Splice Videos
File: src/scripts/splice-videos.sh · Splice random fixed-length clips of one input video into a single output video of a target duration using ffmpeg.
Cuts random fixed-length clips out of one input video and concatenates them into a single output of a target duration. -i/--input (relative to the current directory) and -d/--duration (output length in seconds) are required; -s/--segment sets each random clip’s length in seconds (default 3).
The script skips the first and last 10% of the source, caps the output at ~1 GB (1.5 Mbps estimate), and reuses an existing ./random_clips directory on a rerun (resume path). Concatenation uses ffmpeg -c copy; output goes to ./spliced_videos/output_from_<input>. Valid extensions are read from SPLICE_VIDEOS_FILE_EXTENSIONS in the project root .env (copy .env.example to .env). Extension matching uses true file extensions (text after the last dot), so dotless names are rejected. Both ffmpeg and ffprobe are required — the script exits with an error if either is missing (ffprobe reads source/clip durations).
Pass -n/--dry-run to preview the run: it prints the would-be clips-folder removal, the would-be clip-extraction and concat ffmpeg commands, and the would-be output path, then exits without removing/creating/writing anything. Before it wipes an existing ./random_clips folder the script prompts for confirmation; pass -y/--yes (or -n/--dry-run) to bypass the prompt.
Parameters
| Flag | Required | Default | Description |
|---|---|---|---|
-i, --input | yes | — | Input video (relative to cwd) |
-d, --duration | yes | — | Output length in seconds |
-s, --segment | no | 3 | Each random clip’s length in seconds |
-n, --dry-run | no | off | Print intended changes; make no filesystem change |
-y, --yes | no | off | Skip the confirmation prompt before mutating |
-h, --help | — | — | Print usage and exit |
.env keys
SPLICE_VIDEOS_FILE_EXTENSIONS — comma-separated, case-insensitive, leading dot optional.
Usage
# Show help
bash splice-videos.sh -h
# Splice a 12-second output from clip.mp4
bash splice-videos.sh -i clip.mp4 -d 12
# Use a custom 4-second segment length
bash splice-videos.sh -i clip.mp4 -d 12 -s 4