C++ (Cpp) gst_video_overlay_rectangle_set_global_alpha示例

示例#1

文件： gstgdkpixbufoverlay.c 项目： Lachann/gst-plugins-good

static void
gst_gdk_pixbuf_overlay_update_composition (GstGdkPixbufOverlay * overlay)
{
  GstVideoOverlayComposition *comp;
  GstVideoOverlayRectangle *rect;
  GstVideoMeta *overlay_meta;
  gint x, y, width, height;
  gint video_width =
      GST_VIDEO_INFO_WIDTH (&GST_VIDEO_FILTER (overlay)->in_info);
  gint video_height =
      GST_VIDEO_INFO_HEIGHT (&GST_VIDEO_FILTER (overlay)->in_info);

  if (overlay->comp) {
    gst_video_overlay_composition_unref (overlay->comp);
    overlay->comp = NULL;
  }

  if (overlay->alpha == 0.0 || overlay->pixels == NULL)
    return;

  overlay_meta = gst_buffer_get_video_meta (overlay->pixels);

  x = overlay->offset_x < 0 ?
      video_width + overlay->offset_x - overlay_meta->width +
      (overlay->relative_x * overlay_meta->width) :
      overlay->offset_x + (overlay->relative_x * overlay_meta->width);
  y = overlay->offset_y < 0 ?
      video_height + overlay->offset_y - overlay_meta->height +
      (overlay->relative_y * overlay_meta->height) :
      overlay->offset_y + (overlay->relative_y * overlay_meta->height);

  width = overlay->overlay_width;
  if (width == 0)
    width = overlay_meta->width;

  height = overlay->overlay_height;
  if (height == 0)
    height = overlay_meta->height;

  GST_DEBUG_OBJECT (overlay, "overlay image dimensions: %d x %d, alpha=%.2f",
      overlay_meta->width, overlay_meta->height, overlay->alpha);
  GST_DEBUG_OBJECT (overlay, "properties: x,y: %d,%d (%g%%,%g%%) - WxH: %dx%d",
      overlay->offset_x, overlay->offset_y,
      overlay->relative_x * 100.0, overlay->relative_y * 100.0,
      overlay->overlay_height, overlay->overlay_width);
  GST_DEBUG_OBJECT (overlay, "overlay rendered: %d x %d @ %d,%d (onto %d x %d)",
      width, height, x, y, video_width, video_height);

  rect = gst_video_overlay_rectangle_new_raw (overlay->pixels,
      x, y, width, height, GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE);

  if (overlay->alpha != 1.0)
    gst_video_overlay_rectangle_set_global_alpha (rect, overlay->alpha);

  comp = gst_video_overlay_composition_new (rect);
  gst_video_overlay_rectangle_unref (rect);

  overlay->comp = comp;
}

示例#2

文件： gstgdkpixbufoverlay.c 项目： pli3/gst-plugins-good

static void
gst_gdk_pixbuf_overlay_update_composition (GstGdkPixbufOverlay * overlay)
{
  GstVideoOverlayComposition *comp;
  GstVideoOverlayRectangle *rect;
  gint x, y, width, height;

  if (overlay->comp) {
    gst_video_overlay_composition_unref (overlay->comp);
    overlay->comp = NULL;
  }

  if (overlay->alpha == 0.0)
    return;

  x = overlay->offset_x + (overlay->relative_x * overlay->pixels_width);
  y = overlay->offset_y + (overlay->relative_y * overlay->pixels_height);

  /* FIXME: this should work, but seems to crash */
  if (x < 0)
    x = 0;
  if (y < 0)
    y = 0;

  width = overlay->overlay_width;
  if (width == 0)
    width = overlay->pixels_width;

  height = overlay->overlay_height;
  if (height == 0)
    height = overlay->pixels_height;

  GST_DEBUG_OBJECT (overlay, "overlay image dimensions: %d x %d, alpha=%.2f",
      overlay->pixels_width, overlay->pixels_height, overlay->alpha);
  GST_DEBUG_OBJECT (overlay, "properties: x,y: %d,%d (%g%%,%g%%) - WxH: %dx%d",
      overlay->offset_x, overlay->offset_y,
      overlay->relative_x * 100.0, overlay->relative_y * 100.0,
      overlay->overlay_height, overlay->overlay_width);
  GST_DEBUG_OBJECT (overlay, "overlay rendered: %d x %d @ %d,%d (onto %d x %d)",
      width, height, x, y, overlay->width, overlay->height);

  rect = gst_video_overlay_rectangle_new_argb (overlay->pixels,
      overlay->pixels_width, overlay->pixels_height, overlay->pixels_stride,
      x, y, width, height, GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE);

  if (overlay->alpha != 1.0)
    gst_video_overlay_rectangle_set_global_alpha (rect, overlay->alpha);

  comp = gst_video_overlay_composition_new (rect);
  gst_video_overlay_rectangle_unref (rect);

  overlay->comp = comp;
}