PortAudio 不输出清晰的音频

如何解决PortAudio 不输出清晰的音频

我使用 libav 提取音频帧并将非 S16 格式的帧转换为 S16，以便可以使用端口音频播放。

但是当我播放音频时，它不清楚或有时由于一些调整它根本不好。来自 wav 文件的音频比来自 mp4 文件的音频更清晰一些，但总体而言它不能产生良好的输出。

回调函数：

int patestCallback(const void* inputBuffer,void* outputBuffer,unsigned long framesPerBuffer,const PaStreamCallbackTimeInfo* timeInfo,PaStreamCallbackFlags statusFlags,void* _userData)
{
    uint8_t* out = (uint8_t*)outputBuffer;
    uint8_t* data = (uint8_t*)audioFile.get_converted();
    PaUserData* userData = (PaUserData*)_userData;

    int nb = framesPerBuffer;

    for (int i = 0; i < nb; i+=1) {
        *out++ = data[i];
    }
    return 0;
}

主要功能：

int main() {
    Pa_Initialize();
    PaStream* stream;
    PaUserData data;
    PaStreamParameters  outputParameters;

    int channels = audioFile.pCodecCtx->channels;
    int sr = audioFile.pCodecCtx->sample_rate;
    data.channels = channels;

    printf("channels: %i\nsr: %i\n",channels,sr);

    outputParameters.device = Pa_GetDefaultOutputDevice();
    if (outputParameters.device == paNoDevice) {
        fprintf(stderr,"Error: No default output device.\n");
    }
    outputParameters.channelCount = channels;
    outputParameters.hostApiSpecificStreamInfo = NULL;
    outputParameters.sampleFormat = paUInt8; 
    outputParameters.suggestedLatency = Pa_GetDeviceInfo(outputParameters.device)->defaultLowOutputLatency;
    outputParameters.hostApiSpecificStreamInfo = NULL;

    Pa_OpenStream(&stream,NULL,&outputParameters,sr,2048 * channels,paDitherOff,patestCallback,&data);
    Pa_StartStream(stream);
    Pa_Sleep(8 * 1000);

    Pa_Terminate();
    system("pause");
    return 0;
}

其他全局变量：

char* filename = (char*)"wavFile.wav";
static FileOpener audioFile(filename,(char*)"audio");

struct PaUserData {
    int channels;
};

转换代码：

uint8_t* FileOpener::get_converted()
{
    this->get_next_audio_frame();
    if (this->pCodecCtx->sample_fmt != AV_SAMPLE_FMT_S16) {
        SwrContext* swr = swr_alloc();

        swr_alloc_set_opts(swr,this->pCodecCtx->channel_layout,AV_SAMPLE_FMT_S16,44100,this->pCodecCtx->sample_fmt,this->pCodecCtx->sample_rate,nullptr);
        swr_init(swr);
        int nb = 2048 * this->pCodecCtx->channels;
        buffer = new uint8_t[nb];
        swr_convert(swr,&buffer,nb,(const uint8_t**)pFrame->extended_data,pFrame->nb_samples);
        return this->buffer;
    }
    else {
        return *this->pFrame->extended_data;
    }
}

如何播放清晰的音频？