Help with capturing a single video frame using irfanview

[JendaLinda]

No but if you slide the marker, the video preview will show the current frame.

[j7n]

If you use Media Player Classic Home Cinema and want maximum quality, don't select the JPEG format for saving directly because that saves the image with color subsampling. To make the video display update more rapidly, you can hold down Shift while dragging the seekbar to jump to the nearest keyframe, and then refine the position further with frame stepping. You can also jump with the keyboard using Shift-Right.

For jumping around videos and extracting frames I like to use VirtualDub2. The updated 2 version also comes with codecs included. Here you also hold down Shift to seek, and then use Left or Right to step. The keyframe interval and the memory cache limit how far it can step backwards quickly. VD2 keeps quite a few recent frames in memory, and going backwards is faster than with MPC-HC. Use Export > Single Image, or Video > Copy Source Frame to Clipboard.

I don't know of any free editor that comes with a thumbnail bar / film strip. I'm sure they exist, but often tend not to support all formats, or are slow.

[JendaLinda]

VirtualDub is a very good video editor. I was using it for years. Unfortunately the original version was limited to ancient AVI and MPG video formats, so I had to search for an alternative program and found Avidemux. However Avidemux is not perfect, it's missing some VirtualDub's features and sometimes crashes. VirtualDub2 adds support for modern video formats, so it seems to be a better choice.