I have a simple iPhone app using RemoteIO to record (save
the samples on file) and playback on iPhone GS. It is based on SDK 3.1. It
works now. But the output to the speaker is very low even after turning on the
iPhone speaker to the max using the volume control on the left side of the
iPhone.
I found the following info:
1.
http://www.subfurther.com/blog/?p=507,:
“RemoteIO does not have a gain or volume property. The mixer unit has
volume properties on all input buses and its output bus (0). Therefore, setting
the mixer’s output volume property could be a de facto volume control, if
it’s the last thing before RemoteIO. And it’s somewhat more
appealing than manually multiplying all your samples by a volume factor.”
2.
http://developer.apple.com/iphone/library/codinghowtos/AudioAndVideo/#AUDIO_HARDWARE-ACCESS_THE_HARDWARE_VOLUME_CONTROLLER
mentions: “Global system volume, including your application's volume, is
handled by iPhone OS and is not accessible by applications.”
The Apple built-in Voice Memos and AudioMemos apps can
playback with much louder sound. Also, I can hear clearly when making phone
call using iPhone external speaker.
I am looking for document and even better with sample code
how to increase the volume programmatically – just like Voicve Memos and
AudioMemos apps.
Any pointer is appreciated. Thanks in advance for your help.
Best,
-- On Lee