On Sat, 3 Jan 2004 12:50:27, Robert Scott writes: >On Sun, 4 Jan 2004 02:24:18 +0800, "Teddy Law" ><[EMAIL PROTECTED]> wrote: >>Do anyone have experience in manipulating the microphone of Palm ? e.g. >>Capturing the sound
See the documentation on the PalmOS Sound Manager, particularly the sections on Sampled Sound. Then check the archives of this list for hints and issues (only some formats are supported, etc.) Note that only the newest Sony models support the Sampled Sound Manager, and with notable limitations on the formats supported. >Sure. I use SndStreamCreate to open the sound input. Then my >callback uses MemMove to copy the input buffer to a ring of buffers, >and then call EvtWakeup(). You can't do much in a callback, so leave >the heavy lifting to code that runs from your event loop. ... >I leave the data in sndInt16Little endian format because >I process it all with a PNO ARMlet. Actually, one can do quite a bit inside a native ARM sampled sound callback (others have done entire mp3 decoders, etc.). This has the advantage of avoiding the cost of additional PceNativeCall task switches, which can cost as much as an entire small FFT on some models. See the PalmSource pno-forum for details. Any data reduction that can be performed inside the callback can also help out with cache and performance issues if your foreground task (a game, for instance) is quite CPU intensive. IMHO. YMMV. Ron Nicholson HotPaw Productions http://www.hotpaw.com/rhn/palm -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/support/forums/
