FFmpeg 摄像头采集

FFmpeg 摄像头采集

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

int main(int argc, char *argv[])
{
    AVFormatContext    *pFormatCtx;
    int                i, videoindex;
    AVCodecContext    *pCodecCtx;
    AVCodec            *pCodec;

    av_register_all();
    avformat_network_init();
    pFormatCtx = avformat_alloc_context();

    //Register Device
    avdevice_register_all();

// Win32
    //Show Dshow Device
    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");
    }
    //Show Device Options
    show_dshow_device_option();
    {
        AVFormatContext *pFormatCtx = avformat_alloc_context();
        AVDictionary* options = NULL;
        av_dict_set(&options,"list_options","true",0);
        AVInputFormat *iformat = av_find_input_format("dshow");
        printf("========Device Option Info======\n");
        avformat_open_input(&pFormatCtx,"video=Integrated Camera",iformat,&options);
        printf("================================\n");
    }
    //Show VFW Options
    show_vfw_device();
    {
        AVFormatContext *pFormatCtx = avformat_alloc_context();
        AVInputFormat *iformat = av_find_input_format("vfwcap");
        printf("========VFW Device Info======\n");
        avformat_open_input(&pFormatCtx,"list",iformat,NULL);
        printf("=============================\n");
    }

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

    // DSHOW
    AVInputFormat *ifmt=av_find_input_format("dshow");
    //Set own video device's name
    if(avformat_open_input(&pFormatCtx,"video=Integrated Camera",ifmt,NULL)!=0){
        printf("Couldn't open input stream.\n");
        return -1;
    }
    // VFW
    AVInputFormat *ifmt=av_find_input_format("vfwcap");
    if(avformat_open_input(&pFormatCtx,"0",ifmt,NULL)!=0){
        printf("Couldn't open input stream.\n");
        return -1;
    }
// LINUX
    AVInputFormat *ifmt=av_find_input_format("video4linux2");
    if(avformat_open_input(&pFormatCtx,"/dev/video0",ifmt,NULL)!=0){
        printf("Couldn't open input stream.\n");
        return -1;
    }
// MAC
    show_avfoundation_device();
    //Mac
    AVInputFormat *ifmt=av_find_input_format("avfoundation");
    //Avfoundation
    //[video]:[audio]
    if(avformat_open_input(&pFormatCtx,"0",ifmt,NULL)!=0){
        printf("Couldn't open input stream.\n");
        return -1;
    }

    if(avformat_find_stream_info(pFormatCtx,NULL)<0)
    {
        printf("Couldn't find stream information.\n");
        return -1;
    }

    videoindex=-1;
    for(i=0; i<pFormatCtx->nb_streams; i++)
        if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO)
        {
            videoindex=i;
            break;
        }
    if(videoindex==-1)
    {
        printf("Couldn't find a video stream.\n");
        return -1;
    }

    pCodecCtx=pFormatCtx->streams[videoindex]->codec;
    pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
    if(pCodec==NULL)
    {
        printf("Codec not found.\n");
        return -1;
    }
    if(avcodec_open2(pCodecCtx, pCodec,NULL)<0)
    {
        printf("Could not open codec.\n");
        return -1;
    }

    AVFrame    *pFrame,*pFrameYUV;
    pFrame=av_frame_alloc();
    pFrameYUV=av_frame_alloc();

    struct SwsContext *img_convert_ctx;
    img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL); 

    for (;;) {
        //Wait
        SDL_WaitEvent(&event);
        if(event.type==SFM_REFRESH_EVENT){
            //------------------------------
            if(av_read_frame(pFormatCtx, packet)>=0){
                if(packet->stream_index==videoindex){
                    ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);
                    if(ret < 0){
                        printf("Decode Error.\n");
                        return -1;
                    }
                    if(got_picture){
                        SDL_LockYUVOverlay(bmp);
                        pFrameYUV->data[0]=bmp->pixels[0];
                        pFrameYUV->data[1]=bmp->pixels[2];
                        pFrameYUV->data[2]=bmp->pixels[1];
                        pFrameYUV->linesize[0]=bmp->pitches[0];
                        pFrameYUV->linesize[1]=bmp->pitches[2];
                        pFrameYUV->linesize[2]=bmp->pitches[1];
                        sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data, pFrameYUV->linesize);

                        SDL_UnlockYUVOverlay(bmp); 

                        SDL_DisplayYUVOverlay(bmp, &rect); 

                    }
                }
                av_free_packet(packet);
            }else{
                //Exit Thread
                thread_exit=1;
                break;
            }
        }else if(event.type==SDL_QUIT){
            thread_exit=1;
            break;
        }

    }

    sws_freeContext(img_convert_ctx);

    //av_free(out_buffer);
    av_free(pFrameYUV);
    avcodec_close(pCodecCtx);
    avformat_close_input(&pFormatCtx);

    return 0;
}