[FFmpeg-user] Matroska: Element exceeds containing master element ending at...

[Peter B.]

Hi everyone :)

I've noticed something odd, and I'm not sure if I've made an error or not:
I've created an MKV file with ffmpeg, and when I read that MKV with the
same ffmpeg build right afterwards, I get the following error/warning at
the end:

[matroska,webm @ 0x3f0c600] Element at 0xb3f8d1b ending at 0xb3f92ea
exceeds containing master element ending at 0xb3f8d15

MediaConch [1] says that .mkv is specification-valid.
I've found a similar report on superuser.com [2], but not on Trac.
I'd be very interested in finding out what this means or why it happens.


Thanks you very much in advance,
Peter B.


## Links:
  [1] https://mediaarea.net/MediaConch
  [2]
https://superuser.com/questions/1425822/element-exceeds-containing-master-element-ffmpeg



Commandline and console output here:

*********************
$ ffmpeg-git -i 12bit.mkv -filter_complex "asetnsamples=48000" -f
framemd5 12bit.mkv.framemd5
*********************

ffmpeg version N-93869-gae6486c Copyright (c) 2000-2019 the FFmpeg
developers
  built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.11) 20160609
  configuration: --prefix=/usr/local --enable-gpl --enable-nonfree
--enable-version3 --enable-postproc --enable-ffplay --enable-swscale
--enable-avfilter --enable-pthreads --enable-bzlib --enable-zlib
--enable-decoder=png --enable-encoder=png --samples=../fate-suite
--enable-libfreetype --enable-libopenjpeg --disable-decoder=jpeg2000
--enable-libvpx --enable-libvorbis --enable-libx264 --enable-libx265
  libavutil      56. 27.100 / 56. 27.100
  libavcodec     58. 52.101 / 58. 52.101
  libavformat    58. 27.103 / 58. 27.103
  libavdevice    58.  7.100 / 58.  7.100
  libavfilter     7. 53.101 /  7. 53.101
  libswscale      5.  4.101 /  5.  4.101
  libswresample   3.  4.100 /  3.  4.100
  libpostproc    55.  4.100 / 55.  4.100
Guessed Channel Layout for Input Stream #0.1 : stereo
Input #0, matroska,webm, from '12bit.mkv':
  Metadata:
    COM.APPLE.QUICKTIME.MODEL: MacPro5,1
    COM.APPLE.QUICKTIME.SOFTWARE: Mac OS X 10.9.5 (13F34)
    MAJOR_BRAND     : qt 
    MINOR_VERSION   : 0
    COMPATIBLE_BRANDS: qt 
    COM.APPLE.QUICKTIME.CREATIONDATE: 2014-11-03T15:46:31+0100
    COM.APPLE.QUICKTIME.MAKE: Apple
    ENCODER         : Lavf58.27.103
  Duration: 00:00:34.00, start: 0.000000, bitrate: 44403 kb/s
    Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv422p12le, 702x576,
SAR 59:54 DAR 767:576, 25 fps, 25 tbr, 1k tbn, 1k tbc (default)
    Metadata:
      HANDLER_NAME    : Core Media Video
      ENCODER         : Lavc58.52.101 ffv1
      DURATION        : 00:00:34.000000000
    Stream #0:1: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
(default)
    Metadata:
      HANDLER_NAME    : Core Media Audio
      ENCODER         : Lavc58.52.101 pcm_s16le
      DURATION        : 00:00:33.960000000
File '12bit.mkv.framemd5' already exists. Overwrite ? [y/N] y
Stream mapping:
  Stream #0:1 (pcm_s16le) -> asetnsamples (graph 0)
  asetnsamples (graph 0) -> Stream #0:0 (pcm_s16le)
  Stream #0:0 -> #0:1 (ffv1 (native) -> rawvideo (native))
Press [q] to stop, [?] for help
Output #0, framemd5, to '12bit.mkv.framemd5':
  Metadata:
    COM.APPLE.QUICKTIME.MODEL: MacPro5,1
    COM.APPLE.QUICKTIME.SOFTWARE: Mac OS X 10.9.5 (13F34)
    MAJOR_BRAND     : qt 
    MINOR_VERSION   : 0
    COMPATIBLE_BRANDS: qt 
    COM.APPLE.QUICKTIME.CREATIONDATE: 2014-11-03T15:46:31+0100
    COM.APPLE.QUICKTIME.MAKE: Apple
    encoder         : Lavf58.27.103
    Stream #0:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
(default)
    Metadata:
      encoder         : Lavc58.52.101 pcm_s16le
    Stream #0:1: Video: rawvideo (Y3[10][12] / 0xC0A3359), yuv422p12le,
702x576 [SAR 59:54 DAR 767:576], q=2-31, 242611 kb/s, 25 fps, 25 tbn, 25
tbc (default)
    Metadata:
      HANDLER_NAME    : Core Media Video
      DURATION        : 00:00:34.000000000
      encoder         : Lavc58.52.101 rawvideo
[matroska,webm @ 0x3f0c600] Element at 0xb3f8d1b ending at 0xb3f92ea
exceeds containing master element ending at 0xb3f8d15
frame=  850 fps=112 q=-0.0 Lsize=      69kB time=00:00:34.04 bitrate= 
16.7kbits/s speed=4.49x   
video:1342575kB audio:6375kB subtitle:0kB other streams:0kB global
headers:0kB muxing overhead: unknown