Thought I'd just post my own reply for posterity... I went through dts and got confirmation that the AIFF extensions for Soundtrack are not public information. Like other "mystery" chunks they should just be ignored. To generate transients it looks like one has to go through the Loop Utility app. I guess for a semi-lame implementation a loop-creation/recording app could just save an AIFF file and then have it open in the Loop Utility (with AppleScript) and save it again. If anyone with the ear of the Soundtrack designers is listening, please consider it a feature request that you provide some way for audio editing applications to add the Loop Utility data to AIFF's. An AppleScript dictionary would be tolerable, a LoopUtility.framework would be awesome. I don't see exposing this functionality as doing anything but encouraging more (and more extensible) use of Soundtrack. Not sure whether doing something like setting AIFF markers might help hint the Loop Utility - I'll experiment a little and post again if I find anything useful. - Chris On Dec 1, 2003, at 2:11 PM, Christopher Corbell wrote: I'm new to the list and don't see an archive listed at search.lists.apple.com, apologies if this has been covered before... I'm working on two apps that I'd like to make highly compatible with Soundtrack. Both will output AIFF files that can be used as Soundtrack loops; one will also permit editing of AIFF files and I'd like to preserve as much Soundtrack metadata as possible if the files have already been processed with the Loop Utility, added to Soundtrack catalog etc. I'm wondering if it's possible (either publicly or through dts) to get more information on Soundtrack's extensions to AIFF. In scanning a Soundtrack loop AIFF I see several undocumented chunks, such as 'trns', 'cate', 'basc'. These aren't wrapped in an 'APPL' section - I'm not sure if this means they're general extensions to AIFF that will be documented, or if it just means that nobody really uses the 'APPL' chunk... Is any information available at this level? Also are other AIFF mechanisms honored by Soundtrack, e.g. if my app is rendering a MIDI sequence to AIFF and knows where the beats are, can I use marker chunks to give Soundtrack a hint on beat locations, or does Soundtrack only look at the publicly undocumented 'trns' chunk? FWIW the apps involved are iPiano, to which I'm adding improved AIFF export including loop-segement export with sequences using any SoundFont/DLS bank sounds, and a new Cocoa AudioUnit-host/audio-editor that's in early stages of development. Thanks for any info, Chris _______________________________________________ pro-apps-dev mailing list | pro-apps-dev@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/pro-apps-dev Do not post admin requests to the list. They will be ignored. _______________________________________________ pro-apps-dev mailing list | pro-apps-dev@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/pro-apps-dev Do not post admin requests to the list. They will be ignored.