#include <windows.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #include <math.h> #include "libavcodec\avcodec.h" #include "libavformat\avformat.h" #include "libswscale\swscale.h" static int av_create_bmp(char* filename,uint8_t *pRGBBuffer,int width,int height,int bpp) { BITMAPFILEHEADER bmpheader; BITMAPINFO bmpinfo; FILE *fp; uint8_t *p; uint8_t *q; uint8_t *r; fp = fopen(filename,"wb"); if(!fp)return -1; bmpheader.bfType = ('M'<<8)|'B'; bmpheader.bfReserved1 = 0; bmpheader.bfReserved2 = 0; bmpheader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER); bmpheader.bfSize = bmpheader.bfOffBits + width*height*bpp/8; bmpinfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER); bmpinfo.bmiHeader.biWidth = width; bmpinfo.bmiHeader.biHeight = -height; bmpinfo.bmiHeader.biPlanes = 1; bmpinfo.bmiHeader.biBitCount = bpp; bmpinfo.bmiHeader.biCompression = BI_RGB; bmpinfo.bmiHeader.biSizeImage = 0; bmpinfo.bmiHeader.biXPelsPerMeter = 100; bmpinfo.bmiHeader.biYPelsPerMeter = 100; bmpinfo.bmiHeader.biClrUsed = 0; bmpinfo.bmiHeader.biClrImportant = 0; fwrite(&bmpheader,sizeof(BITMAPFILEHEADER),1,fp); fwrite(&bmpinfo.bmiHeader,sizeof(BITMAPINFOHEADER),1,fp); fwrite(pRGBBuffer,width*height*bpp/8,1,fp); fclose(fp); return 0; } int main() { SwsContext *pSWSCtx; AVFormatContext *pFormatCtx; const char *filename="sample.mpg"; int i,videoStream,y_size; AVCodecContext *pCodecCtx; AVFrame *pFrame; AVFrame *pFrameRGB; int numBytes,frameFinished; uint8_t *buffer; static AVPacket packet; av_register_all(); if(av_open_input_file(&pFormatCtx, filename, NULL, 0, NULL)!=0) printf("error!\n"); if(av_find_stream_info(pFormatCtx)<0) printf("error!\n"); dump_format(pFormatCtx, 0, filename, false); videoStream=-1; for(i=0; i<pFormatCtx->nb_streams; i++) if(pFormatCtx->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO) { videoStream=i; break; } if(videoStream==-1) printf("error!\n");// Didn't find a video stream // 得到视频流编码上下文的指针 pCodecCtx=pFormatCtx->streams[videoStream]->codec; AVCodec *pCodec; // 寻找视频流的解码器 pCodec=avcodec_find_decoder(pCodecCtx->codec_id); if(pCodec==NULL) printf("error!\n");// 找不到解码器 // 通知解码器我们能够处理截断的bit流--ie, // bit流帧边界可以在包中 // 打开解码器 if(avcodec_open(pCodecCtx, pCodec)<0) printf("error!\n"); // 打不开解码器 pFrame=avcodec_alloc_frame(); pFrameRGB = avcodec_alloc_frame(); numBytes=avpicture_get_size(PIX_FMT_BGR24, pCodecCtx->width,pCodecCtx->height); buffer=new uint8_t[numBytes]; avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24,pCodecCtx->width, pCodecCtx->height); pSWSCtx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL); i=0; while(av_read_frame(pFormatCtx,&packet)>=0) { if(packet.stream_index==videoStream) { avcodec_decode_video(pCodecCtx, pFrame, &frameFinished,packet.data, packet.size); if(frameFinished) { if(pFrame->key_frame==1) { sws_scale(pSWSCtx, pFrame->data, pFrame->linesize,0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize); // Save the frame to disk char pic[200]; sprintf(pic,"pic%d.bmp",i); i++; av_create_bmp(pic,pFrameRGB->data[0],pCodecCtx->width,pCodecCtx->height,24); } } } av_free_packet(&packet); } // 释放 RGB 图象 av_free(pFrameRGB); // 释放YUV 帧 av_free(pFrame); sws_freeContext(pSWSCtx); // 关闭解码器(codec) avcodec_close(pCodecCtx); // 关闭视频文件 av_close_input_file(pFormatCtx); return 0; }