Query about screen capture to create video of session


About 35 years ago, in a technical college unit about operating
systems and system administration, using a DEC PDP11/44 running
RSTS/e, for the operating system for the commands, etc, that we were
taught, to do a test (as in an assessment of students' skills), we
used a command, which, from memory, was ATPK, which, from the time of
invoking it, to stopping it, recorded commands entered, and the
responses (this was way before GUI thingies).

I am running UbuntuMATE 16.04.x .

I am aware of, and, use, the Take Screenshot application, and, I am
aware of the Print Screen key, both of which, take instantaneous
images of the screen display, or, in the case of Take Screenshot,
also, selectable parts of the screen display.

Due to our Internet access provider (ISP), supplying and (pretending
to be) supporting, only a single model of a modem/router, for
connecting to what is known in Australia, as the NBN (No B$##@y
Network), with Australia being forced to use the NBN, by the
oppressive feral parliament (acoustic couplers gave more reliable and
stable data connections), with the particular modem/router model,
being bodgy, and, systemically unreliable and erratic, as the problem
that I have shown to a technician from the ISP, involves not in
connecting to the router component of the modem/router, nor, in the
modem component of the modem/router, connecting to the NBN, but, in
the interface between the router and modem components of the
modem/router, so than connections between the router component and the
modem component, are intermittent, erratic, and unstable, and, the ISP
apparently has (in the case of faults with its hardware) a memory no
longer than about 30s, and is deaf. dumb, and, blind, I am hoping to
create, if possible, a brief video, that shows the nature of the
problem, by performing a continuous screen capture, showing what is
displayed, from the time of invoking an application, to the time of
stopping the application, with the application saving the created
video, upon stopping the application.

Is an application available, that can perform a dynamic(?) screen
capture, so, creating a video of what appears on the screen, from the
time that the application is invoked, to the time that the application
is stopped, thence, saving the video, upon the stopping of the
application recording the video?

Thank you in anticipation.