From 2c79fcd98b3f71dab525f2c9361a7f1ad5460df1 Mon Sep 17 00:00:00 2001 From: phil Date: Thu, 7 Feb 2002 18:15:27 +0000 Subject: [PATCH] notes on CoreAudio implementation --- pa_mac_core/notes.txt | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 pa_mac_core/notes.txt diff --git a/pa_mac_core/notes.txt b/pa_mac_core/notes.txt new file mode 100644 index 0000000..094a99c --- /dev/null +++ b/pa_mac_core/notes.txt @@ -0,0 +1,32 @@ +Notes on Core Audio Implementation of PortAudio + +by Phil Burk and Darren Gibbs + +Document last updated Feb 7, 2002 + +WHAT WORKS + +Output with very low latency, <10 msec. +Half duplex input or output. +Full duplex on the same CoreAudio device. +The paFLoat32 sample format. + +KNOWN BUGS OR LIMITATIONS + +We do not yet support simultaneous input and output on different +devices. Note that some CoreAudio devices like the Roland UH30 look +like one device but are actually two different CoreAudio devices. The +BuiltIn audio is typically one CoreAudio device. + +User formats other than the native paFloat32 are not yet supported. + +DEVICE MAPPING + +CoreAudio devices can support both input and output. But the sample +rates supported may be different. So we have map one or two PortAudio +device to each CoreAudio device depending on whether it supports +input, output or both. + +When we query devices, we first get a list of CoreAudio devices. Then +we scan the list and add a PortAudio device for each CoreAudio device +that supports input. Then we make a scan for output devices. -- 2.43.0