Add audio/gstreamer1-plugins-sndio

[tobik]

Summary

New port: audio/gstreamer1-plugins-sndio

An sndio audio sink and source for GStreamer1

WWW: https://github.com/t6/gstreamer1-plugins-sndio/

PR:	215904
Approved by:	??? (mentor)
Differential Revision:	https://reviews.freebsd.org/D????

Test Plan

poudriere testport 10.3/i386, 10.3/amd64, 11.0/amd64 ok
portlint -AC ok

[tobik]

Use my FreeBSD email address

[mat]

audio/gstreamer1-plugins-sndio/Makefile

11 ↗

(On Diff #25240)

If the software has a license file in the sources, please add a LICENSE_FILE line here.

audio/gstreamer1-plugins-sndio/pkg-descr

1 ↗

(On Diff #25240)

This is the same as the COMMENT, pkg-descr is where you put a longer description (a paragraph, at least) of what this does.

audio/gstreamer1-plugins-sndio/pkg-message

1–3 ↗

(On Diff #25240)

A few bits about how we write documentation:

• never address people directly (never use "you")
• never contract (so, "you have", not "you've")

So, something more along the lines of:

The GStreamer sndio plugin has been installed. It has a higher ...

[tobik]

Better pkg-descr and pkg-message

The sources have the license in the file headers only, so there is no
separate license file.

[lme]

I'm okay with it. portlint also likes it.