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Auto Chapters

FFmpeg Builder: Auto Chapters

This flow element automatically generates chapters by analyzing the video for scene changes.

It will first check whether the video already contains chapters. If chapters are found and Replace Existing is disabled, the element will stop processing and trigger Output 2.

If no chapters exist (or Replace Existing is enabled), the video is scanned for scene changes using the Percent threshold. This value determines how significant a visual change must be to count as a new chapter. A good starting value is 45%, though optimal results may vary depending on the content.

Detected scene changes are filtered using Minimum Length, ensuring chapters are not created too close together. Any scene change occurring within this minimum duration since the previous chapter will be ignored.

Once valid chapters are detected, a metadata file is generated and the FFmpeg Builder is updated to use this file so chapters are added during processing.

If no valid scene changes are found, no metadata file is created.

Fields​

  • Chapter Names
    Optional override for chapter names. Use {index} to insert the chapter number.
    For example, Chapter {index} will result in chapters named Chapter 1, Chapter 2, etc.

  • Hardware Decoding
    If enabled, the video is decoded and scaled down to 720p on the GPU before scene detection, and only the smaller frames are passed back for detection. NVIDIA, Intel QSV, VAAPI and VideoToolbox (macOS) are tried in that order, and any disabled with the NoNvidia, NoQsv, NoVaapi or NoVideoToolbox variables are skipped.
    This can be much faster on systems with a slower CPU and a capable GPU, especially for 4K content, but may be slower on systems with a fast CPU. If no hardware decoding is available, or it fails, the CPU is used instead.

  • Minimum Length
    The minimum allowed length of a chapter, in seconds.

  • Percent
    The scene detection threshold percentage. Higher values require more significant visual changes.
    A recommended starting value is 45%.

  • Replace Existing
    If enabled, any existing chapters will be replaced.
    If disabled and chapters already exist, no new chapters will be generated.

  • Rename Existing When the video already has chapters, rename any whose name does not match the Chapter Names format. The existing chapter timings are kept.

Outputs​

  1. Chapters generated or renamed and added to FFMPEG Builder
  2. No chapters were detected or the video already contained chapters