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:
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#define _AFXDLL
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#include<afxwin.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <libavcodec/avcodec.h>
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#include <libavformat/avformat.h>
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#include <libswscale/swscale.h>
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void main()
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{
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CFile file[5];
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BYTE *szTxt[5];
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int nWidth = 0;
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int nHeight= 0;
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int nDataLen=0;
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int nLen;
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CString csFileName;
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for (int fileI = 1; fileI <= 5; fileI ++)
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{
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csFileName.Format("%d.bmp", fileI);
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file[fileI - 1].Open(csFileName,CFile::modeRead | CFile::typeBinary);
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nLen = file[fileI - 1].GetLength();
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szTxt[fileI -1] = new BYTE[nLen];
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file[fileI - 1].Read(szTxt[fileI - 1], nLen);
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file[fileI - 1].Close();
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//BMP bmi;//BITMAPINFO bmi;
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//int nHeadLen = sizeof(BMP);
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BITMAPFILEHEADER bmpFHeader;
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BITMAPINFOHEADER bmpIHeader;
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memcpy(&bmpFHeader,szTxt[fileI -1],sizeof(BITMAPFILEHEADER));
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int nHeadLen = bmpFHeader.bfOffBits - sizeof(BITMAPFILEHEADER);
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memcpy(&bmpIHeader,szTxt[fileI - 1]+sizeof(BITMAPFILEHEADER),nHeadLen);
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nWidth = bmpIHeader.biWidth;// 464;// bmi.bmpInfo.bmiHeader.biWidth;// ;
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nHeight = bmpIHeader.biHeight;//362;// bmi.bmpInfo.bmiHeader.biHeight;// ;
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szTxt[fileI - 1] += bmpFHeader.bfOffBits;
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nDataLen = nLen-bmpFHeader.bfOffBits;
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}
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getchar();
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av_register_all();
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avcodec_register_all();
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AVFrame *m_pRGBFrame = new AVFrame[1]; //RGB帧数据
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AVFrame *m_pYUVFrame = new AVFrame[1];; //YUV帧数据
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AVCodecContext *c= NULL;
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AVCodecContext *in_c= NULL;
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AVCodec *pCodecH264; //编码器
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uint8_t * yuv_buff;//
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//查找h264编码器
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pCodecH264 = avcodec_find_encoder(CODEC_ID_H264);
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if(!pCodecH264)
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{
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fprintf(stderr, "h264 codec not found\n");
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getchar();
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exit(1);
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}
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c= avcodec_alloc_context3(pCodecH264);
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c->bit_rate = 3000000;// put sample parameters
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c->width =nWidth;//
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c->height = nHeight;//
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// frames per second
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AVRational rate;
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rate.num = 1;
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rate.den = 25;
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c->time_base= rate;//(AVRational){1,25};
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c->gop_size = 10; // emit one intra frame every ten frames
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c->max_b_frames=1;
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c->thread_count = 1;
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c->pix_fmt = PIX_FMT_YUV420P;//PIX_FMT_RGB24;
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//av_opt_set(c->priv_data, /*"preset"*/"libvpx-1080p.ffpreset", /*"slow"*/NULL, 0);
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//打开编码器
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if(avcodec_open2(c,pCodecH264,NULL)<0){
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printf("avcodec_open2 failed\n");
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TRACE("不能打开编码库");
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getchar();
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}
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int size = c->width * c->height;
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yuv_buff = (uint8_t *) malloc((size * 3) / 2); // size for YUV 420
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//将rgb图像数据填充rgb帧
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uint8_t * rgb_buff = new uint8_t[nDataLen];
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//图象编码 outbuf_size太小会报错,图像清晰度也会差
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int outbuf_size = 900000;
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uint8_t * outbuf= (uint8_t*)malloc(outbuf_size);
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int u_size = 0;
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FILE *f=NULL;
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char * filename = "myData.h264";
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f = fopen(filename, "wb");
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if (!f)
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{
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TRACE( "could not open %s\n", filename);
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getchar();
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exit(1);
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}
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//初始化SwsContext
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SwsContext * scxt = sws_getContext(c->width,c->height,PIX_FMT_BGR24,c->width,c->height,PIX_FMT_YUV420P,SWS_POINT,NULL,NULL,NULL);
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AVPacket avpkt;
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//AVFrame *pTFrame=new AVFrame
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for (int i=0;i<250;++i)
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{
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//AVFrame *m_pYUVFrame = new AVFrame[1];
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int index = (i / 25) % 5;
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memcpy(rgb_buff,szTxt[index],nDataLen);
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avpicture_fill((AVPicture*)m_pRGBFrame, (uint8_t*)rgb_buff, PIX_FMT_RGB24, nWidth, nHeight);
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//将YUV buffer 填充YUV Frame
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avpicture_fill((AVPicture*)m_pYUVFrame, (uint8_t*)yuv_buff, PIX_FMT_YUV420P, nWidth, nHeight);
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// 翻转RGB图像
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m_pRGBFrame->data[0] += m_pRGBFrame->linesize[0] * (nHeight - 1);
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m_pRGBFrame->linesize[0] *= -1;
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m_pRGBFrame->data[1] += m_pRGBFrame->linesize[1] * (nHeight / 2 - 1);
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m_pRGBFrame->linesize[1] *= -1;
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m_pRGBFrame->data[2] += m_pRGBFrame->linesize[2] * (nHeight / 2 - 1);
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m_pRGBFrame->linesize[2] *= -1;
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//将RGB转化为YUV
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sws_scale(scxt,m_pRGBFrame->data,m_pRGBFrame->linesize,0,c->height,m_pYUVFrame->data,m_pYUVFrame->linesize);
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static int got_packet_ptr = 0;
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av_init_packet(&avpkt);
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avpkt.data = outbuf;
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avpkt.size = outbuf_size;
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u_size = avcodec_encode_video2(c, &avpkt, m_pYUVFrame, &got_packet_ptr);
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m_pYUVFrame->pts++;
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if (u_size == 0)
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{
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fwrite(avpkt.data, 1, avpkt.size, f);
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}
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}
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fclose(f);
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delete []m_pRGBFrame;
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delete []m_pYUVFrame;
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delete []rgb_buff;
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free(outbuf);
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avcodec_close(c);
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av_free(c);
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}
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#ifdef __cplusplus
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}
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#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:
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <windows.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <libavcodec/avcodec.h>
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#include <libavformat/avformat.h>
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#include <libswscale/swscale.h>
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void SaveAsBMP (AVFrame *pFrameRGB, int width, int height, int index, int bpp)
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{
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char buf[5] = {0};
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BITMAPFILEHEADER bmpheader;
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BITMAPINFOHEADER bmpinfo;
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FILE *fp;
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char filename[20] = "";
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_itoa (index, buf, 10);
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strcat (filename, buf);
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strcat (filename, ".bmp");
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if ( (fp = fopen(filename,"wb+")) == NULL )
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{
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printf ("open file failed!\n");
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return;
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}
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bmpheader.bfType = 0x4d42;
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bmpheader.bfReserved1 = 0;
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bmpheader.bfReserved2 = 0;
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bmpheader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
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bmpheader.bfSize = bmpheader.bfOffBits + width*height*bpp/8;
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bmpinfo.biSize = sizeof(BITMAPINFOHEADER);
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bmpinfo.biWidth = width;
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bmpinfo.biHeight = height;
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bmpinfo.biPlanes = 1;
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bmpinfo.biBitCount = bpp;
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bmpinfo.biCompression = BI_RGB;
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bmpinfo.biSizeImage = (width*bpp+31)/32*4*height;
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bmpinfo.biXPelsPerMeter = 100;
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bmpinfo.biYPelsPerMeter = 100;
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bmpinfo.biClrUsed = 0;
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bmpinfo.biClrImportant = 0;
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fwrite (&bmpheader, sizeof(bmpheader), 1, fp);
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fwrite (&bmpinfo, sizeof(bmpinfo), 1, fp);
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fwrite (pFrameRGB->data[0], width*height*bpp/8, 1, fp);
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fclose(fp);
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}
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int main (void)
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{
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unsigned int i = 0, videoStream = -1;
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AVCodecContext *pCodecCtx;
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AVFormatContext *pFormatCtx = NULL;
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AVCodec *pCodec;
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AVFrame *pFrame, *pFrameRGB;
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struct SwsContext *pSwsCtx;
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const char *filename = "myData.h264";
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AVPacket packet;
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int frameFinished;
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int PictureSize;
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uint8_t *buf;
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av_register_all();
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if (avformat_open_input(&pFormatCtx, filename, NULL, NULL) != 0 ){
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printf ("av open input file failed!\n");
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exit (1);
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}
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if ( avformat_find_stream_info(pFormatCtx,NULL) < 0 ){
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printf ("av find stream info failed!\n");
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exit (1);
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}
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for ( i=0; i<pFormatCtx->nb_streams; i++ ){
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if ( pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO ){
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videoStream = i;
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break;
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}
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}
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if (videoStream == -1){
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printf ("find video stream failed!\n");
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exit (1);
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}
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pCodecCtx = pFormatCtx->streams[videoStream]->codec;
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pCodec = avcodec_find_decoder (pCodecCtx->codec_id);
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if (pCodec == NULL){
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printf ("avcode find decoder failed!\n");
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exit (1);
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}
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if ( avcodec_open2(pCodecCtx, pCodec,NULL)<0 ){
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printf ("avcode open failed!\n");
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exit (1);
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}
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pFrame = avcodec_alloc_frame();
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pFrameRGB = avcodec_alloc_frame();
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if ( (pFrame == NULL)||(pFrameRGB == NULL) ){
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printf("avcodec alloc frame failed!\n");
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exit (1);
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}
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PictureSize = avpicture_get_size (PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
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buf = (uint8_t *)av_malloc(PictureSize);
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if ( buf == NULL ){
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printf( "av malloc failed!\n");
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exit(1);
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}
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avpicture_fill ( (AVPicture *)pFrameRGB, buf, PIX_FMT_BGR24, pCodecCtx->width, pCodecCtx->height);
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pSwsCtx = sws_getContext (pCodecCtx->width,
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pCodecCtx->height,
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pCodecCtx->pix_fmt,
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pCodecCtx->width,
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pCodecCtx->height,
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PIX_FMT_BGR24,
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SWS_BICUBIC,
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NULL, NULL, NULL);
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i = 0;
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while(av_read_frame(pFormatCtx, &packet) >= 0){
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if(packet.stream_index == videoStream){
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avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
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if(frameFinished){
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//反转图像
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pFrame->data[0] += pFrame->linesize[0] * (pCodecCtx->height - 1);
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pFrame->linesize[0] *= -1;
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pFrame->data[1] += pFrame->linesize[1] * (pCodecCtx->height / 2 - 1);
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pFrame->linesize[1] *= -1;
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pFrame->data[2] += pFrame->linesize[2] * (pCodecCtx->height / 2 - 1);
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pFrame->linesize[2] *= -1;
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sws_scale (pSwsCtx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
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SaveAsBMP (pFrameRGB, pCodecCtx->width, pCodecCtx->height, i++, 24);
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}
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}
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av_free_packet(&packet);
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}
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while(1){
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packet.data = NULL;
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packet.size = 0;
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avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
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if(frameFinished){
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//反转图像
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pFrame->data[0] += pFrame->linesize[0] * (pCodecCtx->height - 1);
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pFrame->linesize[0] *= -1;
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pFrame->data[1] += pFrame->linesize[1] * (pCodecCtx->height / 2 - 1);
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pFrame->linesize[1] *= -1;
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pFrame->data[2] += pFrame->linesize[2] * (pCodecCtx->height / 2 - 1);
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pFrame->linesize[2] *= -1;
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sws_scale (pSwsCtx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);
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SaveAsBMP (pFrameRGB, pCodecCtx->width, pCodecCtx->height, i++, 24);
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}else{
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break;
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}
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av_free_packet(&packet);
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}
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sws_freeContext (pSwsCtx);
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av_free (pFrame);
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av_free (pFrameRGB);
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avcodec_close (pCodecCtx);
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avformat_close_input (&pFormatCtx);
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return 0;
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}
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#ifdef __cplusplus
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}
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#endif
视频文件保存图片的另外一个方法,看代码
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/*File : yuv2pic
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*Auth : sjin
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*Date : 20141123
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*Mail : [email protected]
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*/
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/*
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* 参考博客http://blog.csdn.net/leixiaohua1020/article/details/25346147
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*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。
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*通过学习本例子可以了解FFmpeg的编码流程。
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*/
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#include <libavcodec/avcodec.h>
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#include <libavformat/avformat.h>
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#include <libswscale/swscale.h>
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#define INPUT_FILE_NAME "yuv420p.yuv"
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#define OUTPUT_FILE_NAME "encode.png"
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#define INPUT_FILE_WDITH 176
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#define INPUT_FILE_HEIGHT 144
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int main(int argc, char* argv[])
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{
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AVFormatContext* pFormatCtx;
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AVOutputFormat* fmt;
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AVStream* video_st;
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AVCodecContext* pCodecCtx;
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AVCodec* pCodec;
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uint8_t* picture_buf;
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AVFrame* picture;
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int size;
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FILE *in_file = fopen(INPUT_FILE_NAME, "rb"); //视频YUV源文件
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int in_w = INPUT_FILE_WDITH;
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int in_h = INPUT_FILE_HEIGHT; //宽高
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const char* out_file = OUTPUT_FILE_NAME; //输出文件路径
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av_register_all();
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#if 0
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//方法1.组合使用几个函数
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pFormatCtx = avformat_alloc_context();
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//猜格式。用MJPEG编码
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fmt = av_guess_format("mjpeg", NULL, NULL);
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pFormatCtx->oformat = fmt;
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//注意:输出路径
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if (avio_open(&pFormatCtx->pb,out_file, AVIO_FLAG_READ_WRITE) < 0){
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printf("输出文件打开失败");
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return -1;
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}
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#else
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//方法2.更加自动化一些
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//分配一个输出(out_file)文件格式的AVFormatContext的上下文句柄
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avformat_alloc_output_context2(&pFormatCtx, NULL, NULL, out_file);
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fmt = pFormatCtx->oformat;
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video_st = avformat_new_stream(pFormatCtx,NULL);
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if (video_st==NULL){
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return -1;
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}
-
#endif
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pCodecCtx = video_st->codec;
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pCodecCtx->codec_id = fmt->video_codec;
-
pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
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pCodecCtx->pix_fmt = PIX_FMT_YUVJ420P;
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pCodecCtx->width = in_w;
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pCodecCtx->height = in_h;
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pCodecCtx->time_base.num = 1;
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pCodecCtx->time_base.den = 25;
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//输出格式信息
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av_dump_format(pFormatCtx, 0, out_file, 1);
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pCodec = avcodec_find_encoder(pCodecCtx->codec_id);
-
if (!pCodec){
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printf("没有找到合适的编码器!");
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return -1;
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}
-
if (avcodec_open2(pCodecCtx, pCodec,NULL) < 0){
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printf("编码器打开失败!");
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return -1;
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}
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//申请解码后保存视频帧的空间,AVFrame结构体
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picture = avcodec_alloc_frame();
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//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;
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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;
-
}
下面是编译的时候,比较好用的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)