Created attachment 161368 [details] Music downloaded from YouTube - the bug occurs with this file. When I edit the tags of an MP4/M4A file that I downloaded from YouTube and save them, all audio content gets stripped away! It might be an issue with libmp4v2metadata.dylib (By the way, why do you need an account here?!) STEPS TO REPRODUCE 1. Open an MP4/M4A audio file 2. Make any changes in the "Tag 2: MP4" section 3. Press the Save button OBSERVED RESULT The file doesn't get corrupted, but the audio length becomes zero-duration and the file size shrinks down to a few bytes to kilobytes, i. e. it will only consist of the tags. EXPECTED RESULT MP4 tags are written and the audio is untouched. SOFTWARE/OS VERSIONS macOS Big Sur 11.6 Kid3 3.9.3 Qt Version: 5.15.2 ADDITIONAL INFORMATION This bug did NOT happen a few months ago, when I last used kid3.
Thanks for the report, I can reproduce it. However, this seems to be a bug in mp4v2, and not in Kid3, because you can uncheck Mp4v2Metadata in the Plugins tab of the preferences, restart Kid3, and then TagLib will be used for m4a files, and it does not delete the audio content. TagLib even supports more Apple-specific iTunes atoms, but it does not support chapters for audiobooks. Could you report a bug to the maintainers of mp4v2 (http://mp4v2.org/)? Kid3 is using their latest version 2.1.3. mp4v2 comes with some tools (e.g. mp4tags), so you probably can install it using brew or MacPorts and then use mp4tags to reproduce the bug without Kid3.
(In reply to Urs Fleisch from comment #1) > Thanks for the report, I can reproduce it. However, this seems to be a bug > in mp4v2, and not in Kid3, because you can uncheck Mp4v2Metadata in the > Plugins tab of the preferences, restart Kid3, and then TagLib will be used > for m4a files, and it does not delete the audio content. TagLib even > supports more Apple-specific iTunes atoms, but it does not support chapters > for audiobooks. > > Could you report a bug to the maintainers of mp4v2 (http://mp4v2.org/)? Kid3 > is using their latest version 2.1.3. mp4v2 comes with some tools (e.g. > mp4tags), so you probably can install it using brew or MacPorts and then use > mp4tags to reproduce the bug without Kid3. I reported the bug at: https://github.com/enzo1982/mp4v2/issues/45