#4954: joint stereo indicator missing from mp3 headers ------------------------------------+------------------------------------ Reporter: pico4743 | Owner: (none) Type: defect | Status: open Priority: normal | Component: avformat Version: git-master | Resolution: Keywords: mp3 | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | ------------------------------------+------------------------------------ Comment (by GraniteStateColin): Correction to my prior post: While this bug still exists in ffmpeg, I was wrong about where the problem lies. After looking inside the MP3 files including with the developer of Mp3tag that reports Joint Stereo output files as Stereo, we can see the bug, as originally posted by pico4743, is a better description. Specifically, ffmpeg DOES output to Joint Stereo, but the header incorrectly says that the file is in Stereo. This confuses several apps that check the MP3 file for stereo format. SoX and libmp3lame do not have this problem, it's specific to ffmpeg's implementation and use of libmp3lame. The examples in the prior post remain correct to demonstrate the problem, just that the problem is the reverse of what I had described (which better aligns with the original poster, @pico4743, who correctly described the problem as being with the header. -- Ticket URL: <https://trac.ffmpeg.org/ticket/4954#comment:11> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker