There are some few but certain conditions where it is possible for the
dest_width to be smaller than x. So we check this before assigning a negative
value to src_width, which is a unsigned and would be promoted to a number that
can segfault videoblend.
https://bugzilla.gnome.org/show_bug.cgi?id=738242
We only allocate 8 bits per component for our temp buffers, which
causes invalid memory accesses if we try to unpack formats that
unpack into a format with 16 bits per component such as e.g. v210.
We don't support blending onto those yet, so just bail out.
The x/y values are meant to be signed.
This bug was introduced by 76c0881549
Conflicts:
gst-libs/gst/video/video-blend.c
gst-libs/gst/video/video-blend.h
gst_buffer_set_qdata() will leak the structure passed to it
when called incorrectly (e.g. on a non-metadata-writable buffer).
This is expected, but we must avoid doing that in valgrind.
Try to avoid floating point maths for each pixel to be blended in
inner loop, and try to avoid the multiplication entirely for the
most common case of the global alpha being 1. Could probably be
refactored a bit more.
