avutil/tests/channel_layout: test generating a custom layout using ambisonic channels and a non diegetic channel with a custom name

Should increase test coverage a bit

Signed-off-by: James Almer <jamrial@gmail.com>

libavutil/tests/channel_layout.c

@@ -206,6 +206,8 @@ int main(void)
     printf("With \"2 channels (FR+FL)\": %34s\n", bp.str);
     CHANNEL_LAYOUT_FROM_STRING("ambisonic 1+FR+FL");
     printf("With \"ambisonic 1+FR+FL\": %35s\n", bp.str);
+    CHANNEL_LAYOUT_FROM_STRING("ambisonic 2+FC@Foo");
+    printf("With \"ambisonic 2+FC@Foo\": %34s\n", bp.str);
     CHANNEL_LAYOUT_FROM_STRING("FL@Foo+FR@Bar");
     printf("With \"FL@Foo+FR@Bar\": %39s\n", bp.str);
     CHANNEL_LAYOUT_FROM_STRING("FR+FL@Foo+USR63@Foo");

tests/ref/fate/channel_layout

@@ -78,6 +78,7 @@ Testing av_channel_layout_from_string
 With "FL+FR+FC+BL+BR+LFE":    6 channels (FL+FR+FC+BL+BR+LFE)
 With "2 channels (FR+FL)":                 2 channels (FR+FL)
 With "ambisonic 1+FR+FL":      ambisonic 1+2 channels (FR+FL)
+With "ambisonic 2+FC@Foo":    ambisonic 2+1 channels (FC@Foo)
 With "FL@Foo+FR@Bar":              2 channels (FL@Foo+FR@Bar)
 With "FR+FL@Foo+USR63@Foo":  3 channels (FR+FL@Foo+USR63@Foo)