[FFmpeg-user] Concatenation of two file does not work correctly

Thu Sep 6 18:44:52 EEST 2018

I found a solution, but I got another one back.

I converted the two videos with:
    ffmpeg -i pauline.mov -acodec aac -vcodec copy pauline.mp4

Now the concatenation works.

But there where a few other files that also had to be concatenated.
For example:
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'joyce.mov':
  Metadata:
    major_brand     : qt  
    minor_version   : 512
    compatible_brands: qt  
    encoder         : Lavf57.56.101
  Duration: 00:00:41.52, start: 0.000000, bitrate: 5299 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc), 1920x1080, 3761 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : DataHandler
      encoder         : Lavc57.64.101 libx264
    Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, s16, 1536 kb/s (default)
    Metadata:
      handler_name    : DataHandler

But when I try to convert that one to mp4 I get a lot of messages
like:
[mp4 @ 0x560dae32d1a0] Non-monotonous DTS in output stream 0:0; previous: -865, current: -1024; changing to -864. This may result in incorrect timestamps in the output file.

And the timing of the first few seconds is completely out of sync.

What could be happening here and how do I solve it?

Cecil Westerhof <Cecil at decebal.nl> writes:

> I have two mov files I want to concatenate.
>
> The first:
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'pauline.mov':
>   Metadata:
>     major_brand     : qt  
>     minor_version   : 512
>     compatible_brands: qt  
>     encoder         : Lavf57.56.101
>   Duration: 00:00:40.09, start: 0.000000, bitrate: 5149 kb/s
>     Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc), 1920x1080, 3609 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>     Metadata:
>       handler_name    : DataHandler
>       encoder         : Lavc57.64.101 libx264
>     Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, s16, 1536 kb/s (default)
>     Metadata:
>       handler_name    : DataHandler
>
> The second:
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'cecil.mov':
>   Metadata:
>     major_brand     : qt  
>     minor_version   : 512
>     compatible_brands: qt  
>     encoder         : Lavf57.56.101
>   Duration: 00:00:12.08, start: 0.000000, bitrate: 5577 kb/s
>     Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc), 1920x1080, 4044 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
>     Metadata:
>       handler_name    : DataHandler
>       encoder         : Lavc57.64.101 libx264
>     Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, s16, 1536 kb/s (default)
>     Metadata:
>       handler_name    : DataHandler
>
> I created a publiciteit.txt with:
> file pauline.mov
> file cecil.mov
>
> And then I call:
> ffmpeg -f concat -i publiciteit.txt -acodec copy -vcodec copy publiciteit.mov
>
> This gives:
> mov,mp4,m4a,3gp,3g2,mj2 @ 0x5614a3e930e0] Auto-inserting h264_mp4toannexb bitstream filter
> Input #0, concat, from 'publiciteit.txt':
>   Duration: N/A, start: -0.037333, bitrate: 5145 kb/s
>     Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc), 1920x1080, 3609 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc
>     Metadata:
>       handler_name    : DataHandler
>       encoder         : Lavc57.64.101 libx264
>     Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, s16, 1536 kb/s
>     Metadata:
>       handler_name    : DataHandler
> File 'publiciteit.mov' already exists. Overwrite ? [y/N] y
> Output #0, mov, to 'publiciteit.mov':
>   Metadata:
>     encoder         : Lavf57.56.101
>     Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc), 1920x1080, q=2-31, 3609 kb/s, 25 fps, 25 tbr, 12800 tbn, 12800 tbc
>     Metadata:
>       handler_name    : DataHandler
>       encoder         : Lavc57.64.101 libx264
>     Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, 1536 kb/s
>     Metadata:
>       handler_name    : DataHandler
> Stream mapping:
>   Stream #0:0 -> #0:0 (copy)
>   Stream #0:1 -> #0:1 (copy)
> Press [q] to stop, [?] for help
> [mov,mp4,m4a,3gp,3g2,mj2 @ 0x5614a3e930e0] Auto-inserting h264_mp4toannexb bitstream filter
> frame= 1054 fps=0.0 q=-1.0 Lsize=   27031kB time=00:00:52.11 bitrate=4249.2kbits/s speed= 458x    
> video:19123kB audio:7884kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.090874%
>
> De size of the original files are 25.8 MB and 8.4 MB. The size of the
> generated file is 27.7 MB. Which seems a bit small.
>
> After the first part of the generated file has been played, I hear the
> sound of the second video, but the screen displays the end of the
> first video for 12 seconds and then the video of the second is shown
> and the audio is way out of sink. And after the audio is finished the
> last 12 seconds of the video are shown without audio.
>
> What could be happening here and how do I solve it.
>
> My version:
> ffmpeg version 3.2.12-1~deb9u1 Copyright (c) 2000-2018 the FFmpeg developers
>   built with gcc 6.3.0 (Debian 6.3.0-18+deb9u1) 20170516
>   configuration: --prefix=/usr --extra-version='1~deb9u1' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libebur128 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
>   libavutil      55. 34.101 / 55. 34.101
>   libavcodec     57. 64.101 / 57. 64.101
>   libavformat    57. 56.101 / 57. 56.101
>   libavdevice    57.  1.100 / 57.  1.100
>   libavfilter     6. 65.100 /  6. 65.100
>   libavresample   3.  1.  0 /  3.  1.  0
>   libswscale      4.  2.100 /  4.  2.100
>   libswresample   2.  3.100 /  2.  3.100
>   libpostproc    54.  1.100 / 54.  1.100

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof