[FFmpeg-user] Copy all/specific streams aborts w/non monotonically increasing dts

[petesea at frontier.com]

On Sat, 4 Apr 2015, PaulYurt wrote:

> To my inexperienced eyes this looks like a DTC stream issue. Ffmpeg 
> reports the DTS audio time is not continuous and ffmpeg is, in the 
> example shown, replacing the time markers with continuous markers.

For the audio streams yes, but not for the subtitle streams.  My question 
was really more about the subtitle streams.  For them, ffmpeg just aborts 
rather then applying the same "correction" logic.

As a test, I found the warning message displayed for the audio streams 
(ffmpeg.c:685) and noticed the code was restricted to video and audio 
streams.  I modified it to include subtitle streams and it worked.  At 
least for my test it generated the same warning message for subtitle 
streams as it does for audio streams, but more importantly it didn't abort 
the copy process.  It created a complete file and as far as I can tell 
there's no issues with the results.  The point in the movie where the 
problem happens has no jumps or missing parts.

It looks like the change to restrict this code to only video and audio 
streams happened on May 3rd 2013:

   http://git.videolan.org/?p=ffmpeg.git;a=commit;h=ee3824f6

What's the reason this same logic shouldn't be applied to subtitle 
streams?