ffmpeg解码视频存为BMP文件
分类： ffmpeg2011-07-28 12:13 8人阅读 评论(0) 收藏 举报
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- #include <windows.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include <string.h>
- #pragma once
- #ifdef __cplusplus
- extern "C" {
- #endif
- #include <libavcodec/avcodec.h>
- #include <libavformat/avformat.h>
- #include <libswscale/swscale.h>
- #ifdef __cplusplus
- }
- #endif
- //定义BMP文件头
- #ifndef _WINGDI_
- #define _WINGDI_
- typedef struct tagBITMAPFILEHEADER {
- WORD bfType;
- DWORD bfSize;
- WORD bfReserved1;
- WORD bfReserved2;
- DWORD bfOffBits;
- } BITMAPFILEHEADER, FAR *LPBITMAPFILEHEADER, *PBITMAPFILEHEADER;
- typedef struct tagBITMAPINFOHEADER{
- DWORD biSize;
- LONG biWidth;
- LONG biHeight;
- WORD biPlanes;
- WORD biBitCount;
- DWORD biCompression;
- DWORD biSizeImage;
- LONG biXPelsPerMeter;
- LONG biYPelsPerMeter;
- DWORD biClrUsed;
- DWORD biClrImportant;
- } BITMAPINFOHEADER, FAR *LPBITMAPINFOHEADER, *PBITMAPINFOHEADER;
- #endif
- //保存BMP文件的函数
- void SaveAsBMP (AVFrame *pFrameRGB, int width, int height, int index, int bpp)
- {
- char buf[5] = {0};
- BITMAPFILEHEADER bmpheader;
- BITMAPINFOHEADER bmpinfo;
- FILE *fp;
- char *filename = new char[255];
- //文件存放路径，根据自己的修改
- sprintf_s(filename,255,"%s%d.bmp","D:/My Documents/Visual Studio 2008/Projects/WriteVideo/Debug/test",index);
- if ( (fp=fopen(filename,"wb+")) == NULL )
- {
- printf ("open file failed!\n");
- return;
- }
- bmpheader.bfType = 0x4d42;
- bmpheader.bfReserved1 = 0;
- bmpheader.bfReserved2 = 0;
- bmpheader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
- bmpheader.bfSize = bmpheader.bfOffBits + width*height*bpp/8;
- bmpinfo.biSize = sizeof(BITMAPINFOHEADER);
- bmpinfo.biWidth = width;
- bmpinfo.biHeight = height;
- bmpinfo.biPlanes = 1;
- bmpinfo.biBitCount = bpp;
- bmpinfo.biCompression = BI_RGB;
- bmpinfo.biSizeImage = (width*bpp+31)/32*4*height;
- bmpinfo.biXPelsPerMeter = 100;
- bmpinfo.biYPelsPerMeter = 100;
- bmpinfo.biClrUsed = 0;
- bmpinfo.biClrImportant = 0;
- fwrite (&bmpheader, sizeof(bmpheader), 1, fp);
- fwrite (&bmpinfo, sizeof(bmpinfo), 1, fp);
- fwrite (pFrameRGB->data[0], width*height*bpp/8, 1, fp);
- fclose(fp);
- }
- //主函数
- int main (void)
- {
- unsigned int i = 0, videoStream = -1;
- AVCodecContext *pCodecCtx;
- AVFormatContext *pFormatCtx;
- AVCodec *pCodec;
- AVFrame *pFrame, *pFrameRGB;
- struct SwsContext *pSwsCtx;
- const char *filename = "D:/My Documents/Visual Studio 2008/Projects/WriteVideo/Debug/DELTA.MPG";
- AVPacket packet;
- int frameFinished;
- int PictureSize;
- uint8_t *buf;
- //注册编解码器
- av_register_all();
- //打开视频文件
- if ( av_open_input_file(&pFormatCtx, filename, NULL, 0, NULL) != 0 )
- {
- printf ("av open input file failed!\n");
- exit (1);
- }
- //获取流信息
- if ( av_find_stream_info(pFormatCtx) < 0 )
- {
- printf ("av find stream info failed!\n");
- exit (1);
- }
- //获取视频流
- 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 ("find video stream failed!\n");
- exit (1);
- }
- pCodecCtx = pFormatCtx->streams[videoStream]->codec;
- pCodec = avcodec_find_decoder (pCodecCtx->codec_id);
- if (pCodec == NULL)
- {
- printf ("avcode find decoder failed!\n");
- exit (1);
- }
- //打开解码器
- if ( avcodec_open(pCodecCtx, pCodec)<0 )
- {
- printf ("avcode open failed!\n");
- exit (1);
- }
- //为每帧图像分配内存
- pFrame = avcodec_alloc_frame();
- pFrameRGB = avcodec_alloc_frame();
- if ( (pFrame==NULL)||(pFrameRGB==NULL) )
- {
- printf("avcodec alloc frame failed!\n");
- exit (1);
- }
- PictureSize = avpicture_get_size (PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
- buf = (uint8_t*)av_malloc(PictureSize);
- if ( buf == NULL )
- {
- printf( "av malloc failed!\n");
- exit(1);
- }
- avpicture_fill ( (AVPicture *)pFrameRGB, buf, PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
- //设置图像转换上下文
- pSwsCtx = sws_getContext (pCodecCtx->width,
- pCodecCtx->height,
- pCodecCtx->pix_fmt,
- pCodecCtx->width,
- pCodecCtx->height,
- PIX_FMT_BGR24,
- 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)
- {
- //反转图像 ，否则生成的图像是上下调到的
- pFrame->data[0] += pFrame->linesize[0] * (pCodecCtx->height - 1);
- pFrame->linesize[0] *= -1;
- pFrame->data[1] += pFrame->linesize[1] * (pCodecCtx->height / 2 - 1);
- pFrame->linesize[1] *= -1;
- pFrame->data[2] += pFrame->linesize[2] * (pCodecCtx->height / 2 - 1);
- pFrame->linesize[2] *= -1;
- //转换图像格式，将解压出来的YUV420P的图像转换为BRG24的图像
- sws_scale (pSwsCtx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
- SaveAsBMP (pFrameRGB, pCodecCtx->width, pCodecCtx->height, i++, 24);
- }
- }
- av_free_packet(&packet);
- }
- sws_freeContext (pSwsCtx);
- av_free (pFrame);
- av_free (pFrameRGB);
- avcodec_close (pCodecCtx);
- av_close_input_file (pFormatCtx);
- return 0;
- }
