ExtAudioFileRead crashes in background

Question

My app plays music in background. I have "audio" key on in Background modes, my audio session looks like:
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
NSError *err = NULL;
[audioSession setCategory:AVAudioSessionCategoryPlayback error:&err];
if( err ){
NSLog(@"There was an error creating the audio session");
[audioSession setMode:AVAudioSessionModeDefault error:&err];
if( err ){
NSLog(@"There was an error setting mote to the audio session");
[[AVAudioSession sharedInstance] setActive:YES error:&err];
if( err ){
NSLog(@"There was an error setting mote to the audio session");
I'm playing via AUGraph which is configured with 2 nodes: Remote I/O and Mixer:
AudioComponentDescription outputcd;
outputcd.componentFlags = 0;
outputcd.componentFlagsMask = 0;
outputcd.componentManufacturer = kAudioUnitManufacturer_Apple;
outputcd.componentSubType = kAudioUnitSubType_RemoteIO;
outputcd.componentType = kAudioUnitType_Output;
// Multichannel mixer unit
AudioComponentDescription MixerUnitDescription;
MixerUnitDescription.componentType = kAudioUnitType_Mixer;
MixerUnitDescription.componentSubType = kAudioUnitSubType_AU3DMixerEmbedded;
MixerUnitDescription.componentManufacturer = kAudioUnitManufacturer_Apple;
MixerUnitDescription.componentFlags = 0; MixerUnitDescription.componentFlagsMask = 0;
Also according to Technical QA I added
UInt32 maxFPS = 4096;
AudioUnitSetProperty(_mixerUnit, kAudioUnitProperty_MaximumFramesPerSlice,kAudioUnitScope_Global, 0, &maxFPS,sizeof(maxFPS));
But still no luck, my app keeps crashing on ExtAudioFileRead in Render callback function approx 10 seconds as i lock iPhone with error code -40.
I can reproduce this bug only on iOS 8.1.2 version. Is this some known iOS issue or am i missing something? Thanks for any help!

Answer 1

My app plays music in background. I have "audio" key on in Background modes, my audio session looks like:
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
NSError *err = NULL;
[audioSession setCategory:AVAudioSessionCategoryPlayback error:&err];
if( err ){
NSLog(@"There was an error creating the audio session");
[audioSession setMode:AVAudioSessionModeDefault error:&err];
if( err ){
NSLog(@"There was an error setting mote to the audio session");
[[AVAudioSession sharedInstance] setActive:YES error:&err];
if( err ){
NSLog(@"There was an error setting mote to the audio session");
I'm playing via AUGraph which is configured with 2 nodes: Remote I/O and Mixer:
AudioComponentDescription outputcd;
outputcd.componentFlags = 0;
outputcd.componentFlagsMask = 0;
outputcd.componentManufacturer = kAudioUnitManufacturer_Apple;
outputcd.componentSubType = kAudioUnitSubType_RemoteIO;
outputcd.componentType = kAudioUnitType_Output;
// Multichannel mixer unit
AudioComponentDescription MixerUnitDescription;
MixerUnitDescription.componentType = kAudioUnitType_Mixer;
MixerUnitDescription.componentSubType = kAudioUnitSubType_AU3DMixerEmbedded;
MixerUnitDescription.componentManufacturer = kAudioUnitManufacturer_Apple;
MixerUnitDescription.componentFlags = 0; MixerUnitDescription.componentFlagsMask = 0;
Also according to Technical QA I added
UInt32 maxFPS = 4096;
AudioUnitSetProperty(_mixerUnit, kAudioUnitProperty_MaximumFramesPerSlice,kAudioUnitScope_Global, 0, &maxFPS,sizeof(maxFPS));
But still no luck, my app keeps crashing on ExtAudioFileRead in Render callback function approx 10 seconds as i lock iPhone with error code -40.
I can reproduce this bug only on iOS 8.1.2 version. Is this some known iOS issue or am i missing something? Thanks for any help!