[B2-devel] Audio sample rate/format switching for Irix

[Brian J. <bjj...@us...>]

I've largely completed audio sample rate/format switching for Irix.
What I have (attached) mostly works.  I still need to hook up the
volume/mute controls, and perhaps the enter/exit stream functions.
But I have some questions:

- What is the sample format provided by MacOS for 8-bit stereo data?
  It doesn't appear to be packed bytes... I put in a unsigned->signed
  translation modeled on the one in the Amiga code (which, by the way,
  doesn't seem quite right, since it doesn't handle carries.  But that
  would only affect the low bits of the results, so perhaps it doesn't
  matter.)  That works fine for 8-bit mono, but 8-bit stereo seems to
  produce the requested sound (on one channel?) interleaved with
  garbage.  All the other combinations of 8/16-bit and mono/stereo
  work fine.

- Using 11KHz and 8KHz sound output (I only tried 16-bit stereo for
  those), most of the beep sounds in the MacOS 7.6 audio control panel
  don't work (they only produce silience), although "simple beep"
  works (it's a bit distorted) and the MacInTalk speech synthesizer
  does just fine.  Odd... any ideas?

- I noticed that stream_thread_cancel is never set to "false" in
  audio_oss_esd.cpp after it's set to "true" by close_audio().  So
  when changing the audio parameteres, won't stream_func() exit as
  soon as open_audio() restarts it?

Thanks,

						Brian

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