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anthwlock / untrunc

Restore a truncated mp4/mov. Improved version of ponchio/untrunc
GNU General Public License v2.0
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Assertion fail with truncated mp4 from VLC record functionality #93

Open vmsh0 opened 3 years ago

vmsh0 commented 3 years ago

I'm trying to recover a truncated file from VLC's recording functionality but the program crashes with as assertion error.

I have a similar file (recorded from VLC, from the same network stream) which I'm using as the good file.

Console output is as follows:


Info: version '3cf5947' using ffmpeg 'n4.4'
Info: reading good.mp4
Info: parsing healthy moov atom ...
ftyp_ = 'isom'
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'good.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 0
    compatible_brands: mp41avc1
    creation_time   : 2021-05-12T13:46:27.000000Z
    playback_requirements: QuickTime 6.0 or greater
    playback_requirements-eng: QuickTime 6.0 or greater
    encoder         : vlc 3.0.13 stream output
    encoder-eng     : vlc 3.0.13 stream output
  Duration: 00:01:21.00, start: 0.000000, bitrate: 543 kb/s
  Stream #0:0(eng): Audio: aac (LC) (mp4a / 0x6134706D), 24000 Hz, mono, fltp, 32 kb/s (default)
    Metadata:
      creation_time   : 2021-05-12T13:46:27.000000Z
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]
  Stream #0:1(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuvj420p(pc), 640x360, 508 kb/s, 8 fps, 8 tbr, 90k tbn, 16 tbc (default)
    Metadata:
      creation_time   : 2021-05-12T13:46:27.000000Z
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
ss: mp4a is_stable: 0
ss: using f=7 span
found avcC after: 102
remaining len:47
parsing avcC ...
len_sps: 24
decoding SPS ...
log2_max_frame_num: 10
avcC got decoded
assuming constant duration of 11250 for 'avc1' (x648)
ss: avc1 is_stable: 0
ss: using f=7 span

ss: reset to default (from 251839 ~= 0.03*default)
ss: max_part_size_: 8388608
calling findMdat on truncated file..
Info: reading mdat from truncated file ...
skipping zeros at: 0 / 32
/usr/include/c++/10.2.0/bits/stl_vector.h:1045: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](std::vector<_Tp, _Alloc>::size_type) [with _Tp = Track; _Alloc = std::allocator<Track>; std::vector<_Tp, _Alloc>::reference = Track&; std::vector<_Tp, _Alloc>::size_type = long unsigned int]: Assertion '__builtin_expect(__n < this->size(), true)' failed.
zsh: abort (core dumped)  untrunc -v good.mp4 bad.mp4```
vmsh0 commented 3 years ago

ffmpeg -i bad.mp4:


  built with gcc 10.2.0 (GCC)
  configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librav1e --enable-librsvg --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nvdec --enable-nvenc --enable-shared --enable-version3
  libavutil      56. 70.100 / 56. 70.100
  libavcodec     58.134.100 / 58.134.100
  libavformat    58. 76.100 / 58. 76.100
  libavdevice    58. 13.100 / 58. 13.100
  libavfilter     7.110.100 /  7.110.100
  libswscale      5.  9.100 /  5.  9.100
  libswresample   3.  9.100 /  3.  9.100
  libpostproc    55.  9.100 / 55.  9.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x5575051f4bc0] moov atom not found
bad.mp4: Invalid data found when processing input```