Pull in video frame fields into local variables. Without this the
compiler must assume that they could've changed on every use and read
them from memory again.
This reduces the inner loop from 6 memory reads per pixels to 4, and the
number of writes stays at 3.
If gst_video_overlay_rectangle_apply_global_alpha is called with
a rectangle with unsuitable alpha, expanding the alpha plane will
fail, and thus lead to dereferencing a NULL src pointer. It's not
certain this will happen in practice, as the function is static
and callers might ensure suitable alpha before calling, but there
is no apparent explicit such check.
Add prologue asserts for proper alpha to explicitely prevent this.
Coverity 1139707
Helps when using dvbsuboverlay in connection with vaapisink
or some other video sink that wants ARGB pixels (dvbsuboverlay
attaches pixels in AYUV format, and we then convert as needed).
Alignment should not be a problem here.
Fix copy'n'paste bug which made us allocate a slice of the
size of a rectangle for the overlay composition, but then
free it passing the size of an overlay composition, which
is not something GSlice takes to kindly, resulting in scary
aborts like:
***MEMORY-ERROR***: GSlice: assertion failed: sinfo->n_allocated > 0
Also, g_slice_new already includes a cast, so remove our
own casts, without which the compiler would probably have
told us about this ages ago.
https://bugzilla.gnome.org/show_bug.cgi?id=680091
extract_alpha and apply_global alpha always return TRUE really,
so just do away with the return value. Convert a g_return_if_fail()
into a g_assert(), since this is only to check internal consistency
and not a guard for public API. Add some locking.
https://bugzilla.gnome.org/show_bug.cgi?id=668483
If we are asked to (un)premultiply,we need to create the new rectangle
with the right flags, so we can find it properly on subsequent cache
lookups (also because it's wrong otherwise).
https://bugzilla.gnome.org/show_bug.cgi?id=668483
We need to copy the pixels before messing with them, not least
because the buffer creation code below assumes it's ok to take
ownership.
Fixes crash caused by double-free.
https://bugzilla.gnome.org/show_bug.cgi?id=668483
Basic API to attach overlay rectangles to buffers,
or blend them directly onto raw video buffers.
To be used primarily for things like subtitles or
logo overlays, not meant to replace videomixer.
Allows us to associate subtitle overlays with
non-raw video surface buffers, so that subtitles
are not lost and can instead be rendered later
when those surfaces are displayed or converted,
whilst re-using all the existing overlay plugins
and not having to teach them about our special
video surfaces. Could also have been made part
of the surface buffer abstraction of course, but
a secondary goal was to consolidate the blending
code for raw video into libgstvideo, and this
kind of API allows us to do both in a way that's
minimally invasive to existing elements, and at
the same time is fairly intuitive.
More features and extensions like the ability to
pass the source data or text/markup directly will
be added later.
https://bugzilla.gnome.org/show_bug.cgi?id=665080
API: gst_video_buffer_get_overlay_composition()
API: gst_video_buffer_set_overlay_composition()
API: gst_video_overlay_composition_new()
API: gst_video_overlay_composition_add_rectangle()
API: gst_video_overlay_composition_n_rectangles()
API: gst_video_overlay_composition_get_rectangle()
API: gst_video_overlay_composition_make_writable()
API: gst_video_overlay_composition_copy()
API: gst_video_overlay_composition_ref()
API: gst_video_overlay_composition_unref()
API: gst_video_overlay_composition_blend()
API: gst_video_overlay_rectangle_new_argb()
API: gst_video_overlay_rectangle_get_pixels_argb()
API: gst_video_overlay_rectangle_get_pixels_unscaled_argb()
API: gst_video_overlay_rectangle_get_render_rectangle()
API: gst_video_overlay_rectangle_set_render_rectangle()
API: gst_video_overlay_rectangle_copy()
API: gst_video_overlay_rectangle_ref()
API: gst_video_overlay_rectangle_unref()
