jnk_cutter

A simple bash script for splitting a video file using ffmpeg into sections, saving each section in an individual file, and also extracting audio from each video into a separate "mp3" (320kbps bitrate is enforced).

Note: the script splits the video and transcodes the sections to 1280x720p but the original audio is preserved. You can override this behaviour by using --no-transcode flag.

By default, the script skips every other section starting from the first one. You can override this behaviour by using --no-skip flag. For example if you pass 2 break times (with -t flag) to the script, sections 1 and 3 will be skipped as shown below:

time:     0-----------------t-----------------t-----------------(end)
sections: |----section 1----|----section 2----|----section 3----|

Installation

jnk_cutter is a simple script and just needs the following tools to work:

• bash
• ffmpeg
• bc (optional)

You should be able to run the script in any environment with bash and ffmpeg support. We test the script on Ubuntu 22.04 and Cygwin 3.4.

Usage

• See help

./jnk_cutter.sh -h

• Just validate the input flags and print the ffmpeg commands but do not execute them

./jnk_cutter.sh --dry-run

• Cut input.mp4 into a single section: form the 1-min mark to the end. The output files will be named: input_1.mp3, input_1.mp4

./jnk_cutter.sh -i input.mp4 -t 00:01:00

• Cut input.mp4 into a single section: form the 1-min mark to the end (similar to the example above). Depending on the frequency of key frames in the original video, a few seconds at the start of output video may appear frozen/corrupted!

./jnk_cutter.sh -i input.mp4 -t 00:01:00 --no-transcode

• Cut input.mp4 into two sections: from the start to the 1-min mark and form the 1-min mark to the end. The output files will be named: input_1.mp3, input_1.mp4, input_2.mp3, input_2.mp4

./jnk_cutter.sh -i input.mp4 -t 00:01:00 --no-skip

• Same as the above but change the output file names to output_*.mp3/mp4. You can define the prefix with a different file extension if you want to change the data container e.g. --output-prefix=output.mkv

./jnk_cutter.sh -i input.mp4 --output-prefix=output -t 00:01:00 --no-skip

• Same as the above but change the output file names to file1.mp3/mp4 & file2.mp3/mp4. (File names which include space or single quotation, must be enclosed in double quotation marks as: --output-files="file 1,file's2") You can define the filenames with a different extension if you want to change the data container e.g. --output-files=file1.mkv,file2.mp4

./jnk_cutter.sh -i input.mp4 --output-files=file1,file2 -t 00:01:00 --no-skip

• Split the files by defining multiple break points. (timing of the output files: start -> 01:00, 01:00 -> 02:00, 02:00 -> 03:00, 03:00 -> end)

./jnk_cutter.sh -i input.mp4 -t 00:01:00 -t 00:02:00 -t 00:03:00 --no-skip

• Split the files by defining multiple break points skipping every other section. (timing of the output files: 01:00 -> 02:00, 03:00 -> end)

./jnk_cutter.sh -i input.mp4 -t 00:01:00 -t 00:02:00 -t 00:03:00

• Split the files by defining multiple break points skipping only the sections 1 & 4. (timing of the output files: 01:00 -> 02:00, 02:00 -> 03:00)

./jnk_cutter.sh -i input.mp4 -t 00:01:00 -t 00:02:00 -t 00:03:00 --skip=1,4

Time Formats

Here’s a few example of valid time formats:

• 12 (will be interpreted as 00h 00m 12s)
• 12.3 (will be interpreted as 00h 00m 12s 300ms)
• 1:23 (will be interpreted as 00h 01m 23s)
• 1:2:3 (will be interpreted as 01h 02m 03s)

See ffmpeg documentation for details on the time definition formats. jnk_cutter currently does not support the ffmpeg time duration formats which include s|ms|us suffixes and/or negative durations -.

License

© 2021-2022 Jnktn.tv distributed under the terms of BSD-3-Clause (see LICENSE)

CLI parser generated using Argbash v2.9.0 (BSD-3-Clause)

See git commits history for the complete list of collaborators.