ffmpeg编码示例

[html]  view plain copy

 // ffmpegTest.cpp : Defines the entry point for the console application.
 //
 //#include "stdafx.h"
 #include "windows.h"
 #include "time.h"

 #include <avformat.h>
 #include <avutil.h>
 #include <avcodec.h>
 #include <swscale.h>
 #pragma comment(lib, "avcodec.lib")
 #pragma comment(lib, "avformat.lib")
 #pragma comment(lib, "avutil.lib")

 void SaveBmp(AVCodecContext *CodecContex, AVFrame *Picture, int width, int height);

 #define MAX_BUF_SIZE 256*1024
 int main(int argc, char* argv[])
 {
     int ret=-1, i=0, videoindex=-1, nComplete=0, len=0, frame_index=0;
     unsigned char *pEnCodeBuf = new unsigned char[MAX_BUF_SIZE];
     char *sourceFile = "5.avi";
     char *destFile = "123.mp4";
     av_register_all();

     AVFormatContext *pInputFormatContext=NULL;
     AVCodec *pInputCodec = NULL;
     AVCodecContext *pInputCodecContext = NULL;
     AVPacket InPack;
     int videoWidth, videoHeight;

     AVOutputFormat *pOutputFmt = NULL;
     AVFormatContext *pOutFormatContext = NULL;
     AVCodecContext *pOutCodecContext = NULL;
     AVCodec *pOutCodec = NULL;
     AVStream *pOutStream = NULL;
     AVPacket OutPack;
     AVFrame OutFrame;
     if(av_open_input_file(&pInputFormatContext, sourceFile, NULL, 0, NULL) !=0 )
     {
         //打开输入文件
         printf("can't open the file %s\n",sourceFile);
         exit(1);
     }

     if(av_find_stream_info(pInputFormatContext)<0)
     {
         //查找流信息
         printf("can't find suitable codec parameters\n");
         goto lk_error;
     }

     for(i=0; i<pInputFormatContext->nb_streams; i++)
     {
         if(pInputFormatContext->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO)
         {
             videoindex=i;
             break;
         }
     }

     if(-1 == videoindex)
     {
         //没有找到视频流
         goto lk_error;
     }

     pInputCodecContext = pInputFormatContext->streams[videoindex]->codec;
     pInputCodec = avcodec_find_decoder(pInputCodecContext->codec_id);
     if(NULL == pInputCodec)
     {
         //没有找到解码器
         goto lk_error;
     }
     if(avcodec_open(pInputCodecContext, pInputCodec) != 0)
     {
         //打开解码器失败
         goto lk_error;
     }

     videoWidth = pInputCodecContext->width;
     videoHeight = pInputCodecContext->height;

     pOutputFmt = guess_format(NULL, destFile, NULL);
     if(NULL == pOutputFmt)
     {
         //分析输出文件格式失败
         goto lk_error;
     }

     pOutFormatContext = av_alloc_format_context();
     if(NULL == pOutFormatContext)
     {
         goto lk_error;
     }

     pOutFormatContext->oformat = pOutputFmt;
     pOutStream = av_new_stream(pOutFormatContext, 0);
     if(NULL == pOutStream)
     {
         //创建流失败
         goto lk_error;
     }

     //设定转换编码参数
     pOutCodecContext = pOutStream->codec;
     pOutCodecContext->codec_id = CODEC_ID_MPEG4;
     pOutCodecContext->codec_type = CODEC_TYPE_VIDEO;
     pOutCodecContext->bit_rate = 98000;
     pOutCodecContext->width = videoWidth;
     pOutCodecContext->height = videoHeight;
     pOutCodecContext->time_base = pInputCodecContext->time_base;
     pOutCodecContext->gop_size = pInputCodecContext->gop_size;
     pOutCodecContext->pix_fmt = pInputCodecContext->pix_fmt;
     pOutCodecContext->max_b_frames = pInputCodecContext->max_b_frames;
     pOutCodecContext->time_base.den = 15;
     pOutCodecContext->time_base.num = 1;
     pOutStream->r_frame_rate = pInputFormatContext->streams[videoindex]->r_frame_rate;

     if (av_set_parameters(pOutFormatContext, NULL) < 0)
     {
         //转换编码参数设置不正确
         goto lk_error;
     }

     strcpy(pOutFormatContext->title, pInputFormatContext->title);
     strcpy(pOutFormatContext->author, pInputFormatContext->author);
     strcpy(pOutFormatContext->copyright, pInputFormatContext->copyright);
     strcpy(pOutFormatContext->comment, pInputFormatContext->comment);
     strcpy(pOutFormatContext->album, pInputFormatContext->album);
     pOutFormatContext->year = pInputFormatContext->year;
     pOutFormatContext->track = pInputFormatContext->track;
     strcpy(pOutFormatContext->genre, pInputFormatContext->genre);

     pOutCodec = avcodec_find_encoder(CODEC_ID_MPEG4);
     if(NULL == pOutCodec)
     {
         //找不到指定编码器
         goto lk_error;
     }

     if(avcodec_open(pOutCodecContext, pOutCodec) < 0)
     {
         //打开指定编码器错误
         goto lk_error;
     }

     if (!(pOutFormatContext->flags & AVFMT_NOFILE))
     {
         if(url_fopen(&pOutFormatContext->pb, destFile, URL_WRONLY)<0)
         {
             //打开输出文件
             goto lk_error;
         }
     }

     if(av_write_header(pOutFormatContext) < 0)
     {
         //写入输出文件头失败
         goto lk_error;
     }

     while(av_read_frame(pInputFormatContext, &InPack) >= 0)
     {
         len = avcodec_decode_video(pInputCodecContext, &OutFrame, &nComplete, InPack.data, InPack.size);
         if(nComplete > 0)
         {
             //解码一帧成功
             SaveBmp(pInputCodecContext, &OutFrame, videoWidth, videoHeight);
             memset(pEnCodeBuf, 0, MAX_BUF_SIZE);
             OutFrame.pts = av_rescale(frame_index, AV_TIME_BASE*(int64_t)pOutCodecContext->time_base.num, pOutCodecContext->time_base.den);
             OutFrame.pict_type = 0;
             len = avcodec_encode_video(pOutCodecContext, pEnCodeBuf, MAX_BUF_SIZE, &OutFrame);
             if (len > 0)
             {
                 av_init_packet(&OutPack);
                 if(pOutCodecContext->coded_frame && pOutCodecContext->coded_frame->key_frame)
                 {
                     OutPack.flags |= PKT_FLAG_KEY;
                 }

                 OutPack.flags = InPack.flags;
                 OutPack.stream_index = InPack.stream_index;
                 OutPack.data = pEnCodeBuf;
                 OutPack.size = len;
                 ret=av_write_frame(pOutFormatContext, &OutPack);
             }
             frame_index++;
         }
         av_free_packet(&OutPack);
     }

     av_write_trailer(pOutFormatContext);
     for(i=0; i<pOutFormatContext->nb_streams; i++)
     {
         av_freep(&pOutFormatContext->streams[i]->codec);
         av_freep(&pOutFormatContext->streams[i]);
     }

 lk_error:
     av_free(pOutCodec);
     av_free(pOutputFmt);
     avcodec_close(pInputCodecContext);
     av_free(pInputFormatContext);
     av_free(pOutFormatContext);

     return 0;
 }

 void SaveBmp(AVCodecContext *CodecContex, AVFrame *Picture, int width, int height)
 {
     AVPicture pPictureRGB;//RGB图片

     static struct SwsContext *img_convert_ctx;
     img_convert_ctx = sws_getContext(width, height, CodecContex->pix_fmt, width, height,\
         PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL);
     avpicture_alloc(&pPictureRGB, PIX_FMT_RGB24, width, height);
     sws_scale(img_convert_ctx, Picture->data, Picture->linesize,\
         0, height, pPictureRGB.data, pPictureRGB.linesize);

     int lineBytes = pPictureRGB.linesize[0], i=0;

     char fileName[1024]={0};
     time_t ltime;
     time(<ime);
     sprintf(fileName, "%d.bmp", ltime);

     FILE *pDestFile = fopen(fileName, "wb");
     BITMAPFILEHEADER btfileHeader;
     btfileHeader.bfType = MAKEWORD(66, 77);
     btfileHeader.bfSize = lineBytes*height;
     btfileHeader.bfReserved1 = 0;
     btfileHeader.bfReserved2 = 0;
     btfileHeader.bfOffBits = 54;

     BITMAPINFOHEADER bitmapinfoheader;
     bitmapinfoheader.biSize = 40;
     bitmapinfoheader.biWidth = width;
     bitmapinfoheader.biHeight = height;
     bitmapinfoheader.biPlanes = 1;
     bitmapinfoheader.biBitCount = 24;
     bitmapinfoheader.biCompression = BI_RGB;
     bitmapinfoheader.biSizeImage = lineBytes*height;
     bitmapinfoheader.biXPelsPerMeter = 0;
     bitmapinfoheader.biYPelsPerMeter = 0;
     bitmapinfoheader.biClrUsed = 0;
     bitmapinfoheader.biClrImportant = 0;

     fwrite(&btfileHeader, 14, 1, pDestFile);
     fwrite(&bitmapinfoheader, 40, 1, pDestFile);
     for(i=height-1; i>=0; i--)
     {
         fwrite(pPictureRGB.data[0]+i*lineBytes, lineBytes, 1, pDestFile);
     }

     fclose(pDestFile);
     avpicture_free(&pPictureRGB);
 }