ffmpeg录音

ffmpeg录音

Qt 5.9
ffmpeg 4.0.1
audacity https://www.audacityteam.org/
cooledit https://download.csdn.net/download/wyy626562203/10565903

#include <stdio.h>
#include <QAudioDeviceInfo>
#include <qDebug>
#include <QTextCodec>


extern "C"
{
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libswscale/swscale.h"
#include "libavdevice/avdevice.h"
}

//Show Dshow Device
void show_dshow_device(){
    AVFormatContext *pFormatCtx = avformat_alloc_context();
    AVDictionary* options = NULL;
    av_dict_set(&options,"list_devices","true",0);
    AVInputFormat *iformat = av_find_input_format("dshow");
    printf("========Device Info=============\n");
    avformat_open_input(&pFormatCtx,"video=dummy",iformat,&options);
    printf("================================\n");
}


int main(int argc, char* argv[])
{

    AVFormatContext *pFormatCtx;
    int             i, audioindex;
    AVCodecContext  *aCodecCtx;
    AVCodec         *aCodec = NULL;
    AVFrame *aFrame;

    // 注册解码器
    av_register_all();

    //注册设备
    avdevice_register_all();//Register Device

    //显示音视频设备
    show_dshow_device();

    pFormatCtx = avformat_alloc_context();

    //使用Qt接口获取输入设备名称
    QString psDevName = "audio=" + QAudioDeviceInfo::availableDevices(QAudio::AudioInput).at(0).deviceName();

    AVInputFormat *ifmt = av_find_input_format("dshow");

    //打开流设备
    if(avformat_open_input(&pFormatCtx,psDevName.toStdString().c_str(),ifmt,NULL)!=0)
    {
        fprintf(stderr,"Couldn't open input stream.\n");
        return -1;
    }

    audioindex = -1;
    aCodecCtx = NULL;

    //寻找音频流
    for(i=0; i<pFormatCtx->nb_streams; i++)
    {
        if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_AUDIO)
        {
            audioindex=i;
            break;
        }
    }

    //没有找到视频流
    if(audioindex==-1)
    {
        printf("Didn't find a video stream.\n");
        return -1;
    }

    //获取解码器上下文
    aCodecCtx = pFormatCtx->streams[audioindex]->codec;

    //获取音频解码器
    aCodec = avcodec_find_decoder(aCodecCtx->codec_id);
    if(aCodec == NULL)
    {
        printf("audio Codec not found.\n");
        return -1;
    }

    //打开音频解码器
    if(avcodec_open2(aCodecCtx, aCodec,NULL)<0)
    {
        printf("Could not open audio codec.\n");
        return -1;
    }

    aFrame=av_frame_alloc();


    int ret, got_frame;

    AVPacket *packet=(AVPacket *)av_malloc(sizeof(AVPacket));

    //打开输出文件
    FILE *fp_pcm=fopen("output.pcm","wb");

    //输出音频信息
    qDebug()<< "sample format:  " << aCodecCtx->sample_fmt << "(0-8bit 1-16bit)";
    qDebug()<< "sample bit:     " << aCodecCtx->bit_rate;
    qDebug()<< "sample rate:    " << aCodecCtx->sample_rate;
    qDebug()<< "sample channels:" << aCodecCtx->channels;

    float Time = 0;

    for(int i=0;;i++)
    {
        if (Time > 30) break; //就采集30秒

        //读取音频数据
        if(av_read_frame(pFormatCtx, packet) < 0)
        {
            break;
        }

        //判断是否是音频流
        if(packet->stream_index==audioindex)
        {
#if 0 //废弃的方法
            ret = avcodec_decode_audio4(aCodecCtx, aFrame, &got_frame, packet);

            if(ret < 0)
            {
                fprintf(stderr,"Audio Error.\n");
                return -1;
            }

            if (got_frame)
            {
                int pcmSize = av_samples_get_buffer_size(NULL,aCodecCtx->channels, aFrame->nb_samples,aCodecCtx->sample_fmt, 1);
                uint8_t * pcmBuffer = aFrame->data[0];

                float useTime = aFrame->nb_samples * 1.0 / aCodecCtx->sample_rate;

                Time += useTime;

                qDebug()<<i<<Time<<useTime;

                fwrite(pcmBuffer,1,pcmSize,fp_pcm); //写入文件

            }
#else   //新方法
           ret = avcodec_send_packet(aCodecCtx, packet);

           if (ret != 0)
           {
               fprintf(stderr,"Audio Error.\n");
               return -1;
           }

           while( avcodec_receive_frame(aCodecCtx, aFrame) == 0)
           {
               int pcmSize = av_samples_get_buffer_size(NULL,aCodecCtx->channels, aFrame->nb_samples,aCodecCtx->sample_fmt, 1);
               uint8_t * pcmBuffer = aFrame->data[0];

               float useTime = aFrame->nb_samples * 1.0 / aCodecCtx->sample_rate;

               Time += useTime;

               qDebug()<<i<<Time<<useTime;

               fwrite(pcmBuffer,1,pcmSize,fp_pcm); //写入文件
           }
#endif

        }
        av_free_packet(packet);
    }

    fclose(fp_pcm);

    if (aFrame != NULL)
    {
        av_free(aFrame);
        aFrame = NULL;
    }

    if (aCodecCtx != NULL)
        avcodec_close(aCodecCtx);

    avformat_close_input(&pFormatCtx);

    avformat_free_context(pFormatCtx);

    return 0;
}