[MPlayer-users] lavf demuxer and iTunes M4A metadata

[Matthew Robinson]

I noticed that the console display of the artist metadata does not always show the correct artist information when playing M4A audio content from iTunes. It looks like iTunes uses two atoms in the udta container, one for the artist name (xA9,'A','R','T') and one for the composer name (xA9,'w','r','t').

When libavformat extracts the artist atom from the udta container, it maps several sub types (including both referenced above) all to the "artist" metadata key. Therefore, when the M4A has both artist and composer fields and composer follows artist in the file, the artists metadata print out on the mplayer console actually shows the composer field.

This can be seen in the switch statement in the mov_read_udta_string() function in mov.c

Anyhow, I'm not really sure what the procedure is for fixing this (can anyone fix bugs and submit?), but as far as implementation, I'd suggest defining new key strings at least for the metadata atom xA9,'w','r','t'.

Matthew.