Heksler is a simple video slicer designed for speed. After setting in- and out-points, heckler transcodes and exports the slice. Heksler has also a cut or shot detection feature to simply skip to the next or previous hard cut in a movie clip.

Heksler is quite accurate, depending on the source material and the settings. If you need absolute frame accuracy, the best practices are:

Transcode instead of copy

ffmpeg can only jump to I-Frames when slicing a video by copying the streams. Depending on the input compression, the result is not frame accurate. Transcoding forces ffmpeg to recompress the input material which makes the result more accurate, since ffmpeg compensates the difference between I-Frames and the in-point. 

Consider the input material

If you use input material specially designed for video editing like, the discussion about I-Frames is obsolete. Formats like ProRes compressed Quicktime consists only of I-Frames. This makes scrubbing really fast in both directions and the export absolutely accurate.

After setting an in and out point, Heksler exports the slice in the same directory as the input file is, renaming it by prepending in and out information to the filename. The export runs in the background. The number of pending export tasks are written green on the upper right side of the application.

Download OSX binary:

– heksler-1.0.dmg.zip

Usage

– Drag and drop a movie into the application
– Heksler is controlled by keyboard only

Keyboard Commands

– Cursor L/R: Frame stepping
– Shift-Cursor L/R: Fast stepping
– Cmd-Cursor L/R: Search next/previous cut
– Cursor Up: Set in point
– Cursor Down: Set out point and save
– Space: Play/Pause
– ",": Jump to first frame
– ".": Jump to last frame
– Caps Lock: Toggle offline cut detection

Cut detection

Cut detection runs in two modes: Offline (red frame enabled with caps lock) and online. Online has an activated preview but runs slower. Offline disables the preview but runs faster.
You can change the minimum length of a detected clip and the threshold of color differences which should be considered as a new clip.

Output format

On the on screen menu you can choose between:
– Apple ProRes or H264/mp4 compression
– Transcoding or simple stream copy
– Bitrate for H264 compression
– Screen size of output file