如何停止音频队列？

Posted 2023-03-10

【中文标题】如何停止音频队列？

【英文标题】：How to stop AudioQueue?

【发布时间】：2012-06-14 13:13:35

【问题描述】：

我正在使用文本到语音，开始音频工作正常，但我无法停止它。这是我如何开始音频：

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, (unsigned long)NULL), ^(void) 
        [[self view] setNeedsDisplay];
        [self synthesizeInBackground];
        [queue waitUntilAllOperationsAreFinished];
        [self setIsSpeaking: false];
        [[self view] setNeedsDisplay];

    ); 

在后台合成

 - (void) synthesizeInBackground 
XLog(@"-----------------------------------entered");


queue = [[NSOperationQueue alloc] init];
XLog(@"queue: %@", queue);

operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(synthesize) object:nil];
XLog(@"operation: %@", operation);

[queue addOperation: operation];

  

合成

- (void)synthesize 
XLog(@"-----------------------------------entered");



NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

callback_userdata userdata;

NSError *error = nil;

self.paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
self.documentsDirectory = [self.paths objectAtIndex:0];
self.path = [self.documentsDirectory stringByAppendingPathComponent:@"readSearchresults.txt"];
IvonaStreamer *streamer = [[IvonaStreamer alloc] initWithVoice:voice withText:[NSString stringWithContentsOfFile:self.path encoding:NSUTF8StringEncoding error:&error] atSpeed:[NSNumber numberWithFloat:-1]];
//IvonaStreamer *streamer = [[IvonaStreamer alloc] initWithVoice:voice withText:@"Dies ist ein Testtext." atSpeed:[NSNumber numberWithFloat:-1]];




if (streamer == nil) 
    XLog(@"Cannot start streamer");
    [self setTtsError: @"Cannot start streamer"];
    return;



userdata.speak = &(self->isSpeaking);
userdata.streamer = streamer;


#define NUM_BUFFERS 3
#define BUFFER_SIZE 22050
OSStatus err;

AudioQueueRef audioQueue;
//XLog(@"audioQueue: %d", audioQueue);
XLog(@"[voice getSampleRate]: %i", [voice getSampleRate]);

AudiostreamBasicDescription deviceFormat;
deviceFormat.mSampleRate = [voice getSampleRate];
deviceFormat.mFormatID = kAudioFormatLinearPCM;
deviceFormat.mFormatFlags = kLinearPCMFormatFlagIsSignedInteger;
deviceFormat.mBytesPerPacket = 2;
deviceFormat.mFramesPerPacket = 1;
deviceFormat.mBytesPerFrame = 2;
deviceFormat.mChannelsPerFrame = 1;
deviceFormat.mBitsPerChannel = 16;
deviceFormat.mReserved = 0;

XLog(@"deviceFormat.mSampleRate: %f", deviceFormat.mSampleRate);
/*
 XLog(@"deviceFormat.mSampleRate: %f", deviceFormat.mSampleRate);
 XLog(@"deviceFormat.mFormatID: %lu", deviceFormat.mFormatID);
 XLog(@"deviceFormat.mFormatFlags: %lu", deviceFormat.mFormatFlags);
 XLog(@"deviceFormat.mBytesPerPacket %lu", deviceFormat.mBytesPerPacket);
 XLog(@"deviceFormat.mFramesPerPacket %lu", deviceFormat.mFramesPerPacket);
 XLog(@"deviceFormat.mBytesPerFrame %lu", deviceFormat.mBytesPerFrame);
 XLog(@"deviceFormat.mChannelsPerFrame %lu", deviceFormat.mChannelsPerFrame);
 XLog(@"deviceFormat.mBitsPerChannel %lu", deviceFormat.mBitsPerChannel);
 XLog(@"deviceFormat.mReserved %lu", deviceFormat.mReserved);
 */

err = AudioQueueNewOutput(&deviceFormat,
                          AudioQueueCallback,
                          &userdata,
                          CFRunLoopGetCurrent(),
                          kCFRunLoopCommonModes,
                          0,
                          &audioQueue);
if (err != noErr) 
    XLog(@"Cannot create audio output");
    [self setTtsError: @"Cannot create audio output"];
    [streamer stop];
    return;


AudioQueueAddPropertyListener(audioQueue, kAudioQueueProperty_IsRunning,
                              AudioQueuePropertyListener, NULL);

for (int i = 0; i < NUM_BUFFERS; i++) 
    AudioQueueBufferRef buffer;

    err = AudioQueueAllocateBuffer(audioQueue, BUFFER_SIZE, &buffer);
    if (err != noErr) 
        XLog(@"Cannot allocate audio buffer");
        [self setTtsError: @"Cannot allocate audio buffer"];
        [streamer stop];
        return;
    

    AudioQueueCallback(&userdata, audioQueue, buffer);


err = AudioQueueStart(audioQueue, NULL);
if (err != noErr) 
    XLog(@"Cannot start audio");
    [self setTtsError: @"Cannot start audio"];
    [streamer stop];
    return;


CFRunLoopRun();

[streamer stop];
[pool release];

AudioQueueCallback

    void AudioQueueCallback(void *userData, AudioQueueRef audioQueue,
                    AudioQueueBufferRef buffer)

//XLog(@"-----------------------------------entered");


void *data = buffer->mAudioData;

UInt32 num_bytes = buffer->mAudioDataBytesCapacity;
//XLog(@"num_bytes: %lu", num_bytes);

UInt32 to_write = num_bytes / sizeof(short);
//XLog(@"to_write: %lu", to_write);

NSInteger num_samples;
//XLog(@"num_samples: %i", num_samples);

IvonaStreamer *streamer = ((callback_userdata*) userData)->streamer;
bool *enabled = ((callback_userdata*) userData)->speak;

//XLog(@"streamer.getWarnings: %@", streamer.getWarnings);


if(!*enabled) 
    XLog(@"!*enabled");
    AudioQueueStop(audioQueue, false);        


num_samples = [streamer synthSamples:to_write toCArray:data];
//XLog(@"num_samples: %i", num_samples);

if (num_samples > 0) 
    //XLog(@"num_samples > 0");
    buffer->mAudioDataByteSize = num_samples * sizeof(short);

    AudioQueueEnqueueBuffer(audioQueue, buffer, 0, NULL);

 else 
    //XLog(@"! (num_samples > 0)");
    AudioQueueStop(audioQueue, false);
    

AudioQueuePropertyListener

void AudioQueuePropertyListener(void *userData, AudioQueueRef audioQueue,
                            AudioQueuePropertyID id)
  

    XLog(@"-----------------------------------entered");

UInt32 isRunning, size = sizeof(isRunning);
AudioQueueGetProperty(audioQueue, kAudioQueueProperty_IsRunning, &isRunning, &size);
if (isRunning == 0) 
    XLog(@"isRunning == 0");
    CFRunLoopStop(CFRunLoopGetCurrent());


if (isRunning != 0) 
    XLog(@"nicht null#######");



  

我尝试在其他方法中停止（UIAlertView 委托方法）：

 if (alertView.tag == 997) 
    if (buttonIndex == 0) 
        XLog(@"vorlesen abbrechen geklickt.");
        [queue cancelAllOperations];
        AudioQueueRef audioQueue;
        //AudioQueueDispose(audioQueue, false);
         AudioQueueStop(audioQueue, false);
      

我正在取消所有操作并调用 AudioQueueDispose，也尝试使用 AudioQueueStop，但这里没有任何效果。

所以我的问题是，如何在此处停止音频？

【参考方案1】：

AudioQueueStop 应该可以工作并且足够了。从 Apples 文档中，AudioQueueReset 是从 AudioQueueStop 调用的。 AudioQueueDispose 如果您想稍后再启动它，那就有点过分了。

【参考方案2】：

我相信你需要在调用 AudioQueueStop 之前调用 AudioQueueReset。

AudioQueueReset (audioQueue);
AudioQueueStop (audioQueue, YES);
AudioQueueDispose (audioQueue, YES);

【讨论】：

正如@Oliver 提到的，AudioQueueReset 来自 AudioQueueStop，所以这不是必需的。