Question

我需要从视频中提取音频，并通过使用搜索栏（something like this）改变音高来实时调整音高。性能需要接近实时。现在至少我需要音调移位音频（有人.aac音频文件）。我发现了一个Superpowered库，但是实例并没有实现音高变换，而且docs不包含有关它的信息。有没有人这样做？或者也许可以帮助我使用另一个库？

我发现这是example和现在我正在尝试这样做：

bool NDKAudioPlayer::process(short *output, unsigned int numberOfSamples) {
double masterBpm = player->currentBpm;

bool silence = !player->process(stereoBuffer, false, numberOfSamples, volume, masterBpm);

if (!silence){
    handler = new LiveTimeStretchingHandler();
    setupLiveTimeStretching(handler, currentSamplerate);
    liveTimeStretchingProcess(stereoBuffer, numberOfSamples, 0, handler);
    delete handler;
}

// The stereoBuffer is ready now, let's put the finished audio into the requested buffers.
if (!silence) SuperpoweredFloatToShortInt(stereoBuffer, output, numberOfSamples);
return !silence;

}

这是我的NDKAudioPlayer类：

class NDKAudioPlayer {
public:

NDKAudioPlayer(unsigned int samplerate, unsigned int buffersize, const char *path, int audioFileOffset, int audioFileLength);
~NDKAudioPlayer();

bool process(short *pInt, unsigned int numberOfSamples);
void onPlayPause(bool play);
void onCentsChanged(int cents);

private:

SuperpoweredAndroidAudioIO *audioSystem;
SuperpoweredAdvancedAudioPlayer *player;
LiveTimeStretchingHandler *handler;
float *stereoBuffer;
float volume;
int currentSamplerate = 0;

};

Answer 1

也许这会帮助有同样问题的人： 我用SuperpoweredAdvancedAudioPlayer类的setPitchShiftCents方法实现了它。这种方法在播放音频时进行音高变换。

Answer 2

您可以使用PlayerExample项目并在audioProcessing回调的开头添加两行：

player->setTempo(1.0, true); // Needed for the pitch shifting to work
player->setPitchShift(-12); // Pitch shift one octave down

使用Superpowered在Android中进行音高变换/时间延长

2 个答案: