). > > >> > > >> release/2.0 with > > >> > > >> diff --git a/libavcodec/utils.c b/libavcodec/utils.c > > >> index 29d5492..57c8d50 100644 > > >> --- a/libavcodec/utils.c > > >> +++ b/libavcodec/utils.c > > >> @@ -2008,7 +2008,7 @@ int attribute_align_arg > > >> avcodec_decode_video2(AVCodecContext *avctx, AVFrame *pi > > >> avci->to_free.extended_data = avci->to_free.data; > > >> memset(picture->buf, 0, sizeof(picture->buf)); > > >> } > > >> - > > >> +av_assert0(picture->pts == 0 || picture->pts == AV_NOPTS_VALUE); > > >> avctx->frame_number++; > > >> av_frame_set_best_effort_timestamp(picture, > > >> guess_correct_pts(avctx, > > >> > > >> causes many tests to fail, indicating that AVFrame.pts was set for > > >> several video decoders, the ffmpeg code is audio decoder specific > > >> and i failed to find a case where it was triggered, i tried IIRC 3 > > >> or so checkouts from the past > > >> > > >> so AVFrame.pts was maybe never set for decoding audio but it was set > > >> for video > > > > > > Can you extend the test to add "|| picture->pts == picture->pkt_pts"? > > > Because thats what it would be set to after the merge. A quick check > > > in the 2.0 code base looks like some decoders did set that, but to the > > > exact same value as pkt_pts (which is what the merge is proposing > > > right now as well) > > > > > > > And I found this (after 2.0): > > http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=a1c5cc429d99216406170eac7e8352860076d3e8 > > > > Which apparently set pts for mpeg4 to a number parsed from the > > bitstream, entirely uncorrelated to container or audio timestamps, so > > using them would have been rather impractical for any real use-cases. > > They can be usfull, some random examples: > > playing MPEG4-ES with timing stored from the bitstream (assuming there > is no demuxer lib used that is capable to extract them) > > forensics, raw video stream could have its timing > recovered, a video with manipulated container timestamps could be > detected. > > error correction, if the container level timestamps are lost or > corrupted the stream level ones can be used to recreate them > > There may be more, these are just some of the top of my head, > not your mainstream multimedia player stuff maybe but they arent > useless > > [...] > They don't belong into the AVFrame.pts field, though. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel