reading WAV file fails due to misdetection as MP1 stream

[Leigh Dyer]

When trying to open a particular WAV file (which was previously converted from a FLAC file using the "flac" tool), FFMPEG appears to misdetect the WAV's content as an MP1 stream, leading to errors that prevent FFMPEG from reading the file. This happens with a built from git-master:

lsd@pinchy:~/projects/ffmpeg/ffmpeg$ ./ffmpeg -i ../blah-snippet.wav -acodec alac -f ipod -y foo.m4a
ffmpeg version N-73646-gc9c7263 Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.9.3 (Debian 4.9.3-1)
  configuration: 
  libavutil      54. 28.100 / 54. 28.100
  libavcodec     56. 48.100 / 56. 48.100
  libavformat    56. 40.100 / 56. 40.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 21.100 /  5. 21.100
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.100 /  1.  2.100
Input #0, wav, from '../blah-snippet.wav':
  Duration: 00:00:05.00, bitrate: 1411 kb/s
    Stream #0:0: Audio: mp1 ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16p, 1411 kb/s
Output #0, ipod, to 'foo.m4a':
  Metadata:
    encoder         : Lavf56.40.100
    Stream #0:0: Audio: alac (alac / 0x63616C61), 44100 Hz, stereo, s16p, 128 kb/s
    Metadata:
      encoder         : Lavc56.48.100 alac
Stream mapping:
  Stream #0:0 -> #0:0 (mp1 (native) -> alac (native))
Press [q] to stop, [?] for help
Multiple frames in a packet from stream 0
[output stream 0:0 @ 0x34d3ea0] 100 buffers queued in output stream 0:0, something may be wrong.
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[ipod @ 0x34d2d20] Non-monotonous DTS in output stream 0:0; previous: 471014, current: 1280; changing to 471015. This may result in incorrect timestamps in the output file.
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
[mp1 @ 0x34d2860] Header missing
Error while decoding stream #0:0: Invalid data found when processing input
...
more of the same errors follow

A snippet of the file is attached.

[Carl Eugen Hoyos]

Regression since 549bbdfb

[Ganesh Ajjanagadde]

Fixed in f6870495e1589f0931f62bdf777fc0ad299e9c14.
Thanks.