kAudioUnitSubType_AudioFilePlayer

gistfile1.m

#import <AudioToolbox/AudioToolbox.h>

- (void)play
{
    AUGraph _AUGraph;
    OSStatus err;
    
    AudioUnit remoteIOUnit;
    AudioUnit audioPlayerUnit;
    AUNode audioPlayerNode, remoteOutputNode;
    
    err = NewAUGraph(&_AUGraph);
    err = AUGraphOpen(_AUGraph);
	
	AudioComponentDescription cd;
	cd.componentType = kAudioUnitType_Output;
	cd.componentSubType = kAudioUnitSubType_RemoteIO;
	cd.componentManufacturer = kAudioUnitManufacturer_Apple;
	cd.componentFlags = cd.componentFlagsMask = 0;
	
    //Node
	err = AUGraphAddNode(_AUGraph, &cd, &remoteOutputNode);
    if (err) {
        LOG(@"err = %ld", err);
    }
    //Get Audio Unit
    err = AUGraphNodeInfo(_AUGraph,
                    remoteOutputNode,
                    NULL,
                    &remoteIOUnit);
    if (err) {
        LOG(@"err = %ld", err);
    }
    
    //Create AudioPlayer
	cd.componentType = kAudioUnitType_Generator;
	cd.componentSubType = kAudioUnitSubType_AudioFilePlayer;
	
    //Node
	err = AUGraphAddNode(_AUGraph, &cd, &audioPlayerNode);
    if (err) {
        LOG(@"err = %ld", err);
    }
    //Get Audio Unit
    err = AUGraphNodeInfo(_AUGraph,
                    audioPlayerNode,
                    NULL,
                    &audioPlayerUnit);
    if (err) {
        LOG(@"err = %ld", err);
    }
        
    err = AUGraphConnectNodeInput(_AUGraph, audioPlayerNode, 0, remoteOutputNode, 0);
    if (err) {
        LOG(@"err = %ld", err);
    }
    err = AUGraphInitialize(_AUGraph);
    if (err) {
        LOG(@"err = %ld", err);
    }

    err = AUGraphStart(_AUGraph);
    if (err) {
        LOG(@"err = %ld", err);
    }
    
    AudioFileID audioFileID;
    NSURL *url = [[NSBundle mainBundle] URLForResource:@"loop" withExtension:@"wav"];
    err = AudioFileOpenURL((__bridge CFURLRef)url,
                           kAudioFileReadPermission,
                           kAudioFileWAVEType, //MP3
                           &audioFileID);
    if (err) {
        LOG(@"err = %ld", err);
    }
        
    AudioFileID audioFileIDs[1];
    audioFileIDs[0] = audioFileID;
    UInt32 size = sizeof(AudioFileID);
    err = AudioUnitSetProperty(audioPlayerUnit,
                               kAudioUnitProperty_ScheduledFileIDs,
                               kAudioUnitScope_Global,
                               0,
                               audioFileIDs,
                               size);
    if (err) {
        LOG(@"err = %ld", err);
    }
    
    ScheduledAudioFileRegion playRegion;
    playRegion.mTimeStamp.mFlags = kAudioTimeStampSampleTimeValid;
    playRegion.mTimeStamp.mSampleTime = 0;
    playRegion.mCompletionProc = NULL;
    playRegion.mCompletionProcUserData = NULL;
    playRegion.mAudioFile = audioFileID;
    playRegion.mLoopCount = -1;
    playRegion.mStartFrame = 0;
    playRegion.mFramesToPlay = -1;
    err = AudioUnitSetProperty(audioPlayerUnit,
                               kAudioUnitProperty_ScheduledFileRegion,
                               kAudioUnitScope_Global,
                               0,
                               &playRegion,
                               sizeof(playRegion));
    if (err) {
        LOG(@"err = %ld", err);
    }
    
    // prime
    UInt32 primeFrames = 0;	// default
    err = AudioUnitSetProperty(audioPlayerUnit,
                               kAudioUnitProperty_ScheduledFilePrime,
                               kAudioUnitScope_Global,
                               0,
                               &primeFrames,
                               sizeof(primeFrames));
    if (err) {
        LOG(@"err = %ld", err);
    }
    
    // set start time (on next render cycle)
    AudioTimeStamp startTime;
    startTime.mFlags = kAudioTimeStampSampleTimeValid;
    startTime.mSampleTime = -1;
    err = AudioUnitSetProperty(audioPlayerUnit,
                               kAudioUnitProperty_ScheduleStartTimeStamp,
                               kAudioUnitScope_Global,
                               0,
                               &startTime,
                               sizeof(startTime));
    if (err) {
        LOG(@"err = %ld", err);
    }
}

Hello ! I saw your code，and I'm learning and using AudioPlayerNode. But, I met a lot of problems and couldn't solve. I couldn't find a person to ask for help In my around，So I take the liberty to ask you some questions. I couldn't find relevant data about how to use AVAudioPlayerNode to play music online. If you know , do you mind telling me something about it?