Question

我尝试在AU渲染块中使用SuperpoweredTimeStretching。例如，在一个通道上输入简单代码。

我现在不更改音频速度（因此，我不需要使用“圆形缓冲区”或类似的东西-缓冲区中的进出采样数是固定的）。但是我有一个非常奇怪的情况。这对我的代码很好，但是如果我不改变音调！

如果我不改变音高-我有一个切片（1024个样本）。但是，如果我更改音调参数-我将有两个切片（每个切片512个样本），这似乎是绝对正常的（我实现了迭代器）。但是，当切片超过一个（两个512，而不是一个1024）时-听起来带有伪像。

我不明白我做错了什么。

SP2001 "Only tab characters are allowed to be used for indentation"

}

Answer 1

我的问题是交错通道出错。

这是正确的代码

return ^AUAudioUnitStatus(AudioUnitRenderActionFlags    *actionFlags,
                              const AudioTimeStamp      *timestamp,
                              AVAudioFrameCount         frameCount,
                              NSInteger             outputBusNumber,
                              AudioBufferList           *outputBufferListPtr,
                              const AURenderEvent       *realtimeEventListHead,
                              AURenderPullInputBlock        pullInputBlock ) {

        pullInputBlock(actionFlags, timestamp, frameCount, 0, renderABLCapture);

        Float32 *sampleDataInLeft = (Float32*) renderABLCapture->mBuffers[0].mData;
        Float32 *sampleDataInRight = (Float32*) renderABLCapture->mBuffers[1].mData;

        Float32 *sampleDataOutLeft  = (Float32*)outputBufferListPtr->mBuffers[0].mData;
        Float32 *sampleDataOutRight = (Float32*)outputBufferListPtr->mBuffers[1].mData;


        SuperpoweredAudiobufferlistElement inputBuffer;
        inputBuffer.samplePosition = 0;
        inputBuffer.startSample = 0;
        inputBuffer.samplesUsed = 0;
        inputBuffer.endSample = frameCount;
        inputBuffer.buffers[0] = SuperpoweredAudiobufferPool::getBuffer(frameCount * 8 + 64);
        inputBuffer.buffers[1] = inputBuffer.buffers[2] = inputBuffer.buffers[3] = NULL;

        SuperpoweredInterleave(sampleDataInLeft, sampleDataInRight, (Float32*)inputBuffer.buffers[0], frameCount);

        timeStretch->setRateAndPitchShift(1.0f, -2);
        timeStretch->setSampleRate(48000);
        timeStretch->process(&inputBuffer, outputBuffers);

        if (outputBuffers->makeSlice(0, outputBuffers->sampleLength)) {

            int numSamples = 0;
            int samplesOffset =0;

            while (true) {

                Float32 *timeStretchedAudio = (Float32 *)outputBuffers->nextSliceItem(&numSamples);
                if (!timeStretchedAudio) break;

                  SuperpoweredDeInterleave(timeStretchedAudio, sampleDataOutLeft + samplesOffset, sampleDataOutRight + samplesOffset, numSamples);

                samplesOffset += numSamples;

            };

            outputBuffers->clear();

        }

        return noErr;
    };

如何在AUInternalRenderBlock中实时使用Superpowered TimeStretching

1 个答案: