✂️ trim.lua

mpv script to create a "precise" clip of video files without transcoding.

❓ Differences from the other similar scripts

• trim.lua is aimed only for extraction of clips with no-transcoding. Encodings will never be occured.
• Without encoding, precise video trimming becomes quite tricky and there is a limit what can be done due to keyframe issues.
  • Tested several softwares on macOS and as far as I know there is no software that can do it accurately. Well, there is, but none were perfect.
  • This script is here to achieve accuracy as much as possible — Making a clip from a file within minimum keyframe distance, without transcoding.

In short, trim.lua turns mpv into a simple lossless video editor.

📦 Install

curl https://raw.githubusercontent.com/aerobounce/trim.lua/master/trim.lua >> ~/.config/mpv/scripts/trim.lua

⚠️ Dependencies

• ffmpeg
• ffprobe
• osascript (to post notification on completion. Only on macOS.)

✂️ Usage

🗜 Concat with ffmpeg

After splitting, you can concat them with a script something like this.

CLIPS=("example_1.mp4" "example_2.mp4")
DESTINATION="concat_example.mp4"

ffmpeg \
    -hide_banner \
    -loglevel verbose \
    -f concat \
    -safe 0 \
    -auto_convert 0 \
    -err_detect ignore_err \
    -i <(
        while read -r; do
            echo "file '$REPLY'"
        done <<< "${CLIPS[*]}"
    ) \
    -copy_unknown \
    -map_chapters 0 \
    -c copy \
    "$DESTINATION"

Known Issues

• Any embedded media other than video / audio will be lost, such as embedded subtitles.

Todo

• Make osascript optional (as it's macOS only feature)
• More accurate keyframe fetching
• ffmpeg and ffprobe paths are hard-coded to /usr/local/bin/...