ios audio: using audioqueue to change the playing progress

Question

ios problem: using audioqueue to change the playing value

Recentlly, I make a music player with audioqueue (not using avplayer ), the player plays local audio files but not the internet files.Now I want to achieve a function that user could change the playing progress with slider.How can I do? In short, how can I use audioqueue to achieve to slide playing progress when it play local file.

Wish your answer with some important code!

---------------------------Append-----------------------
I modify the codes in demo of audio streamer(URL:http://code4app.net/ios/Audio-Streamer/5019d9066803faa344000000), My thinking is as follows in rough:
1、open the stream with a local music file.
2、Create a AudioFileStreamID Obj （audioFileStream）.
3、Create queue in the callback ASPacketsProc.
4、After createqueue, then filled the buffers of the queue in the callback ASPacketsProc.
5、At last, I will call the function to start to play.

Some codes is as followings:

- (void) openReadStream {
  CFURLRef urlPath = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (CFStringRef)filePath, kCFURLPOSIXPathStyle, false);
    stream = CFReadStreamCreateWithFile(kCFAllocatorSystemDefault, urlPath);

    if (CFReadStreamOpen(stream))
    {
        CFStreamClientContext context = {0, self, NULL, NULL, NULL};
        CFReadStreamSetClient(
        stream,
        kCFStreamEventHasBytesAvailable | kCFStreamEventErrorOccurred | kCFStreamEventEndEncountered,
        ASReadStreamCallBack,
        &context);
        CFReadStreamScheduleWithRunLoop(stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
    }
}

static void ASReadStreamCallBack (CFReadStreamRef aStream, CFStreamEventType eventType,void* inClientInfo)
{
    AudioStreamer* streamer = (AudioStreamer *)inClientInfo;
    [streamer handleReadFromStream:aStream eventType:eventType];

}

AudioFileStreamOpen(self,ASPropertyListenerProc,ASPacketsProc,fileTypeHint,&audioFileStream);

- (void)createQueue {
    sampleRate = asbd.mSampleRate;
    packetDuration = asbd.mFramesPerPacket / sampleRate;

    // create the audio queue
    AudioQueueNewOutput(&asbd, ASAudioQueueOutputCallback, self, NULL, NULL, 0, &audioQueue);

    // listen to the "isRunning" property
    AudioQueueAddPropertyListener(audioQueue, kAudioQueueProperty_IsRunning, ASAudioQueueIsRunningCallback, self);

    // get the packet size if it is available
    UInt32 sizeOfUInt32 = sizeof(UInt32);
    AudioFileStreamGetProperty(audioFileStream, kAudioFileStreamProperty_PacketSizeUpperBound, &sizeOfUInt32, &packetBufferSize);

    for (unsigned int i = 0; i < kNumAQBufs; ++i)
    {
    AudioQueueAllocateBuffer(audioQueue, packetBufferSize, &audioQueueBuffer[i]);

    }

}

AudioQueueEnqueueBuffer(audioQueue, fillBuf, packetsFilled, packetDescs);

AudioQueueStart(audioQueue, NULL);

Answer 1

I suppose, you used MPMusicPlayerController class. If you need some code, you must give some data or code too. I don't know, what class you are using...

Though, if you used this, then you can set currentPlaybackTime property, when slider changes.

Let's say, you have this instance:

@property (nonatomic, strong) MPMusicPlayerController *musicPlayer;

Then, probably, you can change play time like this:

- (IBAction)sliderChanged:(id)sender
{
    self.musicPlayer.currentPlaybackTime = self.slider.value;
}