With lots of shared memory instances (e.g. created by a RTP payloader) the
overhead of duplicating the file descriptor and creating extra mappings is
significant. To avoid this, the parent memory maps the whole region and the
shared copies just reuse the same mapping.
https://bugzilla.gnome.org/show_bug.cgi?id=730441
Makes it easier to track how many users there are
Also make it possible to create a dmabuf struct on systems without mmap,
it just won't be possible to map it.
https://bugzilla.gnome.org/show_bug.cgi?id=707793
A successful gst_dmabuf_mem_map must always increment the mmap count.
Otherwise the first gst_dmabuf_mem_unmap will unmap the memory and all
other user will access unmapped memory.
https://bugzilla.gnome.org/show_bug.cgi?id=706680
In decide_allocation function some element may when to test the proposed allocator.
For example like this:
if (gst_query_get_n_allocation_params (query) > 0) {
GstAllocator * allocator;
GstAllocationParams params;
gst_query_parse_nth_allocation_param (query, 0, &allocator, ¶ms);
if (g_strcmp0(allocator->mem_type, GST_ALLOCATOR_DMABUF) == 0)
GST_DEBUG("got dmabuf allocator");
else
GST_DEBUG("got an other allocator");
}
https://bugzilla.gnome.org/show_bug.cgi?id=703659
Create new GstMemory and GstAllocator base on dmabuf.
Memory is not allocated/freed by userland but mapped/unmmaped
from a dmabuf file descriptor when requested.
This allocator is included in a new lib called libgstallocators
https://bugzilla.gnome.org/show_bug.cgi?id=693826
