WARNING

The program uses 100% of the CPU to support parallel encoding, be aware of CPU temperatures!

Dependencies (Linux)

• parallel (linux)
• zenity for UI

Behavior

• Get original video source and create segments of 30 seconds each without re-encoding

• Executes parallel compression with available physical core with the following syntax:

  • parallel -j x where x is the number of physical cores
  • -c:v encoder name of the encoder used, in this case libvpx-vp9
  • -b:v 0 disables fixed bitrate
  • -cfr 40 high compression rate, visually the qualty feels lossless.
  • -c:a libopus for efficient audio encoding
  • -threads x available threads in total.
  • -row-mt 1 enables multi-threading for VP9.
  • -cpu-used x optimized speed encoding, x are physical cores.
  • -tile-columns 4 divides the video in columns to optimize parallel encoding.
  • -frame-parallel 1 enables parallel encoding of frames.

• Concatenates the generated webm segments into a final webm video file.

NOTE: Cores and threads are automatically obtained. Special characters are handled.

Test results

• source: mp4 h264 1920x1080 50FPS 2.5gb
• destination: webm VP9 800mb

NOTE

Results may vary based on the original compression of the file, might compress more, or less.