06-06-2021, 10:55 AM
Turning this thread into a referendum about FLAC and in particular its representation of audio metadata has done nothing to solve the OP's problem.
The original files are legal MPEG4 containers with audio, metadata, and embedded coverart. However they also contain one or more additional objects which apparently do not conform to Apple's specialization of MPEG4 containers for its M4A format. This in turn apparently confuses the PHP library used in moOde to handle media files. Or something like that.
I now have two solutions to the OP's issue. Either can be executed from the command line in moOde.
1) as I showed before, use ffmpeg to convert the suspect M4A files to FLAC. The AAC LC audio object is transcoded to FLAC, the audio metadata and coverart are transfered in the form specified for FLAC. The additional objects in the container are ignored.
2) as I have since found, one can also use ffmpeg to copy the suspect M4A file to a new M4A file. As before, the additional objects in the source container are ignored.
Example
and the resulting track properly plays and displays in moOde just as did the FLAC version I created earlier. Take your pick.
As for the use of metadata in different audio file formats, I find the Picard Tag Mapping Table to be very useful. It is a "list of specific metadata tags defined by MusicBrainz and standard tags, for ID3v2, Vorbis, APEv2, and iTunes MP4."
Regards,
Kent
The original files are legal MPEG4 containers with audio, metadata, and embedded coverart. However they also contain one or more additional objects which apparently do not conform to Apple's specialization of MPEG4 containers for its M4A format. This in turn apparently confuses the PHP library used in moOde to handle media files. Or something like that.
I now have two solutions to the OP's issue. Either can be executed from the command line in moOde.
1) as I showed before, use ffmpeg to convert the suspect M4A files to FLAC. The AAC LC audio object is transcoded to FLAC, the audio metadata and coverart are transfered in the form specified for FLAC. The additional objects in the container are ignored.
2) as I have since found, one can also use ffmpeg to copy the suspect M4A file to a new M4A file. As before, the additional objects in the source container are ignored.
Example
Code:
pi@moode:~ $ file '01 Dance Yrself Clean.m4a'
01 Dance Yrself Clean.m4a: ISO Media, MP4 v2 [ISO 14496-14]
pi@moode:~ $ ffmpeg -i '01 Dance Yrself Clean.m4a' -c copy 01-fixed.m4a
...
pi@moode:~ $ file 01-fixed.m4a
01-fixed.m4a: ISO Media, Apple iTunes ALAC/AAC-LC (.M4A) Audioand the resulting track properly plays and displays in moOde just as did the FLAC version I created earlier. Take your pick.
As for the use of metadata in different audio file formats, I find the Picard Tag Mapping Table to be very useful. It is a "list of specific metadata tags defined by MusicBrainz and standard tags, for ID3v2, Vorbis, APEv2, and iTunes MP4."
Regards,
Kent
