[FFmpeg-devel] [PATCH v2] ffmpeg: allow full range of dts_delta_threshold

[Michael Niedermayer]

On Tue, Apr 14, 2020 at 02:48:47PM +0530, Gyan Doshi wrote:
> For inputs from demuxers with AVFMT_TS_DISCONT flag,
> the existing condition,
> 
>   delta < -1LL*dts_delta_threshold*AV_TIME_BASE
> 
> is rendered superflous due to the fixed threshold in
> 
> pkt_dts + AV_TIME_BASE/10 < FFMAX(ist->pts, ist->dts)
> 
> This prevents users from setting a high threshold to
> avoid discontinuity correction due to errant timestamps.
> 
> Now, the maximum of the two thresholds is used.
> 
> fate-mpeg4-resolution-change call changed to preserve existing
> timestamp correction by ffmpeg.c
> ---
> Tested with multiple satellite MPEG-TS inputs.
> 
>  fftools/ffmpeg.c     | 2 +-
>  tests/fate/mpeg4.mak | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)

breaks:
./ffmpeg -i 'concat:angels.mpg|angels.mpg'  -vsync 0  file.avi

...
frame=   24 fps=0.0 q=12.5 Lsize=     215kB time=00:00:07.50 bitrate= 234.7kbits/s speed=75.5x    
video:84kB audio:110kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 10.697786%

vs.

...
[avi @ 0x5601caccc180] Non-monotonous DTS in output stream 0:1; previous: 219, current: 86; changing to 220. This may result in incorrect timestamps in the output file.
[avi @ 0x5601caccc180] Non-monotonous DTS in output stream 0:1; previous: 220, current: 87; changing to 221. This may result in incorrect timestamps in the output file.
[avi @ 0x5601caccc180] Non-monotonous DTS in output stream 0:1; previous: 221, current: 88; changing to 222. This may result in incorrect timestamps in the output file.
[avi @ 0x5601caccc180] Non-monotonous DTS in output stream 0:1; previous: 222, current: 89; changing to 223. This may result in incorrect timestamps in the output file.
[avi @ 0x5601caccc180] Non-monotonous DTS in output stream 0:1; previous: 223, current: 90; changing to 224. This may result in incorrect timestamps in the output file.
[avi @ 0x5601caccc180] Non-monotonous DTS in output stream 0:1; previous: 224, current: 91; changing to 225. This may result in incorrect timestamps in the output file.
[mpeg4 @ 0x5601cac87540] Invalid pts (72) <= last (83)
Video encoding failed

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

You can kill me, but you cannot change the truth.
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