v-trim

A tiny video trimming utility. ffmpeg required.

This tool is designed for quickly turning short screen-recordings into video files that are more friendly for sharing. It currently:

• sets the codec to H.265
• sets the constant rate factory quite high (30)
• limits the output resolution to a max of 1000px wide
• lowers the framerate to 20

Finally, the tool also allows for small edits and changes of the input recording.

Example Usage

v-trim [input] --trim 5,16 --speed 6,7 .25 --speed 10,11 .4 --rm 8,9 [output]

v-trim file.2020.mp4 --trim 5,16 --speed 6,7 .25 --speed 10,11 1.4 out.mp4

Installation

npm install -g v-trim

Options

| option | alias | arguments | example | description | | --------- | ----- | ------------------------ | ------------ | -------------------------------------------------------------------------------- | | --trim | -t | [slice] | -t 5,15 | Remove everything before the start of the slice, and after the end of the slice. | | --rm | | [slice] | -rm 8,10 | Remove the slice from the result. | | --speed | -s | [slice] [scale-factor] | -s 10,12 2 | Increase (or decrease) the playback of the slice by the given scale-factor. |

Slice

All options take a slice which represents a range of the time in the input video. Slices are two times (the start time and the end time of the slice) separated by a comma. Either time (but not both!) can be ommitted, to indicate that the slice should run to the beginning or end of the file. Slices are automatically clamped to 0 and the end of the video.

Some example slices (of a hypothetical 30s video):

• 5,7 - a 2-second slice starting at 5s and ending at 7s
• ,8.25 - an 8.25-second slice, starting at 0s and ending at 8.25s
• 24, - a 6-second slice, starting at 24s and ending at 30s
• 25,90 - a 5-second slice, starting at 25s and ending at 30s (clamped to the length of the video)
• 0, - a slice of the entire video
• , - not a legal slice! To represent the entire video use: 0,

Example

The following breaks down an example command-line usage to trim and change the speed of a video. We'll assume that the file in question started out as a 30-second video file.

v-trim fun-video.mp4 --trim 5, --speed 8,12 2 --rm 16,24 --speed 27,28 0.5 shorter-video.trimmed.mp4

Here is the effect this command translates the input file into the output file:

• 00s - 05s not included in the output (--trim 5, which is equivalent to --rm 0,5)
• 05s - 08s included as normal (included by default, not affected by any operations)
• 08s - 12s included at 2x speed (--speed 8,12 2; maybe this section is boring, but valueable enough to include in the recording)
• 12s - 16s included as normal (included by default)
• 16s - 24s not included in the output (--rm 16,24; maybe this section is very boring)
• 24s - 27s included as normal (included by default)
• 27s - 28s included at 0.5x speed (--speed 27,28 0.5; maybe this section is very important)
• 28s - 30s included as normal (included by default)