我正在目标 c 中创建一个呼叫应用程序。我的问题在于发送和接收音频流。记录音频缓冲并转换为 nsdata 并通过套接字火箭使用（base64 格式）发送这是很好的工作，但我不知道如何在从服务器接收到 nsdata 后播放此音频缓冲？
我的代码：
视图控制器.h
#import <UIKit/UIKit.h>
#import <AudioToolbox/AudioQueue.h>
#import <AudioToolbox/AudioFile.h>
#import <SocketRocket/SocketRocket.h>
#import <AVFoundation/AVFoundation.h>
#import <AVKit/AVKit.h>
#define NUM_BUFFERS 3
#define SAMPLERATE 16000
//Struct defining recording state
typedef struct {
AudioStreamBasicDescription dataFormat;
AudioQueueRef queue;
AudioQueueBufferRef buffers[NUM_BUFFERS];
AudioFileID audioFile;
SInt64 currentPacket;
bool recording;
} RecordState;
//Struct defining playback state
typedef struct {
AudioStreamBasicDescription dataFormat;
AudioQueueRef queue;
AudioQueueBufferRef buffers[NUM_BUFFERS];
AudioFileID audioFile;
SInt64 currentPacket;
bool playing;
} PlayState;
@interface ViewController : UIViewController <SRWebSocketDelegate> {
RecordState recordState;
PlayState playState;
CFURLRef fileURL;
}
@property (nonatomic, strong) SRWebSocket * webSocket;
@property (weak, nonatomic) IBOutlet UITextView *textView;
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@end
视图控制器.m
#import "ViewController.h"
#import <MediaPlayer/MediaPlayer.h>
id thisClass;
//Declare C callback functions
void AudioInputCallback(void * inUserData, // Custom audio metada
AudioQueueRef inAQ,
AudioQueueBufferRef inBuffer,
const AudioTimeStamp * inStartTime,
UInt32 isNumberPacketDescriptions,
const AudioStreamPacketDescription * inPacketDescs);
void AudioOutputCallback(void * inUserData,
AudioQueueRef outAQ,
AudioQueueBufferRef outBuffer);
@interface ViewController ()
@end
@implementation ViewController{
NSString *documentsDirectory ;
}
@synthesize webSocket;
@synthesize textView;
@synthesize imageView;
// Takes a filled buffer and writes it to disk, "emptying" the buffer
void AudioInputCallback(void * inUserData,
AudioQueueRef inAQ,
AudioQueueBufferRef inBuffer,
const AudioTimeStamp * inStartTime,
UInt32 inNumberPacketDescriptions,
const AudioStreamPacketDescription * inPacketDescs)
{
RecordState * recordState = (RecordState*)inUserData;
if (!recordState->recording)
{
printf("Not recording, returning\n");
}
printf("Writing buffer %lld\n", recordState->currentPacket);
OSStatus status = AudioFileWritePackets(recordState->audioFile,
false,
inBuffer->mAudioDataByteSize,
inPacketDescs,
recordState->currentPacket,
&inNumberPacketDescriptions,
inBuffer->mAudioData);
if (status == 0)
{
recordState->currentPacket += inNumberPacketDescriptions;
NSData * audioData = [NSData dataWithBytes:inBuffer->mAudioData length:inBuffer->mAudioDataByteSize * NUM_BUFFERS];
NSString *base64Encoded = [audioData base64EncodedStringWithOptions:0];
[thisClass sendAudioToSocketAsData:base64Encoded];
}
AudioQueueEnqueueBuffer(recordState->queue, inBuffer, 0, NULL);
}
// Fills an empty buffer with data and sends it to the speaker
void AudioOutputCallback(void * inUserData,
AudioQueueRef outAQ,
AudioQueueBufferRef outBuffer) {
PlayState * playState = (PlayState *) inUserData;
if(!playState -> playing) {
printf("Not playing, returning\n");
return;
}
printf("Queuing buffer %lld for playback\n", playState -> currentPacket);
AudioStreamPacketDescription * packetDescs;
UInt32 bytesRead;
UInt32 numPackets = SAMPLERATE * NUM_BUFFERS;
OSStatus status;
status = AudioFileReadPackets(playState -> audioFile, false, &bytesRead, packetDescs, playState -> currentPacket, &numPackets, outBuffer -> mAudioData);
if (numPackets) {
outBuffer -> mAudioDataByteSize = bytesRead;
status = AudioQueueEnqueueBuffer(playState -> queue, outBuffer, 0, packetDescs);
playState -> currentPacket += numPackets;
}else {
if (playState -> playing) {
AudioQueueStop(playState -> queue, false);
AudioFileClose(playState -> audioFile);
playState -> playing = false;
}
AudioQueueFreeBuffer(playState -> queue, outBuffer);
}
}
- (void) setupAudioFormat:(AudioStreamBasicDescription *) format {
format -> mSampleRate = SAMPLERATE; //
format -> mFormatID = kAudioFormatLinearPCM; //
format -> mFramesPerPacket = 1;
format -> mChannelsPerFrame = 1; //
format -> mBytesPerFrame = 2;
format -> mBytesPerPacket = 2;
format -> mBitsPerChannel = 16; //
format -> mReserved = 0;
format -> mFormatFlags = kLinearPCMFormatFlagIsBigEndian |kLinearPCMFormatFlagIsSignedInteger | kLinearPCMFormatFlagIsPacked;
}
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
char path[256];
[self getFilename:path maxLength:sizeof path];
fileURL = CFURLCreateFromFileSystemRepresentation(NULL, (UInt8*)path, strlen(path), false);
// Init state variables
recordState.recording = false;
thisClass = self;
}
- (void) startRecordingInQueue {
[self setupAudioFormat:&recordState.dataFormat];
recordState.currentPacket = 0;
OSStatus status;
status = AudioQueueNewInput(&recordState.dataFormat, AudioInputCallback, &recordState, CFRunLoopGetCurrent(), kCFRunLoopCommonModes, 0, &recordState.queue);
if(status == 0) {
//Prime recording buffers with empty data
for (int i=0; i < NUM_BUFFERS; i++) {
AudioQueueAllocateBuffer(recordState.queue, SAMPLERATE, &recordState.buffers[i]);
AudioQueueEnqueueBuffer(recordState.queue, recordState.buffers[i], 0, NULL);
}
status = AudioFileCreateWithURL(fileURL, kAudioFileAIFFType, &recordState.dataFormat, kAudioFileFlags_EraseFile, &recordState.audioFile);
if (status == 0) {
recordState.recording = true;
status = AudioQueueStart(recordState.queue, NULL);
if(status == 0) {
NSLog(@"-----------Recording--------------");
NSLog(@"File URL : %@", fileURL);
}
}
}
if (status != 0) {
[self stopRecordingInQueue];
}
}
- (void) stopRecordingInQueue {
recordState.recording = false;
AudioQueueStop(recordState.queue, true);
for (int i=0; i < NUM_BUFFERS; i++) {
AudioQueueFreeBuffer(recordState.queue, recordState.buffers[i]);
}
AudioQueueDispose(recordState.queue, true);
AudioFileClose(recordState.audioFile);
NSLog(@"---Idle------");
NSLog(@"File URL : %@", fileURL);
}
- (IBAction)startRecordingAudio:(id)sender {
NSLog(@"starting recording tapped");
[self startRecordingInQueue];
}
- (IBAction)stopRecordingAudio:(id)sender {
NSLog(@"stop recording tapped");
[self stopRecordingInQueue];
}
- (BOOL) getFilename:(char *) buffer maxLength:(int) maxBufferLength {
NSArray * paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString * docDir = [paths objectAtIndex:0];
NSString * file = [docDir stringByAppendingString:@"recording.aif"];
return [file getCString:buffer maxLength:maxBufferLength encoding:NSUTF8StringEncoding];
}
- (void) sendAudioToSocketAsData:(NSString *) audioData {
[self.webSocket send:audioData];
}
- (IBAction)connectToSocketTapped:(id)sender {
[self startStreaming];
}
- (void) startStreaming {
[self connectToSocket];
}
- (void) connectToSocket {
//Socket Connection Intiliazation
// create the NSURLRequest that will be sent as the handshake
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"ws://localhost:8000"]];
// NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"ws://demos.kaazing.com/echo"]];
// NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://online.attacker-site.com"]];
// create the socket and assign delegate
self.webSocket = [[SRWebSocket alloc] initWithURLRequest:request];
self.webSocket.delegate = self;
// open socket
[self.webSocket open];
}
///--------------------------------------
#pragma mark - SRWebSocketDelegate
///--------------------------------------
- (void)webSocketDidOpen:(SRWebSocket *)webSocket;
{
NSLog(@"Websocket Connected");
}
- (void) webSocket:(SRWebSocket *)webSocket didFailWithError:(NSError *)error {
NSLog(@":( Websocket Failed With Error %@", error);
self.webSocket = nil;
}
- (void) webSocket:(SRWebSocket *)webSocket didReceiveMessage:(id)message {
NSData *decodedData = [[NSData alloc] initWithBase64EncodedString:message options:0];
}
- (void)webSocket:(SRWebSocket *)webSocket didCloseWithCode:(NSInteger)code reason:(NSString *)reason wasClean:(BOOL)wasClean;
{
NSLog(@"WebSocket closed");
self.webSocket = nil;
}
- (void)webSocket:(SRWebSocket *)webSocket didReceivePong:(NSData *)pongPayload;
{
NSLog(@"WebSocket received pong");
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end