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• ffmpeg - convert movie AND show original input (as a resized picture-in-picture, e.g., bottom-right corner) in the final output file

  3 octobre 2019, par raven

  this is my first post on this forum, so please be gentle in case I accidentally do trip over any forum rules that I would not know of yet :).

  I would like to apply some color-grading to underwater GoPro footage. To quicker gauge the effect of my color settings (trial-and-error, as of yet), would like to see the original input video stream as a PIP (e.g., scaled down to 50% or even 30%), in the bottom-right corner of the converted output movie.

  I have one input movie that is going to be color graded. The PIP should use the original as an input, just a scaled-down version of it.

  I would like to use ffmpeg’s "-filter_complex" option to do the PIP, but all examples I can find on "-filter_complex" would use two already existing movies. Instead, I would like to make the color-corrected stream an on-the-fly input to "-filter_complex", which then renders the PIP.

  Is that doable, all in one go ?

  Both the individual snippets below work fine, I now would like to combine these and skip the creation of an intermediate color-graded TMP output which then gets combined, with the original, in a final PIP creation process.
  Your help combining these two separate steps into one single "-filter_complex" action is greatly appreciated !

  Thanks in advance,
  raven.

  [existing code snippets (M$ batch files)]
  
  
  
  ::declarations/defines::
  
  set "INPUT="
  
  set "TMP="
  
  set "OUTPUT="
  
  set "FFMPG="
  
  set "QU=9" :: quality settings
  
  
  
  set "CONV='"0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 0 -1 0:0 -1 0 -1 5 -1 
  
  0 -1 0:0 -1 0 -1 5 -1 0 -1 0'"" :: sharpening convolution filter
  
  
  
  ::color-grading part::
  
  %FFMPG% -i %INPUT% -vf convolution=%CONV%,colorbalance=rs=%rs%:gs=%gs%:bs=%bs%:rm=%rm%:gm=%gm%:bm=%bm%:rh=%rh%:gh=%gh%:bh=%bh% -q:v %QU% -codec:v mpeg4 %TMP%
  
  
  
  ::PIP part::
  
  %FFMPG% -i %TMP% -i %INPUT% -filter_complex "[1]scale=iw/3:ih/3 
  
  [pip]; [0][pip] overlay=main_w-overlay_w-10:main_h-overlay_h-10" -q:v 
  
  %QU% -codec:v mpeg4 %OUTPUT%
  
  
  
  [/existing code]

• Process video with frame averaging to produce long exposure final frame

  4 mars 2020, par user3925023

  I’m looking for a FFMPEG script able to process a video file, create frame averaging and save latest long exposed frame.
  My goal is to process the video enhancing the trasparent TV logo on the screen :
  

  Is this viable via FFMPEG ? thx

• PSNR for YUV files using matlab [duplicate]

  29 février 2016, par apiproj

  This question already has an answer here :

  • Power Signal Noise Ratio (PSNR) of colored jpeg image [closed]
    
    2 answers
    

  In my video streaming application I have two yuv files.One is original which is am streaming over the network after x264 encoding, another is reconstructed decoded yuv file in receiver side.

  How to calculate PSNR value between two YUV files in MATLAB or ldecoder or using any other tool ?

  Thanks in advance.