[FFmpeg-devel] [PATCH 1/3] drawutils: implement uniform and mask blending.
Nicolas George
nicolas.george at normalesup.org
Wed Mar 28 16:25:57 CEST 2012
Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
---
libavfilter/drawutils.c | 224 +++++++++++++++++++++++++++++++++++++++++++++++
libavfilter/drawutils.h | 33 +++++++
2 files changed, 257 insertions(+), 0 deletions(-)
There is room for optimization, but I believe it can already applied.
Note that the handling of subsampling is more accurate than the code
currently present in drawtext; the difference is very much visible in
yuv410p.
diff --git a/libavfilter/drawutils.c b/libavfilter/drawutils.c
index 0243a17..7268967 100644
--- a/libavfilter/drawutils.c
+++ b/libavfilter/drawutils.c
@@ -132,6 +132,8 @@ int ff_draw_init(FFDrawContext *draw, enum PixelFormat format, unsigned flags)
unsigned i, nb_planes = 0;
int pixelstep[MAX_PLANES] = { 0 };
+ if (!desc->name)
+ return AVERROR(EINVAL);
if (desc->flags & ~(PIX_FMT_PLANAR | PIX_FMT_RGB))
return AVERROR(ENOSYS);
for (i = 0; i < desc->nb_components; i++) {
@@ -146,6 +148,8 @@ int ff_draw_init(FFDrawContext *draw, enum PixelFormat format, unsigned flags)
pixelstep[c->plane] != c->step_minus1 + 1)
return AVERROR(ENOSYS);
pixelstep[c->plane] = c->step_minus1 + 1;
+ if (pixelstep[c->plane] >= 8)
+ return AVERROR(ENOSYS);
nb_planes = FFMAX(nb_planes, c->plane + 1);
}
if ((desc->log2_chroma_w || desc->log2_chroma_h) && nb_planes < 3)
@@ -159,6 +163,9 @@ int ff_draw_init(FFDrawContext *draw, enum PixelFormat format, unsigned flags)
draw->hsub[1] = draw->hsub[2] = draw->hsub_max = desc->log2_chroma_w;
draw->vsub[1] = draw->vsub[2] = draw->vsub_max = desc->log2_chroma_h;
}
+ for (i = 0; i < ((desc->nb_components - 1) | 1); i++)
+ draw->comp_mask[desc->comp[i].plane] |=
+ 1 << (desc->comp[i].offset_plus1 - 1);
return 0;
}
@@ -167,6 +174,8 @@ void ff_draw_color(FFDrawContext *draw, FFDrawColor *color, uint8_t rgba[4])
unsigned i;
uint8_t rgba_map[4];
+ if (rgba != color->rgba)
+ memcpy(color->rgba, rgba, sizeof(color->rgba));
if ((draw->desc->flags & PIX_FMT_RGB) && draw->nb_planes == 1 &&
ff_fill_rgba_map(rgba_map, draw->format) >= 0) {
for (i = 0; i < 4; i++)
@@ -246,6 +255,221 @@ void ff_fill_rectangle(FFDrawContext *draw, FFDrawColor *color,
}
}
+static void clip_interval(int wmax, int *x, int *w, int *dx)
+{
+ if (dx)
+ *dx = 0;
+ if (*x < 0) {
+ if (dx)
+ *dx = -*x;
+ *w += *x;
+ *x = 0;
+ }
+ if (*x + *w > wmax)
+ *w = wmax - *x;
+}
+
+static void subsampling_bounds(int sub, int *x, int *w, int *start, int *end)
+{
+ int mask = (1 << sub) - 1;
+
+ *start = (-*x) & mask;
+ *x += *start;
+ *start = FFMIN(*start, *w);
+ *w -= *start;
+ *end = *w & mask;
+ *w >>= sub;
+}
+
+static int component_used(FFDrawContext *draw, int plane, int comp)
+{
+ return (draw->comp_mask[plane] >> comp) & 1;
+}
+
+/* If alpha is in the [ 0 ; 0x1010101 ] range,
+ then alpha * value is in the [ 0 ; 0xFFFFFFFF ] range,
+ and >> 24 gives a correct rounding. */
+static void blend_line(uint8_t *dst, unsigned src, unsigned alpha,
+ int dx, int w, unsigned hsub, int left, int right)
+{
+ unsigned asrc = alpha * src;
+ unsigned tau = 0x1010101 - alpha;
+ int x;
+
+ src *= alpha;
+ if (left) {
+ unsigned suba = (left * alpha) >> hsub;
+ *dst = (*dst * (0x1010101 - suba) + src * suba) >> 24;
+ dst += dx;
+ }
+ for (x = 0; x < w; x++) {
+ *dst = (*dst * tau + asrc) >> 24;
+ dst += dx;
+ }
+ if (right) {
+ unsigned suba = (right * alpha) >> hsub;
+ *dst = (*dst * (0x1010101 - suba) + src * suba) >> 24;
+ }
+}
+
+void ff_blend_rectangle(FFDrawContext *draw, FFDrawColor *color,
+ uint8_t *dst[], int dst_linesize[],
+ int dst_w, int dst_h,
+ int x0, int y0, int w, int h)
+{
+ unsigned alpha, nb_planes, nb_comp, plane, comp;
+ int w_sub, h_sub, x_sub, y_sub, left, right, top, bottom, y;
+ uint8_t *p0, *p;
+
+ /* TODO optimize if alpha = 0xFF */
+ clip_interval(dst_w, &x0, &w, NULL);
+ clip_interval(dst_h, &y0, &h, NULL);
+ if (w <= 0 || h <= 0 || !color->rgba[3])
+ return;
+ /* 0x10203 * alpha + 2 is in the [ 2 ; 0x1010101 - 2 ] range */
+ alpha = 0x10203 * color->rgba[3] + 0x2;
+ nb_planes = (draw->nb_planes - 1) | 1; /* eliminate alpha */
+ for (plane = 0; plane < nb_planes; plane++) {
+ nb_comp = draw->pixelstep[plane];
+ p0 = pointer_at(draw, dst, dst_linesize, plane, x0, y0);
+ w_sub = w;
+ h_sub = h;
+ x_sub = x0;
+ y_sub = y0;
+ subsampling_bounds(draw->hsub[plane], &x_sub, &w_sub, &left, &right);
+ subsampling_bounds(draw->vsub[plane], &y_sub, &h_sub, &top, &bottom);
+ for (comp = 0; comp < nb_comp; comp++) {
+ if (!component_used(draw, plane, comp))
+ continue;
+ p = p0 + comp;
+ if (top) {
+ blend_line(p, color->comp[plane].u8[comp], alpha >> 1,
+ draw->pixelstep[plane], w_sub,
+ draw->hsub[plane], left, right);
+ p += dst_linesize[plane];
+ }
+ for (y = 0; y < h_sub; y++) {
+ blend_line(p, color->comp[plane].u8[comp], alpha,
+ draw->pixelstep[plane], w_sub,
+ draw->hsub[plane], left, right);
+ p += dst_linesize[plane];
+ }
+ if (bottom)
+ blend_line(p, color->comp[plane].u8[comp], alpha >> 1,
+ draw->pixelstep[plane], w_sub,
+ draw->hsub[plane], left, right);
+ }
+ }
+}
+
+static void blend_pixel(uint8_t *dst, unsigned src, unsigned alpha,
+ uint8_t *mask, int mask_linesize, int l2depth,
+ unsigned w, unsigned h, unsigned shift, unsigned xm0)
+{
+ unsigned xm, x, y, t = 0;
+ unsigned xmshf = 3 - l2depth;
+ unsigned xmmod = 7 >> l2depth;
+ unsigned mbits = (1 << (1 << l2depth)) - 1;
+ unsigned mmult = 255 / mbits;
+
+ for (y = 0; y < h; y++) {
+ xm = xm0;
+ for (x = 0; x < w; x++) {
+ t += ((mask[xm >> xmshf] >> ((~xm & xmmod) << l2depth)) & mbits)
+ * mmult;
+ xm++;
+ }
+ mask += mask_linesize;
+ }
+ alpha = (t >> shift) * alpha;
+ *dst = ((0x1010101 - alpha) * *dst + alpha * src) >> 24;
+}
+
+static void blend_line_hv(uint8_t *dst, int dst_delta,
+ unsigned src, unsigned alpha,
+ uint8_t *mask, int mask_linesize, int l2depth, int w,
+ unsigned hsub, unsigned vsub,
+ int xm, int left, int right, int hband)
+{
+ int x;
+
+ if (left) {
+ blend_pixel(dst, src, alpha, mask, mask_linesize, l2depth,
+ left, hband, hsub + vsub, xm);
+ dst += dst_delta;
+ xm += left;
+ }
+ for (x = 0; x < w; x++) {
+ blend_pixel(dst, src, alpha, mask, mask_linesize, l2depth,
+ 1 << hsub, hband, hsub + vsub, xm);
+ dst += dst_delta;
+ xm += 1 << hsub;
+ }
+ if (right)
+ blend_pixel(dst, src, alpha, mask, mask_linesize, l2depth,
+ right, hband, hsub + vsub, xm);
+}
+
+void ff_blend_mask(FFDrawContext *draw, FFDrawColor *color,
+ uint8_t *dst[], int dst_linesize[], int dst_w, int dst_h,
+ uint8_t *mask, int mask_linesize, int mask_w, int mask_h,
+ int l2depth, unsigned endianness, int x0, int y0)
+{
+ unsigned alpha, nb_planes, nb_comp, plane, comp;
+ int xm0, ym0, w_sub, h_sub, x_sub, y_sub, left, right, top, bottom, y;
+ uint8_t *p0, *p, *m;
+
+ clip_interval(dst_w, &x0, &mask_w, &xm0);
+ clip_interval(dst_h, &y0, &mask_h, &ym0);
+ mask += ym0 * mask_linesize;
+ if (mask_w <= 0 || mask_h <= 0 || !color->rgba[3])
+ return;
+ /* alpha is in the [ 0 ; 0x10203 ] range,
+ alpha * mask is in the [ 0 ; 0x1010101 - 4 ] range */
+ alpha = (0x10307 * color->rgba[3] + 0x3) >> 8;
+ nb_planes = (draw->nb_planes - 1) | 1; /* eliminate alpha */
+ for (plane = 0; plane < nb_planes; plane++) {
+ nb_comp = draw->pixelstep[plane];
+ p0 = pointer_at(draw, dst, dst_linesize, plane, x0, y0);
+ w_sub = mask_w;
+ h_sub = mask_h;
+ x_sub = x0;
+ y_sub = y0;
+ subsampling_bounds(draw->hsub[plane], &x_sub, &w_sub, &left, &right);
+ subsampling_bounds(draw->vsub[plane], &y_sub, &h_sub, &top, &bottom);
+ for (comp = 0; comp < nb_comp; comp++) {
+ if (!component_used(draw, plane, comp))
+ continue;
+ p = p0 + comp;
+ m = mask;
+ if (top) {
+ blend_line_hv(p, draw->pixelstep[plane],
+ color->comp[plane].u8[comp], alpha,
+ m, mask_linesize, l2depth, w_sub,
+ draw->hsub[plane], draw->vsub[plane],
+ xm0, left, right, top);
+ p += dst_linesize[plane];
+ m += top * mask_linesize;
+ }
+ for (y = 0; y < h_sub; y++) {
+ blend_line_hv(p, draw->pixelstep[plane],
+ color->comp[plane].u8[comp], alpha,
+ m, mask_linesize, l2depth, w_sub,
+ draw->hsub[plane], draw->vsub[plane],
+ xm0, left, right, 1 << draw->vsub[plane]);
+ p += dst_linesize[plane];
+ m += mask_linesize << draw->vsub[plane];
+ }
+ if (bottom)
+ blend_line_hv(p, draw->pixelstep[plane],
+ color->comp[plane].u8[comp], alpha,
+ m, mask_linesize, l2depth, w_sub,
+ draw->hsub[plane], draw->vsub[plane],
+ xm0, left, right, bottom);
+ }
+ }
+}
+
int ff_draw_round_to_sub(FFDrawContext *draw, int sub_dir, int round_dir,
int value)
{
diff --git a/libavfilter/drawutils.h b/libavfilter/drawutils.h
index 9e98f4e..766f0cc 100644
--- a/libavfilter/drawutils.h
+++ b/libavfilter/drawutils.h
@@ -50,6 +50,7 @@ typedef struct FFDrawContext {
enum PixelFormat format;
unsigned nb_planes;
int pixelstep[MAX_PLANES]; /*< offset between pixels */
+ uint8_t comp_mask[MAX_PLANES]; /*< component is used (except alpha) */
uint8_t hsub[MAX_PLANES]; /*< horizontal subsamling */
uint8_t vsub[MAX_PLANES]; /*< vertical subsamling */
uint8_t hsub_max;
@@ -57,6 +58,7 @@ typedef struct FFDrawContext {
} FFDrawContext;
typedef struct FFDrawColor {
+ uint8_t rgba[4];
union {
uint32_t u32;
uint16_t u16;
@@ -101,6 +103,37 @@ void ff_fill_rectangle(FFDrawContext *draw, FFDrawColor *color,
int dst_x, int dst_y, int w, int h);
/**
+ * Blend a rectangle with an uniform color.
+ */
+void ff_blend_rectangle(FFDrawContext *draw, FFDrawColor *color,
+ uint8_t *dst[], int dst_linesize[],
+ int dst_w, int dst_h,
+ int x0, int y0, int w, int h);
+
+/**
+ * Blend an alpha mask with an uniform color.
+ *
+ * @param draw draw context
+ * @param color color for the overlay;
+ * @param dst destination image
+ * @param dst_linesize line stride of the destination
+ * @param dst_w width of the destination image
+ * @param dst_h height of the destination image
+ * @param mask mask
+ * @param mask_linesize line stride of the mask
+ * @param mask_w width of the mask
+ * @param mask_h height of the mask
+ * @param l2depth log2 of depth of the mask (0 for 1bpp, 3 for 8bpp)
+ * @param endianness bit order of the mask (0: MSB to the left)
+ * @param x0 horizontal position of the overlay
+ * @param y0 vertical position of the overlay
+ */
+void ff_blend_mask(FFDrawContext *draw, FFDrawColor *color,
+ uint8_t *dst[], int dst_linesize[], int dst_w, int dst_h,
+ uint8_t *mask, int mask_linesize, int mask_w, int mask_h,
+ int l2depth, unsigned endianness, int x0, int y0);
+
+/**
* Round a dimension according to subsampling.
*
* @param draw draw context
--
1.7.9.1
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