Question

我是ios开发的新手。我在AudioToolBox框架的帮助下使用Audio Queue Service从https://github.com/vecter/Audio-Queue-Services-Example下载了样本录音机项目。在该示例项目中录制的音频格式为.aif。同时运行下载的示例项目工作正常。在示例项目中使用如何记录.mp3格式的音频。我可以这样做吗？

我已将 kAudioFileAIFFType 更改为 kAudioFileMP3Type 我从nslog收到消息

   //---------nslog message--------------
      Not recording, returning
      Writing buffer 0 
   //------------------

- (void)startRecording
{
[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, 16000, &recordState.buffers[i]);
        AudioQueueEnqueueBuffer (recordState.queue, recordState.buffers[i], 0, NULL);
    }

    status = AudioFileCreateWithURL(fileURL,
                                    kAudioFileMP3Type,
                                    &recordState.dataFormat,
                                    kAudioFileFlags_EraseFile,
                                    &recordState.audioFile);
    if (status == 0)
    {
        recordState.recording = true;        
        status = AudioQueueStart(recordState.queue, NULL);
        if (status == 0)
        {
            labelStatus.text = @"Recording";
        }
    }
}

if (status != 0)
{
    [self stopRecording];
    labelStatus.text = @"Record Failed";
}
}

// --------------------------------------------- ------------------------------

- (void)startPlayback
{
playState.currentPacket = 0;

[self setupAudioFormat:&playState.dataFormat];

OSStatus status;
status = AudioFileOpenURL(fileURL, kAudioFileReadPermission, kAudioFileMP3Type, &playState.audioFile);
if (status == 0)
{
    status = AudioQueueNewOutput(&playState.dataFormat,
                                 AudioOutputCallback,
                                 &playState,
                                 CFRunLoopGetCurrent(),
                                 kCFRunLoopCommonModes,
                                 0,
                                 &playState.queue);

    if (status == 0)
    {
        // Allocate and prime playback buffers
        playState.playing = true;
        for (int i = 0; i < NUM_BUFFERS && playState.playing; i++)
        {
            AudioQueueAllocateBuffer(playState.queue, 16000, &playState.buffers[i]);
            AudioOutputCallback(&playState, playState.queue, playState.buffers[i]);
        }

        status = AudioQueueStart(playState.queue, NULL);
        if (status == 0)
        {
            labelStatus.text = @"Playing";
        }
    }        
}

if (status != 0)
{
    [self stopPlayback];
    labelStatus.text = @"Play failed";
}
}

Answer 1

不，你不能录制到MP3。核心音频文档（核心音频pdf第51页）清楚地解释了这背后的原因。

用他们自己的话说 - ＆gt;
iOS包含表2-5中列出的录制编解码器。如您所见，MP3和AAC录音都不可用。 这是由于这些格式的高CPU开销和随之而来的电池消耗。

iOS：录制音频格式

Apple Lossless
iLBC（互联网低比特率编解码器，语音编解码器）
IMA / ADPCM（也称为IMA-4）
线性PCM
μμLaw和aLaw

音频队列服务示例使用如何在iPhone中以mp3格式录制声音

1 个答案: