/* Gstreamer video blending utility functions
*
* Copied/pasted from gst/videoconvert/videoconvert.c
* Copyright (C) 2010 David Schleef <ds@schleef.org>
* Copyright (C) 2010 Sebastian Dröge <sebastian.droege@collabora.co.uk>
*
* Copyright (C) <2011> Intel Corporation
* Copyright (C) <2011> Collabora Ltd.
* Copyright (C) <2011> Thibault Saunier <thibault.saunier@collabora.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "video-blend.h"
#include "video-orc.h"
#include <string.h>
#ifndef GST_DISABLE_GST_DEBUG
#define GST_CAT_DEFAULT ensure_debug_category()
static GstDebugCategory *
ensure_debug_category (void)
{
static gsize cat_gonce = 0;
if (g_once_init_enter (&cat_gonce)) {
gsize cat_done;
cat_done = (gsize) _gst_debug_category_new ("video-blending", 0,
"video blending");
g_once_init_leave (&cat_gonce, cat_done);
}
return (GstDebugCategory *) cat_gonce;
}
#else
#define ensure_debug_category() /* NOOP */
#endif /* GST_DISABLE_GST_DEBUG */
static void
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)
{
int i;
int r, g, b;
int y, u, v;
for (i = 0; i < width; i++) {
r = tmpline[i * 4 + 1];
g = tmpline[i * 4 + 2];
b = tmpline[i * 4 + 3];
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_yuv_to_rgb (guint8 * tmpline, guint width)
{
int i;
int r, g, b;
int y, u, v;
for (i = 0; i < width; i++) {
y = tmpline[i * 4 + 1];
u = tmpline[i * 4 + 2];
v = tmpline[i * 4 + 3];
r = (298 * y + 459 * v - 63514) >> 8;
g = (298 * y - 55 * u - 136 * v + 19681) >> 8;
b = (298 * y + 541 * u - 73988) >> 8;
tmpline[i * 4 + 1] = CLAMP (r, 0, 255);
tmpline[i * 4 + 2] = CLAMP (g, 0, 255);
tmpline[i * 4 + 3] = CLAMP (b, 0, 255);
}
}
/**
* gst_video_blend_scale_linear_RGBA:
* @src: the #GstVideoInfo describing the video data in @src_buffer
* @src_buffer: the source buffer containing video pixels to scale
* @dest_height: the height in pixels to scale the video data in @src_buffer to
* @dest_width: the width in pixels to scale the video data in @src_buffer to
* @dest: (out): pointer to a #GstVideoInfo structure that will be filled in
* with the details for @dest_buffer
* @dest_buffer: (out): a pointer to a #GstBuffer variable, which will be
* set to a newly-allocated buffer containing the scaled pixels.
*
* Scales a buffer containing RGBA (or AYUV) video. This is an internal
* helper function which is used to scale subtitle overlays, and may be
* deprecated in the near future. Use #GstVideoScaler to scale video buffers
* instead.
*/
/* returns newly-allocated buffer, which caller must unref */
void
gst_video_blend_scale_linear_RGBA (GstVideoInfo * src, GstBuffer * src_buffer,
gint dest_height, gint dest_width, GstVideoInfo * dest,
GstBuffer ** dest_buffer)
{
const guint8 *src_pixels;
int acc;
int y_increment;
int x_increment;
int y1;
int i;
int j;
int x;
int dest_size;
guint dest_stride;
guint src_stride;
guint8 *dest_pixels;
guint8 *tmpbuf;
GstVideoFrame src_frame, dest_frame;
g_return_if_fail (dest_buffer != NULL);
gst_video_info_init (dest);
if (!gst_video_info_set_format (dest, GST_VIDEO_INFO_FORMAT (src),
dest_width, dest_height)) {
g_warn_if_reached ();
return;
}
tmpbuf = g_malloc (dest_width * 8 * 4);
*dest_buffer = gst_buffer_new_and_alloc (GST_VIDEO_INFO_SIZE (dest));
gst_video_frame_map (&src_frame, src, src_buffer, GST_MAP_READ);
gst_video_frame_map (&dest_frame, dest, *dest_buffer, GST_MAP_WRITE);
if (dest_height == 1 || src->height == 1)
y_increment = 0;
else
y_increment = ((src->height - 1) << 16) / (dest_height - 1) - 1;
if (dest_width == 1 || src->width == 1)
x_increment = 0;
else
x_increment = ((src->width - 1) << 16) / (dest_width - 1) - 1;
dest_size = dest_stride = dest_width * 4;
src_stride = GST_VIDEO_FRAME_PLANE_STRIDE (&src_frame, 0);
#define LINE(x) ((tmpbuf) + (dest_size)*((x)&1))
dest_pixels = GST_VIDEO_FRAME_PLANE_DATA (&dest_frame, 0);
src_pixels = GST_VIDEO_FRAME_PLANE_DATA (&src_frame, 0);
acc = 0;
video_orc_resample_bilinear_u32 (LINE (0), src_pixels, 0, x_increment,
dest_width);
y1 = 0;
for (i = 0; i < dest_height; i++) {
j = acc >> 16;
x = acc & 0xffff;
if (x == 0) {
memcpy (dest_pixels + i * dest_stride, LINE (j), dest_size);
} else {
if (j > y1) {
video_orc_resample_bilinear_u32 (LINE (j),
src_pixels + j * src_stride, 0, x_increment, dest_width);
y1++;
}
if (j >= y1) {
video_orc_resample_bilinear_u32 (LINE (j + 1),
src_pixels + (j + 1) * src_stride, 0, x_increment, dest_width);
y1++;
}
video_orc_merge_linear_u8 (dest_pixels + i * dest_stride,
LINE (j), LINE (j + 1), (x >> 8), dest_width * 4);
}
acc += y_increment;
}
gst_video_frame_unmap (&src_frame);
gst_video_frame_unmap (&dest_frame);
g_free (tmpbuf);
}
/*
* A OVER B alpha compositing operation, with:
* alphaG: global alpha to apply on the source color
* -> only needed for premultiplied source
* alphaA: source pixel alpha
* colorA: source pixel color
* alphaB: destination pixel alpha
* colorB: destination pixel color
* alphaD: blended pixel alpha
* -> only needed for premultiplied destination
*/
/* Source non-premultiplied, Destination non-premultiplied */
#define OVER00(alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaA + colorB * alphaB * (255 - alphaA) / 255) / alphaD)
/* Source premultiplied, Destination non-premultiplied */
#define OVER10(alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaG + colorB * alphaB * (255 - alphaA) / 255) / alphaD)
/* Source non-premultiplied, Destination premultiplied */
#define OVER01(alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaA + colorB * (255 - alphaA)) / 255)
/* Source premultiplied, Destination premultiplied */
#define OVER11(alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaG + colorB * (255 - alphaA)) / 255)
#define BLENDC(op, global_alpha, aa, ca, ab, cb, dest_alpha) \
G_STMT_START { \
int c = op(global_alpha, aa, ca, ab, cb, dest_alpha); \
cb = MIN(c, 255); \
} G_STMT_END
/**
* gst_video_blend:
* @dest: The #GstVideoFrame where to blend @src in
* @src: the #GstVideoFrame that we want to blend into
* @x: The x offset in pixel where the @src image should be blended
* @y: the y offset in pixel where the @src image should be blended
* @global_alpha: the global_alpha each per-pixel alpha value is multiplied
* with
*
* Lets you blend the @src image into the @dest image
*/
gboolean
gst_video_blend (GstVideoFrame * dest,
GstVideoFrame * src, gint x, gint y, gfloat global_alpha)
{
gint i, j, global_alpha_val, src_width, src_height, dest_width, dest_height;
gint src_xoff = 0, src_yoff = 0;
guint8 *tmpdestline = NULL, *tmpsrcline = NULL;
gboolean src_premultiplied_alpha, dest_premultiplied_alpha;
void (*matrix) (guint8 * tmpline, guint width);
const GstVideoFormatInfo *sinfo, *dinfo, *dunpackinfo, *sunpackinfo;
g_assert (dest != NULL);
g_assert (src != NULL);
global_alpha_val = 255.0 * global_alpha;
dest_premultiplied_alpha =
GST_VIDEO_INFO_FLAGS (&dest->info) & GST_VIDEO_FLAG_PREMULTIPLIED_ALPHA;
src_premultiplied_alpha =
GST_VIDEO_INFO_FLAGS (&src->info) & GST_VIDEO_FLAG_PREMULTIPLIED_ALPHA;
src_width = GST_VIDEO_FRAME_WIDTH (src);
src_height = GST_VIDEO_FRAME_HEIGHT (src);
dest_width = GST_VIDEO_FRAME_WIDTH (dest);
dest_height = GST_VIDEO_FRAME_HEIGHT (dest);
ensure_debug_category ();
GST_LOG ("blend src %dx%d onto dest %dx%d @ %d,%d", src_width, src_height,
dest_width, dest_height, x, y);
/* In case overlay is completely outside the video, dont render */
if (x + src_width <= 0 || y + src_height <= 0
|| x >= dest_width || y >= dest_height) {
goto nothing_to_do;
}
dinfo = gst_video_format_get_info (GST_VIDEO_FRAME_FORMAT (dest));
sinfo = gst_video_format_get_info (GST_VIDEO_FRAME_FORMAT (src));
if (!sinfo || !dinfo)
goto failed;
dunpackinfo = gst_video_format_get_info (dinfo->unpack_format);
sunpackinfo = gst_video_format_get_info (sinfo->unpack_format);
if (dunpackinfo == NULL || sunpackinfo == NULL)
goto failed;
g_assert (GST_VIDEO_FORMAT_INFO_BITS (sunpackinfo) == 8);
if (GST_VIDEO_FORMAT_INFO_BITS (dunpackinfo) != 8)
goto unpack_format_not_supported;
tmpdestline = g_malloc (sizeof (guint8) * (dest_width + 8) * 4);
tmpsrcline = g_malloc (sizeof (guint8) * (src_width + 8) * 4);
matrix = matrix_identity;
if (GST_VIDEO_INFO_IS_RGB (&src->info) != GST_VIDEO_INFO_IS_RGB (&dest->info)) {
if (GST_VIDEO_INFO_IS_RGB (&src->info)) {
if (src_premultiplied_alpha) {
matrix = matrix_prea_rgb_to_yuv;
src_premultiplied_alpha = FALSE;
} else {
matrix = matrix_rgb_to_yuv;
}
} else {
matrix = matrix_yuv_to_rgb;
}
}
/* If we're here we know that the overlay image fully or
* partially overlaps with the video frame */
/* adjust src image for negative offsets */
if (x < 0) {
src_xoff = -x;
src_width -= src_xoff;
x = 0;
}
if (y < 0) {
src_yoff = -y;
src_height -= src_yoff;
y = 0;
}
/* adjust width/height to render (i.e. clip source image) if the source
* image extends beyond the right or bottom border of the video surface */
if (x + src_width > dest_width)
src_width = dest_width - x;
if (y + src_height > dest_height)
src_height = dest_height - y;
/* Mainloop doing the needed conversions, and blending */
for (i = y; i < y + src_height; i++, src_yoff++) {
dinfo->unpack_func (dinfo, 0, tmpdestline, dest->data, dest->info.stride,
0, i, dest_width);
sinfo->unpack_func (sinfo, 0, tmpsrcline, src->data, src->info.stride,
src_xoff, src_yoff, src_width);
/* FIXME: use the x parameter of the unpack func once implemented */
tmpdestline += 4 * x;
matrix (tmpsrcline, src_width);
#define BLENDLOOP(op, alpha_val) \
G_STMT_START { \
for (j = 0; j < src_width * 4; j += 4) { \
guint8 asrc, adst; \
gint final_alpha; \
\
asrc = tmpsrcline[j] * alpha_val / 255; \
if (!asrc) \
continue; \
\
adst = tmpdestline[j]; \
final_alpha = asrc + adst * (255 - asrc) / 255; \
tmpdestline[j] = final_alpha; \
if (final_alpha == 0) \
final_alpha = 1; \
\
BLENDC (op, alpha_val, asrc, tmpsrcline[j + 1], adst, tmpdestline[j + 1], final_alpha); \
BLENDC (op, alpha_val, asrc, tmpsrcline[j + 2], adst, tmpdestline[j + 2], final_alpha); \
BLENDC (op, alpha_val, asrc, tmpsrcline[j + 3], adst, tmpdestline[j + 3], final_alpha); \
} \
} G_STMT_END
if (G_LIKELY (global_alpha == 1.0)) {
if (src_premultiplied_alpha && dest_premultiplied_alpha) {
BLENDLOOP (OVER11, 255);
} else if (!src_premultiplied_alpha && dest_premultiplied_alpha) {
BLENDLOOP (OVER01, 255);
} else if (src_premultiplied_alpha && !dest_premultiplied_alpha) {
BLENDLOOP (OVER10, 255);
} else {
BLENDLOOP (OVER00, 255);
}
} else {
if (src_premultiplied_alpha && dest_premultiplied_alpha) {
BLENDLOOP (OVER11, global_alpha_val);
} else if (!src_premultiplied_alpha && dest_premultiplied_alpha) {
BLENDLOOP (OVER01, global_alpha_val);
} else if (src_premultiplied_alpha && !dest_premultiplied_alpha) {
BLENDLOOP (OVER10, global_alpha_val);
} else {
BLENDLOOP (OVER00, global_alpha_val);
}
}
#undef BLENDLOOP
/* undo previous pointer adjustments to pass right pointer to g_free */
tmpdestline -= 4 * x;
/* FIXME
* #if G_BYTE_ORDER == LITTLE_ENDIAN
* video_orc_blend_little (tmpdestline, tmpsrcline, dest->width);
* #else
* video_orc_blend_big (tmpdestline, tmpsrcline, src->width);
* #endif
*/
dinfo->pack_func (dinfo, 0, tmpdestline, dest_width,
dest->data, dest->info.stride, dest->info.chroma_site, i, dest_width);
}
g_free (tmpdestline);
g_free (tmpsrcline);
return TRUE;
failed:
{
GST_WARNING ("Could not do the blending");
return FALSE;
}
unpack_format_not_supported:
{
GST_FIXME ("video format %s not supported yet for blending",
gst_video_format_to_string (dinfo->unpack_format));
return FALSE;
}
nothing_to_do:
{
GST_LOG
("Overlay completely outside the video surface, hence not rendering");
return TRUE;
}
}