FFmpeg+SDL（雷神）-（5-2）

(5) FFmpeg+SDL视频播放器
代码记录

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#include "stdafx.h"

#define __STDC_CONSTANT_MACROS

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

int screen_w,screen_h;

//Refresh Event
#define REFRESH_EVENT  (SDL_USEREVENT + 1)
//Break
#define BREAK_EVENT  (SDL_USEREVENT + 2)

int thread_exit=0;
int thread_pause=0;

int refresh_video(void *opaque){
    thread_exit=0;
    while (thread_exit==0) {
        if(thread_pause==0){
        SDL_Event event;
        event.type = REFRESH_EVENT;
        SDL_PushEvent(&event);
        }
        SDL_Delay(40);
    }
    thread_exit=0;
    //Break
    SDL_Event event;
    event.type = BREAK_EVENT;
    SDL_PushEvent(&event);
    return 0;
}



int main(int argc, char* argv[])
{
    AVFormatContext *pFormatCtx;
    int             i, videoindex;
    AVCodecContext  *pCodecCtx;
    AVCodec         *pCodec;
    AVFrame *pFrame,*pFrameYUV;
    uint8_t *out_buffer;
    AVPacket *packet;
    int y_size;
    int ret, got_picture;
    struct SwsContext *img_convert_ctx;
    //输入文件路径
    //char filepath[]="屌丝男士.mov";
    //char filepath[]="Titanic.ts";
    //char filepath[500]={0};
    //strcpy(filepath,argv[1]);

    char *filepath=argv[1];

    int frame_cnt;

    av_register_all();//注册所有组件
    avformat_network_init();
    pFormatCtx = avformat_alloc_context();

    if(avformat_open_input(&pFormatCtx,filepath,NULL,NULL)!=0){//打开输入视频文件
        printf("Couldn't open input stream.\n");
        return -1;
    }
    if(avformat_find_stream_info(pFormatCtx,NULL)<0){//获取视频文件信息
        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("Didn't find a video stream.\n");
        return -1;
    }

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

    pFrame=av_frame_alloc();
    pFrameYUV=av_frame_alloc();
    out_buffer=(uint8_t *)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height));
    avpicture_fill((AVPicture *)pFrameYUV, out_buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);
    packet=(AVPacket *)av_malloc(sizeof(AVPacket));
    //Output Info-----------------------------
    printf("--------------- File Information ----------------\n");
    av_dump_format(pFormatCtx,0,filepath,0);
    printf("-------------------------------------------------\n");
    img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, 
        pCodecCtx->width, pCodecCtx->height, PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL); 

    frame_cnt=0;


    //=======SDL=======
    if(SDL_Init(SDL_INIT_VIDEO)) {  
        printf( "Could not initialize SDL - %s\n", SDL_GetError()); 
        return -1;
    } 

    SDL_Window *screen; 
    screen_w=pCodecCtx->width;
    screen_h=pCodecCtx->height;
    //SDL 2.0 Support for multiple windows
    screen = SDL_CreateWindow("Simplest Video Play SDL2", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
        screen_w, screen_h,SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
    if(!screen) {  
        printf("SDL: could not create window - exiting:%s\n",SDL_GetError());  
        return -1;
    }
    SDL_Renderer* sdlRenderer = SDL_CreateRenderer(screen, -1, 0);  

    Uint32 pixformat=0;
    //IYUV: Y + U + V  (3 planes)
    //YV12: Y + V + U  (3 planes)
    pixformat= SDL_PIXELFORMAT_IYUV;  

    SDL_Texture* sdlTexture = SDL_CreateTexture(sdlRenderer,pixformat, SDL_TEXTUREACCESS_STREAMING,pCodecCtx->width,pCodecCtx->height);

    SDL_Rect sdlRect;

    SDL_Thread *refresh_thread = SDL_CreateThread(refresh_video,NULL,NULL);
    SDL_Event event;

    while(1){
        //Wait
        SDL_WaitEvent(&event);
        if(event.type==REFRESH_EVENT){
            while(1){
                if(av_read_frame(pFormatCtx, packet)<0)//从输入文件读取一帧压缩数据
                    thread_exit=1;

                if(packet->stream_index==videoindex)//只处理视频帧
                    break;
            }
            /*
            * 在此处添加输出H264码流的代码
            * 取自于packet，使用fwrite()
            */
            ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet);//解码一帧压缩数据
            if(ret < 0){
                printf("Decode Error.\n");
                return -1;
            }
            if(got_picture){
                //此处是为了将右边多出来的黑边（硬件导致的）裁剪掉，pFrame->pFrameYUV
                sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, 
                    pFrameYUV->data, pFrameYUV->linesize);
                printf("Decoded frame index: %d\n",frame_cnt);

                SDL_UpdateTexture( sdlTexture, NULL, pFrameYUV->data[0], pFrameYUV->linesize[0]);  
                //FIX: If window is resize
                sdlRect.x = 0;  
                sdlRect.y = 0;  
                sdlRect.w = screen_w;  
                sdlRect.h = screen_h;  
                SDL_RenderClear( sdlRenderer );   
                SDL_RenderCopy( sdlRenderer, sdlTexture, NULL, &sdlRect);  
                SDL_RenderPresent( sdlRenderer );

                frame_cnt++;

            }
            av_free_packet(packet);
        }
        else if(event.type==SDL_WINDOWEVENT){
            //If Resize
            SDL_GetWindowSize(screen,&screen_w,&screen_h);
        }else if(event.type==SDL_KEYDOWN){
            //Pause
            if(event.key.keysym.sym==SDLK_SPACE)
                thread_pause=!thread_pause;
        }else if(event.type==SDL_QUIT){
            thread_exit=1;
        }else if(event.type==BREAK_EVENT){
            break;
        }
    }

    sws_freeContext(img_convert_ctx);

    av_frame_free(&pFrameYUV);
    av_frame_free(&pFrame);
    avcodec_close(pCodecCtx);//关闭解码器
    avformat_close_input(&pFormatCtx);//关闭输入视频文件
    
    return 0;
}

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