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• How to convert a 4K ProRes into different formats with FFmpeg ?

  18 octobre 2018, par adsalpha

  I have a video which is 3840 × 2160 encoded using Apple ProRes 422.

  I need to convert it to the following sizes/codecs without losing in quality :

  1. ProRes 422 1080p ;
  2. H264 4K ;
  3. H264 1080p.

  I need to do it programmatically so I went with FFmpeg. My command is ffmpeg -i input.mov -vf scale=1920:1080 -c:v prores_ks -preset slow output.mov. I don’t like the result – the colors are less saturated.

  What is the right command to do it ?

• Add unique color watermark per frame with FFMpeg

  26 octobre 2018, par Dustin Kerstein

  I’ve been able to add a random color watermark with this code :

  ffmpeg -y -r 100 -i "N%3d.tif" -c:v libx264 -vf "drawbox=y=0:color=random@1:width=8:height=ih:t=fill,scale=1920:1080" -crf 30 -g 10 -profile:v high -level 4.1 -pix_fmt yuv420p test.mp4

  And I know that it’s doable with a script and processing each input frame individually, but I would really like to find a way with FFMpeg to add the watermark during the actual video encoding. It needs to be a unique color per frame. Any ideas on how to accomplish this ?

  Thanks !

• How to play a part of the MP4 video stream ?

  14 novembre 2014, par AgentFire

  I have a URL (<ip>/ipcam/mpeg4.cgi</ip>) which points to my IP camera which is connected via Ethernet.
  Accessing the URL resuls in a infinite stream of video (possibly with audio) data.

  I would like to store this data into a video file and play it later with a video player (HTML5’s video tag is preferred as the player).

  However, a straightforward approach, which is simple saving the stream data into .mp4 file, didn’t work.

  I have looked into the file and here is what I saw (click to enlarge) :

  

  It turned out, there are some HTML headers, which I further on manually excluded using the binary editing tool, and yet no player could play the rest of the file.

  The HTML headers are :

  --myboundary
  
  Content-Type: image/mpeg4
  
  Content-Length: 76241
  
  X-Status: 0
  
  X-Tag: 1693923
  
  X-Flags: 0
  
  X-Alarm: 0
  
  X-Frametype: I
  
  X-Framerate: 30
  
  X-Resolution: 1920*1080
  
  X-Audio: 1
  
  X-Time: 2000-02-03 02:46:31
  
  alarm: 0000

  My question is pretty clear now, and I would like any help or suggestion. I suspect, I have to manually create some MP4 headers myself based on those values above, however, I fail to understand format descriptions such as these.

  I have the following video stream settings on my IP camera (click to enlarge) :

  

  I could also use the ffmpeg tool, but no matter how I try and mix the arguments to the program, it keeps telling me this error :