[FFmpeg-trac] #581(avformat:new): matroskadec errors on blocks with zero data

[FFmpeg]

#581: matroskadec errors on blocks with zero data
------------------------------------+------------------------------------
             Reporter:  crwulff     |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avformat
              Version:  git-master  |               Resolution:
             Keywords:  mkv         |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+------------------------------------

Comment (by crwulff):

 I don't have an easy way to snip out the portion of the video that is
 causing problems it was muxed with a fairly old version of mkvmerge (and
 is over 4 gig). Slicing the clip with the current version of mkvmerge
 strips out the zero length blocks (they really aren't very useful.) Here's
 a couple segments from the mkvinfo dump. I can try to go build the
 referenced version of mkvmerge & libs if you really need a sample, but I
 don't know how involved that is going to be.


 + EBML head
 |+ Doc type: matroska
 |+ Doc type version: 1
 |+ Doc type read version: 1
 + Segment, size 4685769202
 |+ Seek head (subentries will be skipped)
 |+ EbmlVoid (size: 4025)
 |+ Segment information
 | + Timecode scale: 1000000
 | + Muxing application: libebml v0.7.7 + libmatroska v0.8.1
 | + Writing application: mkvmerge v2.1.0 ('Another Place To Fall') built
 on Aug 19 2007 13:40:07
 | + Duration: 6593.045s (01:49:53.045)
 | + Date: Tue Dec 25 21:37:57 2007 UTC
 | + Segment UID: 0xb2 0x9f 0xec 0xff 0x0e 0xf5 0xa6 0xf4 0x84 0xca 0xbb
 0xd2 0x9c 0x09 0x89 0x68
 |+ Segment tracks
 | + A track
 |  + Track number: 1
 |  + Track UID: 1
 |  + Track type: video
 |  + Enabled: 1
 |  + Default flag: 1
 |  + Forced flag: 0
 |  + Lacing flag: 0
 |  + MinCache: 1
 |  + Timecode scale: 1
 |  + Max BlockAddition ID: 0
 |  + Codec ID: V_MPEG4/ISO/AVC
 |  + Codec decode all: 1
 |  + CodecPrivate, length 39 (h.264 profile: High @L5.1) hexdump 01 64 00
 33 ff e1 00 18 67 64 00 33 ac 34 e2 c0
 |  + Default duration: 41.708ms (23.976 fps for a video track)
 |  + Language: eng
 |  + Video track
 |   + Pixel width: 1280
 |   + Pixel height: 720
 |   + Interlaced: 0
 |   + Display width: 16
 |   + Display height: 9
 | + A track
 |  + Track number: 2
 |  + Track UID: 973961
 |  + Track type: audio
 |  + Enabled: 1
 |  + Default flag: 1
 |  + Forced flag: 0
 |  + Lacing flag: 1
 |  + MinCache: 0
 |  + Timecode scale: 1
 |  + Max BlockAddition ID: 0
 |  + Codec ID: A_AC3
 |  + Codec decode all: 1
 |  + Default duration: 32.000ms (31.250 fps for a video track)
 |  + Language: eng
 |  + Audio track
 |   + Sampling frequency: 48000
 |   + Channels: 6
 | + A track
 |  + Track number: 3
 |  + Track UID: 49478588
 |  + Track type: subtitles
 |  + Enabled: 1
 |  + Default flag: 1
 |  + Forced flag: 0
 |  + Lacing flag: 0
 |  + MinCache: 0

 |  + Timecode scale: 1
 |  + Max BlockAddition ID: 0
 |  + Codec ID: S_TEXT/UTF8
 |  + Codec decode all: 1
 |  + Language: eng
 |+ EbmlVoid (size: 1024)
 |+ Cluster

 ...

 | + Block group
 |  + Block (track number 1, 1 frame(s), timecode 337.337s = 00:05:37.337)
 |   + Frame with size 16817 hexdump 00 00 41 ad 41 9a 5b 50 27 21 5f ea d5
 c3 59 16
 |  + Reference block: -83.000000ms
 | + Block group
 |  + Block (track number 3, 1 frame(s), timecode 337.337s = 00:05:37.337)
 |   + Frame with size 24 hexdump c2 b6 20 53 55 43 48 20 41 20 43 4f 4c 44
 20 46
 |  + Block duration: 32.000000ms
 | + Block group
 |  + Block (track number 3, 1 frame(s), timecode 337.370s = 00:05:37.370)
 |   + Frame with size 0 hexdump **<------------- This is the frame that
 errors**
 |  + Block duration: 3903.000000ms
 | + Block group
 |  + Block (track number 2, 8 frame(s), timecode 337.408s = 00:05:37.408)
 |   + Frame with size 1536 hexdump 0b 77 eb d0 1c 30 e1 ff e0 ec 92 40 00
 03 fe ff
 |   + Frame with size 1536 hexdump 0b 77 bd 9b 1c 30 e1 ff e0 ec 92 40 00
 03 ff 0f
 |   + Frame with size 1536 hexdump 0b 77 ef aa 1c 30 e1 ff e0 ec 92 40 00
 03 ff 0f
 |   + Frame with size 1536 hexdump 0b 77 4a 2b 1c 30 e1 ff e0 ec 92 40 00
 03 ff 0f
 |   + Frame with size 1536 hexdump 0b 77 dd 00 1c 30 e1 ff dc ec 92 40 00
 03 fe ff
 |   + Frame with size 1536 hexdump 0b 77 26 40 1c 30 e1 ff dc ec 92 40 00
 03 fe ff
 |   + Frame with size 1536 hexdump 0b 77 75 6b 1c 30 e1 ff dc ec 92 40 00
 03 fe ff
 |   + Frame with size 1536 hexdump 0b 77 00 f9 1c 30 e1 ff dc ec 92 40 00
 03 fe ff

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Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/581#comment:2>
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