ios播放PCM数据

 //
 //  MainViewController.h
 //  RawAudioDataPlayer
 //
 //  Created by SamYou on 12-8-18.
 //  Copyright (c) 2012年 SamYou. All rights reserved.
 //

 #import <UIKit/UIKit.h>
 #import <AudioToolbox/AudioToolbox.h>

 #define QUEUE_BUFFER_SIZE 4 //队列缓冲个数
 #define EVERY_READ_LENGTH 1000 //每次从文件读取的长度
 #define MIN_SIZE_PER_FRAME 2000 //每侦最小数据长度

 @interface MainViewController : UIViewController
 {
     AudioStreamBasicDescription audioDescription;///音频参数
     AudioQueueRef audioQueue;//音频播放队列
     AudioQueueBufferRef audioQueueBuffers[QUEUE_BUFFER_SIZE];//音频缓存
     NSLock *synlock ;///同步控制
     Byte *pcmDataBuffer;//pcm的读文件数据区
     FILE *file;//pcm源文件
 }

 static void AudioPlayerAQInputCallback(void *input, AudioQueueRef inQ, AudioQueueBufferRef outQB);

 -(void)onbutton1clicked;
 -(void)onbutton2clicked;
 -(void)initAudio;
 -(void)readPCMAndPlay:(AudioQueueRef)outQ buffer:(AudioQueueBufferRef)outQB;
 -(void)checkUsedQueueBuffer:(AudioQueueBufferRef) qbuf;

 @end

 //
 //  MainViewController.m
 //  RawAudioDataPlayer
 //
 //  Created by SamYou on 12-8-18.
 //  Copyright (c) 2012年 SamYou. All rights reserved.
 //

 #import "MainViewController.h"

 @interface MainViewController ()

 @end

 @implementation MainViewController

 #pragma mark -
 #pragma mark life cycle

 - (id)init
 {
     self = [super init];
     if (self) {
         NSString *filepath = [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent:@"audio.raw"];
         NSLog(@"filepath = %@",filepath);
         NSFileManager *manager = [NSFileManager defaultManager];
         NSLog(@"file exist = %d",[manager fileExistsAtPath:filepath]);
         NSLog(@"file size = %lld",[[manager attributesOfItemAtPath:filepath error:nil] fileSize]) ;
         file  = fopen([filepath UTF8String], "r");
         if(file)
         {
             fseek(file, 0, SEEK_SET);
             pcmDataBuffer = malloc(EVERY_READ_LENGTH);
         }
         else{
             NSLog(@"!!!!!!!!!!!!!!!!");
         }
         synlock = [[NSLock alloc] init];
     }
     return self;
 }

 -(void)loadView
 {
     [super loadView];
     self.view.backgroundColor = [UIColor grayColor];

     UIButton *button1 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
     button1.frame = CGRectMake(10, 10, 300, 50);
     [button1 setTitle:@"button1" forState:UIControlStateNormal];
     [button1 setTitle:@"button1" forState:UIControlStateHighlighted];
     [button1 addTarget:self action:@selector(onbutton1clicked) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:button1];

     UIButton *button2 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
     button2.frame = CGRectMake(10, 70, 300, 50);
     [button2 setTitle:@"button2" forState:UIControlStateNormal];
     [button2 setTitle:@"button2" forState:UIControlStateHighlighted];
     [button2 addTarget:self action:@selector(onbutton2clicked) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:button2];

 }
 - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
 {
     return (interfaceOrientation == UIInterfaceOrientationPortrait);
 }

 -(void)onbutton1clicked
 {
     [self initAudio];
     NSLog(@"onbutton1clicked");
     AudioQueueStart(audioQueue, NULL);
     for(int i=0;i<QUEUE_BUFFER_SIZE;i++)
     {
         [self readPCMAndPlay:audioQueue buffer:audioQueueBuffers[i]];
     }
     /*
      audioQueue使用的是驱动回调方式，即通过AudioQueueEnqueueBuffer(outQ, outQB, 0, NULL);传入一个buff去播放，播放完buffer区后通过回调通知用户,
      用户得到通知后再重新初始化buff去播放，周而复始,当然，可以使用多个buff提高效率(测试发现使用单个buff会小卡)
      */
 }

 -(void)onbutton2clicked
 {
     NSLog(@"onbutton2clicked");
 }

 #pragma mark -
 #pragma mark player call back
 /*
  试了下其实可以不用静态函数，但是c写法的函数内是无法调用[self ***]这种格式的写法，所以还是用静态函数通过void *input来获取原类指针
  这个回调存在的意义是为了重用缓冲buffer区，当通过AudioQueueEnqueueBuffer(outQ, outQB, 0, NULL);函数放入queue里面的音频文件播放完以后，通过这个函数通知
  调用者，这样可以重新再使用回调传回的AudioQueueBufferRef
  */
 static void AudioPlayerAQInputCallback(void *input, AudioQueueRef outQ, AudioQueueBufferRef outQB)
 {
     NSLog(@"AudioPlayerAQInputCallback");
     MainViewController *mainviewcontroller = (MainViewController *)input;
     [mainviewcontroller checkUsedQueueBuffer:outQB];
     [mainviewcontroller readPCMAndPlay:outQ buffer:outQB];
 }



 -(void)initAudio
 {
     ///设置音频参数
     audioDescription.mSampleRate = 8000;//采样率
     audioDescription.mFormatID = kAudioFormatLinearPCM;
     audioDescription.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
     audioDescription.mChannelsPerFrame = 1;///单声道
     audioDescription.mFramesPerPacket = 1;//每一个packet一侦数据
     audioDescription.mBitsPerChannel = 16;//每个采样点16bit量化
     audioDescription.mBytesPerFrame = (audioDescription.mBitsPerChannel/8) * audioDescription.mChannelsPerFrame;
     audioDescription.mBytesPerPacket = audioDescription.mBytesPerFrame ;
     ///创建一个新的从audioqueue到硬件层的通道
 //  AudioQueueNewOutput(&audioDescription, AudioPlayerAQInputCallback, self, CFRunLoopGetCurrent(), kCFRunLoopCommonModes, 0, &audioQueue);///使用当前线程播
     AudioQueueNewOutput(&audioDescription, AudioPlayerAQInputCallback, self, nil, nil, 0, &audioQueue);//使用player的内部线程播
     ////添加buffer区
     for(int i=0;i<QUEUE_BUFFER_SIZE;i++)
     {
         int result =  AudioQueueAllocateBuffer(audioQueue, MIN_SIZE_PER_FRAME, &audioQueueBuffers[i]);///创建buffer区，MIN_SIZE_PER_FRAME为每一侦所需要的最小的大小，该大小应该比每次往buffer里写的最大的一次还大
         NSLog(@"AudioQueueAllocateBuffer i = %d,result = %d",i,result);
     }
 }

 -(void)readPCMAndPlay:(AudioQueueRef)outQ buffer:(AudioQueueBufferRef)outQB
 {
     [synlock lock];
     int readLength = fread(pcmDataBuffer, 1, EVERY_READ_LENGTH, file);//读取文件
     NSLog(@"read raw data size = %d",readLength);
     outQB->mAudioDataByteSize = readLength;
     Byte *audiodata = (Byte *)outQB->mAudioData;
     for(int i=0;i<readLength;i++)
     {
         audiodata[i] = pcmDataBuffer[i];
     }
     /*
      将创建的buffer区添加到audioqueue里播放
      AudioQueueBufferRef用来缓存待播放的数据区，AudioQueueBufferRef有两个比较重要的参数，AudioQueueBufferRef->mAudioDataByteSize用来指示数据区大小，AudioQueueBufferRef->mAudioData用来保存数据区
      */
     AudioQueueEnqueueBuffer(outQ, outQB, 0, NULL);
     [synlock unlock];
 }

 -(void)checkUsedQueueBuffer:(AudioQueueBufferRef) qbuf
 {
     if(qbuf == audioQueueBuffers[0])
     {
         NSLog(@"AudioPlayerAQInputCallback,bufferindex = 0");
     }
     if(qbuf == audioQueueBuffers[1])
     {
         NSLog(@"AudioPlayerAQInputCallback,bufferindex = 1");
     }
     if(qbuf == audioQueueBuffers[2])
     {
         NSLog(@"AudioPlayerAQInputCallback,bufferindex = 2");
     }
     if(qbuf == audioQueueBuffers[3])
     {
         NSLog(@"AudioPlayerAQInputCallback,bufferindex = 3");
     }
 }






 @end

哥的源代码下载地址      http://download.csdn.net/detail/samguoyi/4509544