使用iphone的remote io unit来录音和放音.
此文的参考价值越来越小了,新版的xcode默认要求arc开发,此类是mrc.AudioSessionAddPropertyListener...这些c函数在ios7也提示过时了.用上AVAudioSession改过来就可以了.变化不大,不接触ios很长时间了.... 20140324
场景:频繁将很小的一段音频录成音频数据.也频繁将一段很小的数据进行播放.直接使用上unit,降低延迟是主要目的.(一般情况下,直接使用audio unit不是最佳选择).
默认情况:
1.一个io unit(其中remote io unit是iphone的三个io unit中的一个)的element 1(也叫bus 1)直接与设备上的输入硬件(比如麦克风)相连;
2.一个io unit的element 0(也叫bus 0)直接与设备上的输出硬件(比如扬声器)相连.
3.remote io unit启用了输出而禁止了输入.
设计模式:
录音设计:设置remote io unit的渲染回调,从输入硬件获得采样传入到回调函数进行渲染,从而获得录音数据.
放音设计:设置remote io unit的输入回调.向回调函数填数据,从而向输出硬件提供数据进行放音.
直接上关键代码:(代码有不少注释)
//
// RootViewController.m
// recorder1
//
// Created by luna on 13-8-5.
// Copyright (c) 2013年 xxx. All rights reserved.
//
#import "RootViewController.h"
#import <AudioToolbox/AudioToolbox.h>
#import "InMemoryAudioFile.h"
#define kChannels 2
#define kOutputBus 0
#define kInputBus 1
@interface RootViewController (){
AudioStreamBasicDescription mAudioFormat;
AudioComponentInstance mAudioUnit;
ExtAudioFileRef mAudioFileRef;
Boolean isRecording;
Boolean isPlaying;
InMemoryAudioFile *inMemoryAudioFile;
}
@end
@implementation RootViewController
- (id)init
{
self = [super init];
if (self) {
isRecording=FALSE;
isPlaying=FALSE;
}
return self;
}
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
}
return self;
}
static void CheckError(OSStatus error,const char *operaton){
if (error==noErr) {
return;
}
char errorString[20]={};
*(UInt32 *)(errorString+1)=CFSwapInt32HostToBig(error);
if (isprint(errorString[1])&&isprint(errorString[2])&&isprint(errorString[3])&&isprint(errorString[4])) {
errorString[0]=errorString[5]='\'';
errorString[6]='\0';
}else{
sprintf(errorString, "%d",(int)error);
}
fprintf(stderr, "Error:%s (%s)\n",operaton,errorString);
exit(1);
}
void audioInterruptionListener(void *inClientData,UInt32 inInterruptionState){
printf("Interrupted! inInterruptionState=%ld\n",inInterruptionState);
//RootViewController *appDelegate=(RootViewController *)inClientData;
switch (inInterruptionState) {
case kAudioSessionBeginInterruption:
break;
case kAudioSessionEndInterruption:
/*
CheckError(AudioSessionSetActive(true), "Couldn't set audio session active");
CheckError(AudioUnitInitialize(appDelegate->mAudioUnit), "Couldn't initialize RIO unit");
CheckError(AudioOutputUnitStart(appDelegate->mAudioUnit), "Couldn't start RIO unit");
*/
break;
default:
break;
}
}
void audioRouteChangeListener( void *inClientData,
AudioSessionPropertyID inID,
UInt32 inDataSize,
const void *inData){
printf("audioRouteChangeListener");
/*
CFStringRef routeStr;
UInt32 properSize=sizeof(routeStr);
AudioSessionGetProperty(kAudioSessionProperty_AudioRoute, &properSize, &routeStr);
NSString *routeNSStr=(NSString *)routeStr;
NSLog(@"audioRouteChange::%@",routeNSStr);//none:ReceiverAndMicrophone ipod:HeadphonesAndMicrophone iphone:HeadsetInOut xiaomi:HeadsetInOut
UIAlertView *alertView=[[UIAlertView alloc] initWithTitle:routeNSStr message:routeNSStr delegate:nil cancelButtonTitle:@"cancel" otherButtonTitles:@"other", nil];
[alertView show];
[alertView release];
*/
}
OSStatus recordCallback(void *inRefCon,
AudioUnitRenderActionFlags *ioActionFlags,
const AudioTimeStamp *inTimeStamp,
UInt32 inBusNumber,
UInt32 inNumberFrames,
AudioBufferList *ioData){
printf("record::%ld,",inNumberFrames);
//double timeInSeconds = inTimeStamp->mSampleTime / kSampleRate;
//printf("\n%fs inBusNumber:%lu inNumberFrames:%lu", timeInSeconds, inBusNumber, inNumberFrames);
AudioBufferList bufferList;
UInt16 numSamples=inNumberFrames*kChannels;
UInt16 samples[numSamples];
memset (&samples, 0, sizeof (samples));
bufferList.mNumberBuffers = 1;
bufferList.mBuffers[0].mData = samples;
bufferList.mBuffers[0].mNumberChannels = kChannels;
bufferList.mBuffers[0].mDataByteSize = numSamples*sizeof(UInt16);
RootViewController* THIS = (RootViewController *)inRefCon;
CheckError(AudioUnitRender(THIS->mAudioUnit,
ioActionFlags,
inTimeStamp,
kInputBus,
inNumberFrames,
&bufferList),"AudioUnitRender failed");
// Now, we have the samples we just read sitting in buffers in bufferList
ExtAudioFileWriteAsync(THIS->mAudioFileRef, inNumberFrames, &bufferList);
return noErr;
}
OSStatus playCallback(void *inRefCon,
AudioUnitRenderActionFlags *ioActionFlags,
const AudioTimeStamp *inTimeStamp,
UInt32 inBusNumber,
UInt32 inNumberFrames,
AudioBufferList *ioData){
printf("play::%ld,",inNumberFrames);
RootViewController* this = (RootViewController *)inRefCon;
/*
UInt8 *frameBuffer = ioData->mBuffers[0].mData;
UInt32 count=inNumberFrames*4;
for (int j = 0; j < count; ){
UInt32 packet=[this->inMemoryAudioFile getNextFrame];
frameBuffer[j]=packet;
frameBuffer[j+1]=packet>>8;
//Above for the left channel, right channel following
frameBuffer[j+2]=packet>>16;
frameBuffer[j+3]=packet>>24;
j+=4;
}
*/
/*
UInt16 *frameBuffer = ioData->mBuffers[0].mData;
UInt32 count=inNumberFrames*2;
for (int j = 0; j < count; ){
UInt32 packet=[this->inMemoryAudioFile getNextFrame];
frameBuffer[j]=packet;//left channel
frameBuffer[j+1]=packet>>16;//right channel
j+=2;
}
*/
UInt32 *frameBuffer = ioData->mBuffers[0].mData;
UInt32 count=inNumberFrames;
for (int j = 0; j < count; j++){
frameBuffer[j] = [this->inMemoryAudioFile getNextFrame];//Stereo channels
}
return noErr;
}
-(void)configAudio{
//Upon launch, the application automatically gets a singleton audio session.
//Initialize a session and registering an interruption callback
CheckError(AudioSessionInitialize(NULL, kCFRunLoopDefaultMode, audioInterruptionListener, self), "couldn't initialize the audio session");
//Add a AudioRouteChange listener
CheckError(AudioSessionAddPropertyListener(kAudioSessionProperty_AudioRouteChange, audioRouteChangeListener, self),"couldn't add a route change listener");
//Is there an audio input device available
UInt32 inputAvailable;
UInt32 propSize=sizeof(inputAvailable);
CheckError(AudioSessionGetProperty(kAudioSessionProperty_AudioInputAvailable, &propSize, &inputAvailable), "not available for the current input audio device");
if (!inputAvailable) {
/*
UIAlertView *noInputAlert =[[UIAlertView alloc] initWithTitle:@"error" message:@"not available for the current input audio device" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[noInputAlert show];
[noInputAlert release];
*/
return;
}
//Adjust audio hardware I/O buffer duration.If I/O latency is critical in your app, you can request a smaller duration.
Float32 ioBufferDuration = .005;
CheckError(AudioSessionSetProperty(kAudioSessionProperty_PreferredHardwareIOBufferDuration, sizeof(ioBufferDuration), &ioBufferDuration),"couldn't set the buffer duration on the audio session");
//Set the audio category
UInt32 audioCategory = kAudioSessionCategory_PlayAndRecord;
CheckError(AudioSessionSetProperty(kAudioSessionProperty_AudioCategory, sizeof(audioCategory), &audioCategory), "couldn't set the category on the audio session");
UInt32 override=true;
AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryDefaultToSpeaker, sizeof(override), &override);
//Get hardware sample rate and setting the audio format
Float64 sampleRate;
UInt32 sampleRateSize=sizeof(sampleRate);
CheckError(AudioSessionGetProperty(kAudioSessionProperty_CurrentHardwareSampleRate, &sampleRateSize, &sampleRate), "Couldn't get hardware samplerate");
mAudioFormat.mSampleRate = sampleRate;
mAudioFormat.mFormatID = kAudioFormatLinearPCM;
mAudioFormat.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
mAudioFormat.mFramesPerPacket = 1;
mAudioFormat.mChannelsPerFrame = kChannels;
mAudioFormat.mBitsPerChannel = 16;
mAudioFormat.mBytesPerFrame = mAudioFormat.mBitsPerChannel*mAudioFormat.mChannelsPerFrame/8;
mAudioFormat.mBytesPerPacket = mAudioFormat.mBytesPerFrame*mAudioFormat.mFramesPerPacket;
mAudioFormat.mReserved = 0;
//Obtain a RemoteIO unit instance
AudioComponentDescription acd;
acd.componentType = kAudioUnitType_Output;
acd.componentSubType = kAudioUnitSubType_RemoteIO;
acd.componentFlags = 0;
acd.componentFlagsMask = 0;
acd.componentManufacturer = kAudioUnitManufacturer_Apple;
AudioComponent inputComponent = AudioComponentFindNext(NULL, &acd);
CheckError(AudioComponentInstanceNew(inputComponent, &mAudioUnit), "Couldn't new AudioComponent instance");
//The Remote I/O unit, by default, has output enabled and input disabled
//Enable input scope of input bus for recording.
UInt32 enable = 1;
UInt32 disable=0;
CheckError(AudioUnitSetProperty(mAudioUnit,
kAudioOutputUnitProperty_EnableIO,
kAudioUnitScope_Input,
kInputBus,
&enable,
sizeof(enable))
, "kAudioOutputUnitProperty_EnableIO::kAudioUnitScope_Input::kInputBus");
//Apply format to output scope of input bus for recording.
CheckError(AudioUnitSetProperty(mAudioUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Output,
kInputBus,
&mAudioFormat,
sizeof(mAudioFormat))
, "kAudioUnitProperty_StreamFormat::kAudioUnitScope_Output::kInputBus");
//Disable buffer allocation for recording(optional)
CheckError(AudioUnitSetProperty(mAudioUnit,
kAudioUnitProperty_ShouldAllocateBuffer,
kAudioUnitScope_Output,
kInputBus,
&disable,
sizeof(disable))
, "kAudioUnitProperty_ShouldAllocateBuffer::kAudioUnitScope_Output::kInputBus");
//Applying format to input scope of output bus for playing
CheckError(AudioUnitSetProperty(mAudioUnit,
kAudioUnitProperty_StreamFormat,
kAudioUnitScope_Input,
kOutputBus,
&mAudioFormat,
sizeof(mAudioFormat)), "kAudioUnitProperty_StreamFormat::kAudioUnitScope_Input::kOutputBus");
//AudioUnitInitialize
CheckError(AudioUnitInitialize(mAudioUnit), "AudioUnitInitialize");
}
-(void)startToRecord{
//Add a callback for recording
AURenderCallbackStruct recorderStruct;
recorderStruct.inputProc = recordCallback;
recorderStruct.inputProcRefCon = self;
CheckError(AudioUnitSetProperty(mAudioUnit,
kAudioOutputUnitProperty_SetInputCallback,
kAudioUnitScope_Input,
kInputBus,
&recorderStruct,
sizeof(recorderStruct))
, "kAudioOutputUnitProperty_SetInputCallback::kAudioUnitScope_Input::kInputBus");
//Remove a callback for playing
AURenderCallbackStruct playStruct;
playStruct.inputProc=0;
playStruct.inputProcRefCon=0;
CheckError(AudioUnitSetProperty(mAudioUnit,
kAudioUnitProperty_SetRenderCallback,
kAudioUnitScope_Input,
kOutputBus,
&playStruct,
sizeof(playStruct)), "kAudioUnitProperty_SetRenderCallback::kAudioUnitScope_Input::kOutputBus");
//Create an audio file for recording
NSString *destinationFilePath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"test.caf"];
CFURLRef destinationURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (CFStringRef)destinationFilePath, kCFURLPOSIXPathStyle, false);
CheckError(ExtAudioFileCreateWithURL(destinationURL, kAudioFileCAFType, &mAudioFormat, NULL, kAudioFileFlags_EraseFile, &mAudioFileRef),"Couldn't create a file for writing");
CFRelease(destinationURL);
AudioOutputUnitStart(mAudioUnit);
}
-(void)stopToRecord{
AudioOutputUnitStop(mAudioUnit);
//Dispose the audio file
CheckError(ExtAudioFileDispose(mAudioFileRef),"ExtAudioFileDispose failed");
}
-(void)startToPlay{
//Remove the input callback
AURenderCallbackStruct recorderStruct;
recorderStruct.inputProc = 0;
recorderStruct.inputProcRefCon = 0;
CheckError(AudioUnitSetProperty(mAudioUnit,
kAudioOutputUnitProperty_SetInputCallback,
kAudioUnitScope_Input,
kInputBus,
&recorderStruct,
sizeof(recorderStruct))
, "kAudioOutputUnitProperty_SetInputCallback::kAudioUnitScope_Input::kInputBus");
//Add a callback for playing
AURenderCallbackStruct playStruct;
playStruct.inputProc=playCallback;
playStruct.inputProcRefCon=self;
CheckError(AudioUnitSetProperty(mAudioUnit,
kAudioUnitProperty_SetRenderCallback,
kAudioUnitScope_Input,
kOutputBus,
&playStruct,
sizeof(playStruct)), "kAudioUnitProperty_SetRenderCallback::kAudioUnitScope_Input::kOutputBus");
inMemoryAudioFile=[[InMemoryAudioFile alloc] init];
NSString *filepath = [[NSHomeDirectory() stringByAppendingPathComponent:@"Documents"] stringByAppendingPathComponent:@"test.caf"];
[inMemoryAudioFile open:filepath];
AudioOutputUnitStart(mAudioUnit);
}
-(void)stopToPlay{
AudioOutputUnitStop(mAudioUnit);
[inMemoryAudioFile release],inMemoryAudioFile=nil;
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self configAudio];
UIButton *button1=[UIButton buttonWithType:UIButtonTypeRoundedRect];
button1.frame=CGRectMake(100, 100, 80, 30);
button1.tag=1;
[button1 setTitle:@"开始录音" forState:UIControlStateNormal];
[button1 addTarget:self action:@selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button1];
UIButton *button2=[UIButton buttonWithType:UIButtonTypeRoundedRect];
button2.frame=CGRectMake(100, 200, 80, 30);
button2.tag=2;
[button2 setTitle:@"开始放音" forState:UIControlStateNormal];
[button2 addTarget:self action:@selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button2];
}
-(void)buttonAction:(UIButton *)button{
if (button.tag==1) {
UIButton *other=(UIButton *)[button.superview viewWithTag:2];
if (isRecording) {
other.enabled=YES;
[self stopToRecord];
[button setTitle:@"开始录音" forState:UIControlStateNormal];
printf("stop record\n");
}else{
other.enabled=NO;
[self startToRecord];
[button setTitle:@"停止录音" forState:UIControlStateNormal];
printf("start record\n");
}
isRecording=!isRecording;
}else if(button.tag==2){
UIButton *other=(UIButton *)[button.superview viewWithTag:1];
if (isPlaying) {
other.enabled=YES;
[self stopToPlay];
[button setTitle:@"开始放音" forState:UIControlStateNormal];
printf("stop play\n");
}else{
other.enabled=NO;
[self startToPlay];
[button setTitle:@"停止放音" forState:UIControlStateNormal];
printf("start play\n");
}
isPlaying=!isPlaying;
}
}
- (void)dealloc{
CheckError(AudioSessionRemovePropertyListenerWithUserData(kAudioSessionProperty_AudioRouteChange, audioRouteChangeListener, self),"couldn't remove a route change listener");
AudioUnitUninitialize(mAudioUnit);
if (inMemoryAudioFile!=nil) {
[inMemoryAudioFile release],inMemoryAudioFile=nil;
}
[super dealloc];
}
@end
既然不少人问InMemoryAudioFile,来源于外国网站,那还是补充上去吧:
InMemoryAudioFile.h
//
// InMemoryAudioFile.h
// HelloWorld
//
// Created by Aran Mulholland on 22/02/09.
// Copyright 2009 Aran Mulholland. All rights reserved.
//
#import <Foundation/Foundation.h>
#import <AudioToolbox/AudioFile.h>
#include <sys/time.h>
@interface InMemoryAudioFile : NSObject {
AudioStreamBasicDescription mDataFormat;
AudioFileID mAudioFile;
UInt32 bufferByteSize;
SInt64 mCurrentPacket;
UInt32 mNumPacketsToRead;
AudioStreamPacketDescription *mPacketDescs;
SInt64 packetCount;
UInt32 *audioData;
SInt64 packetIndex;
}
//opens a wav file
-(OSStatus)open:(NSString *)filePath;
//gets the infor about a wav file, stores it locally
-(OSStatus)getFileInfo;
//gets the next packet from the buffer, returns -1 if we have reached the end of the buffer
-(UInt32)getNextPacket;
//gets the current index (where we are up to in the buffer)
-(SInt64)getIndex;
//reset the index to the start of the file
-(void)reset;
@end
InMemoryAudioFile.m
//
// InMemoryAudioFile.m
// HelloWorld
//
// Created by Aran Mulholland on 22/02/09.
// Copyright 2009 Aran Mulholland. All rights reserved.
//
#import "InMemoryAudioFile.h"
@implementation InMemoryAudioFile
//overide init method
- (id)init
{
self=[super init];
if (self!=nil) {
packetIndex = 0;
}
return self;
}
- (void)dealloc {
//release the AudioBuffer
free(audioData);
[super dealloc];
}
//open and read a wav file
-(OSStatus)open:(NSString *)filePath{
//get a ref to the audio file, need one to open it
CFURLRef audioFileURL = CFURLCreateFromFileSystemRepresentation (NULL, (const UInt8 *)[filePath cStringUsingEncoding:[NSString defaultCStringEncoding]] , strlen([filePath cStringUsingEncoding:[NSString defaultCStringEncoding]]), false);
//open the audio file
OSStatus result = AudioFileOpenURL (audioFileURL, 0x01, 0, &mAudioFile);
//were there any errors reading? if so deal with them first
if (result != noErr) {
NSLog(@"Could not open file: %@", filePath);
packetCount = -1;
}
//otherwise
else{
//get the file info
[self getFileInfo];
//how many packets read? (packets are the number of stereo samples in this case)
NSLog(@"File Opened, packet Count: %lld", packetCount);
UInt32 packetsRead = packetCount;
OSStatus result = -1;
//free the audioBuffer just in case it contains some data
free(audioData);
UInt32 numBytesRead = -1;
//if we didn't get any packets dop nothing, nothing to read
if (packetCount <= 0) { }
//otherwise fill our in memory audio buffer with the whole file (i wouldnt use this with very large files btw)
else{
//allocate the buffer
audioData = (UInt32 *)malloc(sizeof(UInt32) * packetCount);
//read the packets
result = AudioFileReadPackets (mAudioFile, false, &numBytesRead, NULL, 0, &packetsRead, audioData);
}
if (result==noErr){
//print out general info about the file
NSLog(@"Packets read from file: %ld\n", packetsRead);
NSLog(@"Bytes read from file: %ld\n", numBytesRead);
//for a stereo 32 bit per sample file this is ok
NSLog(@"Sample count: %ld\n", numBytesRead / 2);
//for a 32bit per stereo sample at 44100khz this is correct
NSLog(@"Time in Seconds: %f.4\n", ((float)numBytesRead / 4.0) / 44100.0);
}
}
CFRelease (audioFileURL);
return result;
}
- (OSStatus) getFileInfo {
OSStatus result = -1;
//double duration;
if (mAudioFile != nil){
UInt32 dataSize = sizeof packetCount;
result = AudioFileGetProperty(mAudioFile, kAudioFilePropertyAudioDataPacketCount, &dataSize, &packetCount);
if (result==noErr) {
//duration = ((double)packetCount * 2) / 44100;
}
else{
packetCount = -1;
}
}
return result;
}
//gets the next packet from the buffer, if we have reached the end of the buffer return 0
-(UInt32)getNextPacket{
UInt32 returnValue = 0;
//if the packetCount has gone to the end of the file, reset it. Audio will loop.
if (packetIndex >= packetCount){
packetIndex = 0;
NSLog(@"Reset player to beginning of file.");
}
//i always like to set a variable and then return it during development so i can
//see the value while debugging
returnValue = audioData[packetIndex++];
return returnValue;
}
//gets the current index (where we are up to in the buffer)
-(SInt64)getIndex{
return packetIndex;
}
-(void)reset{
packetIndex = 0;
}
@end
如有使用不当,恳请提出,相互交流.