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• save caca (ascii video) to an mp4 video [on hold]

  8 juillet 2013, par user2559158

  No problems viewing a caca file from mplayer (mplayer -vo caca), and it's also possible view the video file as caca with ffmpeg (fmpeg -i file.mp4 -f caca -pix_fmt rgb24 outputfile.mp4), but neither saves the file. Is there anyway to do it ?

• ffmpeg transconding one input video stream and multiple output video streams in the same file

  13 mars 2013, par user2165262

  I am trying to transcode a single video file with 1 video stream and several audio streams to the file having same video stream in different bitrates/sizes with correct padding at the same time.

  the command I use is :

      ffmpeg -y -ss 600 -t 600 -i "INPUT.mkv" -map_chapters -1 -map 0:0 -c:v libx264 -keyint_min 48 -g 96 -bufsize 350k -b:v 350k -minrate 300k -maxrate 400k -profile:v baseline -level 3.0 -preset slow -vf "scale=iw*min(480/iw\,272/ih):ih*min(480/iw\,272/ih),pad=480:272 :(480-iw)/2 :(272-ih)/2" -map 0:0 -c:v libx264 -keyint_min 48 -g 96 -bufsize 650k -b:v 650k -minrate 500k -maxrate 800k -profile:v baseline -level 3.1 -preset slow -vf "scale=iw*min(640/iw\,360/ih):ih*min(640/iw\,360/ih),pad=640:360 :(640-iw)/2 :(360-ih)/2" -map 0:1 -c:a libfaac -b:a 32k -ar 44100 -f mpegts OUTPUT.m2ts
  

  ffmpeg creates two video streams, however the bitrate and resolution for all of them are taken from the last video arguments - i.e. both streams are 640x360 :

      Output #0, mpegts, to 'OUTPUT.m2ts' :
      Stream #0:0(eng) : Video : h264, yuv420p, 640x360 [SAR 559:560 DAR 559:315], q=-1—1, 650 kb/s,     Stream #0:1(eng) : Video : h264, yuv420p, 640x360 [SAR 559:560 DAR 559:315], q=-1—1, 650 kb/s, 90k tbn, 23.98 tbc (default)
      Stream #0:2(rus) : Audio : aac, 44100 Hz, 5.1, s16, 32 kb/s (default)
      Stream mapping :
      Stream #0:0 -> #0:0 (h264 -> libx264)
      Stream #0:0 -> #0:1 (h264 -> libx264)
      Stream #0:1 -> #0:2 (aac -> libfaac)
      Press [q] to stop, [?] for help
  

  Is it practically possible to make transcoding to several bitrates to the same file ?

• FFmpeg - Turn a 1280x720 video into 720x1280 video and add blur

  6 janvier 2021, par offish

  I've searched around and found multiple solutions. I've found one that works well, but the final video ends up being too big which makes the rendering slow.

  


  I'm giving it a 1280x720 video and want it to turn out like shown here with 720x1280 as the resolution.

  


  -lavfi "[0:v]scale=256/81*iw:256/81*ih,boxblur=luma_radius=min(h\,w)/40:luma_power=3:chroma_radius=min(cw\,ch)/40:chroma_power=1[bg];[bg][0:v]overlay=(W-w)/2:(H-h)/2,setsar=1,crop=w=iw*81/256"


  


  This video ends up being 1280x2274 instead of 720x1280, everything else is fine except the speed and resolution.

  


  -lavfi [0:v]scale=16/9*iw:16/9*ih,boxblur=luma_radius=min(h\,w)/40:luma_power=3:chroma_radius=min(cw\,ch)/40:chroma_power=1[bg];[bg][0:v]overlay=(W-w)/2:(H-h)/2,setsar=1,crop=w=720:h=1280


  


  This cuts the original video, but ends up being 720x1280, faster than the first solution.

  


  -lavfi "[0:v]scale=256/81*iw:256/81*ih,boxblur=luma_radius=min(h\,w)/40:luma_power=3:chroma_radius=min(cw\,ch)/40:chroma_power=1[bg];[bg][0:v]overlay=(W-w)/2:(H-h)/2,setsar=1,crop=w=iw*81/256,scale=720:1280"


  


  This is the same as the first one, but it gets scaled again. It has the correct resolution, but is way to slow for my liking (only about 3.6 it/s, when I've tried other solutions which fluctuates around 35 it/s).

  


  I guess my scaling is wrong, but I don't understand what I should multiply and divide by, to get the result I'm looking for.

  


  Thanks.