Opened 6 years ago
Closed 6 years ago
#7447 closed defect (duplicate)
Decoding ogg (vorbis) appends extra samples to output
| Reported by: | evesira | 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:
ffmpeg incorrectly decodes ogg (vorbis) files, appending extra samples at the end of the audio output. The amount of samples added doesn't seem to be correlated to file size or anything else. The added samples seem to always be digital silence.
This ticket stemmed from this issue reported in the Chrome browser:
https://bugs.chromium.org/p/chromium/issues/detail?id=884526#c10
This issue causes the inability to seamlessly and correctly loop layered and synced ogg tracks of the same exact length after they have been decoded by ffmpeg.
Vorbis was designed to be capable of sample-perfect looping, so being able to reconstruct the file exactly is possible and necessary.
How to reproduce:
% ffmpeg -i test.ogg test.wav ffmpeg version: ffmpeg-20180919-e33b28c-win64-static (Zeranoe)
Test ogg file:
https://instaud.io/_/2HtN.ogg
input file is exactly 6.00 seconds long, or 264,600 samples at 44.1 kHz
output file is 265,536 samples long, 936 samples added
Other softwares that support loading of oggs, such as Audacity, Wavosaur, Ocen, etc (which presumably use libvorbis and not ffmpeg), correctly decode the test file as 264,600 samples long.
Sounds like a duplicate of ticket #6367.