Software or method to enable [easy] chapter editing by keyframes

[hayeled]

Want to add chapters to video (mkv, x265) files. Need chapters to precisely line up with keyframes to achieve smooth and instantaneous playback transition when skipping from chapter to chapter. Have been using mkvToolnix for this by alternating back and forth between the [Chapter Editor / Info Tool] tabs to manually determine keyframe timestamp closest to desired chapter start time.

As an example: say I want a chapter mark at 00:01:00. I check Info tool tab and scroll until I find nearest keyframe, which may be 00:01:04.271. Manually set that time as the chapter start point, then repeat the process for every chapter. This is a dreadfully slow and tedious process.

Is there any (freeware?) software that can either:

Automatically detect the nearest keyframe based on an approximate timestamp entry, and use that keyframe timestamp as the chapter start point

OR

Create a new keyframe at a point in the file based on a desired chapter start time

...or any other suggestions if you get what I'm trying to do and can think of a better way of doing it.

Thanks.

[manono]

Choose them at scene changes

[hayeled]

Choose them at scene changes

Thanks for the reply manono. Not sure I understand what you mean though... is there an option to automatically detect scene changes in mkvtoolnix?

[johnmeyer]

While not free, VideoRedo will navigate directly to i-frames (press and hold the Ctrl key before pressing right or left arrows on keyboard). In that program, you can change the navigation behavior via the Preference settings. Perhaps mkvtoolnix has a preference setting as well.

[manono]

is there an option to automatically detect scene changes in mkvtoolnix?

I don't know as I don't use it. But it can't be too hard to know where you want to insert chapters (every so many minutes or at major changes in the story) and scroll to near that place to look for a scene change. When creating DVD chapters I find the scene change I want and set the chapter I want at the frame before and the chapter point gets set on the next frame - the one right after the scene change, which will be an I-frame.

VirtualDub2 can also find all the keyframes, at scene changes or otherwise.