[libav-tools] avconv produces mpeg files that confuse vlc

John Finlay finlay at moeraki.com
Wed Oct 2 22:13:31 CEST 2013


I have a 720p video file in a mpegts format that I want to trim a bit 
from the front and back of and convert to a mpeg format. I use a command 
like:

avconv -ss 0:1:23.456 -i file.ts -map 0 -c copy -t 0:54:32.111 file.mpg

to do the triming and conversion but when I try to  view the result 
using vlc there is no audio output and when I check the audio tracks I 
see something like 70 tracks available and when I look at the codec info 
I see even more streams listed (~100+). How do I get the result I am 
looking for i.e. a lossless trim?

The avconv info is:

avconv version 0.8.6-4:0.8.6-0ubuntu0.12.04.1, Copyright (c) 2000-2013 
the Libav developers
   built on Apr  2 2013 17:02:36 with gcc 4.6.3
avconv 0.8.6-4:0.8.6-0ubuntu0.12.04.1
libavutil    51. 22. 1 / 51. 22. 1
libavcodec   53. 35. 0 / 53. 35. 0
libavformat  53. 21. 1 / 53. 21. 1
libavdevice  53.  2. 0 / 53.  2. 0
libavfilter   2. 15. 0 /  2. 15. 0
libswscale    2.  1. 0 /  2.  1. 0
libpostproc  52.  0. 0 / 52.  0. 0


The avprobe of a typical file is:

avprobe version 0.8.6-4:0.8.6-0ubuntu0.12.04.1, Copyright (c) 2007-2013 
the Libav developers
   built on Apr  2 2013 17:02:36 with gcc 4.6.3
[mpegts @ 0x1b209c0] Continuity check failed for pid 0 expected 15 got 6
[mpegts @ 0x1b209c0] PES packet size mismatch
[mpegts @ 0x1b209c0] PES packet size mismatch
Input #0, mpegts, from '/mythtv/sda/recordings/1091_20131001190000.mpg':
   Duration: 00:59:59.16, start: 43236.008711, bitrate: 11900 kb/s
   Program 1
     Stream #0.0[0x31]: Video: mpeg2video (Main), yuv420p, 1280x720 [PAR 
1:1 DAR 16:9], 19392 kb/s, 59.96 fps, 59.94 tbr, 90k tbn, 119.88 tbc
     Stream #0.1[0x34](eng): Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s
     Stream #0.2[0x35](spa): Audio: ac3, 48000 Hz, stereo, s16, 192 kb/s

avprobe of the converted file is:

avprobe version 0.8.6-4:0.8.6-0ubuntu0.12.04.1, Copyright (c) 2007-2013 
the Libav developers
   built on Apr  2 2013 17:02:36 with gcc 4.6.3
Input #0, mpeg, from 'video.mpg':
   Duration: 00:58:07.80, start: 1.082000, bitrate: 11618 kb/s
     Stream #0.0[0x80]: Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s
     Stream #0.1[0x81]: Audio: ac3, 48000 Hz, stereo, s16, 192 kb/s
     Stream #0.2[0x1e0]: Video: mpeg2video (Main), yuv420p, 1280x720 
[PAR 1:1 DAR 16:9], 19392 kb/s, 59.96 fps, 59.94 tbr, 90k tbn, 119.88 tbc

John


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