Hi all,
I have been fighting this beast for a while now, and
progress is being made slowly but surely, but It seems I have hit a brick wall.
I can capture the audio data using the ‘guts’
more or less of complex play through and another sample … and the raw
audio from the mac à> to
server à> back to mac works fine. The
issue seems to be when I try and send it to a PC or run it through an ADPCM
Codec that all heck breaks loose . mac -> codec-enc ---- codec-dec –
mac fails with loud screeching noises and sending it off to a pc gives about
the same results.
It appears I am getting 32bit audio data from the hardware (Bytes
per frame == 4) single channel and the raw data appears to be BigEndian (00 00
xx xx) ---
I found the flags to set 16bit capture but setunitproperties
fails if I try and change it -- that would be question one … is it
possible to change the #bytes in captured stream? If I configure from midi
configuration utility it seems to let me set it to 16 bit, but this seems to be
ignored when I open the device / audio unit
The other question is is this data stream really just
LinearPCM or is there some other kind of encoding going on. If it was just
audio data, it would seem I could do something like value/256 à out à value *256
and it would work .. but this (test case that has no use) causes playback to
fail. Is there some other kind of information encoded in the bitstream that is
getting lost when I try and process it this way.
Thanks for your help
Bill
iLinc Communications
Bill Cunning
Senior Software Developer
email@hidden
www.ilinc.com
165 Jordan Road
Troy, NY 12180
877.960.1700, X454