I need a screenshot program that will freeze the current content (in my case, a streaming live lecture) and allow me to take a regional screenshot. In other words, once I hit the screencapture shortcut, the streaming content should freeze at the current frame, allowing me to drag and select a region, the screenshot is saved, and then I can repeat as needed. Without this feature, I may start a regional drag on a formula the speaker is showing, but in the meantime the speaker has moved on to another slide and I can't capture the info I need for my notes.
The only Mac program I've found that does this freeze before capture is Snapz Pro X. The problem with this program is that the screen capture process is multiple steps and not built for rapid screen captures. The steps include typing the shortcut combo, mouse clicking from a number of available buttons to select the capture mode, moving or resizing the existing regional capture settings, and finally taking the screenshot by hitting return. Unfortunately, there isn't a way to set in the preferences or custom shortcut combo to automatically do a regional snapshot. Also, you also have to start from the last region you took -- so if you need to take a smaller region that is within the boundaries of the prior snap, you have to drag it out of the way first.
Are there any programs besides Snapz Pro X that will allow a regional snap that freezes the current screen contents?