@Phyllis/GG
I summaryze my steps if it can help.
Consider I don't want that you make a special build every month only for me, it will waste always your time. I add that every month, when a new release come out, I make a build for myself how explained in manual and how Sam wrote to me some time ago in CV-mailing-lists (Thanks Sam!)

- Fresh installation of OS-UbuntuStudio_16.04LTS_64bit from live DVD (because, like in AV-Linux, there is, inside, a complete suite of programs that I use) offline.
- In folder /usr/lib/x86_64linux-gnu/ I can see that there are libva.so.1 and libvdpau.so.1.
- Tested better the "cinelerra-5.1-ub16-without-vaapi-x86_64-static" (20190509) release but when I exit from cin a segv message come out (no dump is created):
Cinelerra Infinity - built: May  9 2019 08:43:54
** segv at 0x7faf9a91d690 in pid 3683, tid 3683
or ** segv at 0x7f5273775690 in pid 3567, tid 3567
or ** segv at 0x7fce0db7a690 in pid 3866, tid 3866
- Tested some cin release and before 20190430 it works fine.

-With the new cin 20190430 release:
Cinelerra Infinity - built: Apr 30 2019 13:31:49
- run cin, and:  error while loading shared libraries: libva-x11.so1: cannot open shared object file.
Then I download from a online PC the deb file and type
"sudo su dpkg -i libva-x11-1_1.7.0-1_amd64.deb" to install the .deb file
- run cin and: error while loading shared libraries: libva-drm.so1: cannot open shared object file.
Then I download from a online PC the deb file and type
"sudo su dpkg -i libva-drm1_1.7.0-1_amd64.deb" to install the .deb file
run cin and it works as usually but when I quit from cin:
** segv at 0x7fada1940690 in pid 3317, tid 3317
and for another session (for example)
** segv at 0x7f02cdbbb690 in pid 3516, tid 3516

Also consider I am using dpkg command and probably I am wrong.
I think that I am wasting your time and the patience of the other users. I'm so sorry.