java - Android OpenSL "pAudioSrc: data format 2 not allowed"- 拒绝 SL_DATAFORMAT_PCM？

Question

我正在尝试创建一个带有缓冲区队列源和输出混合接收器的 AudioPlayer。我已经使用与 ndk 示例中显示的格式非常相似的 pcm 格式配置源，但 OpenSL 拒绝 SL_DATAFORMAT_PCM(“数据格式 2”)。这对我来说没有任何意义。

这是错误(在三星 Galaxy S2 上):

02-27 15:43:47.315: E/libOpenSLES(12681): pAudioSrc: data format 2 not allowed
02-27 15:43:47.315: W/libOpenSLES(12681): Leaving Engine::CreateAudioPlayer (SL_RESULT_CONTENT_UNSUPPORTED)

这是相关代码:

SLuint32 channels = 2;
SLuint32 speakers = SL_SPEAKER_FRONT_LEFT | SL_SPEAKER_FRONT_RIGHT;
SLuint32 sr = SL_SAMPLINGRATE_48;

//...
SLDataFormat_PCM format_pcm = {
    SL_DATAFORMAT_PCM,
    channels,
    sr,
    SL_PCMSAMPLEFORMAT_FIXED_16,
    SL_PCMSAMPLEFORMAT_FIXED_16,
    speakers,
    SL_BYTEORDER_LITTLEENDIAN
};

// Configure audio player source
SLDataLocator_AndroidBufferQueue loc_bufq =
    {SL_DATALOCATOR_ANDROIDBUFFERQUEUE, 2};
SLDataSource audioSrc = {&loc_bufq, &format_pcm};

// configure audio player sink
SLDataLocator_OutputMix loc_outmix =
    {SL_DATALOCATOR_OUTPUTMIX, outputMixObject};
SLDataSink audioSnk = {&loc_outmix, NULL};

// create audio player
const SLInterfaceID iidsOutPlayer[] = {SL_IID_ANDROIDBUFFERQUEUESOURCE};
const SLboolean reqsOutPlayer[] = {SL_BOOLEAN_TRUE};
result = (*engineItf)->CreateAudioPlayer(
                        engineItf,
                        &(outPlayerObject),
                        &audioSrc, &audioSnk,
                        1, iidsOutPlayer,reqsOutPlayer);

有谁知道是什么原因造成的？谢谢!

Answer 1

可能是您的设备不支持音频采样率。试试 SL_SAMPLINGRATE_8而不是 SL_SAMPLINGRATE_48 或选择其他设备 (Nexus 4/HTC One) 进行测试。

如果您在语音通信时听到失真的声音，请增加录音机缓冲区大小，您也可以尝试更改采样率。其他采样率选项有:SL_SAMPLINGRATE_16、SL_SAMPLINGRATE_32、SL_SAMPLINGRATE_44_1 等

每个 Android 设备都有特定/首选的缓冲区大小和采样率。您可以从以下 Java 代码段中获得首选缓冲区大小和采样率。请注意，audioManager.getProperty() 不适用于 API 级别<17。

AudioManager audioManager = (AudioManager) this.getSystemService(Context.AUDIO_SERVICE);
String rate = audioManager.getProperty(AudioManager.PROPERTY_OUTPUT_SAMPLE_RATE);
String size = audioManager.getProperty(AudioManager.PROPERTY_OUTPUT_FRAMES_PER_BUFFER);
Log.d("Buffer Size and sample rate", "Size :" + size + " & Rate: " + rate);