[MPlayer-users] m4a meta data

[Reimar Döffinger]

On Tue, Jun 10, 2008 at 04:30:47PM -0500, Christopher Reder wrote:
> > On Monday 09 June 2008 18:25:12 Christopher Reder wrote:
> > > Is there a flag or some other setting for mplayer such that I can
> > > use it in slave mode to retrieve the meta data (title, artist,
> > > album) of a m4a file?  I can retrieve it from a mp3 file, but not
> > > m4a.  I looked via google and saw that there is a different
> > > structure for m4a in atom type format, but wondered if there was a
> > > switch or library needed to make them readable.
> > >
> > > Thanks for the help.
> 
> > if by m4a you mean mov or mp4 then IIRC at least
> > the lavf demuxer should retrieve and show those properties
> 
> 
> > Yes, I was speaking of a mp4 audio file.  I would like to use the slave
> > mode of mplayer to send it a "get_meta_artist" command and have it
> > retrieve the artist info from the m4a file (file originally made by
> >iTunes).  The following is the output I get trying the lavf (perhaps I am
> > using this incorrectly?)  I want to retrieve Norah Jones from this...
> 
> > Thanks
> > Christopher
> 
> > root at dci:/media/sda1/Norah Jones/Come Away with Me$ mplayer -demuxer lavf > -slave
> >  -quiet -ao alsa:device=hw=0.1 01\ Don\'t\ Know\ Why.m4a
> > MPlayer 1.0rc2-4.1.2 (C) 2000-2007 MPlayer Team
> > CPU: ARM
> 
> > Playing 01 Don't Know Why.m4a.
> > libavformat file format detected.
> > [lavf] Audio stream found, -aid 0
> > ==========================================================================
> > Forced audio codec: mad
> > Opening audio decoder: [faad] AAC (MPEG2/4 Advanced Audio Coding)
> > FAAD: compressed input bitrate missing, assuming 128kbit/s!
> > AUDIO: 44100 Hz, 2 ch, s16le, 128.0 kbit/9.07% (ratio: 16000->176400)
> > Selected audio codec: [faad] afm: faad (FAAD AAC (MPEG-2/MPEG-4 Audio)
> > decoder)
> > ==========================================================================
> > AO: [alsa] 44100Hz 2ch s16le (2 bytes per sample)
> > Video: no video
> > Starting playback...
> > get_meta_artist
> > ANS_META_ARTIST=''
> 
> Has anyone been able to retrieve M4a/mp4 data from mplayer?

Well, my guess is that the problem is exactly there: The file probably
contains only iPod metadata, no mov and not mp4 metadata (yes, it seems
they managed to make three formats that are almost the same except a few
details, guaranteeing a usability nightmare...).

Greetings,
Reimar Döffinger