[FFmpeg-devel] [PATCH] lavfi/buffersrc: push the frame deeper if requested.

[Michael Niedermayer]

On Sat, Jun 24, 2017 at 04:54:38PM +0200, Michael Niedermayer wrote:
> On Tue, Jun 20, 2017 at 07:59:26PM +0200, Paul B Mahol wrote:
> > On 12/24/16, Nicolas George <george at nsup.org> wrote:
> > > Le quartidi 4 nivose, an CCXXV, Michael Niedermayer a ecrit :
> > >> theres a change with "-af apad=pad_len=10000 -shortest" (no -vframes)
> > >> the file is not sharable, this change undoes the effect of the
> > >> non-recursive patch
> > >>
> > >> use of vframes generally shows differences which seem to return to what
> > >> things were before the "non recursive patch"
> > >
> > > Thanks for checking. Then I shall push shortly.
> > 
> > This breaks :shortest=1 in all framesync filters, so I'm for reverting this.
> 
> The revert broke alot
> I would suggest to undo the revert and go through the normal review
> process
> 
> examples of breakages:
> ./ffmpeg -i bgc.sub.dub.ogm -vframes 3 subs.webm
> 
> (produces 1 instead of 3 frames in the output)
> 
> 
> ./ffmpeg -i 2014-10-17\ 11.31\ i95Dev\ -\ Carlo\ Pazolini\ _\ KWI\ -\ Meeting.g2m  -max_muxing_queue_size 8000 -vframes 2 g2m5.avi
> 
> fails:
> [libmp3lame @ 0x3a5aee0] Queue input is backward in time
> [avi @ 0x3a5e280] Too large number of skipped frames 194211 > 60000  54.1kbits/s speed= 129x
> av_interleaved_write_frame(): Invalid argument
> [avi @ 0x3a5e280] Too large number of skipped frames 194111 > 60000
> frame=    2 fps=1.1 q=2.0 Lsize=    1857kB time=00:03:14.35 bitrate=  78.3kbits/s speed= 103x
> video:149kB audio:1519kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 11.380948%
> Conversion failed!
> (iam not sure i can share this one)
> 
> 
> ./ffmpeg -i ~/videos/matrixbench_mpeg2.mpg -vframes 20 -vcodec libx265 -omit_video_pes_length 0 -pix_fmt yuv420p file2.ts
> 
> the change results in the aditional warnings on playback of the resulting file:
> [mpegts @ 0x3d10100] start time for stream 1 is not set in estimate_timings_from_pts
> [mpegts @ 0x3d10100] Could not find codec parameters for stream 1 (Audio: mp3 ([3][0][0][0] / 0x0003), 0 channels, s16p): unspecified frame size
> Consider increasing the value for the 'analyzeduration' and 'probesize' options

Heres an example without vframes:

./ffmpeg-good -v 0 -i ~/tickets/3539/crash.swf -map 0 -t 1 -f framecrc -
vs.
./ffmpeg -v 0 -i ~/tickets/3539/crash.swf -map 0 -t 1 -f framecrc -

new code returns fewer frames

http://samples.ffmpeg.org/ffmpeg-bugs/trac/ticket3539/crash.swf




[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The misfortune of the wise is better than the prosperity of the fool.
-- Epicurus
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20170624/e9ba62dc/attachment.sig>