ffmpeg fails silently and generates corrupt file if -ss is used on MP3 file with wrong length

[Federico Dossena]

Summary of the bug:
I have an MP3 file that seems to have the incorrect length specified in the header.
The file says it's 11m38s long, but it's actually 3m52s.
Normally if I try this:

ffmpeg -ss 600 -i file.mp3 ...

I would get an error, and an exit code != 0; however with this file, I get exit code == 0, and a corrupt output.

Here's the data needed to reproduce the bug, as well as the log: ​https://drive.google.com/file/d/1Ua5hyB8iwULI6px-wRu9n4AqpDGE1F4c/view?usp=sharing

How to reproduce:
Download the linked archive and run this command

% ffmpeg -ss 600 -i "01-Do Whats Good For Me.mp3" -c:a libopus test.opus
ffmpeg version 3.4, official build, on Win64 (also happens on linux amd64)

It should produce an error, but instead it executes normally and test.opus is corrupt

[Carl Eugen Hoyos]

Please test current FFmpeg git head and provide the command line you tested including the complete, uncut console output to make this a valid ticket. If libopus output is not required to reproduce the issue, please use an internal encoder, not one that has an external depedency.

[Federico Dossena]

The bug is still present in the latest version, here's the log.

C:\Users\Federico\Desktop>ffmpeg -v 9 -loglevel 99 -ss 600 -i "01-Do Whats Good For Me.mp3" -c:a libopus test.opus
ffmpeg version N-90425-gdb2a7c947e Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 7.3.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
  libavutil      56. 12.100 / 56. 12.100
  libavcodec     58. 15.100 / 58. 15.100
  libavformat    58. 10.100 / 58. 10.100
  libavdevice    58.  2.100 / 58.  2.100
  libavfilter     7. 13.100 /  7. 13.100
  libswscale      5.  0.102 /  5.  0.102
  libswresample   3.  0.101 /  3.  0.101
  libpostproc    55.  0.100 / 55.  0.100
Splitting the commandline.
Reading option '-v' ... matched as option 'v' (set logging level) with argument '9'.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument '99'.
Reading option '-ss' ... matched as option 'ss' (set the start time offset) with argument '600'.
Reading option '-i' ... matched as input url with argument '01-Do Whats Good For Me.mp3'.
Reading option '-c:a' ... matched as option 'c' (codec name) with argument 'libopus'.
Reading option 'test.opus' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option v (set logging level) with argument 9.
Successfully parsed a group of options.
Parsing a group of options: input url 01-Do Whats Good For Me.mp3.
Applying option ss (set the start time offset) with argument 600.
Successfully parsed a group of options.
Opening an input file: 01-Do Whats Good For Me.mp3.
[NULL @ 00000226f13ca4c0] Opening '01-Do Whats Good For Me.mp3' for reading
[file @ 00000226f13cb640] Setting default whitelist 'file,crypto'
Probing mp3 score:51 size:1792
[mp3 @ 00000226f13ca4c0] Format mp3 probed with size=2048 and score=51
id3v2 ver:3 flags:00 len:246
[mp3 @ 00000226f13ca4c0] Skipping 417 bytes of junk at 256.
[mp3 @ 00000226f13ca4c0] Before avformat_find_stream_info() pos: 673 bytes read:32768 seeks:0 nb_streams:1
[mp3 @ 00000226f13ca4c0] All info found
[mp3 @ 00000226f13ca4c0] Estimating duration from bitrate, this may be inaccurate
[mp3 @ 00000226f13ca4c0] stream 0: start_time: 0.000 duration: 698.036
[mp3 @ 00000226f13ca4c0] format: start_time: 0.000 duration: 698.036 bitrate=74 kb/s
[mp3 @ 00000226f13ca4c0] After avformat_find_stream_info() pos: 12961 bytes read:32768 seeks:0 frames:50
Input #0, mp3, from '01-Do Whats Good For Me.mp3':
  Metadata:
    title           : Do What's Good For Me
    comment         : ThuGGinOutLaW
    track           : 1
    album           : The Very Best Of 2 Unlimited
    artist          : 2 Unlimited
    genre           : Dance
    date            : 2006
    id3v2_priv.AverageLevel: \xa3\x1e\x00\x00
    id3v2_priv.PeakValue: \xff\x7f\x00\x00
  Duration: 00:11:38.04, start: 0.000000, bitrate: 74 kb/s
    Stream #0:0, 50, 1/14112000: Audio: mp3, 44100 Hz, stereo, s16p, 74 kb/s
Successfully opened the file.
Parsing a group of options: output url test.opus.
Applying option c:a (codec name) with argument libopus.
Successfully parsed a group of options.
Opening an output file: test.opus.
File 'test.opus' already exists. Overwrite ? [y/N] y
[file @ 00000226f13cc440] Setting default whitelist 'file,crypto'
Successfully opened the file.
Stream mapping:
  Stream #0:0 -> #0:0 (mp3 (native) -> opus (libopus))
Press [q] to stop, [?] for help
cur_dts is invalid (this is harmless if it occurs once at the start per stream)
detected 12 logical cores
[graph_0_in_0_0 @ 00000226f13e9040] Setting 'time_base' to value '1/44100'
[graph_0_in_0_0 @ 00000226f13e9040] Setting 'sample_rate' to value '44100'
[graph_0_in_0_0 @ 00000226f13e9040] Setting 'sample_fmt' to value 's16p'
[graph_0_in_0_0 @ 00000226f13e9040] Setting 'channel_layout' to value '0x3'
[graph_0_in_0_0 @ 00000226f13e9040] tb:1/44100 samplefmt:s16p samplerate:44100 chlayout:0x3
[format_out_0_0 @ 00000226f13e9d40] Setting 'sample_fmts' to value 's16|flt'
[format_out_0_0 @ 00000226f13e9d40] Setting 'sample_rates' to value '48000|24000|16000|12000|8000'
[format_out_0_0 @ 00000226f13e9d40] auto-inserting filter 'auto_resampler_0' between the filter 'Parsed_anull_0' and the filter 'format_out_0_0'
[AVFilterGraph @ 00000226f13eb680] query_formats: 5 queried, 9 merged, 3 already done, 0 delayed
[auto_resampler_0 @ 00000226f13e9c40] picking s16 out of 2 ref:s16p
[auto_resampler_0 @ 00000226f13e9c40] [SWR @ 00000226f146a000] Using s16p internally between filters
[auto_resampler_0 @ 00000226f13e9c40] ch:2 chl:stereo fmt:s16p r:44100Hz -> ch:2 chl:stereo fmt:s16 r:48000Hz
[libopus @ 00000226f13cbe40] No bit rate set. Defaulting to 96000 bps.
Output #0, opus, to 'test.opus':
  Metadata:
    title           : Do What's Good For Me
    comment         : ThuGGinOutLaW
    track           : 1
    album           : The Very Best Of 2 Unlimited
    artist          : 2 Unlimited
    genre           : Dance
    date            : 2006
    id3v2_priv.AverageLevel: \xa3\x1e\x00\x00
    id3v2_priv.PeakValue: \xff\x7f\x00\x00
    encoder         : Lavf58.10.100
    Stream #0:0, 0, 1/48000: Audio: opus (libopus), 48000 Hz, stereo, s16, delay 312, 96 kb/s
    Metadata:
      encoder         : Lavc58.15.100 libopus
      title           : Do What's Good For Me
      DESCRIPTION     : ThuGGinOutLaW
      TRACKNUMBER     : 1
      album           : The Very Best Of 2 Unlimited
      artist          : 2 Unlimited
      genre           : Dance
      date            : 2006
      id3v2_priv.AverageLevel: \xa3\x1e\x00\x00
      id3v2_priv.PeakValue: \xff\x7f\x00\x00
cur_dts is invalid (this is harmless if it occurs once at the start per stream)
    Last message repeated 1 times
[out_0_0 @ 00000226f13e8040] EOF on sink link out_0_0:default.
No more output streams to write to, finishing.
size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x
video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Input file #0 (01-Do Whats Good For Me.mp3):
  Input stream #0:0 (audio): 1 packets read (104 bytes); 1 frames decoded (1152 samples);
  Total: 1 packets (104 bytes) demuxed
Output file #0 (test.opus):
  Output stream #0:0 (audio): 0 frames encoded (0 samples); 0 packets muxed (0 bytes);
  Total: 0 packets (0 bytes) muxed
1 frames successfully decoded, 0 decoding errors
[AVIOContext @ 00000226f13e7440] Statistics: 0 seeks, 2 writeouts
[AVIOContext @ 00000226f13d3880] Statistics: 6460473 bytes read, 0 seeks