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• FFmpeg : avcodec_encode_video() and JPEG images

  2 février 2012, par user105909

  I'm trying to encode a series of .jpg files into a video using the ffmpeg library, and I can't seem to get the frames to encode. (I have to use the ffmpeg library, and using ffmpeg from a command line is not an option in my case.)

  Except for the part where I'm trying to open JPG files as AVFrames, my code is more or less the same thing as found in api-example.c from the ffmpeg library. When I populate the frames as the example does, everything works as expected. In the code below, I fail to encode any frames. Obviously the trouble is related to how I'm opening the JPG files, but I can't figure out what.

  I'm opening the image like this :

  AVFrame* open_image(const char* imageFileName, int width, int height, long * bufSize)
  
  {
  
      AVFormatContext *pFormatCtx;
  
  
  
      if(av_open_input_file(&pFormatCtx, imageFileName, NULL, 0, NULL)!=0)
  
      {
  
          printf("Can't open image file '%s'\n", imageFileName);
  
          return NULL;
  
      }       
  
  
  
      AVCodecContext *pCodecCtx;
  
  
  
      pCodecCtx = pFormatCtx->streams[0]->codec;
  
      pCodecCtx->width = width;
  
      pCodecCtx->height = height;
  
      pCodecCtx->pix_fmt = PIX_FMT_YUV420P;
  
  
  
      // Find the decoder for the video stream
  
      AVCodec *pCodec = avcodec_find_decoder(pCodecCtx->codec_id);
  
      if (!pCodec)
  
      {
  
          printf("Codec not found\n");
  
          return NULL;
  
      }
  
  
  
      // Open codec
  
      if(avcodec_open(pCodecCtx, pCodec)<0)
  
      {
  
          printf("Could not open codec\n");
  
          return NULL;
  
      }
  
  
  
      AVFrame *pFrame = avcodec_alloc_frame();
  
      if (!pFrame)
  
      {
  
          LOGV(TAG, "Can't allocate memory for AVFrame\n");
  
          return NULL;
  
      }
  
  
  
      int frameFinished;
  
      int numBytes;
  
  
  
      // Determine required buffer size and allocate buffer
  
      numBytes = avpicture_get_size(PIX_FMT_YUVJ420P, pCodecCtx->width, pCodecCtx->height);
  
  
  
      // ***
  
      *bufSize = numBytes;
  
      // ***
  
  
  
      uint8_t *buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));
  
  
  
      avpicture_fill((AVPicture *) pFrame, buffer, PIX_FMT_YUVJ420P, pCodecCtx->width, pCodecCtx->height);
  
  
  
      // Read frame
  
  
  
      AVPacket packet;
  
  
  
      int framesNumber = 0;
  
      while (av_read_frame(pFormatCtx, &packet) >= 0)
  
      {
  
          if(packet.stream_index != 0)
  
              continue;
  
  
  
          int ret = avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
  
          if (ret > 0)
  
          {
  
              sprintf(buf, "Frame is decoded, size %d", ret);
  
              LOGV(TAG, buf);
  
              pFrame->quality = 4;
  
              return pFrame;
  
          }
  
          else {
  
              // printf("Error [%d] while decoding frame: %s\n", ret, strerror(AVERROR(ret)));
  
              sprintf(buf, "Error %d decoding frame: %s", ret, strerror(AVERROR(ret)));
  
              LOGV(TAG, buf);
  
          }
  
      }
  
  }

  ...and attempting to encode them like this :

  DIR * dir = opendir(path);
  
  int i = 0;
  
  
  
  if (dir != NULL) {
  
  
  
      for(struct dirent *ent = readdir(dir); ent != NULL; ent = readdir(dir)) {
  
          fflush(stdout);
  
  
  
          printf("%s/%s", path, ent->d_name);
  
          LOGV(TAG, filename);
  
  
  
          // If not a jpg file, pass it over
  
          const char * ext = strrchr(filename, '.');
  
          if((!ext) || (strcmp(ext, ".jpg"))) {
  
              continue;
  
          }
  
  
  
          /*** NOTE: Is this where I've gone wrong? Bufsize is set in open_image based on av_picture_size() */
  
          long bufSize = 0L;
  
          AVFrame * frame = open_image(filename, width, height, &bufSize);
  
          if(frame) {
  
              // This is what it needs to do, and it does not work.
  
              // Causes:
  
              // Wrong format?
  
              // Wrong buffer size?
  
              uint8_t * picBuf = (uint8_t *)malloc(bufSize);
  
  
  
              out_size = avcodec_encode_video(c, picBuf, bufSize, frame);
  
  
  
              printf("encoding frame %3d (size=%5d)\n", i++, out_size);
  
              /** On the first image, out_size is 0. On the next, it's -1, and fails. */
  
  
  
              if(out_size < 0) {
  
                  printf("Error encoding frame");
  
                  return -6;
  
              }
  
  
  
              fwrite(picBuf, 1, bufSize, f);
  
  
  
              free(picBuf);
  
              av_free(frame);
  
          }
  
          else {
  
              printf("Couldn't open image");
  
              return -5;
  
          }
  
      }
  
  
  
      closedir(dir);
  
  } 
  
  else {
  
      printf("Couldn't open directory %s\n", path);
  
      return -4;
  
  }

  Could someone point me in the right direction ?

• pjsip build for iOS 5, won't make

  14 novembre 2013, par user1423591

  I retrieved the latest build from the SVN trunk on Friday and attempted to build following the directions on the getting started wiki.

  make dep seems to execute without any problems, but make fails on Samples.mak. It appears there are no rules to make any of the samples when the platform is "arm-apple-darwin9".

  If I open the Xcode project at this point, libavcodec and all it's related libraries are missing as well as LibSDL. There's not mention of a requirement to install SDL and ffmpeg beforehand, so not sure what to do there.

• Revision 38410 : début du grand chambardement ... Je commite maintenant car cela ne ...

  28 mai 2010, par kent1@… — Log

  début du grand chambardement ... Je commite maintenant car cela ne devrait pas casser les anciennes fonctionnalités... Beaucoup de nouvelles avec l’apparition de la fonction de journalisation inc/journal qui est voué à surcharger celle de la future version 2.2 de SPIP On journalise pour l’instant : (...)