FaSTTUBe/GST-Tensordecoder-ov_ep
37
0
Fork 0
Code Issues Pull Requests 1 Actions Packages Projects Releases Wiki Activity

pango: pass pre-multiplied alpha to overlay composition directly

Browse Source 
We now support pre-multiplied alpha in the overlay composition API,
and can avoid multiple conversions if the the overlay also supports
pre-multiplied alpha. We should probably also have mapped the
buffer as READWRITE when unpremultiplying.
This commit is contained in:
Tim-Philipp Müller 2012-07-02 18:49:38 +01:00
parent 1d413ace64
commit 52056653be
1 changed files with 1 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
ext/pango/gstbasetextoverlay.c
View File

@ -1173,12 +1173,6 @@ gst_base_text_overlay_adjust_values_with_fontdesc (GstBaseTextOverlay * overlay,
overlay->outline_offset = MINIMUM_OUTLINE_OFFSET;
}
#define CAIRO_UNPREMULTIPLY(a,r,g,b) G_STMT_START { \
*b = (a > 0) ? MIN ((*b * 255 + a / 2) / a, 255) : 0; \
*g = (a > 0) ? MIN ((*g * 255 + a / 2) / a, 255) : 0; \
*r = (a > 0) ? MIN ((*r * 255 + a / 2) / a, 255) : 0; \
} G_STMT_END
static void
gst_base_text_overlay_get_pos (GstBaseTextOverlay * overlay,
gint * xpos, gint * ypos)
@ -1245,27 +1239,6 @@ gst_base_text_overlay_get_pos (GstBaseTextOverlay * overlay,
*ypos += overlay->deltay;
}
static inline void
gst_base_text_overlay_unpremultiply (GstBaseTextOverlay * overlay)
{
guint i, j;
guint8 *pimage, *text_image;
GstMapInfo map;
gst_buffer_map (overlay->text_image, &map, GST_MAP_READ);
text_image = map.data;
for (i = 0; i < overlay->image_height; i++) {
pimage = text_image + 4 * (i * overlay->image_width);
for (j = 0; j < overlay->image_width; j++) {
CAIRO_UNPREMULTIPLY (pimage[CAIRO_ARGB_A], &pimage[CAIRO_ARGB_R],
&pimage[CAIRO_ARGB_G], &pimage[CAIRO_ARGB_B]);
pimage += 4;
}
}
gst_buffer_unmap (overlay->text_image, &map);
}
static inline void
gst_base_text_overlay_set_composition (GstBaseTextOverlay * overlay)
{
@ -1278,7 +1251,7 @@ gst_base_text_overlay_set_composition (GstBaseTextOverlay * overlay)
rectangle = gst_video_overlay_rectangle_new_argb (overlay->text_image,
overlay->image_width, overlay->image_height, 4 * overlay->image_width,
xpos, ypos, overlay->image_width, overlay->image_height,
GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE);
GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA);
if (overlay->composition)
gst_video_overlay_composition_unref (overlay->composition);
@ -1443,9 +1416,6 @@ gst_base_text_overlay_render_pangocairo (GstBaseTextOverlay * overlay,
overlay->baseline_y = ink_rect.y;
g_mutex_unlock (GST_BASE_TEXT_OVERLAY_GET_CLASS (overlay)->pango_lock);
/* As the GstVideoOverlayComposition supports only unpremultiply ARGB,
* we need to unpremultiply it */
gst_base_text_overlay_unpremultiply (overlay);
gst_base_text_overlay_set_composition (overlay);
}