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cairotextoverlay: Don't render text outside the frame boundaries

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Fixes bug #611986.
This commit is contained in:
Sebastian Dröge 2010-03-15 13:40:38 +01:00
parent ba6dbaecfc
commit a7a0afa5c4
1 changed files with 33 additions and 28 deletions
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61
ext/cairo/gsttextoverlay.c
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@ -665,41 +665,46 @@ gst_text_overlay_shade_y (GstCairoTextOverlay * overlay, guchar * dest,
static inline void static inline void
gst_text_overlay_blit_1 (GstCairoTextOverlay * overlay, guchar * dest, gst_text_overlay_blit_1 (GstCairoTextOverlay * overlay, guchar * dest,
guchar * text_image, gint val, guint dest_stride) guchar * text_image, gint val, guint dest_stride, gint y0)
{ {
gint i, j; gint i, j;
gint x, a, y; gint x, a, y;
gint y0 = 0; gint y1;
y = val; y = val;
y0 = MIN (y0, overlay->height);
y1 = MIN (y0 + overlay->font_height, overlay->height);
for (i = 0; i < overlay->font_height; i++) { for (i = y0; i < y1; i++) {
for (j = 0; j < overlay->width; j++) { for (j = 0; j < overlay->width; j++) {
x = dest[(i + y0) * dest_stride + j]; x = dest[i * dest_stride + j];
a = text_image[4 * (i * overlay->width + j) + 1]; a = text_image[4 * ((i - y0) * overlay->width + j) + 1];
dest[(i + y0) * dest_stride + j] = (y * a + x * (255 - a)) / 255; dest[i * dest_stride + j] = (y * a + x * (255 - a)) / 255;
} }
} }
} }
static inline void static inline void
gst_text_overlay_blit_sub2x2 (GstCairoTextOverlay * overlay, guchar * dest, gst_text_overlay_blit_sub2x2 (GstCairoTextOverlay * overlay, guchar * dest,
guchar * text_image, gint val, guint dest_stride) guchar * text_image, gint val, guint dest_stride, gint y0)
{ {
gint i, j; gint i, j;
gint x, a, y; gint x, a, y;
gint y0 = 0; gint y1;
y0 = MIN (y0, overlay->height);
y1 = MIN (y0 + overlay->font_height, overlay->height);
y = val; y = val;
for (i = 0; i < overlay->font_height; i += 2) { for (i = y0; i < y1; i += 2) {
for (j = 0; j < overlay->width; j += 2) { for (j = 0; j < overlay->width; j += 2) {
x = dest[(i / 2 + y0) * dest_stride + j / 2]; x = dest[(i / 2) * dest_stride + j / 2];
a = (text_image[4 * (i * overlay->width + j) + 1] + a = (text_image[4 * ((i - y0) * overlay->width + j) + 1] +
text_image[4 * (i * overlay->width + j + 1) + 1] + text_image[4 * ((i - y0) * overlay->width + j + 1) + 1] +
text_image[4 * ((i + 1) * overlay->width + j) + 1] + text_image[4 * ((i - y0 + 1) * overlay->width + j) + 1] +
text_image[4 * ((i + 1) * overlay->width + j + 1) + 1] + 2) / 4; text_image[4 * ((i - y0 + 1) * overlay->width + j + 1) + 1] + 2) / 4;
dest[(i / 2 + y0) * dest_stride + j / 2] = (y * a + x * (255 - a)) / 255; dest[(i / 2) * dest_stride + j / 2] = (y * a + x * (255 - a)) / 255;
} }
} }
} }
@ -745,25 +750,25 @@ gst_text_overlay_push_frame (GstCairoTextOverlay * overlay,
/* blit outline text on video image */ /* blit outline text on video image */
gst_text_overlay_blit_1 (overlay, gst_text_overlay_blit_1 (overlay,
y + (ypos / 1) * I420_Y_ROWSTRIDE (overlay->width), y,
overlay->text_outline_image, 0, I420_Y_ROWSTRIDE (overlay->width)); overlay->text_outline_image, 0, I420_Y_ROWSTRIDE (overlay->width), ypos);
gst_text_overlay_blit_sub2x2 (overlay, gst_text_overlay_blit_sub2x2 (overlay,
u + (ypos / 2) * I420_U_ROWSTRIDE (overlay->width), u,
overlay->text_outline_image, 128, I420_U_ROWSTRIDE (overlay->width)); overlay->text_outline_image, 128, I420_U_ROWSTRIDE (overlay->width),
gst_text_overlay_blit_sub2x2 (overlay, ypos);
v + (ypos / 2) * I420_V_ROWSTRIDE (overlay->width), gst_text_overlay_blit_sub2x2 (overlay, v, overlay->text_outline_image, 128,
overlay->text_outline_image, 128, I420_V_ROWSTRIDE (overlay->width)); I420_V_ROWSTRIDE (overlay->width), ypos);
/* blit text on video image */ /* blit text on video image */
gst_text_overlay_blit_1 (overlay, gst_text_overlay_blit_1 (overlay,
y + (ypos / 1) * I420_Y_ROWSTRIDE (overlay->width), y,
overlay->text_fill_image, 255, I420_Y_ROWSTRIDE (overlay->width)); overlay->text_fill_image, 255, I420_Y_ROWSTRIDE (overlay->width), ypos);
gst_text_overlay_blit_sub2x2 (overlay, gst_text_overlay_blit_sub2x2 (overlay,
u + (ypos / 2) * I420_U_ROWSTRIDE (overlay->width), u,
overlay->text_fill_image, 128, I420_U_ROWSTRIDE (overlay->width)); overlay->text_fill_image, 128, I420_U_ROWSTRIDE (overlay->width), ypos);
gst_text_overlay_blit_sub2x2 (overlay, gst_text_overlay_blit_sub2x2 (overlay,
v + (ypos / 2) * I420_V_ROWSTRIDE (overlay->width), v,
overlay->text_fill_image, 128, I420_V_ROWSTRIDE (overlay->width)); overlay->text_fill_image, 128, I420_V_ROWSTRIDE (overlay->width), ypos);
return gst_pad_push (overlay->srcpad, video_frame); return gst_pad_push (overlay->srcpad, video_frame);
} }