GstObject: add support for setting uniquely numbered names for simplicity, e.g. videoqueue-%u

Submitted by Nirbheek Chauhan @nirbheek

Link to original bug (#748233)

Description

Created attachment 302051
gstobject: Add support for a format-specifier suffix

Similar to how the default name for an element is automatically assigned to be unique, it would be useful to be able to pass a custom name that can be automatically made unique.

For instance, if I have a program with a complex pipeline with queues in several different contexts (after decoders, after tees, etc), I want to be able to specify a context-specific name such as "video-decoder-queue-%u", "tee-queue-%u", etc which will become "video-decoder-queue-0", "video-decoder-queue-1", and so on. This makes parsing debug logs much easier when you see "video-decoder-queue-12" instead of "queue34".

The attached patch implements this.

gst_element_factory_make (queue, "somequeue-%u");

will create "some-queue-0", "some-queue-1", etc using the same infrastructure as the code that does the default name generation.

Patch 302051, "gstobject: Add support for a format-specifier suffix":
0001-gstobject-Add-support-for-a-format-specifier-suffix.patch