FFMPEG_avi转码到mp4(aac+h264)源码

001#include <ffmpeg/avcodec.h>

002#include <ffmpeg/avformat.h>

003#include <stdio.h>

004#include <ffmpeg/avutil.h>

005#include <stdio.h>

006#include <stdlib.h>

007#include <string.h>

008void pstrcpy(char *buf, int buf_size, const char *str)

009{

010    int c;//why int here

011    char *q = buf;

012 

013    if (buf_size <= 0)

014        return;

015 

016    for(;;) {

017        c = *str++;

018        if (c == 0 || q >= buf + buf_size - 1)

019            break;

020        *q++ = c;

021    }

022    *q = '\0';

023}

024main(int argc,char **argv)

025{  

026  const char *input_file_name="/home/movie.avi";

027  av_register_all();//注册库中所有可用的文件格式和编码器

028  AVFormatContext *ic;

029  //输入文件处理部分

030  ic=av_alloc_format_context();

031  if(av_open_input_file(&ic,input_file_name,NULL,0,NULL)!=0)

032  {

033     printf("can't open the file %s\n",input_file_name);

034     exit(1);

035  }//打开输入文件 

036  if(av_find_stream_info(ic)<0)

037  {

038     printf("can't find suitable codec parameters\n");

039     exit(1);

040  }//取出流信息

041   

042  dump_format(ic,0,input_file_name,0);//列出输入文件的相关流信息

043  int i;

044  int videoindex=-1;int audioindex=-1;

045  for(i=0;i<ic->nb_streams;i++)

046  {  

047     if(ic->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO)

048         {

049            videoindex=i;

050          //printf("video\n");

051         }

052         else if(ic->streams[i]->codec->codec_type==CODEC_TYPE_AUDIO)

053         {

054          //printf("audio\n");

055            audioindex=i;

056         }

057  }

058   if(videoindex==-1)

059   {

060          printf("can't find video stream\n");

061          exit(1);

062   }//没有找到视频流

063    

064    

065  AVCodecContext *vCodecCtx;

066  vCodecCtx=ic->streams[videoindex]->codec;//取得视频流编码上下文指针

067  AVCodec *vCodec;

068  vCodec=avcodec_find_decoder(vCodecCtx->codec_id);

069  if(vCodec==NULL)

070  {

071     printf("can't find suitable video decoder\n");

072     exit(1);

073  }//找到合适的视频解码器

074  if(avcodec_open(vCodecCtx,vCodec)<0)

075  {

076     printf("can't open the video decoder\n");

077     exit(1);

078  }//打开该视频解码器

079   

080   

081   if(audioindex==-1)

082     {

083        printf("can't find audio stream\n");

084        exit(1);

085     }//没有找到音频流

086  AVCodecContext *aCodecCtx;

087  aCodecCtx=ic->streams[audioindex]->codec;

088  AVCodec *aCodec;

089  aCodec=avcodec_find_decoder(aCodecCtx->codec_id);

090  if(aCodec==NULL)

091  {

092     printf("can't find suitable audio decoder\n");

093     exit(1);

094  }//找到合适的音频解码器

095  if(avcodec_open(aCodecCtx,aCodec)<0)

096  {

097     printf("can't open the audio decoder\n");

098     exit(1);

099  }//打开该音频解码器

100   

101   

102//下面为输出文件处理部分

103    const char *output_file_name="/home/result.aac";

104    AVOutputFormat *fmt;

105    AVFormatContext *oc;

106    AVCodecContext *oVcc,*oAcc;

107    AVCodec *oVc,*oAc;

108    AVStream *video_st,*audio_st;

109    AVFrame *oVFrame,*oAFrame;

110    double video_pts;

111    oVFrame=avcodec_alloc_frame();

112    fmt=guess_format(NULL,output_file_name,NULL);

113    if(!fmt)

114    {

115           printf("could not deduce output format from outfile extension\n");

116           exit(0);

117    }//判断是否可以判断输出文件的编码格式

118    oc=av_alloc_format_context();

119    if(!oc)

120    {

121           printf("Memory error\n");

122           exit(0);

123    }

124    oc->oformat=fmt;

125   pstrcpy(oc->filename,sizeof(oc->filename),output_file_name);

126   

127    video_st=av_new_stream(oc,0);

128    if(!video_st)

129    {

130          printf("could not alloc video stream\n");

131          exit(0);

132    }

133    oVcc=avcodec_alloc_context();

134    oVcc=video_st->codec;

135    oVcc->codec_id=CODEC_ID_H264;

136    oVcc->codec_type=CODEC_TYPE_VIDEO;

137    oVcc->bit_rate=1000000;

138    oVcc->width=320;

139    oVcc->height=240;

140    oVcc->time_base=vCodecCtx->time_base;

141    oVcc->gop_size=vCodecCtx->gop_size;

142    //oVcc->pix_fmt=vCodecCtx->pix_fmt;

143    oVcc->pix_fmt=vCodecCtx->pix_fmt;

144    oVcc->max_b_frames=vCodecCtx->max_b_frames;

145    video_st->r_frame_rate=ic->streams[videoindex]->r_frame_rate;// frame rate

146   // audio_st=av_new_stream(oc,oc->nb_streams);   //

147    audio_st=av_new_stream(oc,1);

148    if(!audio_st)

149    {

150           printf("could not alloc audio stream\n");

151           exit(0);

152    } 

153   // avcodec_get_context_defaults2(audio_st->codec,CODEC_TYPE_AUDIO);

154   avcodec_get_context_defaults(audio_st->codec);//  do what

155    oAcc=avcodec_alloc_context();

156    oAcc=audio_st->codec;

157    oAcc->codec_id=CODEC_ID_AAC;

158    oAcc->codec_type=CODEC_TYPE_AUDIO;

159    oAcc->bit_rate=aCodecCtx->bit_rate;// bit rate

160    oAcc->sample_rate=aCodecCtx->sample_rate;

161    oAcc->channels=2;

162    if (av_set_parameters(oc, NULL) < 0)

163    {

164           printf( "Invalid output format parameters\n");                       

165              exit(0);                             

166    }//设置必要的输出参数

167    strcpy(oc->title,ic->title);

168    strcpy(oc->author,ic->author);

169    strcpy(oc->copyright,ic->copyright);

170    strcpy(oc->comment,ic->comment);

171    strcpy(oc->album,ic->album);

172    oc->year=ic->year;

173    oc->track=ic->track;

174    strcpy(oc->genre,ic->genre);

175    dump_format(oc,0,output_file_name,1);//列出输出文件的相关流信息

176    oVc=avcodec_find_encoder(CODEC_ID_H264);

177    if(!oVc)

178    {

179       printf("can't find suitable video encoder\n");

180           exit(0);

181    }//找到合适的视频编码器

182    if(avcodec_open(oVcc,oVc)<0)

183    {

184           printf("can't open the output video codec\n");

185           exit(0);

186    }//打开视频编码器

187    oAc=avcodec_find_encoder(CODEC_ID_AAC);

188    if(!oAc)

189    {

190           printf("can't find suitable audio encoder\n");

191           exit(0);

192    }//找到合适的音频编码器

193    if(avcodec_open(oAcc,oAc)<0)

194    {

195           printf("can't open the output audio codec");

196           exit(0);

197    }//打开音频编码器

198    /*if(url_exist(output_file_name))

199    {

200       printf("the output file name %s has exist,please select other\n",output_file_name);

201       exit(0);

202    }//判断该输出文件是否已经存在*/

203    if (!(oc->flags & AVFMT_NOFILE))

204    {

205       if(url_fopen(&oc->pb,output_file_name,URL_WRONLY)<0)

206       {

207              printf("can't open the output file %s\n",output_file_name);

208              exit(0);

209       }//打开输出文件

210    }

211    if(!oc->nb_streams)

212    {

213           fprintf(stderr,"output file dose not contain any stream\n");

214           exit(0);

215    }//查看输出文件是否含有流信息

216  if(av_write_header(oc)<0)

217  {

218      fprintf(stderr, "Could not write header for output file\n");

219      exit(1);

220  }

221   

222AVPacket packet;

223  uint8_t *ptr,*out_buf;

224  int out_size;

225  static short *samples=NULL;

226  static unsigned int samples_size=0;

227  uint8_t *video_outbuf,*audio_outbuf;

228  int video_outbuf_size,audio_outbuf_size;

229  video_outbuf_size=400000;

230  video_outbuf= (unsigned char *) malloc(video_outbuf_size);

231  audio_outbuf_size = 10000;

232    //audio_outbuf = av_malloc(audio_outbuf_size);

233  audio_outbuf = (unsigned char *) malloc(audio_outbuf_size);

234  int flag;int frameFinished;int len;int frame_index=0,ret;

235          while(av_read_frame(ic,&packet)>=0)//从输入文件中读取一个包

236       {

237          if(packet.stream_index==videoindex)//判断是否为当前视频流中的包

238          {

239         len=avcodec_decode_video(vCodecCtx,oVFrame,&frameFinished,packet.data,packet.size);//若为视频包，解码该视频包

240                 if(len<0)

241                 {

242                    printf("Error while decoding\n");

243                    exit(0);

244                 }

245      

246         if(frameFinished)//判断视频祯是否读完

247          

248         {

249             fflush(stdout);

250             oVFrame->pts=av_rescale(frame_index,AV_TIME_BASE*(int64_t)oVcc->time_base.num,oVcc->time_base.den);

251             oVFrame->pict_type=0;

252             out_size = avcodec_encode_video(oVcc, video_outbuf, video_outbuf_size, oVFrame);  

253             if (out_size > 0)           

254             {                 

255                 AVPacket pkt;              

256                 av_init_packet(&pkt);                             

257                 if(oVcc->coded_frame && oVcc->coded_frame->key_frame)                                      

258                     pkt.flags |= PKT_FLAG_KEY;                                      

259                     pkt.flags = packet.flags;                    

260                     pkt.stream_index= video_st->index;                                              

261                     pkt.data= video_outbuf;                                                        

262                     pkt.size= out_size;                                            

263                     ret=av_write_frame(oc, &pkt);                                      

264             }

265             frame_index++;

266         }

267         else

268            {

269              printf(".....\n");                                      

270             }

271                   #if 0

272                   if(ret!=0)

273                    {

274                      printf("while write video frame error\n");

275                     // exit(0);

276                    }

277                    #endif

278                   

279          }else if(packet.stream_index==audioindex)

280      {

281         len=packet.size;

282         ptr=packet.data;

283             int ret=0;

284             while(len>0)

285             {

286                    out_buf=NULL;

287                    out_size=0;

288                    if(&packet)

289               samples=(short *)av_fast_realloc(samples,&samples_size,FFMAX(packet.size*sizeof

290(*samples),AVCODEC_MAX_AUDIO_FRAME_SIZE));

291                    out_size=samples_size;

292                    ret=avcodec_decode_audio(aCodecCtx,samples,&out_size,ptr,len);//若为音频包，解码该音频包

293                    if(ret<0)

294                    {

295                       printf("while decode audio failure\n");

296                       exit(0);

297                    }

298            fflush(stdout);

299            ptr+=ret;

300            len-=ret;

301            if(out_size<=0)

302               continue;

303            out_buf=(uint8_t *)samples;

304            AVPacket pkt;

305            av_init_packet(&pkt);

306            pkt.size= avcodec_encode_audio(oAcc, audio_outbuf, audio_outbuf_size, (short int*)out_buf);

307            pkt.pts= av_rescale_q(oAcc->coded_frame->pts, oAcc->time_base, audio_st->time_base);

308            pkt.flags |= PKT_FLAG_KEY;

309            pkt.stream_index= audioindex;

310            pkt.data= audio_outbuf;

311            

312          #if 1

313            if (av_write_frame(oc, &pkt) != 0)

314                    {

315               fprintf(stderr, "Error while writing audio frame\n");

316               exit(1);

317                }

318              #endif 

319             }

320          }

321          av_free_packet(&packet);

322       }

323       

324av_write_trailer(oc);

325 

326for(i = 0; i < oc->nb_streams; i++)

327{           

328  av_freep(&oc->streams[i]->codec);                      

329  av_freep(&oc->streams[i]);                          

330}

331//url_fclose(oc);

332av_free(oc);

333av_free(oVFrame);

334av_free(out_buf);

335avcodec_close(vCodecCtx);

336avcodec_close(aCodecCtx);

337av_close_input_file(ic);

338 

339}