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

[Michael Niedermayer]

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




[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Take away the freedom of one citizen and you will be jailed, take away
the freedom of all citizens and you will be congratulated by your peers
in Parliament.
-------------- 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/bce7d3b2/attachment.sig>