视频解码图片

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

#pragma comment( lib, "avcodec.lib" )
#pragma comment( lib, "avdevice.lib" )
#pragma comment( lib, "avformat.lib" )
#pragma comment( lib, "avutil.lib" )
#pragma comment( lib, "swscale.lib" )

#include <windows.h>

static int av_create_bmp(char* filename,uint8_t *pRGBBuffer,int width,int height,int bpp)
{
	BITMAPFILEHEADER bmpheader;
	BITMAPINFO bmpinfo;
	FILE *fp;

	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;

	uint8_t* pBuffer = new uint8_t[width * bpp / 8];
	int byteWidth = width * bpp / 8;
	for( int h = 0; h < height / 2; ++h )
	{
		memcpy( pBuffer, pRGBBuffer + h * byteWidth, byteWidth );
		memcpy( pRGBBuffer + h * byteWidth, pRGBBuffer + (height - h - 1) * byteWidth, byteWidth );
		memcpy( pRGBBuffer + (height - h - 1) * byteWidth, pBuffer, byteWidth );
	}
	delete[] pBuffer;

	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="F:\ACG\缘之空\[SumiSora][Yosuga_no_Sora][BDRip][CM01][720P].mp4";   
	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!
");   

	if(av_find_stream_info(pFormatCtx)<0)   
		printf("error!
");   

	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;   
			continue;   
		}   
		if(videoStream==-1)   
			printf("error!
");// Didn't find a video stream   

		pCodecCtx=pFormatCtx->streams[videoStream]->codec;   
		AVCodec *pCodec;   

		pCodec=avcodec_find_decoder(pCodecCtx->codec_id);   
		if(pCodec==NULL)   
			printf("error!
");


		if(avcodec_open(pCodecCtx, pCodec)<0)   
			printf("error!
"); 
		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_BGR24,pCodecCtx->width, pCodecCtx->height);   
		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)   
				{   
					if(pFrame->key_frame==1 || pFrame->pict_type == FF_P_TYPE)//这里取到关键帧数据   
					{   
						sws_scale(pSWSCtx, pFrame->data, pFrame->linesize,0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);   
						i++;  
						static char path[100] = {0};
						sprintf( path, "E:/video/img_%d.bmp", i - 1);
						av_create_bmp( path,pFrameRGB->data[0],pCodecCtx->width,pCodecCtx->height,24);
					}   
				}   
			}   
			av_free_packet(&packet);   
		}   

		av_free(pFrameRGB);   

		av_free(pFrame);   

		sws_freeContext(pSWSCtx);   

		avcodec_close(pCodecCtx);   

		av_close_input_file(pFormatCtx);   

		return 0;   

}