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• How to scale watermark in percent with ffmpeg ? [duplicate]

  31 décembre 2015, par user3390767

  This question already has an answer here :

  • How to scale and position watermark to scale ?
    
    1 answer
    

  I run a video site, but watermark logo still in different sizes in every video with different resolution.
  My question : is there a way to scale watermark image in every video by some kind of percentage ?
  I use next command :

  /usr/bin/ffmpeg -i video_in.mp4 -f mp4 -vcodec libx264 -r 30 -movflags
  faststart -profile:v baseline -vf "movie=logo.png, scale=200:37
  [watermark] ; [in][watermark] overlay=10:10 [out]" -s 640x360 -acodec
  libfaac -ab 128k -ar 44100 video_out.mp4

  So as you see the scale of watermark is static, but I want to make it dynamic. Is there way to do this in percentage by depending of video resolution ?

  Cheers !

• ffmpeg : RGB to YUV conversion loses color and scale

  27 avril 2015, par learner

  I am trying to convert RGB frames to YUV420P format in ffmpeg/libav. Following is the code for conversion and also the images before and after conversion. The converted image loses all color information and also the scale changes significantly. Does anybody have idea how to handle this ? I am completely new to ffmpeg/libav !

  // Did we get a video frame?
  
     if(frameFinished)
  
     {
  
         i++;
  
         sws_scale(img_convert_ctx, (const uint8_t * const *)pFrame->data,
  
                   pFrame->linesize, 0, pCodecCtx->height,
  
                   pFrameRGB->data, pFrameRGB->linesize);                   
  
  
  
         //==============================================================
  
         AVFrame *pFrameYUV = avcodec_alloc_frame();
  
         // Determine required buffer size and allocate buffer
  
         int numBytes2 = avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width,                                 
  
                                            pCodecCtx->height);
  
         uint8_t *buffer = (uint8_t *)av_malloc(numBytes2*sizeof(uint8_t));
  
  
  
         avpicture_fill((AVPicture *)pFrameYUV, buffer, PIX_FMT_RGB24,
  
                         pCodecCtx->width, pCodecCtx->height);
  
  
  
  
  
         rgb_to_yuv_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,  
  
                                         PIX_FMT_RGB24,
  
                                         pCodecCtx->width,pCodecCtx->height, 
  
                                         PIX_FMT_RGB24,
  
                                         SWS_BICUBIC, NULL,NULL,NULL);
  
  
  
         sws_scale(rgb_to_yuv_ctx, pFrameRGB->data, pFrameRGB->linesize, 0, 
  
                   pCodecCtx->height, pFrameYUV->data, pFrameYUV->linesize);
  
  
  
         sws_freeContext(rgb_to_yuv_ctx);
  
  
  
         SaveFrame(pFrameYUV, pCodecCtx->width, pCodecCtx->height, i);
  
  
  
         av_free(buffer);
  
         av_free(pFrameYUV);
  
     }

  

  

• I want to scale three videos and one background image using ffmpeg

  24 octobre 2016, par Bhushan kumar

  I have three video’s and a image i have combined all four together using ffmpeg overlay filter but don’t know how to arrange theme like this :

  

  I’m currently doing like this

  ffmpeg -i bk.jpg -i Movie1.mp4 -i Movie2.mp4 -i Movie3.mp4
  -filter_complex "[0:v]pad=1280:720 [ov1],[1:v][ov1]overlay=25:25 [ov2],[2:v][ov2]overlay=20:20 [ov3],[3:v][ov3]overlay=20:20 [ov4]" -s
  1280*720 -map [ov4] output.mp4`

  Thanks any help will be appreciated