FFMPEG_avi轉碼到mp4(aac+h264)源碼

#include <ffmpeg/avcodec.h>
#include <ffmpeg/avformat.h>
#include <stdio.h>
#include <ffmpeg/avutil.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void pstrcpy(char *buf, int buf_size, const char *str)
{
    int c;//why int here
    char *q = buf;

    if (buf_size <= 0)
        return;

    for(;;) {
        c = *str++;
        if (c == 0 || q >= buf + buf_size - 1)
            break;
        *q++ = c;
    }
    *q = '\0';
}
main(int argc,char **argv)
{   
  const char *input_file_name="/home/movie.avi";
  av_register_all();//註冊庫中全部可用的文件格式和編碼器
  AVFormatContext *ic;
  //輸入文件處理部分
  ic=av_alloc_format_context();
  if(av_open_input_file(&ic,input_file_name,NULL,0,NULL)!=0)
  {
     printf("can't open the file %s\n",input_file_name);
     exit(1);
  }//打開輸入文件  
  if(av_find_stream_info(ic)<0)
  {
     printf("can't find suitable codec parameters\n");
     exit(1);
  }//取出流信息
  
  dump_format(ic,0,input_file_name,0);//列出輸入文件的相關流信息
  int i;
  int videoindex=-1;int audioindex=-1;
  for(i=0;i<ic->nb_streams;i++)
  {   
     if(ic->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO)
         {
            videoindex=i;
          //printf("video\n");
         }
         else if(ic->streams[i]->codec->codec_type==CODEC_TYPE_AUDIO)
         {
          //printf("audio\n");
            audioindex=i;
         }
  }
   if(videoindex==-1)
   {
          printf("can't find video stream\n");
          exit(1);
   }//沒有找到視頻流
   
   
  AVCodecContext *vCodecCtx;
  vCodecCtx=ic->streams[videoindex]->codec;//取得視頻流編碼上下文指針
  AVCodec *vCodec;
  vCodec=avcodec_find_decoder(vCodecCtx->codec_id);
  if(vCodec==NULL)
  {
     printf("can't find suitable video decoder\n");
     exit(1);
  }//找到合適的視頻解碼器
  if(avcodec_open(vCodecCtx,vCodec)<0)
  {
     printf("can't open the video decoder\n");
     exit(1);
  }//打開該視頻解碼器
  
  
   if(audioindex==-1)
     {
        printf("can't find audio stream\n");
        exit(1);
     }//沒有找到音頻流
  AVCodecContext *aCodecCtx;
  aCodecCtx=ic->streams[audioindex]->codec;
  AVCodec *aCodec;
  aCodec=avcodec_find_decoder(aCodecCtx->codec_id);
  if(aCodec==NULL)
  {
     printf("can't find suitable audio decoder\n");
     exit(1);
  }//找到合適的音頻解碼器
  if(avcodec_open(aCodecCtx,aCodec)<0)
  {
     printf("can't open the audio decoder\n");
     exit(1);
  }//打開該音頻解碼器
  
  
//下面爲輸出文件處理部分
    const char *output_file_name="/home/result.aac";
    AVOutputFormat *fmt;
    AVFormatContext *oc;
    AVCodecContext *oVcc,*oAcc;
    AVCodec *oVc,*oAc;
    AVStream *video_st,*audio_st;
    AVFrame *oVFrame,*oAFrame;
    double video_pts;
    oVFrame=avcodec_alloc_frame();
    fmt=guess_format(NULL,output_file_name,NULL);
    if(!fmt)
    {
           printf("could not deduce output format from outfile extension\n");
           exit(0);
    }//判斷是否能夠判斷輸出文件的編碼格式
    oc=av_alloc_format_context();
    if(!oc)
    {
           printf("Memory error\n");
           exit(0);
    }
    oc->oformat=fmt;
   pstrcpy(oc->filename,sizeof(oc->filename),output_file_name);
  
    video_st=av_new_stream(oc,0);
    if(!video_st)
    {
          printf("could not alloc video stream\n");
          exit(0);
    }
    oVcc=avcodec_alloc_context();
    oVcc=video_st->codec;
    oVcc->codec_id=CODEC_ID_H264;
    oVcc->codec_type=CODEC_TYPE_VIDEO;
    oVcc->bit_rate=1000000;
    oVcc->width=320;
    oVcc->height=240;
    oVcc->time_base=vCodecCtx->time_base;
    oVcc->gop_size=vCodecCtx->gop_size;
    //oVcc->pix_fmt=vCodecCtx->pix_fmt;
    oVcc->pix_fmt=vCodecCtx->pix_fmt;
    oVcc->max_b_frames=vCodecCtx->max_b_frames;
    video_st->r_frame_rate=ic->streams[videoindex]->r_frame_rate;// frame rate
   // audio_st=av_new_stream(oc,oc->nb_streams);   //
    audio_st=av_new_stream(oc,1);
    if(!audio_st)
    {
           printf("could not alloc audio stream\n");
           exit(0);
    }  
   // avcodec_get_context_defaults2(audio_st->codec,CODEC_TYPE_AUDIO);
   avcodec_get_context_defaults(audio_st->codec);//  do what
    oAcc=avcodec_alloc_context();
    oAcc=audio_st->codec;
    oAcc->codec_id=CODEC_ID_AAC;
    oAcc->codec_type=CODEC_TYPE_AUDIO;
    oAcc->bit_rate=aCodecCtx->bit_rate;// bit rate
    oAcc->sample_rate=aCodecCtx->sample_rate;
    oAcc->channels=2;
    if (av_set_parameters(oc, NULL) < 0)
    {
           printf( "Invalid output format parameters\n");                        
              exit(0);                              
    }//設置必要的輸出參數
    strcpy(oc->title,ic->title);
    strcpy(oc->author,ic->author);
    strcpy(oc->copyright,ic->copyright);
    strcpy(oc->comment,ic->comment);
    strcpy(oc->album,ic->album);
    oc->year=ic->year;
    oc->track=ic->track;
    strcpy(oc->genre,ic->genre);
    dump_format(oc,0,output_file_name,1);//列出輸出文件的相關流信息
    oVc=avcodec_find_encoder(CODEC_ID_H264);
    if(!oVc)
    {
       printf("can't find suitable video encoder\n");
           exit(0);
    }//找到合適的視頻編碼器
    if(avcodec_open(oVcc,oVc)<0)
    {
           printf("can't open the output video codec\n");
           exit(0);
    }//打開視頻編碼器
    oAc=avcodec_find_encoder(CODEC_ID_AAC);
    if(!oAc)
    {
           printf("can't find suitable audio encoder\n");
           exit(0);
    }//找到合適的音頻編碼器
    if(avcodec_open(oAcc,oAc)<0)
    {
           printf("can't open the output audio codec");
           exit(0);
    }//打開音頻編碼器
    /*if(url_exist(output_file_name))
    {
       printf("the output file name %s has exist,please select other\n",output_file_name);
       exit(0);
    }//判斷該輸出文件是否已經存在*/
    if (!(oc->flags & AVFMT_NOFILE))
    {
       if(url_fopen(&oc->pb,output_file_name,URL_WRONLY)<0)
       {
              printf("can't open the output file %s\n",output_file_name);
              exit(0);
       }//打開輸出文件
    }
    if(!oc->nb_streams)
    {
           fprintf(stderr,"output file dose not contain any stream\n");
           exit(0);
    }//查看輸出文件是否含有流信息
  if(av_write_header(oc)<0)
  {
      fprintf(stderr, "Could not write header for output file\n");
      exit(1);
  }
  
AVPacket packet;
  uint8_t *ptr,*out_buf;
  int out_size;
  static short *samples=NULL;
  static unsigned int samples_size=0;
  uint8_t *video_outbuf,*audio_outbuf;
  int video_outbuf_size,audio_outbuf_size;
  video_outbuf_size=400000;
  video_outbuf= (unsigned char *) malloc(video_outbuf_size);
  audio_outbuf_size = 10000;
    //audio_outbuf = av_malloc(audio_outbuf_size);
  audio_outbuf = (unsigned char *) malloc(audio_outbuf_size);
  int flag;int frameFinished;int len;int frame_index=0,ret;
          while(av_read_frame(ic,&packet)>=0)//從輸入文件中讀取一個包
       {
          if(packet.stream_index==videoindex)//判斷是否爲當前視頻流中的包
          {
         len=avcodec_decode_video(vCodecCtx,oVFrame,&frameFinished,packet.data,packet.size);//若爲視頻包，解碼該視頻包
                 if(len<0)
                 {
                    printf("Error while decoding\n");
                    exit(0);
                 }
     
         if(frameFinished)//判斷視頻禎是否讀完
         
         {
             fflush(stdout);
             oVFrame->pts=av_rescale(frame_index,AV_TIME_BASE*(int64_t)oVcc->time_base.num,oVcc->time_base.den);
             oVFrame->pict_type=0;
             out_size = avcodec_encode_video(oVcc, video_outbuf, video_outbuf_size, oVFrame);   
             if (out_size > 0)            
             {                  
                 AVPacket pkt;               
                 av_init_packet(&pkt);                              
                 if(oVcc->coded_frame && oVcc->coded_frame->key_frame)                                       
                     pkt.flags |= PKT_FLAG_KEY;                                       
                     pkt.flags = packet.flags;                     
                     pkt.stream_index= video_st->index;                                               
                     pkt.data= video_outbuf;                                                         
                     pkt.size= out_size;                                             
                     ret=av_write_frame(oc, &pkt);                                       
             }
             frame_index++;
         }
         else
            {
              printf(".....\n");                                       
             }
                   #if 0
                   if(ret!=0)
                    {
                      printf("while write video frame error\n");
                     // exit(0);
                    }
                    #endif
                  
          }else if(packet.stream_index==audioindex)
      {
         len=packet.size;
         ptr=packet.data;
             int ret=0;
             while(len>0)
             {
                    out_buf=NULL;
                    out_size=0;
                    if(&packet)
               samples=(short *)av_fast_realloc(samples,&samples_size,FFMAX(packet.size*sizeof
(*samples),AVCODEC_MAX_AUDIO_FRAME_SIZE));
                    out_size=samples_size;
                    ret=avcodec_decode_audio(aCodecCtx,samples,&out_size,ptr,len);//若爲音頻包，解碼該音頻包
                    if(ret<0)
                    {
                       printf("while decode audio failure\n");
                       exit(0);
                    }
            fflush(stdout);
            ptr+=ret;
            len-=ret;
            if(out_size<=0)
               continue;
            out_buf=(uint8_t *)samples;
            AVPacket pkt;
            av_init_packet(&pkt);
            pkt.size= avcodec_encode_audio(oAcc, audio_outbuf, audio_outbuf_size, (short int*)out_buf);
            pkt.pts= av_rescale_q(oAcc->coded_frame->pts, oAcc->time_base, audio_st->time_base);
            pkt.flags |= PKT_FLAG_KEY;
            pkt.stream_index= audioindex;
            pkt.data= audio_outbuf;
           
          #if 1
            if (av_write_frame(oc, &pkt) != 0)
                    {
               fprintf(stderr, "Error while writing audio frame\n");
               exit(1);
                }
              #endif  
             }
          }
          av_free_packet(&packet);
       }
      
av_write_trailer(oc);

for(i = 0; i < oc->nb_streams; i++)
{            
  av_freep(&oc->streams[i]->codec);                       
  av_freep(&oc->streams[i]);                           
}
//url_fclose(oc);
av_free(oc);
av_free(oVFrame);
av_free(out_buf);
avcodec_close(vCodecCtx);
avcodec_close(aCodecCtx);
av_close_input_file(ic);

}