Some streaming applications, such as play:Sub for iOS, need to download m4a files completely before they start playing.
This happens with m4a tracks encoded by jack, but not with tracks purchased from Apple.
This can be solved by adding the "--moov-before-mdat " option to the fdkaac command line.
This will cause the tags and album art to be placed in front of the encoded music data.
It's likely possible to add this option using a custom jack4rc, but this option should be added to the default command line.
Some streaming applications, such as play:Sub for iOS, need to download m4a files completely before they start playing. This happens with m4a tracks encoded by jack, but not with tracks purchased from Apple.
This can be solved by adding the "--moov-before-mdat " option to the fdkaac command line. This will cause the tags and album art to be placed in front of the encoded music data.
It's likely possible to add this option using a custom jack4rc, but this option should be added to the default command line.