ffmpeg Black Split

Split a video based on black frames.

This tool uses the blackdetect filter from ffmpeg to determine the periods of black content.

It can cut the video into segments based on these periods, and also output the detected black and content periods as JSON.

Author: Werner Robitza werner.robitza@gmail.com

Contents:

• Requirements
• Installation
• Usage
  • JSON Output
  • Extended Usage
• API
• License

Requirements

• Python 3.9 or higher
• FFmpeg:
  • download a static build from their website)
  • put the ffmpeg executable in your $PATH

Installation

Simply run it via uv:

uvx ffmpeg-black-split

Or install via pipx. Or with pip:

pip3 install --user ffmpeg_black_split

Usage

Run:

ffmpeg-black-split <input-file>

This might take a while depending on the length of your input file. It'll then split the video into parts, prefixed by the original filename. The audio and video streams will be copied as-is.

The output will be placed in the current directory, with each file being named <input>_<start>-<end>.mkv.

Note that by default, cutting is not that accurate, as stream-copying is used. If you want to re-encode using x264, you can use the --no-copy flag. (Future versions may have better options for encoding.)

Choose a different output extension by specifying the --output-extension option. The default is mkv.

Pass the --no-split option to disable the actual splitting.

JSON Output

Example to get just the JSON output:

ffmpeg-black-split input.mkv -p -v --no-split 2>/dev/null

Returns:

{
  "black_periods": [
    {
      "start": 0.0,
      "end": 5.0,
      "duration": 5.0
    },
    {
      "start": 10.0,
      "end": 15.0,
      "duration": 5.0
    },
    {
      "start": 20.0,
      "end": 25.0,
      "duration": 5.0
    }
  ],
  "content_periods": [
    {
      "start": 5.0,
      "end": 10.0
    },
    {
      "start": 10.0,
      "end": 20.0
    },
    {
      "start": 20.0,
      "end": null
    }
  ]
}

Extended Usage

See ffmpeg-black-split -h for more:

usage: ffmpeg-black-split [-h] [-d BLACK_MIN_DURATION] [-r PICTURE_BLACK_RATIO_TH] [-t PIXEL_BLACK_TH]
                   [-o OUTPUT_DIRECTORY] [-e OUTPUT_EXTENSION] [--no-split] [--no-copy] [-p] [-v]
                   [--ffmpeg-path FFMPEG_PATH]
                   input

ffmpeg-black-split v0.4.0

positional arguments:
  input                 input file

options:
  -h, --help            show this help message and exit
  -d BLACK_MIN_DURATION, --black-min-duration BLACK_MIN_DURATION
                        Set the minimum detected black duration expressed in seconds. It must be
                        a non-negative floating point number. (default: 2.0)
  -r PICTURE_BLACK_RATIO_TH, --picture-black-ratio-th PICTURE_BLACK_RATIO_TH
                        Set the threshold for considering a picture 'black' (default: 0.98)
  -t PIXEL_BLACK_TH, --pixel-black-th PIXEL_BLACK_TH
                        Set the threshold for considering a pixel 'black' (default: 0.1)
  -o OUTPUT_DIRECTORY, --output-directory OUTPUT_DIRECTORY
                        Set the output directory. Default is the current working directory.
                        (default: None)
  -e OUTPUT_EXTENSION, --output-extension OUTPUT_EXTENSION
                        Set the ffmpeg output extension. Default is 'mkv'. Choose 'mov' for
                        QuickTime-compatible files. (default: mkv)
  --no-split            Don't split the video into segments. (default: False)
  --no-copy             Don't stream-copy, but re-encode the video. This is useful in case of
                        conversion errors when using different output formats. (default: False)
  -p, --progress        Show a progress bar on stderr (default: False)
  -v, --verbose         Print verbose info to stderr, and JSON of black and content periods to
                        stdout (default: False)
  --ffmpeg-path FFMPEG_PATH
                        Path to ffmpeg executable (default: ffmpeg)

API

The program exposes an API that you can use yourself:

from ffmpeg_black_split import FfmpegBlackSplit

ffbs = FfmpegBlackSplit("input.mkv")
ffbs.detect_black_periods()
ffbs.cut_all_periods("/path/to/output/folder")

For more usage please read the docs.

License

ffmpeg_black_split, Copyright (c) 2022-2024 Werner Robitza

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.