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• swscale : save ebx register when it is not available

  16 décembre 2016, par Andreas Cadhalpun

  swscale : save ebx register when it is not available
  Configure checks if the ebx register can be used for asm and it has to
  
  be saved if and only if this is not the case.
  
  Without this the build fails when configuring with —toolchain=hardened
  
  — disable-pic on i386 using gcc 4.8 :
  
  error : PIC register clobbered by ’%ebx’ in ’asm’
  In that case gcc 4.8 reserves the ebx register for the GOT needed for
  
  PIE, so it can’t be used in asm directly.
  Reviewed-by : Michael Niedermayer <michael@niedermayer.cc>
  
  Signed-off-by : Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
  

  • [DH] libswscale/x86/hscale_fast_bilinear_simd.c

• converting images to mp4 using ffmpeg on iphone

  29 novembre 2011, par user633901

  Up till now, i can create mpeg1 but with no luck for mp4.Maybe we can talk and share information.Someone told me that i have to set some flags for using mp4.But i am stuck at using it...

  following is the working code :

  av_register_all();
  
  printf("Video encoding\n"); 
  
  
  
  /// find the mpeg video encoder 
  
  //codec=avcodec_find_encoder(CODEC_ID_MPEG1VIDEO); 
  
  codec = avcodec_find_encoder(CODEC_ID_MPEG4); 
  
  
  
  if (!codec) { 
  
      fprintf(stderr, "codec not found\n"); 
  
      exit(1); 
  
  } 
  
  
  
  c = avcodec_alloc_context(); 
  
  picture = avcodec_alloc_frame(); 
  
  
  
  // put sample parameters 
  
  c->bit_rate = 400000;
  
  /// resolution must be a multiple of two 
  
  c->width = 240; 
  
  c->height = 320; 
  
  //c->codec_id = fmt->video_codec;
  
  //frames per second 
  
  c->time_base= (AVRational){1,25}; 
  
  c->gop_size = 10; /// emit one intra frame every ten frames 
  
  c->max_b_frames=1; 
  
  c->pix_fmt =PIX_FMT_YUV420P; // PIX_FMT_YUV420P
  
  
  
  if (avcodec_open(c, codec) < 0) { 
  
      fprintf(stderr, "could not open codec\n"); 
  
      exit(1); 
  
  }
  
  
  
  f = fopen([[NSHomeDirectory() stringByAppendingPathComponent:@"test.mp4"] UTF8String], "wb"); 
  
  
  
  if (!f) { 
  
      fprintf(stderr, "could not open %s\n",[@"test.mp4" UTF8String]); 
  
      exit(1); 
  
  } 
  
  
  
  // alloc image and output buffer 
  
  outbuf_size = 100000; 
  
  outbuf = malloc(outbuf_size); 
  
  size = c->width * c->height; 
  
  
  
  #pragma mark - 
  
  
  
  AVFrame* outpic = avcodec_alloc_frame(); 
  
  int nbytes = avpicture_get_size(PIX_FMT_YUV420P, c->width, c->height); //this is half size of numbytes. 
  
  
  
  //create buffer for the output image 
  
  uint8_t* outbuffer = (uint8_t*)av_malloc(nbytes); 
  
  
  
  #pragma mark -  
  
  for(k=0;k<1;k++) { 
  
      for(i=0;i<25;i++) { 
  
          fflush(stdout); 
  
  
  
          int numBytes = avpicture_get_size(PIX_FMT_RGBA, c->width, c->height); 
  
          uint8_t *buffer = (uint8_t *)av_malloc(numBytes*sizeof(uint8_t)); 
  
  
  
          UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:@"%d.png", i+1]]; 
  
          CGImageRef newCgImage = [image CGImage]; 
  
  
  
          CGDataProviderRef dataProvider = CGImageGetDataProvider(newCgImage); 
  
          CFDataRef bitmapData = CGDataProviderCopyData(dataProvider); 
  
          buffer = (uint8_t *)CFDataGetBytePtr(bitmapData);   
  
          /////////////////////////// 
  
          //outbuffer=(uint8_t *)CFDataGetBytePtr(bitmapData); 
  
          ////////////////////////// 
  
          avpicture_fill((AVPicture*)picture, buffer, PIX_FMT_RGBA, c->width, c->height); 
  
          avpicture_fill((AVPicture*)outpic, outbuffer, PIX_FMT_YUV420P, c->width, c->height);//does not have image data. 
  
  
  
          struct SwsContext* fooContext = sws_getContext(c->width, c->height, 
  
                                                        PIX_FMT_RGBA, 
  
                                                        c->width, c->height, 
  
                                                        PIX_FMT_YUV420P, 
  
                                                        SWS_FAST_BILINEAR, NULL, NULL, NULL); 
  
  
  
          //perform the conversion 
  
          sws_scale(fooContext, picture->data, picture->linesize, 0, c->height, outpic->data, outpic->linesize); 
  
          // Here is where I try to convert to YUV 
  
  
  
          // encode the image 
  
          out_size = avcodec_encode_video(c, outbuf, outbuf_size, outpic); 
  
          printf("encoding frame %3d (size=%5d)\n", i, out_size); 
  
          fwrite(outbuf, 1, out_size, f); 
  
  
  
          free(buffer); 
  
          buffer = NULL;
  
      }
  
  
  
      // get the delayed frames 
  
      for(; out_size; i++) { 
  
          fflush(stdout); 
  
  
  
          out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL); 
  
          printf("write frame %3d (size=%5d)\n", i, out_size); 
  
          fwrite(outbuf, 1, outbuf_size, f);       
  
      } 
  
  }
  
  
  
  // add sequence end code to have a real mpeg file 
  
  outbuf[0] = 0x00; 
  
  outbuf[1] = 0x00; 
  
  outbuf[2] = 0x01; 
  
  outbuf[3] = 0xb7; 
  
  fwrite(outbuf, 1, 4, f); 
  
  fclose(f); 
  
  free(picture_buf);
  
  free(outbuf); 
  
  
  
  avcodec_close(c); 
  
  av_free(c); 
  
  av_free(picture); 
  
  //av_free(outpic); 
  
  printf("\n"); 

  my msn:hieeli@hotmail.com

• Revision 60456083e9 : Do joint motion search iteratively Allow motion search multiple times iterative

  11 mai 2013, par Yunqing Wang

  Changed Paths :
   Modify /vp9/encoder/vp9_rdopt.c

  
  
  Do joint motion search iteratively

  Allow motion search multiple times iteratively, and break out
  the loop if this search couldn't find better motion vectors.
  Limit the maximum number of search to 2.

  Tests results :
  1. stdhd set : 0.311%(overall psnr) ; 0.346%(ssim).
  positive gain on 10 out of 16 clips(best : 2.746% on sunflower ;
  worst : -0.434% on old_town_cross).
  2. derf set : 0.016%(overall psnr) ; 0.062%(ssim).
  positive gain on half of the clips(best : 0.499% on bowing ;
  worst : -0.387 on city).

  Change-Id : Ibf0a51776d4caf7707be0586346db08128117559