Badly interleaved partial AVI file causes audio/video desync

[gjdfgh]

Reproducible with streams.videolan.org/issues/ffmpeg/yet-another-broken-interleaved-avi.avi and

dd if=yet-another-broken-interleaved-avi.avi of=test.avi bs=1048576 count=200

The problem description is exactly the same as #333, except with partial files (the complete test file as linked above works fine, just cutting it makes it fail).

Just like with bug #333 (before it was fixed), it causes desync after some time of normal playback in ffplay/mplayer, and it works correctly with mplayer -demuxer avi.

Compared to playback of the complete file, the following ffplay message is missing:

[avi @ 0x7f94980008c0] non-interleaved AVI

which possibly means that the demuxer fails to recognize the file as badly interleaved if the trailing part of the file is missing.

[Carl Eugen Hoyos]

Please add a command line that allows to reproduce the problem together with complete, uncut console output.

[gjdfgh]

On a file cut to the length of 65932192 bytes:

ffplay ../yet-another\ broken-interleaved-avi.avi -loglevel debug
ffplay version N-47450-g217b10d Copyright (c) 2003-2012 the FFmpeg developers
  built on Dec  5 2012 11:03:58 with gcc 4.7 (Debian 4.7.2-4)
  configuration: --prefix=/tmp/ffmpeg_temp
  libavutil      52. 11.101 / 52. 11.101
  libavcodec     54. 79.100 / 54. 79.100
  libavformat    54. 44.100 / 54. 44.100
  libavdevice    54.  3.102 / 54.  3.102
  libavfilter     3. 24.100 /  3. 24.100
  libswscale      2.  1.103 /  2.  1.103
  libswresample   0. 17.102 /  0. 17.102
[avi @ 0x90344a0] Format avi probed with size=2048 and score=100
[avi @ 0x9003100] use odml:1
st:0 removing common factor 10 from timebase
st:1 removing common factor 384 from timebase
[avi @ 0x90344a0] File position before avformat_find_stream_info() is 10252
[avi @ 0x90344a0] All info found
rfps: 29.666667 0.013650
    Last message repeated 1 times
rfps: 29.750000 0.007180
    Last message repeated 1 times
rfps: 29.833333 0.002771
    Last message repeated 1 times
rfps: 29.916667 0.000422
    Last message repeated 1 times
rfps: 30.000000 0.000134
    Last message repeated 1 times
rfps: 30.083333 0.001906
    Last message repeated 1 times
rfps: 30.166667 0.005738
    Last message repeated 1 times
rfps: 30.250000 0.011631
    Last message repeated 1 times
rfps: 30.333333 0.019584
    Last message repeated 1 times
rfps: 59.583333 0.018872
    Last message repeated 1 times
rfps: 59.666667 0.011084
    Last message repeated 1 times
rfps: 59.750000 0.005356
    Last message repeated 1 times
rfps: 59.833333 0.001688
    Last message repeated 1 times
rfps: 59.916667 0.000081
    Last message repeated 1 times
rfps: 60.000000 0.000534
    Last message repeated 1 times
rfps: 29.970030 0.000000
    Last message repeated 1 times
rfps: 59.940060 0.000000
    Last message repeated 1 times
[avi @ 0x90344a0] File position after avformat_find_stream_info() is 303757
Input #0, avi, from '../yet-another broken-interleaved-avi.avi':
  Duration: 00:23:29.35, start: 0.000000, bitrate: 374 kb/s
    Stream #0:0, 41, 100/2997: Video: mpeg4 (DIVX / 0x58564944), yuv420p, 640x480, 1/30000, 29.97 fps, 29.97 tbr, 29.97 tbn, 30k tbc
    Stream #0:1, 40, 3/125: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16p, 128 kb/s
[mpeg4 @ 0x903c920] detected 2 logical cores
[mpeg4 @ 0x904c140] looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag
Frame changed from size:0x0 to size:640x480  14KB sq=    0B f=0/0   
[buffer @ 0x903c8a0] Setting entry with key 'video_size' to value '640x480'
[buffer @ 0x903c8a0] Setting entry with key 'pix_fmt' to value '0'
[buffer @ 0x903c8a0] Setting entry with key 'time_base' to value '100/2997'
[buffer @ 0x903c8a0] Setting entry with key 'pixel_aspect' to value '0/1'
[ffplay_buffer @ 0x9078de0] w:640 h:480 pixfmt:yuv420p tb:100/2997 fr:0/1 sar:0/1 sws_param:
[ffplay_crop @ 0x903da40] w:640 h:480 sar:0/1 -> w:640 h:480 sar:0/1
ALSA lib pcm.c:7339:(snd_pcm_recover) underrun occurred  0B f=0/0  

You experience A/V desync and eventually audio underruns after about 50 seconds. mplayer -demuxer avi has no such problems.

[Carl Eugen Hoyos]

FFmpeg does not support non-interleaved avi files without index, ie if the index gets removed from a non-interleaved avi, it cannot be played anymore with ffplay and mplayer -demuxer lavf

[gjdfgh]

mplayer -demuxer avi can play it. You need to add -idx to seek in it.

(I'm assuming the index is located in the last few megabytes of the avi file, so an incomplete avi file would always be without index.)

[Carl Eugen Hoyos]

Replying to gjdfgh:

mplayer -demuxer avi can play it. You need to add -idx to seek in it.

Sorry, there was a typo in my message, it should read "it cannot be played ... with ffplay and mplayer -demuxer lavf"