Hi, I need help from an expert of the audio stack.
I'm currently writting an opensource SIP application (http:// code.google.com/p/csipsimple/) based on a native sip stack (pjsip). I've ported the audio driver for android (naive portage using JNI) (the key file : http://code.google.com/p/csipsimple/source/browse/trunk/pjsip_android/apps/pjsip/project/pjmedia/src/pjmedia-audiodev/android_jni_dev.cpp ). Everything works well on HTC devices. But when run on devices from other manufacturers things becomes instable (seems to be related to the CPU load and/or frequency use for the stream). The result is that on some device (sony X10, samsung galaxy spica, galaxy S...), sometimes and after about 10 seconds of streaming, audio track become totally blocked in its write method. No audio is streamed anymore. And worse, flush and stop method does nothing. AudioTrackTread is still blocked. And worse... then even if you kill my app, no other app can use audio : if you try to play music or place a gsm call you'll have absolutely no sound. After a lot of tests, and searches, I have some questions to make sure I handle properly the stream mode. I've read that we should always ensure AudioTrack buffer is never empty. What will happen if audiotrack becomes empty? Can this explain the fact it freeze audioTrack in my case? Same question when audioTrack becomes full. Another thing that should be clarified for me is the impact of the audioManager settings on audio routing : I noticed that some settings such as Bluetooth SCO is only taken into account if you stop audio track and play it again (in my case, it's totally destroyed and re- created, but I think that play/pause should be enough). Is there rules about the fact we *should* pause/start stream before changing audio settings? Other settings seems to work as expected while in streaming (speaker, mute etc)... but I'm wondering if it's ensured in all devices and if it is the good way. Last thing for now, it's not really optimized in term of CPU (and some codecs need a lot of cpu) can it be the reason of this lock in the audio track write method? To help you to enter my code (if you want to have a look - that would be really nice :) ) : It's an audio driver integrated in pjsip. There is a method to create the stream : here I create an AudioTrack & a AudioRecord - taking as buffer size the value given by minBufferSize A method to start the stream : that callback a method from my app to set up audio modes that create a thread that play the track, goes in a while loop, get a frame from sip stack and write it into the audio track that create a thread that play the record, get a record frame in a while loop and transmit it to the sip stack A method to stop the stream : that put flags to stop thread, join threads and stop track/record A method to destroy stream : that release the track/record objects. Thanks in advance for any help that you can provide :) (and sorry for my poor english .. hope it's still understandable) -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
