Re: AU docs feedback
Re: AU docs feedback
- Subject: Re: AU docs feedback
- From: Alberto Ricci <email@hidden>
- Date: Wed, 18 Sep 2002 11:25:51 +0200
Lubor Prikryl recently pointed out:
- I haven't found mp3/mp4 converter in Apple components, currently
all this functionality should be done using Quicktime, does Apple
plan to add such (highly optimized) format converter audiounit?
Regarding this, I have a question for you all. I need to let the user
open any kind of sound that QT can decode, any duration. Since the
AUConverter unit and AudioToolbox/AudioFile can only decode
pcm-formatted files (AIFF, wave, SD), AFAIK, I am faced with the
following dilemma: should I
- open the sound (can be an mp3, mp4, AIFC, whatever) and convert it
to pcm format storing it in a buffer before any further action is
taken?
In this way, my AUGraph can get the audio from this Float64 buffer
without any conversion taking place. It is slower when opening the
file, but faster when running through the AUGraph.
or
- keep the sound in its original format and set the render callback
to a routine that calls SoundConverterFillBuffer on the encoded
sound, so that format conversion and decompression is done at real
time. This takes up some precious CPU time which I could use for
sound processing, but it makes loading the sound files faster.
or
- first convert any non-pcm sounds to a temporary file in Float64
format on disk, then feed my AUGraph with the data contained in that
file. Actually, this is almost the same as the first solution I
listed, although there would be no limit on the sound file size
(>4GB) since I wouldn't be keeping it in memory.
What do you think is the best way to do it?
Thanks,
Alberto.
_______________________________________________
coreaudio-api mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/coreaudio-api
Do not post admin requests to the list. They will be ignored.