Re: Calling ExtAudioFileDispose() on a large MP4 audio file causes a crash
Re: Calling ExtAudioFileDispose() on a large MP4 audio file causes a crash
- Subject: Re: Calling ExtAudioFileDispose() on a large MP4 audio file causes a crash
- From: William Stewart <email@hidden>
- Date: Mon, 16 Nov 2009 16:54:39 -0800
On Nov 16, 2009, at 4:25 PM, Christopher Liscio wrote:
On Nov 16, 2009, at 6:18 PM, William Stewart wrote:
That is correct, apple lossless is not a valid format in an MPEG-4
file
After further thought, this does make sense. ALAC is not part of
any open specification, and hence has no place in the MPEG-4
standard container. Fair enough to keep it part of M4A.
I would record to a CAF file - is that possible?
Not given my initial goals/design.
I create MPEG-4 files because I can write iTunes-compatible metadata
into the files myself, including generated album art, notes, title,
artist, etc. That way, files passed around via email/etc retain
metadata, and can be dragged into another copy of TapeDeck with no
loss of that information.
Furthermore, dragging files into iTunes works as expected, and it's
totally compatible with iPods.
As far as I know, there's nowhere I can stash the above data into a
CAF file so that iTunes/QuickLook/Finder/etc can see them. For
instance, if you use QuickLook to preview a tape created using
TapeDeck, you get an image like this:
http://www.supermegaultragroovy.com/img/drop/td_qlpreview.png
That information comes from Spotlight, and we should be providing this
information from the CAF files (if we aren't it would be good to have
a bug so we can fix this)
However, the CAF file won't work directly yet with iPod/iTunes, so you
have that drawback.
Bill
It's pretty slick stuff, and I'd like to keep it that way. :)
I had considered another workaround, which was to try and catch the
exception generated by the AudioFileClose() API, and simply patch up
the resulting MPEG-4 file manually. Unfortunately, the file is left
without even a moov atom at the top level, so I understand it's
effectively damaged beyond any use at this point.
Data loss is frustrating, and dealing with angry customers that lost
important recordings of 2h+ meetings is even more so. :P
(Speaking of which, if you folks _do_ know of a clever way to
retrieve data from these interrupted AudioFIleClose() calls, I'd
love to hear about it so I can help some of my customers out.)
Thanks,
Chris Liscio
http://supermegaultragroovy.com
Learn _your_ music with Capo: http://capoapp.com
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