Opened 5 years ago

Closed 5 years ago

#2312 closed defect (invalid)

AVI (Matrox-compatible) file doubling up in size

Reported by: wleo75 Owned by:
Priority: normal Component: undetermined
Version: unspecified Keywords:
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description

Summary of the bug:
How to reproduce:

% ffmpeg -y -i samplein.mxf -f avi -vcodec dvvideo -an -vf crop=720:480:0:32 sampleout.avi

ffmpeg version N-49069-gc74d465
built on Jan 20 2013 23:39:19 with gcc 4.7.2 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --enable-zlib --enable-filter=frei0r
libavutil      52. 15.100 / 52. 15.100
libavcodec     54. 89.100 / 54. 89.100
libavformat    54. 61.101 / 54. 61.101
libavdevice    54.  3.102 / 54.  3.102
libavfilter     3. 32.101 /  3. 32.101
libswscale      2.  2.100 /  2.  2.100
libswresample   0. 17.102 /  0. 17.102
libpostproc    52.  2.100 / 52.  2.100

The AVi generated ends up with 2X the file size. Mediainfo reports the bitrate as 24.4 Mbps (exactly the same as any other Matrox AVI file); however, if you consider the file size, the overall bitrate is 57.6 Mbps. Sometimes, there are also issues playing out the output files.

Source file:
https://s3.amazonaws.com/vid-share-3/samplein.mxf

Output:
https://s3.amazonaws.com/vid-share-3/sampleout.avi

The same thing happens when tested on Linux.

Change History (2)

comment:1 Changed 5 years ago by llogan

Please include the complete, full, and uncut ffmpeg console output (or at least the first and last 50 lines in the case of repeating messages).

comment:2 Changed 5 years ago by cehoyos

  • Component changed from FFmpeg to undetermined
  • Priority changed from important to normal
  • Resolution set to invalid
  • Status changed from new to closed
  • Version set to unspecified

Your input sample is high-bitrate MPEG2. It is possible to re-encode your sample so that the output file has less than 3% of the size of the input file, depending on the used codec and settings. (Unrelated but interesting: Even using highest quality MPEG-1 re-encoding, the size was still reduced to far below 10%.)
dvvideo has a defined bit-rate (defined by the specification, not the FFmpeg developers) that cannot be changed. This bit-rate is (even) higher than the bit-rate of your input file.

For future questions: Please remember that this is a bug tracker, not a support forum, see http://ffmpeg.org/contact.html for the ffmpeg-user mailing list.

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