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video-blend: fix blending 8-bit and 16-bit frames together

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Replace hardcoded 255s with the correct max value for the given color
depth. Use 64-bit integer in calculations where overflow may occur.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/1000>
This commit is contained in:
Jakub Adam 2020-07-14 20:44:18 +02:00 committed by GStreamer Merge Bot
parent 5950fc1aae
commit 2d198ff10b
1 changed files with 30 additions and 23 deletions
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53
gst-libs/gst/video/video-blend.c
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@ -243,6 +243,7 @@ gst_video_blend_scale_linear_RGBA (GstVideoInfo * src, GstBuffer * src_buffer,
/*
* A OVER B alpha compositing operation, with:
* max: maximum value a color can have
* alphaG: global alpha to apply on the source color
* -> only needed for premultiplied source
* alphaA: source pixel alpha
@ -254,24 +255,30 @@ gst_video_blend_scale_linear_RGBA (GstVideoInfo * src, GstBuffer * src_buffer,
*/
/* Source non-premultiplied, Destination non-premultiplied */
#define OVER00(alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaA + colorB * alphaB * (255 - alphaA) / 255) / alphaD)
#define OVER00_8BIT(max, alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaA + colorB * alphaB * (max - alphaA) / max) / alphaD)
#define OVER00_16BIT(max, alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaA + (guint64) colorB * alphaB * (max - alphaA) / max) / alphaD)
/* Source premultiplied, Destination non-premultiplied */
#define OVER10(alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaG + colorB * alphaB * (255 - alphaA) / 255) / alphaD)
#define OVER10_8BIT(max, alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaG + colorB * alphaB * (max - alphaA) / max) / alphaD)
#define OVER10_16BIT(max, alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaG + (guint64) colorB * alphaB * (max - alphaA) / max) / alphaD)
/* Source non-premultiplied, Destination premultiplied */
#define OVER01(alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaA + colorB * (255 - alphaA)) / 255)
#define OVER01(max, alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaA + colorB * (max - alphaA)) / max)
/* Source premultiplied, Destination premultiplied */
#define OVER11(alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaG + colorB * (255 - alphaA)) / 255)
#define OVER11(max, alphaG, alphaA, colorA, alphaB, colorB, alphaD) \
((colorA * alphaG + colorB * (max - alphaA)) / max)
#define BLENDC(op, max, global_alpha, aa, ca, ab, cb, dest_alpha) \
G_STMT_START { \
int c = op((global_alpha), (aa), (ca), (ab), (cb), (dest_alpha)); \
int c = op((max), (global_alpha), (aa), (ca), (ab), (cb), (dest_alpha)); \
cb = MIN(c, (max)); \
} G_STMT_END
@ -302,8 +309,6 @@ gst_video_blend (GstVideoFrame * dest,
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 =
@ -347,6 +352,8 @@ gst_video_blend (GstVideoFrame * dest,
/* Source is always 8 bit but destination might be 8 or 16 bit */
bpp = 4 * (GST_VIDEO_FORMAT_INFO_BITS (dunpackinfo) / 8);
global_alpha_val = (bpp == 4) ? 255.0 * global_alpha : 65535.0 * global_alpha;
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)) {
@ -408,7 +415,7 @@ gst_video_blend (GstVideoFrame * dest,
guint final_alpha; \
dest_type * dest = (dest_type *) tmpdestline; \
\
asrc = ((guint) tmpsrcline[j]) * alpha_val / 255; \
asrc = ((guint) tmpsrcline[j]) * alpha_val / max; \
asrc = asrc << shift; \
if (asrc == 0) \
continue; \
@ -432,9 +439,9 @@ gst_video_blend (GstVideoFrame * dest,
} else if (!src_premultiplied_alpha && dest_premultiplied_alpha) {
BLENDLOOP (OVER01, guint8, 255, 0, 255);
} else if (src_premultiplied_alpha && !dest_premultiplied_alpha) {
BLENDLOOP (OVER10, guint8, 255, 0, 255);
BLENDLOOP (OVER10_8BIT, guint8, 255, 0, 255);
} else {
BLENDLOOP (OVER00, guint8, 255, 0, 255);
BLENDLOOP (OVER00_8BIT, guint8, 255, 0, 255);
}
} else {
if (src_premultiplied_alpha && dest_premultiplied_alpha) {
@ -442,23 +449,23 @@ gst_video_blend (GstVideoFrame * dest,
} else if (!src_premultiplied_alpha && dest_premultiplied_alpha) {
BLENDLOOP (OVER01, guint8, 255, 0, global_alpha_val);
} else if (src_premultiplied_alpha && !dest_premultiplied_alpha) {
BLENDLOOP (OVER10, guint8, 255, 0, global_alpha_val);
BLENDLOOP (OVER10_8BIT, guint8, 255, 0, global_alpha_val);
} else {
BLENDLOOP (OVER00, guint8, 255, 0, global_alpha_val);
BLENDLOOP (OVER00_8BIT, guint8, 255, 0, global_alpha_val);
}
}
} else {
g_assert (bpp == 8);
if (G_LIKELY (global_alpha_val == 255)) {
if (G_LIKELY (global_alpha_val == 65535)) {
if (src_premultiplied_alpha && dest_premultiplied_alpha) {
BLENDLOOP (OVER11, guint16, 65535, 8, 255);
BLENDLOOP (OVER11, guint16, 65535, 8, 65535);
} else if (!src_premultiplied_alpha && dest_premultiplied_alpha) {
BLENDLOOP (OVER01, guint16, 65535, 8, 255);
BLENDLOOP (OVER01, guint16, 65535, 8, 65535);
} else if (src_premultiplied_alpha && !dest_premultiplied_alpha) {
BLENDLOOP (OVER10, guint16, 65535, 8, 255);
BLENDLOOP (OVER10_16BIT, guint16, 65535, 8, 65535);
} else {
BLENDLOOP (OVER00, guint16, 65535, 8, 255);
BLENDLOOP (OVER00_16BIT, guint16, 65535, 8, 65535);
}
} else {
if (src_premultiplied_alpha && dest_premultiplied_alpha) {
@ -466,9 +473,9 @@ gst_video_blend (GstVideoFrame * dest,
} else if (!src_premultiplied_alpha && dest_premultiplied_alpha) {
BLENDLOOP (OVER01, guint16, 65535, 8, global_alpha_val);
} else if (src_premultiplied_alpha && !dest_premultiplied_alpha) {
BLENDLOOP (OVER10, guint16, 65535, 8, global_alpha_val);
BLENDLOOP (OVER10_16BIT, guint16, 65535, 8, global_alpha_val);
} else {
BLENDLOOP (OVER00, guint16, 65535, 8, global_alpha_val);
BLENDLOOP (OVER00_16BIT, guint16, 65535, 8, global_alpha_val);
}
}
}