Opened 11 years ago
Last modified 11 years ago
#3563 new defect
wrong duration reported by ffmpeg
Reported by: | chinshou | Owned by: | |
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Priority: | normal | Component: | avformat |
Version: | git-master | Keywords: | wav mp3 |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | no | |
Analyzed by developer: | no |
Description
Summary of the bug:
ffmpeg reported attached mp3 file with duration 00:07:52. But VLC and windows media player report it has duration with 03:56
How to reproduce:
% ffplay -i HIT_118.MP3 ffplay version N-62460-gef818d8 Copyright (c) 2003-2014 the FFmpeg developers built on Apr 14 2014 22:01:48 with gcc 4.8.2 (GCC) configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetyp e --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --ena ble-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-l ibopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libsp eex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-aa cenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavp ack --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable -zlib libavutil 52. 76.100 / 52. 76.100 libavcodec 55. 58.103 / 55. 58.103 libavformat 55. 37.100 / 55. 37.100 libavdevice 55. 13.100 / 55. 13.100 libavfilter 4. 4.100 / 4. 4.100 libswscale 2. 6.100 / 2. 6.100 libswresample 0. 18.100 / 0. 18.100 libpostproc 52. 3.100 / 52. 3.100 Input #0, wav, from 'HIT_118.MP3': 0KB vq= 0KB sq= 0B f=0/0 Duration: 00:07:52.72, bitrate: 27 kb/s Stream #0:0: Audio: mp3 (U[0][0][0] / 0x0055), 22050 Hz, stereo, s16p, 56 kb /s 6.06 M-A: 0.000 fd= 0 aq= 1KB vq= 0KB sq= 0B f=0/0
Attachments (1)
Change History (5)
by , 11 years ago
Attachment: | HIT_118.MP3 added |
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follow-up: 2 comment:1 by , 11 years ago
Keywords: | mp3 added |
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Version: | unspecified → git-master |
comment:2 by , 11 years ago
comment:3 by , 11 years ago
Component: | undetermined → avformat |
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Keywords: | wav added |
The file contains a 'fact' chunk, and the wav demuxer is using it to calculate the duration, whereas other players seem to be ignoring it.
The value of the chunk is 10423511, which when divided by the sample rate gives 7:52 minutes. If you then divide that by number of channels you get the actual length of 3:56.
The spec says that the 'fact' chunk value should be number of samples per channel, so chances are the value in this file is wrong (being total samples across all channels instead of samples per channel), but I don't have any other stereo non-pcm wav files with 'fact' chunks to verify that.
comment:4 by , 11 years ago
Jamal, do you know of a work around that could be used to get the duration on a file with this problem?
How was the sample created?