README 

This sample program uses the VCHIQ audio service to playback a short sound
sample. You can listen to it via a HDMI monitor, which is capable of output
sound, or via the 3.5mm headphone jack otherwise (not on the Raspberry Pi Zero).
When the playback is over, it will be re-started again after two seconds.

The provided (compressed) sound sample in sound.h.gz is recorded with 44100 Hz
sample rate and 8 bit Mono (to keep it small). You can provide 16 bit Stereo
sound on your own (e.g. by exporting it as 16 bit signed raw data without header
from Audacity and converting it into ASCII with a little program). The sound.h
file has to look like that in this case:

#define SOUND_CHANNELS		2
#define SOUND_BITS		16

signed short Sound[] =
{
1,0,-2,0,2,0,-2,0,2,1,-1,-1,0,1,0,-2,0,3,0,-3,1,3,-2,-2,
...
};

Please note that you may have to increase KERNEL_MAX_SIZE in the file
include/circle/sysconfig.h, if your kernel.img is about 2 MBytes big or bigger
after build. It will not run otherwise.

The VCHIQ audio service always plays 16 bit Stereo sound in Circle but other
8/16 bit Mono/Stereo formats will be converted while playing back.
