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Code Issues 1 Projects Releases Wiki Activity

video: overlays may now have premultiplied alpha

Browse source 
https://bugzilla.gnome.org/show_bug.cgi?id=666177
This commit is contained in:
Vincent Penquerc'h 2011-12-14 14:14:47 +00:00
parent 95be60de15
commit 5cf87eedc4
6 changed files with 242 additions and 60 deletions
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1
docs/libs/gst-plugins-base-libs-sections.txt
View file

@ -2345,6 +2345,7 @@ gst_video_overlay_rectangle_get_render_rectangle
gst_video_overlay_rectangle_get_seqnum
gst_video_overlay_rectangle_set_render_rectangle
gst_video_overlay_rectangle_copy
gst_video_overlay_rectangle_get_flags
<SUBSECTION Standard>
GST_TYPE_VIDEO_OVERLAY_COMPOSITION
GST_VIDEO_OVERLAY_COMPOSITION

102
gst-libs/gst/video/video-blend.c
View file

@ -1155,6 +1155,34 @@ matrix_identity (guint8 * tmpline, guint width)
{
}
static void
matrix_prea_rgb_to_yuv (guint8 * tmpline, guint width)
{
int i;
int a, r, g, b;
int y, u, v;
for (i = 0; i < width; i++) {
a = tmpline[i * 4 + 0];
r = tmpline[i * 4 + 1];
g = tmpline[i * 4 + 2];
b = tmpline[i * 4 + 3];
if (a) {
r = (r * 255 + a / 2) / a;
g = (g * 255 + a / 2) / a;
b = (b * 255 + a / 2) / a;
}
y = (47 * r + 157 * g + 16 * b + 4096) >> 8;
u = (-26 * r - 87 * g + 112 * b + 32768) >> 8;
v = (112 * r - 102 * g - 10 * b + 32768) >> 8;
tmpline[i * 4 + 1] = CLAMP (y, 0, 255);
tmpline[i * 4 + 2] = CLAMP (u, 0, 255);
tmpline[i * 4 + 3] = CLAMP (v, 0, 255);
}
}
static void
matrix_rgb_to_yuv (guint8 * tmpline, guint width)
{
@ -1221,10 +1249,15 @@ lookup_getput (GetPutLine * getput, GstVideoFormat fmt)
return FALSE;
}
#define BLEND(ret, alpha, v0, v1) \
{ \
#define BLEND00(ret, alpha, v0, v1) \
G_STMT_START { \
ret = (v0 * alpha + v1 * (255 - alpha)) / 255; \
}
} G_STMT_END
#define BLEND10(ret, alpha, v0, v1) \
G_STMT_START { \
ret = v0 + (v1 * (255 - alpha)) / 255; \
} G_STMT_END
void
video_blend_scale_linear_RGBA (GstBlendVideoFormatInfo * src,
@ -1289,7 +1322,7 @@ video_blend_scale_linear_RGBA (GstBlendVideoFormatInfo * src,
/* Update src, our reference to the old src->pixels is lost */
video_blend_format_info_init (src, dest_pixels, dest_height, dest_width,
src->fmt);
src->fmt, src->premultiplied_alpha);
g_free (tmpbuf);
}
@ -1310,10 +1343,21 @@ video_blend (GstBlendVideoFormatInfo * dest,
guint i, j;
guint8 alpha;
GetPutLine getputdest, getputsrc;
gint src_stride;
guint8 *tmpdestline = NULL, *tmpsrcline = NULL;
gboolean src_premultiplied_alpha;
gint src_stride = src->width * 4;
guint8 *tmpdestline = g_malloc (sizeof (guint8) * (dest->width + 8) * 4);
guint8 *tmpsrcline = g_malloc (sizeof (guint8) * (dest->width + 8) * 4);
g_return_val_if_fail (dest, FALSE);
g_return_val_if_fail (src, FALSE);
/* we do no support writing to premultiplied alpha, though that should
just be a matter of adding blenders below (BLEND01 and BLEND11) */
g_return_val_if_fail (!dest->premultiplied_alpha, FALSE);
src_premultiplied_alpha = src->premultiplied_alpha;
src_stride = src->width * 4;
tmpdestline = g_malloc (sizeof (guint8) * (dest->width + 8) * 4);
tmpsrcline = g_malloc (sizeof (guint8) * (dest->width + 8) * 4);
ensure_debug_category ();
@ -1324,9 +1368,18 @@ video_blend (GstBlendVideoFormatInfo * dest,
if (!lookup_getput (&getputsrc, src->fmt))
goto failed;
if (gst_video_format_is_rgb (src->fmt) != gst_video_format_is_rgb (dest->fmt))
getputsrc.matrix = gst_video_format_is_rgb (src->fmt) ?
matrix_rgb_to_yuv : matrix_yuv_to_rgb;
if (gst_video_format_is_rgb (src->fmt) != gst_video_format_is_rgb (dest->fmt)) {
if (gst_video_format_is_rgb (src->fmt)) {
if (src_premultiplied_alpha) {
getputsrc.matrix = matrix_prea_rgb_to_yuv;
src_premultiplied_alpha = FALSE;
} else {
getputsrc.matrix = matrix_rgb_to_yuv;
}
} else {
getputsrc.matrix = matrix_yuv_to_rgb;
}
}
/* adjust src pointers for negative sizes */
if (x < 0) {
@ -1358,14 +1411,29 @@ video_blend (GstBlendVideoFormatInfo * dest,
/* Here dest and src are both either in AYUV or ARGB
* TODO: Make the orc version working properly*/
for (j = 0; j < src->width * 4; j += 4) {
alpha = tmpsrcline[j];
#define BLENDLOOP(blender) \
do { \
for (j = 0; j < src->width * 4; j += 4) { \
alpha = tmpsrcline[j]; \
\
blender (tmpdestline[j + 1], alpha, tmpsrcline[j + 1], tmpdestline[j + 1]); \
blender (tmpdestline[j + 2], alpha, tmpsrcline[j + 2], tmpdestline[j + 2]); \
blender (tmpdestline[j + 3], alpha, tmpsrcline[j + 3], tmpdestline[j + 3]); \
} \
} while(0)
BLEND (tmpdestline[j + 1], alpha, tmpsrcline[j + 1], tmpdestline[j + 1]);
BLEND (tmpdestline[j + 2], alpha, tmpsrcline[j + 2], tmpdestline[j + 2]);
BLEND (tmpdestline[j + 3], alpha, tmpsrcline[j + 3], tmpdestline[j + 3]);
if (src_premultiplied_alpha && dest->premultiplied_alpha) {
/* BLENDLOOP (BLEND11); */
} else if (!src_premultiplied_alpha && dest->premultiplied_alpha) {
/* BLENDLOOP (BLEND01); */
} else if (src_premultiplied_alpha && !dest->premultiplied_alpha) {
BLENDLOOP (BLEND10);
} else {
BLENDLOOP (BLEND00);
}
#undef BLENDLOOP
/* FIXME
* #if G_BYTE_ORDER == LITTLE_ENDIAN
* orc_blend_little (tmpdestline, tmpsrcline, dest->width);
@ -1403,7 +1471,8 @@ failed:
*/
void
video_blend_format_info_init (GstBlendVideoFormatInfo * info,
guint8 * pixels, guint height, guint width, GstVideoFormat fmt)
guint8 * pixels, guint height, guint width, GstVideoFormat fmt,
gboolean premultiplied_alpha)
{
guint nb_component = gst_video_format_has_alpha (fmt) ? 4 : 3;
@ -1417,6 +1486,7 @@ video_blend_format_info_init (GstBlendVideoFormatInfo * info,
info->height = height;
info->pixels = pixels;
info->fmt = fmt;
info->premultiplied_alpha = premultiplied_alpha;
info->size = gst_video_format_get_size (fmt, height, width);
fill_planes (info);

5
gst-libs/gst/video/video-blend.h
View file

@ -53,6 +53,8 @@ struct _GstBlendVideoFormatInfo
guint8 * pixels;
gsize size;
gboolean premultiplied_alpha;
/* YUV components: Y=0, U=1, V=2, A=3
* RGB components: R=0, G=1, B=2, A=3 */
gint offset[MAX_VIDEO_PLANES];
@ -61,7 +63,8 @@ struct _GstBlendVideoFormatInfo
void video_blend_format_info_init (GstBlendVideoFormatInfo * info,
guint8 *pixels, guint height,
guint width, GstVideoFormat fmt);
guint width, GstVideoFormat fmt,
gboolean premultiplied_alpha);
void video_blend_scale_linear_RGBA (GstBlendVideoFormatInfo * src,
gint dest_height, gint dest_width);

187
gst-libs/gst/video/video-overlay-composition.c
View file

@ -108,6 +108,9 @@ struct _GstVideoOverlayRectangle
/* The format of the data in pixels */
GstVideoFormat format;
/* The flags associated to this rectangle */
GstVideoOverlayFormatFlags flags;
/* Refcounted blob of memory, no caps or timestamps */
GstBuffer *pixels;
@ -501,7 +504,7 @@ gst_video_overlay_composition_blend (GstVideoOverlayComposition * comp,
}
video_blend_format_info_init (&video_info, GST_BUFFER_DATA (video_buf),
h, w, fmt);
h, w, fmt, FALSE);
num = comp->num_rectangles;
GST_LOG ("Blending composition %p with %u rectangles onto video buffer %p "
@ -518,7 +521,8 @@ gst_video_overlay_composition_blend (GstVideoOverlayComposition * comp,
video_blend_format_info_init (&rectangle_info,
GST_BUFFER_DATA (rect->pixels), rect->height, rect->width,
rect->format);
rect->format,
!!(rect->flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA));
needs_scaling = gst_video_overlay_rectangle_needs_scaling (rect);
if (needs_scaling) {
@ -706,6 +710,22 @@ gst_video_overlay_rectangle_instance_init (GstMiniObject * mini_obj)
#endif
}
static inline gboolean
gst_video_overlay_rectangle_check_flags (GstVideoOverlayFormatFlags flags)
{
/* Check flags only contains flags we know about */
return (flags & ~(GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA)) == 0;
}
static gboolean
gst_video_overlay_rectangle_is_same_alpha_type (GstVideoOverlayFormatFlags
flags1, GstVideoOverlayFormatFlags flags2)
{
return ((flags1 ^ flags2) & GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA)
== 0;
}
/**
* gst_video_overlay_rectangle_new_argb:
* @pixels: (transfer none): a #GstBuffer pointing to the pixel memory
@ -718,7 +738,7 @@ gst_video_overlay_rectangle_instance_init (GstMiniObject * mini_obj)
* overlay rectangle should be rendered to
* @render_width: the render width of this rectangle on the video
* @render_height: the render height of this rectangle on the video
* @flags: flags (currently unused)
* @flags: flags
*
* Creates a new video overlay rectangle with ARGB pixel data. The layout
* of the components in memory is B-G-R-A on little-endian platforms
@ -726,9 +746,9 @@ gst_video_overlay_rectangle_instance_init (GstMiniObject * mini_obj)
* platforms (corresponding to #GST_VIDEO_FORMAT_ARGB). In other words,
* pixels are treated as 32-bit words and the lowest 8 bits then contain
* the blue component value and the highest 8 bits contain the alpha
* component value. The RGB values are non-premultiplied. This is the
* format that is used by most hardware, and also many rendering libraries
* such as Cairo, for example.
* component value. Unless specified in the flags, the RGB values are
* non-premultiplied. This is the format that is used by most hardware,
* and also many rendering libraries such as Cairo, for example.
*
* Returns: (transfer full): a new #GstVideoOverlayRectangle. Unref with
* gst_video_overlay_rectangle_unref() when no longer needed.
@ -748,7 +768,7 @@ gst_video_overlay_rectangle_new_argb (GstBuffer * pixels,
g_return_val_if_fail (stride >= (4 * width), NULL);
g_return_val_if_fail (height > 0 && width > 0, NULL);
g_return_val_if_fail (render_height > 0 && render_width > 0, NULL);
g_return_val_if_fail (flags == 0, NULL);
g_return_val_if_fail (gst_video_overlay_rectangle_check_flags (flags), NULL);
rect = (GstVideoOverlayRectangle *)
gst_mini_object_new (GST_TYPE_VIDEO_OVERLAY_RECTANGLE);
@ -758,6 +778,7 @@ gst_video_overlay_rectangle_new_argb (GstBuffer * pixels,
#else
rect->format = GST_VIDEO_FORMAT_ARGB;
#endif
rect->pixels = gst_buffer_ref (pixels);
rect->width = width;
@ -769,11 +790,13 @@ gst_video_overlay_rectangle_new_argb (GstBuffer * pixels,
rect->render_width = render_width;
rect->render_height = render_height;
rect->flags = flags;
rect->seq_num = gst_video_overlay_get_seqnum ();
GST_LOG ("new rectangle %p: %ux%u => %ux%u @ %u,%u, seq_num %u, format %u, "
"pixels %p", rect, width, height, render_width, render_height, render_x,
render_y, rect->seq_num, rect->format, pixels);
"flags %x, pixels %p", rect, width, height, render_width, render_height,
render_x, render_y, rect->seq_num, rect->format, rect->flags, pixels);
return rect;
}
@ -846,37 +869,61 @@ gst_video_overlay_rectangle_set_render_rectangle (GstVideoOverlayRectangle *
rectangle->render_height = render_height;
}
/**
* gst_video_overlay_rectangle_get_pixels_argb:
* @rectangle: a #GstVideoOverlayRectangle
* @stride: (out) (allow-none): address of guint variable where to store the
* row stride of the ARGB pixel data in the buffer
* @flags: flags (unused)
*
* Returns: (transfer none): a #GstBuffer holding the ARGB pixel data with
* row stride @stride and width and height of the render dimensions as per
* gst_video_overlay_rectangle_get_render_rectangle(). This function does
* not return a reference, the caller should obtain a reference of her own
* with gst_buffer_ref() if needed.
*
* Since: 0.10.36
*/
GstBuffer *
gst_video_overlay_rectangle_get_pixels_argb (GstVideoOverlayRectangle *
rectangle, guint * stride, GstVideoOverlayFormatFlags flags)
static void
gst_video_overlay_rectangle_premultiply (GstBlendVideoFormatInfo * info)
{
int i, j;
for (j = 0; j < info->height; ++j) {
guint8 *line = info->pixels + info->stride[0] * j;
for (i = 0; i < info->width; ++i) {
int a = line[0];
line[1] = line[1] * a / 255;
line[2] = line[2] * a / 255;
line[3] = line[3] * a / 255;
line += 4;
}
}
}
static void
gst_video_overlay_rectangle_unpremultiply (GstBlendVideoFormatInfo * info)
{
int i, j;
for (j = 0; j < info->height; ++j) {
guint8 *line = info->pixels + info->stride[0] * j;
for (i = 0; i < info->width; ++i) {
int a = line[0];
if (a) {
line[1] = MIN ((line[1] * 255 + a / 2) / a, 255);
line[2] = MIN ((line[2] * 255 + a / 2) / a, 255);
line[3] = MIN ((line[3] * 255 + a / 2) / a, 255);
}
line += 4;
}
}
}
static GstBuffer *
gst_video_overlay_rectangle_get_pixels_argb_internal (GstVideoOverlayRectangle *
rectangle, guint * stride, GstVideoOverlayFormatFlags flags,
gboolean unscaled)
{
GstVideoOverlayRectangle *scaled_rect = NULL;
GstBlendVideoFormatInfo info;
GstBuffer *buf;
GList *l;
guint wanted_width = unscaled ? rectangle->width : rectangle->render_width;
guint wanted_height = unscaled ? rectangle->height : rectangle->render_height;
g_return_val_if_fail (GST_IS_VIDEO_OVERLAY_RECTANGLE (rectangle), NULL);
g_return_val_if_fail (flags == 0, NULL);
g_return_val_if_fail (stride != NULL, NULL);
g_return_val_if_fail (gst_video_overlay_rectangle_check_flags (flags), NULL);
/* This assumes we don't need to adjust the format */
if (rectangle->render_width == rectangle->width &&
rectangle->render_height == rectangle->height) {
if (wanted_width == rectangle->width &&
wanted_height == rectangle->height &&
gst_video_overlay_rectangle_is_same_alpha_type (rectangle->flags,
flags)) {
*stride = rectangle->stride;
return rectangle->pixels;
}
@ -886,8 +933,10 @@ gst_video_overlay_rectangle_get_pixels_argb (GstVideoOverlayRectangle *
for (l = rectangle->scaled_rectangles; l != NULL; l = l->next) {
GstVideoOverlayRectangle *r = l->data;
if (r->width == rectangle->render_width &&
r->height == rectangle->render_height) {
if (r->width == wanted_width &&
r->height == wanted_height &&
gst_video_overlay_rectangle_is_same_alpha_type (rectangle->flags,
flags)) {
/* we'll keep these rectangles around until finalize, so it's ok not
* to take our own ref here */
scaled_rect = r;
@ -901,10 +950,20 @@ gst_video_overlay_rectangle_get_pixels_argb (GstVideoOverlayRectangle *
/* not cached yet, do the scaling and put the result into our cache */
video_blend_format_info_init (&info, GST_BUFFER_DATA (rectangle->pixels),
rectangle->height, rectangle->width, rectangle->format);
rectangle->height, rectangle->width, rectangle->format,
!!(rectangle->flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA));
video_blend_scale_linear_RGBA (&info, rectangle->render_height,
rectangle->render_width);
if (wanted_width != rectangle->width || wanted_height != rectangle->height) {
video_blend_scale_linear_RGBA (&info, wanted_height, wanted_width);
}
if (!gst_video_overlay_rectangle_is_same_alpha_type (rectangle->flags, flags)) {
if (rectangle->flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA) {
gst_video_overlay_rectangle_unpremultiply (&info);
} else {
gst_video_overlay_rectangle_premultiply (&info);
}
}
buf = gst_buffer_new ();
GST_BUFFER_DATA (buf) = info.pixels;
@ -912,8 +971,8 @@ gst_video_overlay_rectangle_get_pixels_argb (GstVideoOverlayRectangle *
GST_BUFFER_SIZE (buf) = info.size;
scaled_rect = gst_video_overlay_rectangle_new_argb (buf,
rectangle->render_width, rectangle->render_height, info.stride[0],
0, 0, rectangle->render_width, rectangle->render_height, 0);
wanted_width, wanted_height, info.stride[0],
0, 0, wanted_width, wanted_height, rectangle->flags);
gst_buffer_unref (buf);
@ -928,6 +987,29 @@ done:
return scaled_rect->pixels;
}
/**
* gst_video_overlay_rectangle_get_pixels_argb:
* @rectangle: a #GstVideoOverlayRectangle
* @stride: (out) (allow-none): address of guint variable where to store the
* row stride of the ARGB pixel data in the buffer
* @flags: flags
*
* Returns: (transfer none): a #GstBuffer holding the ARGB pixel data with
* row stride @stride and width and height of the render dimensions as per
* gst_video_overlay_rectangle_get_render_rectangle(). This function does
* not return a reference, the caller should obtain a reference of her own
* with gst_buffer_ref() if needed.
*
* Since: 0.10.36
*/
GstBuffer *
gst_video_overlay_rectangle_get_pixels_argb (GstVideoOverlayRectangle *
rectangle, guint * stride, GstVideoOverlayFormatFlags flags)
{
return gst_video_overlay_rectangle_get_pixels_argb_internal (rectangle,
stride, flags, FALSE);
}
/**
* gst_video_overlay_rectangle_get_pixels_unscaled_argb:
* @rectangle: a #GstVideoOverlayRectangle
@ -937,7 +1019,7 @@ done:
* rectangle in pixels
* @stride: (out): address of guint variable where to store the row
* stride of the ARGB pixel data in the buffer
* @flags: flags for future use (unused)
* @flags: flags
*
* Retrieves the pixel data as it is. This is useful if the caller can
* do the scaling itself when handling the overlaying. The rectangle will
@ -959,13 +1041,34 @@ gst_video_overlay_rectangle_get_pixels_unscaled_argb (GstVideoOverlayRectangle *
g_return_val_if_fail (width != NULL, NULL);
g_return_val_if_fail (height != NULL, NULL);
g_return_val_if_fail (stride != NULL, NULL);
g_return_val_if_fail (flags == 0, NULL);
*width = rectangle->width;
*height = rectangle->height;
*stride = rectangle->stride;
return gst_video_overlay_rectangle_get_pixels_argb_internal (rectangle,
stride, flags, TRUE);
}
return rectangle->pixels;
/**
* gst_video_overlay_rectangle_get_flags:
* @rectangle: a #GstVideoOverlayRectangle
*
* Retrieves the flags associated with a #GstVideoOverlayRectangle.
* This is useful if the caller can handle both premultiplied alpha and
* non premultiplied alpha, for example. By knowing whether the rectangle
* uses premultiplied or not, it can request the pixel data in the format
* it is stored in, to avoid unnecessary conversion.
*
* Returns: the #GstVideoOverlayFormatFlags associated with the rectangle.
*
* Since: 0.10.37
*/
GstVideoOverlayFormatFlags
gst_video_overlay_rectangle_get_flags (GstVideoOverlayRectangle * rectangle)
{
g_return_val_if_fail (GST_IS_VIDEO_OVERLAY_RECTANGLE (rectangle),
GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE);
return rectangle->flags;
}
/**
@ -992,7 +1095,7 @@ gst_video_overlay_rectangle_copy (GstVideoOverlayRectangle * rectangle)
copy = gst_video_overlay_rectangle_new_argb (rectangle->pixels,
rectangle->width, rectangle->height, rectangle->stride,
rectangle->x, rectangle->y,
rectangle->render_width, rectangle->render_height, 0);
rectangle->render_width, rectangle->render_height, rectangle->flags);
return copy;
}

6
gst-libs/gst/video/video-overlay-composition.h
View file

@ -95,13 +95,15 @@ gst_video_overlay_rectangle_unref (GstVideoOverlayRectangle * comp)
/**
* GstVideoOverlayFormatFlags:
* @GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE: no flags
* @GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA: RGB are premultiplied by A/255. Since: 0.10.37
*
* Overlay format flags.
*
* Since: 0.10.36
*/
typedef enum {
GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE = 0
GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE = 0,
GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA = 1
} GstVideoOverlayFormatFlags;
GType gst_video_overlay_rectangle_get_type (void);
@ -138,6 +140,8 @@ GstBuffer * gst_video_overlay_rectangle_get_pixels_unscaled_arg
guint * stride,
GstVideoOverlayFormatFlags flags);
GstVideoOverlayFormatFlags gst_video_overlay_rectangle_get_flags (GstVideoOverlayRectangle * rectangle);
/**
* GstVideoOverlayComposition:
*

1
win32/common/libgstvideo.def
View file

@ -52,6 +52,7 @@ EXPORTS
gst_video_overlay_rectangle_get_type
gst_video_overlay_rectangle_new_argb
gst_video_overlay_rectangle_set_render_rectangle
gst_video_overlay_rectangle_get_flags
gst_video_parse_caps_chroma_site
gst_video_parse_caps_color_matrix
gst_video_parse_caps_framerate