/* GStreamer
* Copyright (C) 2018 Sebastian Dröge <sebastian@centricular.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:element-overlaycomposition
*
* The overlaycomposition element renders an overlay using an application
* provided draw function.
*
* A more interesting example can be found at
* https://cgit.freedesktop.org/gstreamer/gst-plugins-base/tree/tests/examples/overlaycomposition/overlaycomposition.c
*
* <refsect2>
* <title>Example code</title>
* |[
*
* #include <gst/gst.h>
* #include <gst/video/video.h>
*
* ...
*
* typedef struct {
* gboolean valid;
* GstVideoInfo info;
* } OverlayState;
*
* ...
*
* static void
* prepare_overlay (GstElement * overlay, GstCaps * caps, gint window_width,
* gint window_height, gpointer user_data)
* {
* OverlayState *s = (OverlayState *)user_data;
*
* if (gst_video_info_from_caps (&s->info, caps))
* s->valid = TRUE;
* }
*
* static GstVideoOverlayComposition *
* draw_overlay (GstElement * overlay, GstSample * sample, gpointer user_data)
* {
* OverlayState *s = (OverlayState *)user_data;
* GstBuffer *buffer;
* GstVideoOverlayRectangle *rect;
* GstVideoOverlayComposition *comp;
* GstVideoInfo info;
* GstVideoFrame frame;
* gint x, y;
* guint8 *data;
*
* if (!s->valid)
* return NULL;
*
* gst_video_info_set_format (&info, GST_VIDEO_FORMAT_BGRA, 16, 16);
* buffer = gst_buffer_new_and_alloc (info.size);
* gst_buffer_add_video_meta (buffer, GST_VIDEO_FRAME_FLAG_NONE,
* GST_VIDEO_INFO_FORMAT(&info),
* GST_VIDEO_INFO_WIDTH(&info),
* GST_VIDEO_INFO_HEIGHT(&info));
*
* gst_video_frame_map (&frame, &info, buffer, GST_MAP_WRITE);
*
* // Overlay a half-transparent blue 16x16 rectangle in the middle
* // of the frame
* data = GST_VIDEO_FRAME_PLANE_DATA(&frame, 0);
* for (y = 0; y < 16; y++) {
* guint8 *line = &data[y * GST_VIDEO_FRAME_PLANE_STRIDE (&frame, 0)];
* for (x = 0; x < 16; x++) {
* guint8 *pixel = &line[x * 4];
*
* pixel[0] = 255;
* pixel[1] = 0;
* pixel[2] = 0;
* pixel[3] = 127;
* }
* }
*
* gst_video_frame_unmap (&frame);
* rect = gst_video_overlay_rectangle_new_raw (buffer,
* s->info.width / 2 - 8,
* s->info.height / 2 - 8,
* 16, 16,
* GST_VIDEO_OVERLAY_FORMAT_FLAG_NONE);
* comp = gst_video_overlay_composition_new (rect);
* gst_video_overlay_rectangle_unref (rect);
* gst_buffer_unref (buffer);
*
* return comp;
* }
*
* ...
*
* overlay = gst_element_factory_make ("overlaycomposition", "overlay");
*
* g_signal_connect (overlay, "draw", G_CALLBACK (draw_overlay),
* overlay_state);
* g_signal_connect (overlay, "caps-changed",
* G_CALLBACK (prepare_overlay), overlay_state);
* ...
*
* ]|
* </refsect2>
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include "gstoverlaycomposition.h"
GST_DEBUG_CATEGORY_STATIC (gst_overlay_composition_debug);
#define GST_CAT_DEFAULT gst_overlay_composition_debug
#define OVERLAY_COMPOSITION_CAPS GST_VIDEO_CAPS_MAKE (GST_VIDEO_OVERLAY_COMPOSITION_BLEND_FORMATS)
#define ALL_CAPS OVERLAY_COMPOSITION_CAPS ";" \
GST_VIDEO_CAPS_MAKE_WITH_FEATURES ("ANY", GST_VIDEO_FORMATS_ALL)
enum
{
SIGNAL_CAPS_CHANGED,
SIGNAL_DRAW,
LAST_SIGNAL
};
static guint overlay_composition_signals[LAST_SIGNAL];
static GstStaticCaps overlay_composition_caps =
GST_STATIC_CAPS (OVERLAY_COMPOSITION_CAPS);
static gboolean
can_blend_caps (GstCaps * incaps)
{
gboolean ret;
GstCaps *caps;
caps = gst_static_caps_get (&overlay_composition_caps);
ret = gst_caps_is_subset (incaps, caps);
gst_caps_unref (caps);
return ret;
}
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (ALL_CAPS)
);
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS (ALL_CAPS)
);
#define parent_class gst_overlay_composition_parent_class
G_DEFINE_TYPE (GstOverlayComposition, gst_overlay_composition,
GST_TYPE_ELEMENT);
static GstFlowReturn gst_overlay_composition_sink_chain (GstPad * pad,
GstObject * parent, GstBuffer * buffer);
static gboolean gst_overlay_composition_sink_event (GstPad * pad,
GstObject * parent, GstEvent * event);
static gboolean gst_overlay_composition_sink_query (GstPad * pad,
GstObject * parent, GstQuery * query);
static gboolean gst_overlay_composition_src_query (GstPad * pad,
GstObject * parent, GstQuery * query);
static GstStateChangeReturn gst_overlay_composition_change_state (GstElement *
element, GstStateChange transition);
static void
gst_overlay_composition_class_init (GstOverlayCompositionClass * klass)
{
GstElementClass *gstelement_class = (GstElementClass *) klass;
GST_DEBUG_CATEGORY_INIT (gst_overlay_composition_debug, "overlaycomposition",
0, "Overlay Composition");
gst_element_class_set_static_metadata (gstelement_class,
"Overlay Composition", "Filter/Editor/Video",
"Overlay Composition", "Sebastian Dröge <sebastian@centricular.com>");
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&src_template));
gst_element_class_add_pad_template (gstelement_class,
gst_static_pad_template_get (&sink_template));
gstelement_class->change_state = gst_overlay_composition_change_state;
/**
* GstOverlayComposition::draw:
* @overlay: Overlay element emitting the signal.
* @sample: #GstSample containing the current buffer, caps and segment.
*
* This signal is emitted when the overlay should be drawn.
*
* Returns: #GstVideoOverlayComposition or %NULL
*/
overlay_composition_signals[SIGNAL_DRAW] =
g_signal_new ("draw",
G_TYPE_FROM_CLASS (klass),
0,
0,
NULL,
NULL,
g_cclosure_marshal_generic,
GST_TYPE_VIDEO_OVERLAY_COMPOSITION, 1, GST_TYPE_SAMPLE);
/**
* GstOverlayComposition::caps-changed:
* @overlay: Overlay element emitting the signal.
* @caps: The #GstCaps of the element.
* @window_width: The window render width of downstream, or 0.
* @window_height: The window render height of downstream, or 0.
*
* This signal is emitted when the caps of the element has changed.
*
* The window width and height define the resolution at which the frame is
* going to be rendered in the end by e.g. a video sink (i.e. the window
* size).
*/
overlay_composition_signals[SIGNAL_CAPS_CHANGED] =
g_signal_new ("caps-changed",
G_TYPE_FROM_CLASS (klass),
0,
0, NULL, NULL, g_cclosure_marshal_generic, G_TYPE_NONE, 3, GST_TYPE_CAPS,
G_TYPE_UINT, G_TYPE_UINT);
}
static void
gst_overlay_composition_init (GstOverlayComposition * self)
{
self->sinkpad = gst_pad_new_from_static_template (&sink_template, "sink");
gst_pad_set_chain_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_overlay_composition_sink_chain));
gst_pad_set_event_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_overlay_composition_sink_event));
gst_pad_set_query_function (self->sinkpad,
GST_DEBUG_FUNCPTR (gst_overlay_composition_sink_query));
gst_element_add_pad (GST_ELEMENT (self), self->sinkpad);
self->srcpad = gst_pad_new_from_static_template (&src_template, "src");
gst_pad_set_query_function (self->srcpad,
GST_DEBUG_FUNCPTR (gst_overlay_composition_src_query));
gst_element_add_pad (GST_ELEMENT (self), self->srcpad);
}
static GstStateChangeReturn
gst_overlay_composition_change_state (GstElement * element,
GstStateChange transition)
{
GstOverlayComposition *self = GST_OVERLAY_COMPOSITION (element);
GstStateChangeReturn state_ret;
switch (transition) {
default:
break;
}
state_ret =
GST_ELEMENT_CLASS (gst_overlay_composition_parent_class)->change_state
(element, transition);
if (state_ret == GST_STATE_CHANGE_FAILURE)
return state_ret;
switch (transition) {
case GST_STATE_CHANGE_READY_TO_PAUSED:
gst_segment_init (&self->segment, GST_FORMAT_UNDEFINED);
break;
case GST_STATE_CHANGE_PAUSED_TO_READY:
memset (&self->info, 0, sizeof (self->info));
self->window_width = self->window_height = 0;
self->attach_compo_to_buffer = FALSE;
if (self->sample) {
gst_sample_unref (self->sample);
self->sample = NULL;
}
gst_caps_replace (&self->caps, NULL);
gst_segment_init (&self->segment, GST_FORMAT_UNDEFINED);
break;
default:
break;
}
return state_ret;
}
/* Based on gstbasetextoverlay.c */
static gboolean
gst_overlay_composition_negotiate (GstOverlayComposition * self, GstCaps * caps)
{
gboolean upstream_has_meta = FALSE;
gboolean caps_has_meta = FALSE;
gboolean alloc_has_meta = FALSE;
gboolean attach = FALSE;
gboolean ret = TRUE;
guint width, height;
GstCapsFeatures *f;
GstCaps *overlay_caps;
GstQuery *query;
guint alloc_index;
GST_DEBUG_OBJECT (self, "performing negotiation");
/* Clear any pending reconfigure to avoid negotiating twice */
gst_pad_check_reconfigure (self->srcpad);
self->window_width = self->window_height = 0;
if (!caps)
caps = gst_pad_get_current_caps (self->sinkpad);
else
gst_caps_ref (caps);
if (!caps || gst_caps_is_empty (caps))
goto no_format;
/* Check if upstream caps have meta */
if ((f = gst_caps_get_features (caps, 0))) {
upstream_has_meta = gst_caps_features_contains (f,
GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION);
}
/* Initialize dimensions */
width = self->info.width;
height = self->info.height;
if (upstream_has_meta) {
overlay_caps = gst_caps_ref (caps);
} else {
GstCaps *peercaps;
/* BaseTransform requires caps for the allocation query to work */
overlay_caps = gst_caps_copy (caps);
f = gst_caps_get_features (overlay_caps, 0);
gst_caps_features_add (f,
GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION);
/* Then check if downstream accept overlay composition in caps */
/* FIXME: We should probably check if downstream *prefers* the
* overlay meta, and only enforce usage of it if we can't handle
* the format ourselves and thus would have to drop the overlays.
* Otherwise we should prefer what downstream wants here.
*/
peercaps = gst_pad_peer_query_caps (self->srcpad, overlay_caps);
caps_has_meta = !gst_caps_is_empty (peercaps);
gst_caps_unref (peercaps);
GST_DEBUG_OBJECT (self, "caps have overlay meta %d", caps_has_meta);
}
if (upstream_has_meta || caps_has_meta) {
/* Send caps immediatly, it's needed by GstBaseTransform to get a reply
* from allocation query */
ret = gst_pad_set_caps (self->srcpad, overlay_caps);
/* First check if the allocation meta has compositon */
query = gst_query_new_allocation (overlay_caps, FALSE);
if (!gst_pad_peer_query (self->srcpad, query)) {
/* no problem, we use the query defaults */
GST_DEBUG_OBJECT (self, "ALLOCATION query failed");
/* In case we were flushing, mark reconfigure and fail this method,
* will make it retry */
if (GST_PAD_IS_FLUSHING (self->srcpad))
ret = FALSE;
}
alloc_has_meta = gst_query_find_allocation_meta (query,
GST_VIDEO_OVERLAY_COMPOSITION_META_API_TYPE, &alloc_index);
GST_DEBUG_OBJECT (self, "sink alloc has overlay meta %d", alloc_has_meta);
if (alloc_has_meta) {
const GstStructure *params;
gst_query_parse_nth_allocation_meta (query, alloc_index, ¶ms);
if (params) {
if (gst_structure_get (params, "width", G_TYPE_UINT, &width,
"height", G_TYPE_UINT, &height, NULL)) {
GST_DEBUG_OBJECT (self, "received window size: %dx%d", width, height);
g_assert (width != 0 && height != 0);
}
}
}
gst_query_unref (query);
}
/* Update render size if needed */
self->window_width = width;
self->window_height = height;
/* For backward compatibility, we will prefer blitting if downstream
* allocation does not support the meta. In other case we will prefer
* attaching, and will fail the negotiation in the unlikely case we are
* force to blit, but format isn't supported. */
if (upstream_has_meta) {
attach = TRUE;
} else if (caps_has_meta) {
if (alloc_has_meta) {
attach = TRUE;
} else {
/* Don't attach unless we cannot handle the format */
attach = !can_blend_caps (caps);
}
} else {
ret = can_blend_caps (caps);
}
/* If we attach, then pick the overlay caps */
if (attach) {
GST_DEBUG_OBJECT (self, "Using caps %" GST_PTR_FORMAT, overlay_caps);
/* Caps where already sent */
} else if (ret) {
GST_DEBUG_OBJECT (self, "Using caps %" GST_PTR_FORMAT, caps);
ret = gst_pad_set_caps (self->srcpad, caps);
}
self->attach_compo_to_buffer = attach;
if (!ret) {
GST_DEBUG_OBJECT (self, "negotiation failed, schedule reconfigure");
gst_pad_mark_reconfigure (self->srcpad);
}
g_signal_emit (self, overlay_composition_signals[SIGNAL_CAPS_CHANGED], 0,
caps, self->window_width, self->window_height, NULL);
gst_caps_unref (overlay_caps);
gst_caps_unref (caps);
return ret;
no_format:
{
if (caps)
gst_caps_unref (caps);
gst_pad_mark_reconfigure (self->srcpad);
return FALSE;
}
}
static gboolean
gst_overlay_composition_sink_event (GstPad * pad, GstObject * parent,
GstEvent * event)
{
GstOverlayComposition *self = GST_OVERLAY_COMPOSITION (parent);
gboolean ret = FALSE;
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_SEGMENT:
gst_event_copy_segment (event, &self->segment);
ret = gst_pad_event_default (pad, parent, event);
break;
case GST_EVENT_CAPS:{
GstCaps *caps;
gst_event_parse_caps (event, &caps);
if (!gst_video_info_from_caps (&self->info, caps)) {
gst_event_unref (event);
ret = FALSE;
break;
}
if (!gst_overlay_composition_negotiate (self, caps)) {
gst_event_unref (event);
ret = FALSE;
break;
}
gst_caps_replace (&self->caps, caps);
ret = TRUE;
gst_event_unref (event);
break;
}
case GST_EVENT_FLUSH_STOP:
gst_segment_init (&self->segment, GST_FORMAT_UNDEFINED);
ret = gst_pad_event_default (pad, parent, event);
break;
default:
ret = gst_pad_event_default (pad, parent, event);
break;
}
return ret;
}
/* Based on gstbasetextoverlay.c */
/**
* add_feature_and_intersect:
*
* Creates a new #GstCaps containing the (given caps +
* given caps feature) + (given caps intersected by the
* given filter).
*
* Returns: the new #GstCaps
*/
static GstCaps *
add_feature_and_intersect (GstCaps * caps,
const gchar * feature, GstCaps * filter)
{
int i, caps_size;
GstCaps *new_caps;
new_caps = gst_caps_copy (caps);
caps_size = gst_caps_get_size (new_caps);
for (i = 0; i < caps_size; i++) {
GstCapsFeatures *features = gst_caps_get_features (new_caps, i);
if (!gst_caps_features_is_any (features)) {
gst_caps_features_add (features, feature);
}
}
gst_caps_append (new_caps, gst_caps_intersect_full (caps,
filter, GST_CAPS_INTERSECT_FIRST));
return new_caps;
}
/* Based on gstbasetextoverlay.c */
/* intersect_by_feature:
*
* Creates a new #GstCaps based on the following filtering rule.
*
* For each individual caps contained in given caps, if the
* caps uses the given caps feature, keep a version of the caps
* with the feature and an another one without. Otherwise, intersect
* the caps with the given filter.
*
* Returns: the new #GstCaps
*/
static GstCaps *
intersect_by_feature (GstCaps * caps, const gchar * feature, GstCaps * filter)
{
int i, caps_size;
GstCaps *new_caps;
new_caps = gst_caps_new_empty ();
caps_size = gst_caps_get_size (caps);
for (i = 0; i < caps_size; i++) {
GstStructure *caps_structure = gst_caps_get_structure (caps, i);
GstCapsFeatures *caps_features =
gst_caps_features_copy (gst_caps_get_features (caps, i));
GstCaps *filtered_caps;
GstCaps *simple_caps =
gst_caps_new_full (gst_structure_copy (caps_structure), NULL);
gst_caps_set_features (simple_caps, 0, caps_features);
if (gst_caps_features_contains (caps_features, feature)) {
gst_caps_append (new_caps, gst_caps_copy (simple_caps));
gst_caps_features_remove (caps_features, feature);
filtered_caps = gst_caps_ref (simple_caps);
} else {
filtered_caps = gst_caps_intersect_full (simple_caps, filter,
GST_CAPS_INTERSECT_FIRST);
}
gst_caps_unref (simple_caps);
gst_caps_append (new_caps, filtered_caps);
}
return new_caps;
}
/* Based on gstbasetextoverlay.c */
static GstCaps *
gst_overlay_composition_sink_query_caps (GstOverlayComposition * self,
GstCaps * filter)
{
GstCaps *peer_caps = NULL, *caps = NULL, *overlay_filter = NULL;
if (filter) {
/* filter caps + composition feature + filter caps
* filtered by the software caps. */
GstCaps *sw_caps = gst_static_caps_get (&overlay_composition_caps);
overlay_filter = add_feature_and_intersect (filter,
GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION, sw_caps);
gst_caps_unref (sw_caps);
GST_DEBUG_OBJECT (self->sinkpad, "overlay filter %" GST_PTR_FORMAT,
overlay_filter);
}
peer_caps = gst_pad_peer_query_caps (self->srcpad, overlay_filter);
if (overlay_filter)
gst_caps_unref (overlay_filter);
if (peer_caps) {
GST_DEBUG_OBJECT (self->sinkpad, "peer caps %" GST_PTR_FORMAT, peer_caps);
if (gst_caps_is_any (peer_caps)) {
/* if peer returns ANY caps, return filtered src pad template caps */
caps = gst_caps_copy (gst_pad_get_pad_template_caps (self->srcpad));
} else {
/* duplicate caps which contains the composition into one version with
* the meta and one without. Filter the other caps by the software caps */
GstCaps *sw_caps = gst_static_caps_get (&overlay_composition_caps);
caps = intersect_by_feature (peer_caps,
GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION, sw_caps);
gst_caps_unref (sw_caps);
}
gst_caps_unref (peer_caps);
} else {
/* no peer, our padtemplate is enough then */
caps = gst_pad_get_pad_template_caps (self->sinkpad);
}
if (filter) {
GstCaps *intersection = gst_caps_intersect_full (filter, caps,
GST_CAPS_INTERSECT_FIRST);
gst_caps_unref (caps);
caps = intersection;
}
GST_DEBUG_OBJECT (self->sinkpad, "returning %" GST_PTR_FORMAT, caps);
return caps;
}
/* Based on gstbasetextoverlay.c */
static GstCaps *
gst_overlay_composition_src_query_caps (GstOverlayComposition * self,
GstCaps * filter)
{
GstCaps *peer_caps = NULL, *caps = NULL, *overlay_filter = NULL;
if (filter) {
/* duplicate filter caps which contains the composition into one version
* with the meta and one without. Filter the other caps by the software
* caps */
GstCaps *sw_caps = gst_static_caps_get (&overlay_composition_caps);
overlay_filter =
intersect_by_feature (filter,
GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION, sw_caps);
gst_caps_unref (sw_caps);
}
peer_caps = gst_pad_peer_query_caps (self->sinkpad, overlay_filter);
if (overlay_filter)
gst_caps_unref (overlay_filter);
if (peer_caps) {
GST_DEBUG_OBJECT (self->srcpad, "peer caps %" GST_PTR_FORMAT, peer_caps);
if (gst_caps_is_any (peer_caps)) {
/* if peer returns ANY caps, return filtered sink pad template caps */
caps = gst_caps_copy (gst_pad_get_pad_template_caps (self->sinkpad));
} else {
/* return upstream caps + composition feature + upstream caps
* filtered by the software caps. */
GstCaps *sw_caps = gst_static_caps_get (&overlay_composition_caps);
caps = add_feature_and_intersect (peer_caps,
GST_CAPS_FEATURE_META_GST_VIDEO_OVERLAY_COMPOSITION, sw_caps);
gst_caps_unref (sw_caps);
}
gst_caps_unref (peer_caps);
} else {
/* no peer, our padtemplate is enough then */
caps = gst_pad_get_pad_template_caps (self->srcpad);
}
if (filter) {
GstCaps *intersection;
intersection =
gst_caps_intersect_full (filter, caps, GST_CAPS_INTERSECT_FIRST);
gst_caps_unref (caps);
caps = intersection;
}
GST_DEBUG_OBJECT (self->srcpad, "returning %" GST_PTR_FORMAT, caps);
return caps;
}
static gboolean
gst_overlay_composition_sink_query (GstPad * pad, GstObject * parent,
GstQuery * query)
{
GstOverlayComposition *self = GST_OVERLAY_COMPOSITION (parent);
gboolean ret = FALSE;
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_CAPS:{
GstCaps *filter, *caps;
gst_query_parse_caps (query, &filter);
caps = gst_overlay_composition_sink_query_caps (self, filter);
gst_query_set_caps_result (query, caps);
gst_caps_unref (caps);
ret = TRUE;
break;
}
default:
ret = gst_pad_query_default (pad, parent, query);
break;
}
return ret;
}
static gboolean
gst_overlay_composition_src_query (GstPad * pad, GstObject * parent,
GstQuery * query)
{
GstOverlayComposition *self = GST_OVERLAY_COMPOSITION (parent);
gboolean ret = FALSE;
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_CAPS:{
GstCaps *filter, *caps;
gst_query_parse_caps (query, &filter);
caps = gst_overlay_composition_src_query_caps (self, filter);
gst_query_set_caps_result (query, caps);
gst_caps_unref (caps);
ret = TRUE;
break;
}
default:
ret = gst_pad_query_default (pad, parent, query);
break;
}
return ret;
}
static GstFlowReturn
gst_overlay_composition_sink_chain (GstPad * pad, GstObject * parent,
GstBuffer * buffer)
{
GstOverlayComposition *self = GST_OVERLAY_COMPOSITION (parent);
GstVideoOverlayComposition *compo = NULL;
GstVideoOverlayCompositionMeta *upstream_compo_meta;
if (gst_pad_check_reconfigure (self->srcpad)) {
if (!gst_overlay_composition_negotiate (self, NULL)) {
gst_pad_mark_reconfigure (self->srcpad);
gst_buffer_unref (buffer);
GST_OBJECT_LOCK (self->srcpad);
if (GST_PAD_IS_FLUSHING (self->srcpad)) {
GST_OBJECT_UNLOCK (self->srcpad);
return GST_FLOW_FLUSHING;
}
GST_OBJECT_UNLOCK (self->srcpad);
return GST_FLOW_NOT_NEGOTIATED;
}
}
if (!self->sample) {
self->sample = gst_sample_new (buffer, self->caps, &self->segment, NULL);
} else {
self->sample = gst_sample_make_writable (self->sample);
gst_sample_set_buffer (self->sample, buffer);
gst_sample_set_caps (self->sample, self->caps);
gst_sample_set_segment (self->sample, &self->segment);
}
g_signal_emit (self, overlay_composition_signals[SIGNAL_DRAW], 0,
self->sample, &compo);
/* Don't store the buffer in the sample any longer, otherwise it will not
* be writable below as we have one reference in the sample and one in
* this function.
*
* If the sample is not writable itself then the application kept an
* reference itself.
*/
if (gst_sample_is_writable (self->sample)) {
gst_sample_set_buffer (self->sample, NULL);
}
if (!compo) {
GST_DEBUG_OBJECT (self->sinkpad,
"Application did not provide an overlay composition");
return gst_pad_push (self->srcpad, buffer);
}
/* If upstream attached a meta, we can safely add our own things
* in it. Upstream must've checked that downstream supports it */
upstream_compo_meta = gst_buffer_get_video_overlay_composition_meta (buffer);
if (upstream_compo_meta) {
GstVideoOverlayComposition *merged_compo =
gst_video_overlay_composition_copy (upstream_compo_meta->overlay);
guint i, n;
GST_DEBUG_OBJECT (self->sinkpad,
"Appending to upstream overlay composition");
n = gst_video_overlay_composition_n_rectangles (compo);
for (i = 0; i < n; i++) {
GstVideoOverlayRectangle *rect =
gst_video_overlay_composition_get_rectangle (compo, i);
gst_video_overlay_composition_add_rectangle (merged_compo, rect);
}
gst_video_overlay_composition_unref (compo);
gst_video_overlay_composition_unref (upstream_compo_meta->overlay);
upstream_compo_meta->overlay = merged_compo;
} else if (self->attach_compo_to_buffer) {
GST_DEBUG_OBJECT (self->sinkpad, "Attaching as meta");
buffer = gst_buffer_make_writable (buffer);
gst_buffer_add_video_overlay_composition_meta (buffer, compo);
gst_video_overlay_composition_unref (compo);
} else {
GstVideoFrame frame;
buffer = gst_buffer_make_writable (buffer);
if (!gst_video_frame_map (&frame, &self->info, buffer, GST_MAP_READWRITE)) {
gst_video_overlay_composition_unref (compo);
goto map_failed;
}
gst_video_overlay_composition_blend (compo, &frame);
gst_video_frame_unmap (&frame);
gst_video_overlay_composition_unref (compo);
}
return gst_pad_push (self->srcpad, buffer);
map_failed:
{
GST_ERROR_OBJECT (self->sinkpad, "Failed to map buffer");
gst_buffer_unref (buffer);
return GST_FLOW_ERROR;
}
}
static gboolean
plugin_init (GstPlugin * plugin)
{
return gst_element_register (plugin, "overlaycomposition", GST_RANK_NONE,
GST_TYPE_OVERLAY_COMPOSITION);
}
GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
GST_VERSION_MINOR,
overlaycomposition,
"Renders overlays on top of video frames",
plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN)