#include "video-overlay-composition.h"
#include "video-blend.h"
+#include <string.h>
struct _GstVideoOverlayComposition
{
* rectangles have expired. */
guint seq_num;
+ /* global alpha: global alpha value of the rectangle. Each each per-pixel
+ * alpha value of image-data will be multiplied with the global alpha value
+ * during blending.
+ * Can be used for efficient fading in/out of overlay rectangles.
+ * GstElements that render OverlayCompositions and don't support global alpha
+ * should simply ignore it.*/
+ gfloat global_alpha;
+
+ /* track alpha-values already applied: */
+ gfloat applied_global_alpha;
+ /* store initial per-pixel alpha values: */
+ guint8 *initial_alpha;
+
/* FIXME: we may also need a (private) way to cache converted/scaled
* pixel blobs */
#if !GLIB_CHECK_VERSION (2, 31, 0)
video_blend_format_info_init (&rectangle_info,
GST_BUFFER_DATA (rect->pixels), rect->height, rect->width,
rect->format,
- !!(rect->flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA));
+ ! !(rect->flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA));
needs_scaling = gst_video_overlay_rectangle_needs_scaling (rect);
if (needs_scaling) {
rect->render_width);
}
- ret = video_blend (&video_info, &rectangle_info, rect->x, rect->y);
+ ret = video_blend (&video_info, &rectangle_info, rect->x, rect->y,
+ rect->global_alpha);
if (!ret) {
GST_WARNING ("Could not blend overlay rectangle onto video buffer");
}
rect->scaled_rectangles =
g_list_delete_link (rect->scaled_rectangles, rect->scaled_rectangles);
}
+
+ g_free (rect->initial_alpha);
#if !GLIB_CHECK_VERSION (2, 31, 0)
g_static_mutex_free (&rect->lock);
#else
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;
+ return (flags & ~(GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA |
+ GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA)) == 0;
}
static gboolean
rect->render_width = render_width;
rect->render_height = render_height;
+ rect->global_alpha = 1.0;
+ rect->applied_global_alpha = 1.0;
+ rect->initial_alpha = NULL;
+
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, "
- "flags %x, pixels %p", rect, width, height, render_width, render_height,
- render_x, render_y, rect->seq_num, rect->format, rect->flags, pixels);
+ "flags %x, pixels %p, global_alpha=%f", rect, width, height, render_width,
+ render_height, render_x, render_y, rect->seq_num, rect->format,
+ rect->flags, pixels, rect->global_alpha);
return rect;
}
}
}
+
+static gboolean
+gst_video_overlay_rectangle_extract_alpha (GstVideoOverlayRectangle * rect)
+{
+ guint8 *src, *dst;
+ int offset = 0;
+ int alpha_size = rect->stride * rect->height / 4;
+
+ g_free (rect->initial_alpha);
+ rect->initial_alpha = NULL;
+
+ rect->initial_alpha = g_malloc (alpha_size);
+ src = GST_BUFFER_DATA (rect->pixels);
+ dst = rect->initial_alpha;
+ while (offset < alpha_size) {
+ dst[offset] = src[offset * 4 + ARGB_A];
+ ++offset;
+ }
+ return TRUE;
+}
+
+
+static gboolean
+gst_video_overlay_rectangle_apply_global_alpha (GstVideoOverlayRectangle * rect,
+ float global_alpha)
+{
+ guint8 *src, *dst;
+ guint offset = 0;
+
+ g_return_val_if_fail (!(rect->applied_global_alpha != 1.0
+ && rect->initial_alpha == NULL), FALSE);
+
+ if (global_alpha == rect->applied_global_alpha)
+ return TRUE;
+
+ if (rect->initial_alpha == NULL &&
+ !gst_video_overlay_rectangle_extract_alpha (rect))
+ return FALSE;
+
+ src = rect->initial_alpha;
+ rect->pixels = gst_buffer_make_writable (rect->pixels);
+ dst = GST_BUFFER_DATA (rect->pixels);
+ while (offset < (rect->height * rect->stride / 4)) {
+ guint doff = offset * 4;
+ guint8 na = (guint8) src[offset] * global_alpha;
+ if (! !(rect->flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA)) {
+ dst[doff + ARGB_R] =
+ (guint8) ((double) (dst[doff + ARGB_R] * 255) / (double) dst[doff +
+ ARGB_A]) * na / 255;
+ dst[doff + ARGB_G] =
+ (guint8) ((double) (dst[doff + ARGB_G] * 255) / (double) dst[doff +
+ ARGB_A]) * na / 255;
+ dst[doff + ARGB_B] =
+ (guint8) ((double) (dst[doff + ARGB_B] * 255) / (double) dst[doff +
+ ARGB_A]) * na / 255;
+ }
+ dst[doff + ARGB_A] = na;
+ ++offset;
+ }
+
+ rect->applied_global_alpha = global_alpha;
+ return TRUE;
+}
+
static GstBuffer *
gst_video_overlay_rectangle_get_pixels_argb_internal (GstVideoOverlayRectangle *
rectangle, guint * stride, GstVideoOverlayFormatFlags flags,
GList *l;
guint wanted_width = unscaled ? rectangle->width : rectangle->render_width;
guint wanted_height = unscaled ? rectangle->height : rectangle->render_height;
+ gboolean apply_global_alpha;
+ gboolean revert_global_alpha;
g_return_val_if_fail (GST_IS_VIDEO_OVERLAY_RECTANGLE (rectangle), NULL);
g_return_val_if_fail (stride != NULL, NULL);
g_return_val_if_fail (gst_video_overlay_rectangle_check_flags (flags), NULL);
+ apply_global_alpha =
+ (! !(rectangle->flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA)
+ && !(flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA));
+ revert_global_alpha =
+ (! !(rectangle->flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA)
+ && ! !(flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA));
+
/* This assumes we don't need to adjust the format */
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;
+ /* don't need to apply/revert global-alpha either: */
+ if ((!apply_global_alpha
+ || rectangle->applied_global_alpha == rectangle->global_alpha)
+ && (!revert_global_alpha || rectangle->applied_global_alpha == 1.0)) {
+ *stride = rectangle->stride;
+ return rectangle->pixels;
+ } else {
+ /* only apply/revert global-alpha */
+ scaled_rect = rectangle;
+ goto done;
+ }
}
/* see if we've got one cached already */
if (scaled_rect != NULL)
goto done;
- /* not cached yet, do the scaling and put the result into our cache */
+ /* not cached yet, do the preprocessing 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->flags & GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA));
+ ! !(rectangle->flags &
+ GST_VIDEO_OVERLAY_FORMAT_FLAG_PREMULTIPLIED_ALPHA));
if (wanted_width != rectangle->width || wanted_height != rectangle->height) {
+ /* we could check the cache for a scaled rect with global_alpha == 1 here */
video_blend_scale_linear_RGBA (&info, wanted_height, wanted_width);
} else {
/* if we don't have to scale, we have to modify the alpha values, so we
scaled_rect = gst_video_overlay_rectangle_new_argb (buf,
wanted_width, wanted_height, info.stride[0],
0, 0, wanted_width, wanted_height, new_flags);
-
+ if (rectangle->global_alpha != 1.0)
+ gst_video_overlay_rectangle_set_global_alpha (scaled_rect,
+ rectangle->global_alpha);
gst_buffer_unref (buf);
GST_RECTANGLE_LOCK (rectangle);
GST_RECTANGLE_UNLOCK (rectangle);
done:
+ if (apply_global_alpha
+ && scaled_rect->applied_global_alpha != rectangle->global_alpha) {
+ if (!gst_video_overlay_rectangle_apply_global_alpha (scaled_rect,
+ rectangle->global_alpha))
+ return NULL; /* return original data? */
+ gst_video_overlay_rectangle_set_global_alpha (scaled_rect,
+ rectangle->global_alpha);
+ } else if (revert_global_alpha && scaled_rect->applied_global_alpha != 1.0) {
+ if (!gst_video_overlay_rectangle_apply_global_alpha (scaled_rect, 1.0))
+ return NULL; /* return original data? */
+ }
*stride = scaled_rect->stride;
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
+ * If a global_alpha value != 1 is set for the rectangle, the caller
+ * should set the #GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA flag
+ * if he wants to apply global-alpha himself. If the flag is not set
+ * global_alpha is applied internally before returning the pixel-data.
*
* Returns: (transfer none): a #GstBuffer holding the ARGB pixel data with
* row stride @stride and width and height of the render dimensions as per
* 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
+ * @flags: flags.
+ * If a global_alpha value != 1 is set for the rectangle, the caller
+ * should set the #GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA flag
+ * if he wants to apply global-alpha himself. If the flag is not set
+ * global_alpha is applied internally before returning the pixel-data.
*
* 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
}
/**
+ * gst_video_overlay_rectangle_get_global_alpha:
+ * @rectangle: a #GstVideoOverlayRectangle
+ *
+ * Retrieves the global-alpha value associated with a #GstVideoOverlayRectangle.
+ *
+ * Returns: the global-alpha value associated with the rectangle.
+ *
+ * Since: 0.10.37
+ */
+gfloat
+gst_video_overlay_rectangle_get_global_alpha (GstVideoOverlayRectangle *
+ rectangle)
+{
+ g_return_val_if_fail (GST_IS_VIDEO_OVERLAY_RECTANGLE (rectangle), -1);
+
+ return rectangle->global_alpha;
+}
+
+/**
+ * gst_video_overlay_rectangle_set_global_alpha:
+ * @rectangle: a #GstVideoOverlayRectangle
+ *
+ * Sets the global alpha value associated with a #GstVideoOverlayRectangle. Per-
+ * pixel alpha values are multiplied with this value. Valid
+ * values: 0 <= global_alpha <= 1; 1 to deactivate.
+ *
+ # @rectangle must be writable, meaning its refcount must be 1. You can
+ * make the rectangles inside a #GstVideoOverlayComposition writable using
+ * gst_video_overlay_composition_make_writable() or
+ * gst_video_overlay_composition_copy().
+ *
+ * Since: 0.10.37
+ */
+void
+gst_video_overlay_rectangle_set_global_alpha (GstVideoOverlayRectangle *
+ rectangle, gfloat global_alpha)
+{
+ g_return_if_fail (GST_IS_VIDEO_OVERLAY_RECTANGLE (rectangle));
+ g_return_if_fail (global_alpha >= 0 && global_alpha <= 1);
+
+ if (rectangle->global_alpha != global_alpha) {
+ rectangle->global_alpha = global_alpha;
+ if (global_alpha != 1)
+ rectangle->flags |= GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA;
+ else
+ rectangle->flags &= ~GST_VIDEO_OVERLAY_FORMAT_FLAG_GLOBAL_ALPHA;
+ /* update seq_num automatically to signal the consumer, that data has changed
+ * note, that this might mislead renderers, that can handle global-alpha
+ * themselves, because what they want to know is whether the actual pixel data
+ * has changed. */
+ rectangle->seq_num = gst_video_overlay_get_seqnum ();
+ }
+}
+
+/**
* gst_video_overlay_rectangle_copy:
* @rectangle: (transfer none): a #GstVideoOverlayRectangle to copy
*
rectangle->width, rectangle->height, rectangle->stride,
rectangle->x, rectangle->y,
rectangle->render_width, rectangle->render_height, rectangle->flags);
+ if (rectangle->global_alpha != 1)
+ gst_video_overlay_rectangle_set_global_alpha (copy,
+ rectangle->global_alpha);
return copy;
}
* (meaning there will never be a rectangle with the same sequence number as
* a composition).
*
+ * Using the sequence number of a rectangle as an indicator for changed
+ * pixel-data of a rectangle is dangereous. Some API calls, like e.g.
+ * gst_video_overlay_rectangle_set_global_alpha(), automatically update
+ * the per rectangle sequence number, which is misleading for renderers/
+ * consumers, that handle global-alpha themselves. For them the
+ * pixel-data returned by gst_video_overlay_rectangle_get_pixels_*()
+ * wont be different for different global-alpha values. In this case a
+ * renderer could also use the GstBuffer pointers as a hint for changed
+ * pixel-data.
+ *
* Returns: the sequence number of @rectangle
*
* Since: 0.10.36
projects / platform / upstream / gstreamer.git / commitdiff