将float[]转换为unsigned char*或BYTE*

C++: Convert float[] to unsigned char* or BYTE*

本文关键字：char BYTE unsigned float 转换      更新时间：2023-10-16

我正在开发一个项目，我需要将PCM 16位2通道声音转换为IEEE Float 32位2通道。

要做到这一点，我使用以下代码:

void CAudioConverter::ConvI16ToF32(BYTE* pcmFrom, BYTE* floatTo, int length)
{
    short* src = reinterpret_cast<short*>(pcmFrom);
    float* dst = reinterpret_cast<float*>(floatTo);
    for (int n = 0; n < length; n++)
    {
        dst[n] = static_cast<float>(src[n]) / 32768.0f;
    }
}

我已经初始化变量__pcm32_bytesPerFrame:

WAVEFORMATEX* closestFormat;
ws->default_pb_dev->GetMixFormat(&closestFormat);
__pcm32_bytesPerFrame = closestFormat->nAvgBytesPerSec * (prm->samples_per_frame * 1000 / (prm->clock_rate * closestFormat->nChannels)) / 1000;

strm -> pb_max_frame_count是:

hr = ws->default_pb_dev->GetBufferSize(&ws->pb_max_frame_count);

我在一个专用线程中有一个while循环，它的作用是:

hr = strm->default_pb_dev->GetCurrentPadding(&padding);
incoming_frame = __pcm32_bytesPerFrame / 4;
frame_to_render = strm->pb_max_frame_count - padding;
if (frame_to_render >= incoming_frame)
{ 
    frame_to_render = incoming_frame;
} else {
    /* Don't get new frame because there's no space */
    frame_to_render = 0;
}
if (frame_to_render > 0)
{
    pjmedia_frame frame;
hr = strm->pb_client->GetBuffer(frame_to_render, &cur_pb_buf);
if (FAILED(hr)) {
    continue;
}
void* destBuffer = (void*)malloc(strm->bytes_per_frame*frame_to_render*sizeof(pj_uint16_t));
if (strm->fmt_id == PJMEDIA_FORMAT_L16) {

/* PCM mode */
    frame.type = PJMEDIA_FRAME_TYPE_AUDIO;
    frame.size = strm->bytes_per_frame;
    frame.timestamp.u64 = strm->pb_timestamp.u64;
    frame.bit_info = 0;
    frame.buf = destBuffer;
}
status = (*strm->pb_cb)(strm->user_data, &frame);
CAudioConverter* conv = new CAudioConverter();
conv->ConvI16ToF32((BYTE*)destBuffer, cur_pb_buf, frame_to_render);
hr = strm->pb_client->ReleaseBuffer(frame_to_render, 0);
(...)

但是，要将声音发送到WASAPI捕获缓冲区，我需要一个BYTE*。我怎么能填补我的'floatTo'参数?

任何想法?

谢谢

这个呢:

void CAudioConverter::ConvI16ToF32(BYTE* pcmFrom, BYTE* floatTo, int length)
{
    short* src = reinterpret_cast<short*>(pcmFrom);
    float* dst = reinterpret_cast<float*>(floatTo);
    for (int n = 0; n < length; n++)
    {
        dst[n] = static_cast<float>(src[n]) / 32768.0f;
    }   
}

另外，确保length表示pcmFrom和floatTo中的元素数，而不是分配的字节数。在您的情况下，pcmFrom应该分配length*2字节，floatTo需要length*4字节的空间。

相关文章：