static bool coreaudio_init_format(struct coreaudio_data *ca)
{
AudioStreamBasicDescription desc;
OSStatus stat;
UInt32 size = sizeof(desc);
stat = get_property(ca->unit, kAudioUnitProperty_StreamFormat,
SCOPE_INPUT, BUS_INPUT, &desc, &size);
if (!ca_success(stat, ca, "coreaudio_init_format", "get input format"))
return false;
/* Certain types of devices have no limit on channel count, and
* there's no way to know the actual number of channels it's using,
* so if we encounter this situation just force to stereo */
if (desc.mChannelsPerFrame > 8) {
desc.mChannelsPerFrame = 2;
desc.mBytesPerFrame = 2 * desc.mBitsPerChannel / 8;
desc.mBytesPerPacket =
desc.mFramesPerPacket * desc.mBytesPerFrame;
}
stat = set_property(ca->unit, kAudioUnitProperty_StreamFormat,
SCOPE_OUTPUT, BUS_INPUT, &desc, size);
if (!ca_success(stat, ca, "coreaudio_init_format", "set output format"))
return false;
if (desc.mFormatID != kAudioFormatLinearPCM) {
ca_warn(ca, "coreaudio_init_format", "format is not PCM");
return false;
}
ca->format = convert_ca_format(desc.mFormatFlags, desc.mBitsPerChannel);
if (ca->format == AUDIO_FORMAT_UNKNOWN) {
ca_warn(ca, "coreaudio_init_format", "unknown format flags: "
"%u, bits: %u",
(unsigned int)desc.mFormatFlags,
(unsigned int)desc.mBitsPerChannel);
return false;
}
ca->sample_rate = (uint32_t)desc.mSampleRate;
ca->speakers = convert_ca_speaker_layout(desc.mChannelsPerFrame);
if (ca->speakers == SPEAKERS_UNKNOWN) {
ca_warn(ca, "coreaudio_init_format", "unknown speaker layout: "
"%u channels",
(unsigned int)desc.mChannelsPerFrame);
return false;
}
return true;
}
static bool coreaudio_init_format(struct coreaudio_data *ca)
{
AudioStreamBasicDescription desc;
OSStatus stat;
UInt32 size = sizeof(desc);
stat = get_property(ca->unit, kAudioUnitProperty_StreamFormat,
SCOPE_INPUT, BUS_INPUT, &desc, &size);
if (!ca_success(stat, ca, "coreaudio_init_format", "get input format"))
return false;
stat = set_property(ca->unit, kAudioUnitProperty_StreamFormat,
SCOPE_OUTPUT, BUS_INPUT, &desc, size);
if (!ca_success(stat, ca, "coreaudio_init_format", "set output format"))
return false;
if (desc.mFormatID != kAudioFormatLinearPCM) {
ca_warn(ca, "coreaudio_init_format", "format is not PCM");
return false;
}
ca->format = convert_ca_format(desc.mFormatFlags, desc.mBitsPerChannel);
if (ca->format == AUDIO_FORMAT_UNKNOWN) {
ca_warn(ca, "coreaudio_init_format", "unknown format flags: "
"%u, bits: %u",
(unsigned int)desc.mFormatFlags,
(unsigned int)desc.mBitsPerChannel);
return false;
}
ca->sample_rate = (uint32_t)desc.mSampleRate;
ca->speakers = convert_ca_speaker_layout(desc.mChannelsPerFrame);
if (ca->speakers == SPEAKERS_UNKNOWN) {
ca_warn(ca, "coreaudio_init_format", "unknown speaker layout: "
"%u channels",
(unsigned int)desc.mChannelsPerFrame);
return false;
}
return true;
}