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I am trying to convert an AVI file to an MP4 file. The video stream is an XVID whereas the audio stream is MP3.

The problem is that the resulting MP4 file is not playable in QuickTime Player on a Mac. It plays on VLC. While it's not a deal-breaker, I would like to know how to result such issues.

The command and it's output is as follows:

$ ffmpeg -i 103.avi -codec copy -f mp4 103.mp4

ffmpeg version N-60163-g78a9f18 Copyright (c) 2000-2014 the FFmpeg developers
  built on Jan 25 2014 14:03:47 with Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
  configuration: 
  libavutil      52. 63.100 / 52. 63.100
  libavcodec     55. 49.100 / 55. 49.100
  libavformat    55. 26.100 / 55. 26.100
  libavdevice    55.  5.102 / 55.  5.102
  libavfilter     4.  1.101 /  4.  1.101
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
Input #0, avi, from '103.avi':
  Metadata:
    encoder         : Lavf55.26.100
  Duration: 00:49:36.43, start: 0.000000, bitrate: 986 kb/s
    Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID / 0x44495658), yuv420p, 512x368 [SAR 1:1 DAR 32:23], 23.98 tbr, 23.98 tbn, 23.98 tbc
    Stream #0:1: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16p, 121 kb/s
Output #0, mp4, to '103.mp4':
  Metadata:
    encoder         : Lavf55.26.100
    Stream #0:0: Video: mpeg4 ( [0][0][0] / 0x0020), yuv420p, 512x368 [SAR 1:1 DAR 32:23], q=2-31, 11988 tbn, 23.98 tbc
    Stream #0:1: Audio: mp3 (i[0][0][0] / 0x0069), 48000 Hz, stereo, 121 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
[mp4 @ 0x7fe5ca01fa00] pts has no value
    Last message repeated 1555 times
[mp4 @ 0x7fe5ca01fa00] pts has no value9kB time=00:01:17.70 bitrate=1458.0kbits/s    
    Last message repeated 1041 times
[mp4 @ 0x7fe5ca01fa00] pts has no value49kB time=00:02:08.42 bitrate=1661.6kbits/s    
    Last message repeated 1906 times
[mp4 @ 0x7fe5ca01fa00] pts has no value53kB time=00:03:40.39 bitrate=1537.1kbits/s    
    Last message repeated 2136 times
[mp4 @ 0x7fe5ca01fa00] pts has no value93kB time=00:05:35.80 bitrate=1307.4kbits/s    
    Last message repeated 3519 times
[mp4 @ 0x7fe5ca01fa00] pts has no value32kB time=00:08:32.18 bitrate=1150.5kbits/s    
    Last message repeated 2813 times
[mp4 @ 0x7fe5ca01fa00] pts has no value88kB time=00:11:18.01 bitrate=1090.9kbits/s    
    Last message repeated 3057 times
[mp4 @ 0x7fe5ca01fa00] pts has no value39kB time=00:14:00.42 bitrate=1028.7kbits/s    
    Last message repeated 3731 times
[mp4 @ 0x7fe5ca01fa00] pts has no value11kB time=00:16:57.72 bitrate= 991.0kbits/s    
    Last message repeated 2658 times
[mp4 @ 0x7fe5ca01fa00] pts has no value76kB time=00:19:25.70 bitrate= 978.1kbits/s    
    Last message repeated 2167 times
[mp4 @ 0x7fe5ca01fa00] pts has no value70kB time=00:21:17.11 bitrate= 990.8kbits/s    
    Last message repeated 3663 times
[mp4 @ 0x7fe5ca01fa00] pts has no value20kB time=00:24:42.06 bitrate= 938.1kbits/s    
    Last message repeated 2335 times
[mp4 @ 0x7fe5ca01fa00] pts has no value79kB time=00:26:53.90 bitrate= 950.6kbits/s    
    Last message repeated 4153 times
[mp4 @ 0x7fe5ca01fa00] pts has no value06kB time=00:30:59.94 bitrate= 895.4kbits/s    
    Last message repeated 3168 times
[mp4 @ 0x7fe5ca01fa00] pts has no value87kB time=00:33:35.43 bitrate= 888.5kbits/s    
    Last message repeated 1565 times
[mp4 @ 0x7fe5ca01fa00] pts has no value02kB time=00:34:56.47 bitrate= 914.0kbits/s    
    Last message repeated 2792 times
[mp4 @ 0x7fe5ca01fa00] pts has no value10kB time=00:37:34.42 bitrate= 909.6kbits/s    
    Last message repeated 2503 times
[mp4 @ 0x7fe5ca01fa00] pts has no value49kB time=00:39:48.76 bitrate= 916.2kbits/s    
    Last message repeated 1714 times
[mp4 @ 0x7fe5ca01fa00] pts has no value70kB time=00:41:16.64 bitrate= 928.7kbits/s    
    Last message repeated 2060 times
[mp4 @ 0x7fe5ca01fa00] pts has no value79kB time=00:43:04.79 bitrate= 935.2kbits/s    
    Last message repeated 1349 times
[mp4 @ 0x7fe5ca01fa00] pts has no value46kB time=00:44:06.57 bitrate= 951.6kbits/s    
    Last message repeated 2354 times
[mp4 @ 0x7fe5ca01fa00] pts has no value67kB time=00:45:56.33 bitrate= 967.9kbits/s    
    Last message repeated 2668 times
[mp4 @ 0x7fe5ca01fa00] pts has no value50kB time=00:48:14.72 bitrate= 964.9kbits/s    
    Last message repeated 1655 times
frame=71363 fps=5738 q=-1.0 Lsize=  355528kB time=00:49:36.43 bitrate= 978.5kbits/s    
video:309630kB audio:44196kB subtitle:0 global headers:0kB muxing overhead 0.481011%

If I then copy the mp4 again, I get the following results:

$ ffmpeg -i 103.mp4 -codec copy -f mp4 103-new.mp4

ffmpeg version N-60163-g78a9f18 Copyright (c) 2000-2014 the FFmpeg developers
  built on Jan 25 2014 14:03:47 with Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
  configuration: 
  libavutil      52. 63.100 / 52. 63.100
  libavcodec     55. 49.100 / 55. 49.100
  libavformat    55. 26.100 / 55. 26.100
  libavdevice    55.  5.102 / 55.  5.102
  libavfilter     4.  1.101 /  4.  1.101
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
[mpeg4 @ 0x7fcddb018000] Video uses a non-standard and wasteful way to store B-frames ('packed B-frames'). Consider using a tool like VirtualDub or avidemux to fix it.
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '103.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2mp41
    encoder         : Lavf55.26.100
  Duration: 00:49:36.44, start: 0.000000, bitrate: 978 kb/s
    Stream #0:0(und): Video: mpeg4 (Advanced Simple Profile) (mp4v / 0x7634706D), yuv420p, 512x368 [SAR 1:1 DAR 32:23], 852 kb/s, 23.98 fps, 23.98 tbr, 11988 tbn, 23.98 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 48000 Hz, stereo, s16p, 121 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Output #0, mp4, to '103-new.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2mp41
    encoder         : Lavf55.26.100
    Stream #0:0(und): Video: mpeg4 ( [0][0][0] / 0x0020), yuv420p, 512x368 [SAR 1:1 DAR 32:23], q=2-31, 852 kb/s, 23.98 fps, 11988 tbn, 11988 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: mp3 (i[0][0][0] / 0x0069), 48000 Hz, stereo, 121 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame=71363 fps=5505 q=-1.0 Lsize=  355528kB time=00:49:36.43 bitrate= 978.5kbits/s    
video:309567kB audio:44196kB subtitle:0 global headers:0kB muxing overhead 0.498835%
share|improve this question

1 Answer 1

up vote 10 down vote accepted

First, a background on why this error exists. AVI does not support variable frame rate video. So somewhere at the start of the file the frame rate is recorded. mp4 does support variable frame rate, so it is required that the duration of each frame is known. In ffmpeg the pts generation for fixed frame rate video is usually handled by the decoder. but by using -codec copy, you are bypassing the decoder.

The solution is specifying -fflags +genpts (must be before the input file is specified with -i).

share|improve this answer
    
Thanks very much for the background detail and the suggested solution. That explains it a bit. So something like ffmpeg -i 103.avi -fflags +genpts -codec copy -f mp4 103.mp4? I actually tried that before posting here but it didn't fix the issue in my case. Do you know how to use avidemux to fix this issue as suggested by the 2nd log? –  Umar Farooq Khawaja Feb 1 at 20:51
3  
@UmarFarooqKhawaja -fflags +genpts needs to go before -i. –  Andrew Marshall Apr 1 at 23:56
    
It worked fine, but, the resulting mp4 file is not seek-able in quick time player.. Any clue..? –  Tony Thomas Jul 15 at 6:40
    
In my humble opinion, this is because quicktime player is dumb (A more accurate description is that it's probably missing an index). –  Wyatt8740 Aug 21 at 5:27
    
hmmm, I wonder why some of the videos converted from AVI to MP4 with the flag is sped up with no audio after I load them to my iPad. They play fine on VLC (Windows 7). –  sunk818 yesterday

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