ffmpeg

Video conversion tool. More information: https://ffmpeg.org.

• Extract the sound from a video and save it as MP3:
  ffmpeg -i {{video.mp4}} -vn {{sound}}.mp3
• Save a video as GIF, scaling the height to 1000px and setting framerate to 15:
  ffmpeg -i {{video.mp4}} -vf 'scale=-1:{{1000}}' -r {{15}} {{output.gif}}
• Combine numbered images (frame_1.jpg, frame_2.jpg, etc) into a video or GIF:
  ffmpeg -i {{frame_%d.jpg}} -f image2 {{video.mpg|video.gif}}
• Quickly extract a single frame from a video at time mm:ss and save it as a 128x128 resolution image:
  ffmpeg -ss {{mm:ss}} -i {{video.mp4}} -frames 1 -s {{128x128}} -f image2 {{image.png}}
• Trim a video from a given start time mm:ss to an end time mm2:ss2 (omit the -to flag to trim till the end):
  ffmpeg -ss {{mm:ss}} -to {{mm2:ss2}} -i {{video.mp4}} -codec copy {{output.mp4}}
• Convert AVI video to MP4. AAC Audio @ 128kbit, h264 Video @ CRF 23:
  ffmpeg -i {{input_video}}.avi -codec:a aac -b:a 128k -codec:v libx264 -crf 23 {{output_video}}.mp4
• Remux MKV video to MP4 without re-encoding audio or video streams:
  ffmpeg -i {{input_video}}.mkv -codec copy {{output_video}}.mp4
• Convert MP4 video to VP9 codec. For the best quality, use a CRF value (recommended range 15-35) and -b:v MUST be 0:
  ffmpeg -i {{input_video}}.mp4 -codec:v libvpx-vp9 -crf {{30}} -b:v 0 -codec:a libopus -vbr on -threads {{number_of_threads}} {{output_video}}.webm