Opened 2 weeks ago
Last modified 2 weeks ago
#10995 new defect
MP3 stream not copied *losslessly* with `-c:a copy`
Reported by: | TheBigBadBoy | Owned by: | |
---|---|---|---|
Priority: | normal | Component: | undetermined |
Version: | 6.1.1 | Keywords: | MP3 lossless copy |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | no | |
Analyzed by developer: | no |
Description
Summary of the bug: When copying MP3 streams to a new file, the MP3 stream in the decoded new file does not match the input one (streamhash).
How to reproduce:
% ffmpeg -i stripped.mp3 -c:a copy out.mp3 % ffmpeg -v warning -i stripped.mp3 -f streamhash - 0,a,SHA256=ab1e0a0724ec4fae47c483073550723c74ad29bf6b79a93fc0861c0603ffdec4 % ffmpeg -v warning -i out.mp3 -f streamhash - 0,a,SHA256=7deac27714db19d69767c196b3d2a728e2c5dc3291351f117e5cf01b952ff16b ffmpeg version n6.1.1 Copyright (c) 2000-2023 the FFmpeg developers built with gcc 13.2.1 (GCC) 20230801
Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.
Change History (2)
comment:1 by , 2 weeks ago
comment:2 by , 2 weeks ago
The file has a lot of discard padding at the end: 383 samples of the penultimate frame and all samples (1152) of the last one. These 383 samples cause the difference between your file and the remuxed file.
Sample uploaded to https://streams.videolan.org/ffmpeg/incoming/10995/
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I didn't know the filesize limit is 2.5MB.
Here is the link to the file
stripped.mp3
(7MB): https://mega.nz/file/9qI03IxB#pcdXc3kPvmpGfueIjsixipCsASkwfD8uX12WtFutIpU