gstreamer/subprojects/gst-docs/examples/tutorials/basic-tutorial-15.c
Piotr Brzeziński 3bb8700577 macos: Add wrapper API to run a NSApplication in the main thread
On macOS, a Cocoa event loop is needed in the main thread to ensure
things like opening a GL window work correctly. In the past, this was
patched into glib via Cerbero, but that prevented us from updating it.
This workaround simply runs an NSApplication and then calls the
main function on a secondary thread, allowing GStreamer to correctly
display windows and/or system permission prompts, for example.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3532>
2022-12-13 17:50:32 +00:00

122 lines
3.4 KiB
C

#include <clutter-gst/clutter-gst.h>
#ifdef __APPLE__
#include <TargetConditionals.h>
#endif
/* Setup the video texture once its size is known */
void
size_change (ClutterActor * texture, gint width, gint height,
gpointer user_data)
{
ClutterActor *stage;
gfloat new_x, new_y, new_width, new_height;
gfloat stage_width, stage_height;
ClutterAnimation *animation = NULL;
stage = clutter_actor_get_stage (texture);
if (stage == NULL)
return;
clutter_actor_get_size (stage, &stage_width, &stage_height);
/* Center video on window and calculate new size preserving aspect ratio */
new_height = (height * stage_width) / width;
if (new_height <= stage_height) {
new_width = stage_width;
new_x = 0;
new_y = (stage_height - new_height) / 2;
} else {
new_width = (width * stage_height) / height;
new_height = stage_height;
new_x = (stage_width - new_width) / 2;
new_y = 0;
}
clutter_actor_set_position (texture, new_x, new_y);
clutter_actor_set_size (texture, new_width, new_height);
clutter_actor_set_rotation (texture, CLUTTER_Y_AXIS, 0.0, stage_width / 2, 0,
0);
/* Animate it */
animation =
clutter_actor_animate (texture, CLUTTER_LINEAR, 10000, "rotation-angle-y",
360.0, NULL);
clutter_animation_set_loop (animation, TRUE);
}
int
tutorial_main (int argc, char *argv[])
{
GstElement *pipeline, *sink;
ClutterTimeline *timeline;
ClutterActor *stage, *texture;
/* clutter-gst takes care of initializing Clutter and GStreamer */
if (clutter_gst_init (&argc, &argv) != CLUTTER_INIT_SUCCESS) {
g_error ("Failed to initialize clutter\n");
return -1;
}
stage = clutter_stage_get_default ();
/* Make a timeline */
timeline = clutter_timeline_new (1000);
g_object_set (timeline, "loop", TRUE, NULL);
/* Create new texture and disable slicing so the video is properly mapped onto it */
texture =
CLUTTER_ACTOR (g_object_new (CLUTTER_TYPE_TEXTURE, "disable-slicing",
TRUE, NULL));
g_signal_connect (texture, "size-change", G_CALLBACK (size_change), NULL);
/* Build the GStreamer pipeline */
pipeline =
gst_parse_launch
("playbin uri=https://www.freedesktop.org/software/gstreamer-sdk/data/media/sintel_trailer-480p.webm",
NULL);
/* Instantiate the Clutter sink */
sink = gst_element_factory_make ("autocluttersink", NULL);
if (sink == NULL) {
/* Revert to the older cluttersink, in case autocluttersink was not found */
sink = gst_element_factory_make ("cluttersink", NULL);
}
if (sink == NULL) {
g_printerr ("Unable to find a Clutter sink.\n");
return -1;
}
/* Link GStreamer with Clutter by passing the Clutter texture to the Clutter sink */
g_object_set (sink, "texture", texture, NULL);
/* Add the Clutter sink to the pipeline */
g_object_set (pipeline, "video-sink", sink, NULL);
/* Start playing */
gst_element_set_state (pipeline, GST_STATE_PLAYING);
/* start the timeline */
clutter_timeline_start (timeline);
/* Add texture to the stage, and show it */
clutter_group_add (CLUTTER_GROUP (stage), texture);
clutter_actor_show_all (stage);
clutter_main ();
/* Free resources */
gst_element_set_state (pipeline, GST_STATE_NULL);
gst_object_unref (pipeline);
return 0;
}
int
main (int argc, char *argv[])
{
#if defined(__APPLE__) && TARGET_OS_MAC && !TARGET_OS_IPHONE
return gst_macos_main (tutorial_main, argc, argv, NULL);
#else
return tutorial_main (argc, argv);
#endif
}