使用ffmpeg将BMP图片编码为x264视频文件,将H264视频保存为BMP图片,yuv视频文件保存为图片的代码

  ffmpeg开源库，实现将bmp格式的图片编码成x264文件，并将编码好的H264文件解码保存为BMP文件。

实现将视频文件yuv格式保存的图片格式的測试，图像格式png,jpg, gif等等測试均OK


  自己依据博客的代码，vs2010搭建的測试环境。资源下载 

   详细代码：

#define _AFXDLL  
#include<afxwin.h> 
#ifdef  __cplusplus
extern "C" {
#endif

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>
	void main()
	{
		CFile file[5];
		BYTE *szTxt[5];

		int nWidth = 0;
		int nHeight= 0;

		int nDataLen=0;

		int nLen;

		CString csFileName;
		for (int fileI = 1; fileI <= 5; fileI ++)
		{
			csFileName.Format("%d.bmp", fileI);
			file[fileI - 1].Open(csFileName,CFile::modeRead | CFile::typeBinary);
			nLen = file[fileI - 1].GetLength();

			szTxt[fileI -1] = new BYTE[nLen];
			file[fileI - 1].Read(szTxt[fileI - 1], nLen);
			file[fileI - 1].Close();

			//BMP bmi;//BITMAPINFO bmi;
			//int nHeadLen = sizeof(BMP);
			BITMAPFILEHEADER bmpFHeader;
			BITMAPINFOHEADER bmpIHeader;
			memcpy(&bmpFHeader,szTxt[fileI -1],sizeof(BITMAPFILEHEADER));

			int nHeadLen = bmpFHeader.bfOffBits - sizeof(BITMAPFILEHEADER);
			memcpy(&bmpIHeader,szTxt[fileI - 1]+sizeof(BITMAPFILEHEADER),nHeadLen);

			nWidth = bmpIHeader.biWidth;// 464;// bmi.bmpInfo.bmiHeader.biWidth;// ;
			nHeight = bmpIHeader.biHeight;//362;// bmi.bmpInfo.bmiHeader.biHeight;// ;

			szTxt[fileI - 1] += bmpFHeader.bfOffBits;
			nDataLen = nLen-bmpFHeader.bfOffBits;
		}
		getchar();
		av_register_all();
		avcodec_register_all();
		AVFrame *m_pRGBFrame =  new AVFrame[1];  //RGB帧数据  
		AVFrame *m_pYUVFrame = new AVFrame[1];;  //YUV帧数据
		AVCodecContext *c= NULL;
		AVCodecContext *in_c= NULL;
		AVCodec *pCodecH264; //编码器
		uint8_t * yuv_buff;//

		//查找h264编码器
		pCodecH264 = avcodec_find_encoder(CODEC_ID_H264);
		if(!pCodecH264)
		{
			fprintf(stderr, "h264 codec not found
");
			getchar();
			exit(1);
		}

		c= avcodec_alloc_context3(pCodecH264);
		c->bit_rate = 3000000;// put sample parameters 
		c->width =nWidth;// 
		c->height = nHeight;// 

		// frames per second 
		AVRational rate;
		rate.num = 1;
		rate.den = 25;
		c->time_base= rate;//(AVRational){1,25};
		c->gop_size = 10; // emit one intra frame every ten frames 
		c->max_b_frames=1;
		c->thread_count = 1;
		c->pix_fmt = PIX_FMT_YUV420P;//PIX_FMT_RGB24;

		//av_opt_set(c->priv_data, /*"preset"*/"libvpx-1080p.ffpreset", /*"slow"*/NULL, 0);
		//打开编码器
		if(avcodec_open2(c,pCodecH264,NULL)<0){
			printf("avcodec_open2 failed
");
			TRACE("不能打开编码库");
			getchar();
		}

		int size = c->width * c->height;

		yuv_buff = (uint8_t *) malloc((size * 3) / 2); // size for YUV 420 

		//将rgb图像数据填充rgb帧
		uint8_t * rgb_buff = new uint8_t[nDataLen];

		//图象编码 outbuf_size太小会报错，图像清晰度也会差
		int outbuf_size = 900000;
		uint8_t * outbuf= (uint8_t*)malloc(outbuf_size); 
		int u_size = 0;
		FILE *f=NULL; 
		char * filename = "myData.h264";
		f = fopen(filename, "wb");
		if (!f)
		{
			TRACE( "could not open %s
", filename);
			getchar();
			exit(1);
		}

		//初始化SwsContext
		SwsContext * scxt = sws_getContext(c->width,c->height,PIX_FMT_BGR24,c->width,c->height,PIX_FMT_YUV420P,SWS_POINT,NULL,NULL,NULL);

		AVPacket avpkt;

		//AVFrame *pTFrame=new AVFrame
		for (int i=0;i<250;++i)
		{

			//AVFrame *m_pYUVFrame = new AVFrame[1];

			int index = (i / 25) % 5;
			memcpy(rgb_buff,szTxt[index],nDataLen);

			avpicture_fill((AVPicture*)m_pRGBFrame, (uint8_t*)rgb_buff, PIX_FMT_RGB24, nWidth, nHeight);

			//将YUV buffer 填充YUV Frame
			avpicture_fill((AVPicture*)m_pYUVFrame, (uint8_t*)yuv_buff, PIX_FMT_YUV420P, nWidth, nHeight);

			// 翻转RGB图像
			m_pRGBFrame->data[0]  += m_pRGBFrame->linesize[0] * (nHeight - 1);
			m_pRGBFrame->linesize[0] *= -1;                   
			m_pRGBFrame->data[1]  += m_pRGBFrame->linesize[1] * (nHeight / 2 - 1);
			m_pRGBFrame->linesize[1] *= -1;
			m_pRGBFrame->data[2]  += m_pRGBFrame->linesize[2] * (nHeight / 2 - 1);
			m_pRGBFrame->linesize[2] *= -1;


			//将RGB转化为YUV
			sws_scale(scxt,m_pRGBFrame->data,m_pRGBFrame->linesize,0,c->height,m_pYUVFrame->data,m_pYUVFrame->linesize);

			static int got_packet_ptr = 0;
			av_init_packet(&avpkt);
			avpkt.data = outbuf;
			avpkt.size = outbuf_size;
			u_size = avcodec_encode_video2(c, &avpkt, m_pYUVFrame, &got_packet_ptr);
			m_pYUVFrame->pts++;
			if (u_size == 0)
			{
				fwrite(avpkt.data, 1, avpkt.size, f);
			}
		}

		fclose(f); 
		delete []m_pRGBFrame;
		delete []m_pYUVFrame;
		delete []rgb_buff;
		free(outbuf);
		avcodec_close(c);
		av_free(c);

	}

#ifdef  __cplusplus
}
#endif

 全然依照博客中的代码測试发现会报以下的信息，并且在播放过程中，画面都是模糊的。改动了outbuff_size的大小攻克了这个问题。



 

疑问：为什么要循环250次？有知道麻烦解答下！
for (int i=0;i<250;++i)

将H264视频保存为BMP图片，详细代码例如以下：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>

#ifdef  __cplusplus
extern "C" {
#endif

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>

void SaveAsBMP (AVFrame *pFrameRGB, int width, int height, int index, int bpp)
{
	char buf[5] = {0};
	BITMAPFILEHEADER bmpheader;
	BITMAPINFOHEADER bmpinfo;
	FILE *fp;

	char filename[20] = "";
	_itoa (index, buf, 10);
	strcat (filename, buf);
	strcat (filename, ".bmp");

	if ( (fp = fopen(filename,"wb+")) == NULL )
	{
		printf ("open file failed!
");
		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);
}


int main (void)
{
	unsigned int i = 0, videoStream = -1;
	AVCodecContext *pCodecCtx;
	AVFormatContext *pFormatCtx = NULL;
	AVCodec *pCodec;
	AVFrame *pFrame, *pFrameRGB;
	struct SwsContext *pSwsCtx;
	const char *filename = "myData.h264";
	AVPacket packet;
	int frameFinished;
	int PictureSize;
	uint8_t *buf;

	av_register_all();

	if (avformat_open_input(&pFormatCtx, filename, NULL, NULL) != 0 ){
		printf ("av open input file failed!
");
		exit (1);
	}

	if ( avformat_find_stream_info(pFormatCtx,NULL) < 0 ){
		printf ("av find stream info failed!
");
		exit (1);
	}

	for ( i=0; i<pFormatCtx->nb_streams; i++ ){
		if ( pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO ){
			videoStream = i;
			break;
		}
	}

	if (videoStream == -1){
		printf ("find video stream failed!
");
		exit (1);
	}

	pCodecCtx = pFormatCtx->streams[videoStream]->codec;

	pCodec = avcodec_find_decoder (pCodecCtx->codec_id);
	if (pCodec == NULL){
		printf ("avcode find decoder failed!
");
		exit (1);
	}




	if ( avcodec_open2(pCodecCtx, pCodec,NULL)<0 ){
		printf ("avcode open failed!
");
		exit (1);
	}

	pFrame = avcodec_alloc_frame();
	pFrameRGB = avcodec_alloc_frame();

	if ( (pFrame == NULL)||(pFrameRGB == NULL) ){
		printf("avcodec alloc frame failed!
");
		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!
");
		exit(1);
	}

	avpicture_fill ( (AVPicture *)pFrameRGB, buf, 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_video2(pCodecCtx, pFrame, &frameFinished, &packet);

			if(frameFinished){ 
					//反转图像
				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;

				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);
	}

	while(1){  
		packet.data = NULL;  
		packet.size = 0;  
		avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);

		if(frameFinished){ 
			//反转图像
			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;

			sws_scale (pSwsCtx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);

			SaveAsBMP (pFrameRGB, pCodecCtx->width, pCodecCtx->height, i++, 24);
		}else{
			break;
		}

		av_free_packet(&packet);  
	}  

	sws_freeContext (pSwsCtx);
	av_free (pFrame);
	av_free (pFrameRGB);
	avcodec_close (pCodecCtx);
	avformat_close_input (&pFormatCtx);

	return 0;
}

#ifdef  __cplusplus
}
#endif


视频文件保存图片的另外一个方法，看代码

/*File : yuv2pic
 *Auth : sjin
 *Date : 20141123
 *Mail : 413977243@qq.com
 */

/* 
 * 參考博客http://blog.csdn.net/leixiaohua1020/article/details/25346147
 *本程序实现了YUV420P像素数据编码为JPEG图片。是最简单的FFmpeg编码方面的教程。
 *通过学习本样例能够了解FFmpeg的编码流程。
 */
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>

#define INPUT_FILE_NAME  "yuv420p.yuv"
#define OUTPUT_FILE_NAME "encode.png"
#define INPUT_FILE_WDITH  176
#define INPUT_FILE_HEIGHT 144

int main(int argc, char* argv[])
{
	AVFormatContext* pFormatCtx;
	AVOutputFormat* fmt;
	AVStream* video_st;
	AVCodecContext* pCodecCtx;
	AVCodec* pCodec;

	uint8_t* picture_buf;
	AVFrame* picture;
	int size;

	FILE *in_file = fopen(INPUT_FILE_NAME, "rb");	//视频YUV源文件 
	int in_w = INPUT_FILE_WDITH;
	int in_h = INPUT_FILE_HEIGHT;									//宽高
	const char* out_file = OUTPUT_FILE_NAME;					//输出文件路径

	av_register_all();
#if 0
	//方法1.组合使用几个函数
	pFormatCtx = avformat_alloc_context();
	//猜格式。用MJPEG编码
	fmt = av_guess_format("mjpeg", NULL, NULL);
	pFormatCtx->oformat = fmt;
	//注意：输出路径
	if (avio_open(&pFormatCtx->pb,out_file, AVIO_FLAG_READ_WRITE) < 0){
		printf("输出文件打开失败");
		return -1;
	}
#else
	//方法2.更加自己主动化一些
    //分配一个输出（out_file）文件格式的AVFormatContext的上下文句柄
	avformat_alloc_output_context2(&pFormatCtx, NULL, NULL, out_file);
	fmt = pFormatCtx->oformat;

	video_st = avformat_new_stream(pFormatCtx,NULL);
	if (video_st==NULL){
		return -1;
	}
#endif
	pCodecCtx = video_st->codec;
	pCodecCtx->codec_id = fmt->video_codec;
	pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
	pCodecCtx->pix_fmt = PIX_FMT_YUVJ420P;

	pCodecCtx->width = in_w;  
	pCodecCtx->height = in_h;

	pCodecCtx->time_base.num = 1;  
	pCodecCtx->time_base.den = 25;   
	//输出格式信息
	av_dump_format(pFormatCtx, 0, out_file, 1);

	pCodec = avcodec_find_encoder(pCodecCtx->codec_id);
	if (!pCodec){
		printf("没有找到合适的编码器！");
		return -1;
	}
	if (avcodec_open2(pCodecCtx, pCodec,NULL) < 0){
		printf("编码器打开失败！");
		return -1;
	}
	
    //申请解码后保存视频帧的空间，AVFrame结构体
	picture = avcodec_alloc_frame();
    //即使我们申请的一帧的内存，当转换的时候，我们仍须要内存去保存原始的数据
    //利用以下的函数来获得原始数据帧的大小，手动分配内存
	size = avpicture_get_size(pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);
	picture_buf = (uint8_t *)av_malloc(size);
	if (!picture_buf){
		return -1;
	}
    //设置指定图像的參数，并指着图像数据缓冲区
	avpicture_fill((AVPicture *)picture, picture_buf, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height);

	//写文件头
	avformat_write_header(pFormatCtx,NULL);

	AVPacket pkt;
	int y_size = pCodecCtx->width * pCodecCtx->height;
	av_new_packet(&pkt,y_size*3);
	//读入YUV
	if (fread(picture_buf, 1, y_size*3/2, in_file) < 0){
		printf("文件读取错误");
		return -1;
	}

    //翻转图像
	picture->data[0] = picture_buf;  // 亮度Y
	picture->data[1] = picture_buf+ y_size;  // U 
	picture->data[2] = picture_buf+ y_size*5/4; // V
	int got_picture=0;
	//编码
	int ret = avcodec_encode_video2(pCodecCtx, &pkt,picture, &got_picture);
	if(ret < 0){
		printf("编码错误！
");
		return -1;
	}
	if (got_picture==1){
		pkt.stream_index = video_st->index;
		ret = av_write_frame(pFormatCtx, &pkt);
	}

	av_free_packet(&pkt);
	//写文件尾
	av_write_trailer(pFormatCtx);

	printf("编码成功！
");

	if (video_st){
		avcodec_close(video_st->codec);
		av_free(picture);
		av_free(picture_buf);
	}
	
	avio_close(pFormatCtx->pb);
	avformat_free_context(pFormatCtx);

	fclose(in_file);

	return 0;
}

以下是编译的时候，比較好用的Makefile文件
# use pkg-config for getting CFLAGS and LDLIBS
FFMPEG_LIBS=    libavdevice                        
                libavformat                        
                libavfilter                        
                libavcodec                         
                libswresample                      
                libswscale                         
                libavutil                          

CFLAGS += -Wall -O2 -g
CFLAGS := $(shell pkg-config --cflags $(FFMPEG_LIBS)) $(CFLAGS)
LDLIBS := $(shell pkg-config --libs $(FFMPEG_LIBS)) $(LDLIBS)

EXAMPLES=  yuv2pic
                						
OBJS=$(addsuffix .o,$(EXAMPLES))

# the following examples make explicit use of the math library
LDLIBS += -lx264 -m32 -pthread -lm -ldl

.phony:all clean

all: $(OBJS) $(EXAMPLES)

clean:
	rm $(EXAMPLES) $(OBJS)


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原文地址：https://www.cnblogs.com/blfshiye/p/4280429.html