static void gst_imx_compositor_update_overall_region(GstImxCompositor *compositor)
{
GList *walk;
gboolean first = TRUE;
/* Catch redundant calls */
if (compositor->overall_region_valid)
return;
if ((compositor->overall_width != 0) && (compositor->overall_height != 0))
{
/* If the width and height of the overall region are fixed to specific
* values by the caller, use these, and don't look at the canvases
* in the input pads. */
compositor->overall_region.x2 = compositor->overall_width;
compositor->overall_region.y2 = compositor->overall_height;
}
else
{
/* Overall width and/or height are set to 0. This means the caller wants
* the overall region to adapt to the sizes of the input canvases. The
* overall region must encompass and show all of them (exception:
* pads with negative xpos/ypos coordinates can have their canvas lie
* either partially or fully outside of the overall region).
* To compute this overall region, walk through all pads and merge their
* outer canvas regions together. */
walk = GST_ELEMENT(compositor)->sinkpads;
while (walk != NULL)
{
GstImxCompositorPad *compositor_pad = GST_IMX_COMPOSITOR_PAD_CAST(walk->data);
GstImxRegion *outer_region = &(compositor_pad->canvas.outer_region);
/* Update the outer region, since the xpos/ypos/width/height pad properties
* might have changed */
gst_imx_compositor_pad_compute_outer_region(compositor_pad);
/* The pad canvasses are *not* updated here. This is because in order for
* these updates to be done, a valid overall region needs to exist first.
* And the whole point of this loop is to compute said region.
* Furthermore, canvas updates anyway are unnecessary here. They'll be
* done later, during frame aggregation, when necessary. The only
* value that is needed here from the canvas is the outer region, and
* this one is already computed above. */
if (first)
{
/* This is the first visited pad, so just copy its outer region */
compositor->overall_region = *outer_region;
first = FALSE;
}
else
gst_imx_region_merge(&(compositor->overall_region), &(compositor->overall_region), outer_region);
GST_DEBUG_OBJECT(compositor, "current outer region: %" GST_IMX_REGION_FORMAT " merged overall region: %" GST_IMX_REGION_FORMAT, GST_IMX_REGION_ARGS(outer_region), GST_IMX_REGION_ARGS(&(compositor->overall_region)));
/* Move to next pad */
walk = g_list_next(walk);
}
}
/* Make sure the overall region starts at (0,0), since any other topleft
* coordinates make little sense */
compositor->overall_region.x1 = 0;
compositor->overall_region.y1 = 0;
/* Now that the overall region is computed, walk through the individual
* outer regions, and check if any of them completely cover the overall region
* If so, the compositor does not have to clear the frame first (= filling
* the overall region with fill_region), thus saving bandwidth */
compositor->region_fill_necessary = TRUE;
walk = GST_ELEMENT(compositor)->sinkpads;
while (walk != NULL)
{
GstImxCompositorPad *compositor_pad = GST_IMX_COMPOSITOR_PAD_CAST(walk->data);
GstImxRegion *outer_region = &(compositor_pad->canvas.outer_region);
/* Check if the outer region completely contains the overall region */
if (gst_imx_region_contains(&(compositor->overall_region), outer_region) == GST_IMX_REGION_CONTAINS_FULL)
{
/* disable filling if this outer region is opaque
* (because it will completely cover the overall region) */
compositor->region_fill_necessary = (compositor_pad->alpha < 1.0);
break;
}
walk = g_list_next(walk);
}
compositor->overall_region_valid = TRUE;
}
static void gst_imx_video_compositor_update_overall_region(GstImxVideoCompositor *compositor)
{
GList *walk;
gboolean first = TRUE;
/* Catch redundant calls */
if (compositor->overall_region_valid)
return;
if ((compositor->overall_width != 0) && (compositor->overall_height != 0))
{
/* If the width and height of the overall region are fixed to specific
* values by the caller, use these, and don't look at the canvases
* in the input pads. */
compositor->overall_region.x2 = compositor->overall_width;
compositor->overall_region.y2 = compositor->overall_height;
}
else
{
/* Overall width and/or height are set to 0. This means the caller wants
* the overall region to adapt to the sizes of the input canvases. The
* overall region must encompass and show all of them (exception:
* pads with negative xpos/ypos coordinates can have their canvas lie
* either partially or fully outside of the overall region).
* To compute this overall region, walk through all pads and merge their
* outer canvas regions together. */
walk = GST_ELEMENT(compositor)->sinkpads;
while (walk != NULL)
{
GstImxVideoCompositorPad *compositor_pad = GST_IMX_VIDEO_COMPOSITOR_PAD_CAST(walk->data);
GstImxRegion *outer_region = &(compositor_pad->canvas.outer_region);
/* Update the outer region, since the xpos/ypos/width/height pad properties
* might have changed */
gst_imx_video_compositor_pad_compute_outer_region(compositor_pad);
/* The pad canvasses are *not* updated here. This is because in order for
* these updates to be done, a valid overall region needs to exist first.
* And the whole point of this loop is to compute said region.
* Furthermore, canvas updates anyway are unnecessary here. They'll be
* done later, during frame aggregation, when necessary. The only
* value that is needed here from the canvas is the outer region, and
* this one is already computed above. */
if (first)
{
/* This is the first visited pad, so just copy its outer region */
compositor->overall_region = *outer_region;
first = FALSE;
}
else
gst_imx_region_merge(&(compositor->overall_region), &(compositor->overall_region), outer_region);
GST_DEBUG_OBJECT(compositor, "current outer region: %" GST_IMX_REGION_FORMAT " merged overall region: %" GST_IMX_REGION_FORMAT, GST_IMX_REGION_ARGS(outer_region), GST_IMX_REGION_ARGS(&(compositor->overall_region)));
/* Move to next pad */
walk = g_list_next(walk);
}
}
/* Make sure the overall region starts at (0,0), since any other topleft
* coordinates make little sense */
compositor->overall_region.x1 = 0;
compositor->overall_region.y1 = 0;
/* Now that the overall region is computed, walk through the individual
* outer regions, and check if any of them completely cover the overall region
* If so, the compositor does not have to clear the frame first (= filling
* the overall region with fill_region), thus saving bandwidth */
compositor->region_fill_necessary = TRUE;
walk = GST_ELEMENT(compositor)->sinkpads;
while (walk != NULL)
{
GstImxVideoCompositorPad *compositor_pad = GST_IMX_VIDEO_COMPOSITOR_PAD_CAST(walk->data);
GstImxRegion *outer_region = &(compositor_pad->canvas.outer_region);
GstVideoInfo *info = &(GST_IMXBP_VIDEO_AGGREGATOR_PAD(compositor_pad)->info);
/* Check if the outer region completely contains the overall region */
if (gst_imx_region_contains(&(compositor->overall_region), outer_region) == GST_IMX_REGION_CONTAINS_FULL)
{
/* The outer region completely contains the inner region.
* If the video frames are opaque, then this means that
* their pixels will fully overwrite the entire overall
* region, so it does not have to be initially filled
* with the background color. This is used as a way for
* improving performance. Even if there are multiple
* input video streams which each have outer regions
* that fully contain the overall region, all it takes
* is for just one of these to be 100% opaque, and the
* region fill is not necessary. So, if such a fully
* opaque region that completely covers the overall
* region is found, exit the loop immediately, otherwise
* keep looking at the other pads.
*
* Also, blending may be necessary even if alpha is 1.0,
* since video frames might themselves have alpha values
* per-pixel (GST_VIDEO_INFO_HAS_ALPHA() returns TRUE in
* this case then). */
compositor->region_fill_necessary = (compositor_pad->alpha < 1.0) || GST_VIDEO_INFO_HAS_ALPHA(info);
if (!compositor->region_fill_necessary)
break;
}
walk = g_list_next(walk);
}
compositor->overall_region_valid = TRUE;
}
