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测试，图像格式png,jpg, gif等等测试均OK

自己根据博客的代码，vs2010搭建的测试环境。资源下载

具体代码：

#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\n");
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\n");
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\n", 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

完全按照博客中的代码测试发现会报下面的信息，而且在播放过程中，画面都是模糊的。修改了outbuff_size的大小解决了这个问题。

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，具体代码如下：

#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!\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);
}

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!\n");
exit (1);
}

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

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

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);

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
*/

/*
* 参考博客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。
*通过学习本例子可以了解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，我们仍需要内存去保存原始的数据
//利用下面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;
}
//设置指定图像的参数，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！\n");
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！\n");

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;
}

# 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)

参考资料：

1、http://blog.csdn.net/eightdegree/article/details/7425635#reply

2、http://blog.csdn.net/leixiaohua1020/article/details/25346147