AndrewFG;665859 Wrote: > Unfortunately I think there is still a part of this story missing... > > Apple .M4A music files consist of a raw data music stream, that is > wrapped inside an ISO MPEG4 file container. > > MPEG4 is an open ISO standard that defines a nestable structure of > "boxes", where each such box has a name, and a predefined data payload. > The ISO standard specifies some of the standard box names and their > respective payloads. But the standard is extensible and allows vendors > to add their own box definitions, and define their respective payloads. > This works fine, because if a particular client does not understand the > contents of a particular box type, it can ignore it and jump over to > the next box. > > One such standard MPEG4 box is the music stream box; it may contain > MP3, MP4, AAC, ALAC or proprietary raw stream data. Therefore it is of > course excellent news that Apple has open sourced the ALAC format, > because it increases the number of public domain raw data stream > payload formats that the standard MPEG4 music stream box can carry. > > BUT, Apple still still uses other (proprietary) boxes to carry the > track meta-data (i.e. the tags). These Apple proprietary metadata boxes > obviously fit within the overall ISO format, and their names are known, > and their payload structures have been reverse engineered. (So for > example the SBS Scanner knows how to parse the tags). HOWEVER, so far > as I know, these meta data tags have NOT been open sourced by Apple, so > they could change the payload structures at whim, and thus "break" any > third party applications that rely on them... > > => Dear Apple, please also open source your meta data boxes!!
Interesting. Has anybody looked at the source that was just released to see if perhaps they've included the proprietary tagging code? It seems to me that Apple opensourced the code to lay the groundwork for wider adoption of AirPlay by other vendors. Providing only half the story here makes no sense. -- maggior Rich --------- Setup: 2 SB3s, 4 Booms, 1 Duet, 1 Receiver, 1 Touch, iPeng on iPod Touch, SqueezeCommander on Xoom. SuSE 11.0 Server running SqueezeBoxServer 7.5.5, MusicIP, and SqueezeSlave. Current library stats: 37,509 songs, 2,934 albums, 515 artists. http://www.last.fm/user/maggior ------------------------------------------------------------------------ maggior's Profile: http://forums.slimdevices.com/member.php?userid=9080 View this thread: http://forums.slimdevices.com/showthread.php?t=91185 _______________________________________________ discuss mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/discuss
