AudioUnitScheduleParameters: ramped kMultiChannelMixerParam_Volume
AudioUnitScheduleParameters: ramped kMultiChannelMixerParam_Volume
- Subject: AudioUnitScheduleParameters: ramped kMultiChannelMixerParam_Volume
- From: uɐıʇəqɐz pnoqɥɒɯ <email@hidden>
- Date: Fri, 11 Jun 2010 14:16:16 -0700
Bug Reporter ids: 8084919 & 8084938
I was disappointed when the following code did nothing:
AudioUnitParameterEvent inEvent;
memset(&inEvent, 0, sizeof(inEvent));
inEvent.scope = kAudioUnitScope_Input;
inEvent.element = 2;
inEvent.parameter = kMultiChannelMixerParam_Volume;
inEvent.eventType = kParameterEvent_Ramped;
// for this set of frames, what are the ramping values associated with the begin/end times?
inEvent.eventValues.ramp.startValue = 1.0;
inEvent.eventValues.ramp.endValue = 0;
inEvent.eventValues.ramp.durationInFrames = 1000*1024;
inEvent.eventValues.ramp.startBufferOffset = 2000*1024;
result = AudioUnitScheduleParameters(userData->mMixer, &inEvent, 1);
if(result != 0)
printf("cant set up the scheduled param: %d\r\n", result);
}
I was trying to have scheduled and smooth fade of audio starting about two seconds in the future, where the fade would take about one second. The above code gave me no errors and did nothing to the volume. Replacing _Ramped with _Immediate, I got an immediate volume change from 1 to 0.
If you too would like to see CoreAudio add ramped support for scheduled volume changes to input or output of the multiChannelMixer, then file a Bug Reporter request.
If you too would like AudioUnitScheduleParameters to return an error when a type is not supported, i.e. _Ramped, then file a Bug Reporter bug. _______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden