[FFmpeg-user] Stuck preparing to compile ffmpeg from git source

[Mark Filipak]

Preface:
This is a resubmittal of a prior request that provoked a shit-storm. Shit-storms discourage replies 
from people who might otherwise reply. I have carefully outlined all my steps and have endeavored to 
outline my rationales. Kindly trust that I have good reasons for cross-compiling. My objective is 
simply to create a bug ticket that richardjp will accept. Thanks - M.

Hello,

Perhaps someone who compiles from source can/will help me get unstuck (or knows of a better way).

Thanks much,
Mark.

Here:
https://trac.ffmpeg.org/ticket/8612#comment:20
richardjp recommmended compiling ffmpeg from git sources & retesting. Okay, that's reasonable. Thank 
you, Richard.

Here:
http://trac.ffmpeg.org/wiki/CompilationGuide
-- thank you for the guide, ffmpeg team -- I decided that "Cross compiling for Windows" is the way 
to go [Note 1].

Here:
http://trac.ffmpeg.org/wiki/CompilationGuide/CrossCompilingForWindows
I read:
"Tip: The FFmpeg Windows Build Helpers script can automatically cross-compile FFmpeg for Windows."
Since "automatic" sounds good, I took the link.

Following instructions here:
https://github.com/rdp/ffmpeg-windows-build-helpers
I'm stuck at this step:
./cross_compile_ffmpeg.sh
which declares: "your meson version is too old 0.40.1 wanted 0.47"

I found 
https://files.pythonhosted.org/packages/4f/6a/79cc8a3bbb5baacbb39f6bd958f55dd4e6fbb25a776fbe9d0048aa2c106b/meson-0.54.0.tar.gz
Is meson 0.54 okay?

I unzipped meson-0.54.0.tar.gz to here:
/media/sf_D/Setup/Linux/meson-0.54.0

I next attempted to install meson 0.54 via Synaptic's menu: 'File'>'Add downloaded packages', 
'Select directory' dialog.
I browsed to '/media/sf_D/Setup/Linux/meson-0.54.0' and clicked "Open". Nothing happened.

I next tried Synaptic's 'File'>'Generate package download script'. It responded,
"Nothing to install/upgrade
"Please select the "Mark all Upgrades" button or some packages to install/upgrade."
I cannot find a "Mark all Upgrades" button.
I had 'meson' selected.

Stuck. I can't proceed. True: This is a Synaptic problem, but you folks must do this all the time. 
What do you do?

[Note 1] I'm pretty sure that a git project requires continuous access to the Internet. My Internet 
access is solely via a VBox Linux guest, so it seems reasonable that ffmpeg must be compiled from 
within Linux. Since I actually run ffmpeg in Windows (not Linux), it seems reasonable to 
cross-compile for Windows. Disclaimer: All of the preceding are my best guesses but may be wrong.