[FFmpeg-trac] #2210(FFmpeg:new): AC3 channel layout change midstream causes severe errors

[FFmpeg]

#2210: AC3 channel layout change midstream causes severe errors
---------------------------------+---------------------------------------
             Reporter:  agni451  |                     Type:  defect
               Status:  new      |                 Priority:  important
            Component:  FFmpeg   |                  Version:  unspecified
             Keywords:           |               Blocked By:
             Blocking:           |  Reproduced by developer:  0
Analyzed by developer:  0        |
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 Summary of the bug:
 How to reproduce:
 {{{
 % ffmpeg -v verbose -y -i "C:\PATH\ORIG.ts" -c:v mpeg2video -q:vscale 0
 -flags +ilme+ildct -top 1 -c:a ac3 -ab 384k -ac 6 -async 48000
 "C:\PATH\FIX.ts"
 ffmpeg version N-46469-gc995644
 built on Nov 5 2012
 }}}

 The input I'm using is a TV program recorded in Media Center, so it has an
 MPEG2 stream and a 6ch ac3 stream.  I use the commandline above in an
 effort to correct for missing audio/video frames, and it works great if
 I've already removed the commercials from the stream (using DGIndexNV to
 copy the pieces I want).  However, I've noticed that DGIndexNV does not
 compensate for the initial audio delay in the stream, so the end of the
 audio cuts out before the video.  I want to start trimming at specific
 frames, and the only way to do that is to fix the stream first using the
 above commandline.  Then I find the frames at which I need to cut, and use
 tsmuxer to do it.  Since the commandline above also fixes the initial
 delay, I don't have to worry about the audio being off.

 However, some of the recorded shows with commercials experience an audio
 channel number and layout change around the commercials, going from 6ch
 48000 --> 2ch stereo, then switching back.  This causes extreme problems
 with the fixed stream using the above commandline, as I suddenly start
 getting messages like " st:0 PTS: 100320 DTS: 100320 < 64387716 invalid,
 clipping" and adding very large segments of silent audio (like 10
 minutes).

 In the log I am attaching, you will see that the audio changes from 6ch to
 stereo or vice versa a total of 6 times.  The one that takes place at
 44:17.120 results in the entire rest of the clip being silent.  I don't
 think I'm missing any features that might fix this, so I'm posting it as a
 bug.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2210>
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