3 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
4 * Copyright (C) 2002,2007 David A. Schleef <ds@schleef.org>
5 * Copyright (C) 2008 Julien Isorce <julien.isorce@gmail.com>
6 * Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
25 * SECTION:element-gltestsrc
29 * The gltestsrc element is used to produce test video texture.
30 * The video test produced can be controlled with the "pattern"
33 * <title>Example launch line</title>
36 * gst-launch-1.0 -v gltestsrc pattern=smpte ! glimagesink
38 * Shows original SMPTE color bars in a window.
47 #include "gstgltestsrc.h"
48 #include "gltestsrc.h"
49 #include <gst/gst-i18n-plugin.h>
51 #define USE_PEER_BUFFERALLOC
52 #define SUPPORTED_GL_APIS (GST_GL_API_OPENGL | GST_GL_API_OPENGL3 | GST_GL_API_GLES2)
54 GST_DEBUG_CATEGORY_STATIC (gl_test_src_debug);
55 #define GST_CAT_DEFAULT gl_test_src_debug
61 PROP_TIMESTAMP_OFFSET,
67 static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
70 GST_STATIC_CAPS ("video/x-raw(" GST_CAPS_FEATURE_MEMORY_GL_MEMORY "), "
71 "format = (string) RGBA, "
72 "width = " GST_VIDEO_SIZE_RANGE ", "
73 "height = " GST_VIDEO_SIZE_RANGE ", "
74 "framerate = " GST_VIDEO_FPS_RANGE ","
75 "texture-target = (string) 2D")
79 #define gst_gl_test_src_parent_class parent_class
80 G_DEFINE_TYPE (GstGLTestSrc, gst_gl_test_src, GST_TYPE_PUSH_SRC);
82 static void gst_gl_test_src_set_pattern (GstGLTestSrc * gltestsrc,
84 static void gst_gl_test_src_set_property (GObject * object, guint prop_id,
85 const GValue * value, GParamSpec * pspec);
86 static void gst_gl_test_src_get_property (GObject * object, guint prop_id,
87 GValue * value, GParamSpec * pspec);
89 static gboolean gst_gl_test_src_setcaps (GstBaseSrc * bsrc, GstCaps * caps);
90 static GstCaps *gst_gl_test_src_fixate (GstBaseSrc * bsrc, GstCaps * caps);
92 static gboolean gst_gl_test_src_is_seekable (GstBaseSrc * psrc);
93 static gboolean gst_gl_test_src_do_seek (GstBaseSrc * bsrc,
94 GstSegment * segment);
95 static gboolean gst_gl_test_src_query (GstBaseSrc * bsrc, GstQuery * query);
96 static void gst_gl_test_src_set_context (GstElement * element,
97 GstContext * context);
98 static GstStateChangeReturn gst_gl_test_src_change_state (GstElement * element,
99 GstStateChange transition);
101 static void gst_gl_test_src_get_times (GstBaseSrc * basesrc,
102 GstBuffer * buffer, GstClockTime * start, GstClockTime * end);
103 static GstFlowReturn gst_gl_test_src_fill (GstPushSrc * psrc,
105 static gboolean gst_gl_test_src_start (GstBaseSrc * basesrc);
106 static gboolean gst_gl_test_src_stop (GstBaseSrc * basesrc);
107 static gboolean gst_gl_test_src_decide_allocation (GstBaseSrc * basesrc,
110 static gboolean gst_gl_test_src_callback (gpointer stuff);
112 static gboolean gst_gl_test_src_init_shader (GstGLTestSrc * gltestsrc);
114 #define GST_TYPE_GL_TEST_SRC_PATTERN (gst_gl_test_src_pattern_get_type ())
116 gst_gl_test_src_pattern_get_type (void)
118 static GType gl_test_src_pattern_type = 0;
119 static const GEnumValue pattern_types[] = {
120 {GST_GL_TEST_SRC_SMPTE, "SMPTE 100% color bars", "smpte"},
121 {GST_GL_TEST_SRC_SNOW, "Random (television snow)", "snow"},
122 {GST_GL_TEST_SRC_BLACK, "100% Black", "black"},
123 {GST_GL_TEST_SRC_WHITE, "100% White", "white"},
124 {GST_GL_TEST_SRC_RED, "Red", "red"},
125 {GST_GL_TEST_SRC_GREEN, "Green", "green"},
126 {GST_GL_TEST_SRC_BLUE, "Blue", "blue"},
127 {GST_GL_TEST_SRC_CHECKERS1, "Checkers 1px", "checkers-1"},
128 {GST_GL_TEST_SRC_CHECKERS2, "Checkers 2px", "checkers-2"},
129 {GST_GL_TEST_SRC_CHECKERS4, "Checkers 4px", "checkers-4"},
130 {GST_GL_TEST_SRC_CHECKERS8, "Checkers 8px", "checkers-8"},
131 {GST_GL_TEST_SRC_CIRCULAR, "Circular", "circular"},
132 {GST_GL_TEST_SRC_BLINK, "Blink", "blink"},
133 {GST_GL_TEST_SRC_MANDELBROT, "Mandelbrot Fractal", "mandelbrot"},
137 if (!gl_test_src_pattern_type) {
138 gl_test_src_pattern_type =
139 g_enum_register_static ("GstGLTestSrcPattern", pattern_types);
141 return gl_test_src_pattern_type;
145 gst_gl_test_src_class_init (GstGLTestSrcClass * klass)
147 GObjectClass *gobject_class;
148 GstBaseSrcClass *gstbasesrc_class;
149 GstPushSrcClass *gstpushsrc_class;
150 GstElementClass *element_class;
152 GST_DEBUG_CATEGORY_INIT (gl_test_src_debug, "gltestsrc", 0,
153 "Video Test Source");
155 gobject_class = (GObjectClass *) klass;
156 gstbasesrc_class = (GstBaseSrcClass *) klass;
157 gstpushsrc_class = (GstPushSrcClass *) klass;
158 element_class = GST_ELEMENT_CLASS (klass);
160 gobject_class->set_property = gst_gl_test_src_set_property;
161 gobject_class->get_property = gst_gl_test_src_get_property;
163 g_object_class_install_property (gobject_class, PROP_PATTERN,
164 g_param_spec_enum ("pattern", "Pattern",
165 "Type of test pattern to generate", GST_TYPE_GL_TEST_SRC_PATTERN,
166 GST_GL_TEST_SRC_SMPTE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
167 g_object_class_install_property (gobject_class,
168 PROP_TIMESTAMP_OFFSET, g_param_spec_int64 ("timestamp-offset",
170 "An offset added to timestamps set on buffers (in ns)", G_MININT64,
171 G_MAXINT64, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
172 g_object_class_install_property (gobject_class, PROP_IS_LIVE,
173 g_param_spec_boolean ("is-live", "Is Live",
174 "Whether to act as a live source", FALSE,
175 G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
177 gst_element_class_set_metadata (element_class, "Video test source",
178 "Source/Video", "Creates a test video stream",
179 "David A. Schleef <ds@schleef.org>");
181 gst_element_class_add_static_pad_template (element_class, &src_factory);
183 element_class->set_context = gst_gl_test_src_set_context;
184 element_class->change_state = gst_gl_test_src_change_state;
186 gstbasesrc_class->set_caps = gst_gl_test_src_setcaps;
187 gstbasesrc_class->is_seekable = gst_gl_test_src_is_seekable;
188 gstbasesrc_class->do_seek = gst_gl_test_src_do_seek;
189 gstbasesrc_class->query = gst_gl_test_src_query;
190 gstbasesrc_class->get_times = gst_gl_test_src_get_times;
191 gstbasesrc_class->start = gst_gl_test_src_start;
192 gstbasesrc_class->stop = gst_gl_test_src_stop;
193 gstbasesrc_class->fixate = gst_gl_test_src_fixate;
194 gstbasesrc_class->decide_allocation = gst_gl_test_src_decide_allocation;
196 gstpushsrc_class->fill = gst_gl_test_src_fill;
200 gst_gl_test_src_init (GstGLTestSrc * src)
202 gst_gl_test_src_set_pattern (src, GST_GL_TEST_SRC_SMPTE);
204 src->timestamp_offset = 0;
206 /* we operate in time */
207 gst_base_src_set_format (GST_BASE_SRC (src), GST_FORMAT_TIME);
208 gst_base_src_set_live (GST_BASE_SRC (src), FALSE);
212 gst_gl_test_src_fixate (GstBaseSrc * bsrc, GstCaps * caps)
214 GstStructure *structure;
216 GST_DEBUG ("fixate");
218 caps = gst_caps_make_writable (caps);
220 structure = gst_caps_get_structure (caps, 0);
222 gst_structure_fixate_field_nearest_int (structure, "width", 320);
223 gst_structure_fixate_field_nearest_int (structure, "height", 240);
224 gst_structure_fixate_field_nearest_fraction (structure, "framerate", 30, 1);
226 caps = GST_BASE_SRC_CLASS (parent_class)->fixate (bsrc, caps);
232 gst_gl_test_src_set_pattern (GstGLTestSrc * gltestsrc, gint pattern_type)
234 gltestsrc->set_pattern = pattern_type;
238 gst_gl_test_src_set_property (GObject * object, guint prop_id,
239 const GValue * value, GParamSpec * pspec)
241 GstGLTestSrc *src = GST_GL_TEST_SRC (object);
245 gst_gl_test_src_set_pattern (src, g_value_get_enum (value));
247 case PROP_TIMESTAMP_OFFSET:
248 src->timestamp_offset = g_value_get_int64 (value);
251 gst_base_src_set_live (GST_BASE_SRC (src), g_value_get_boolean (value));
259 gst_gl_test_src_get_property (GObject * object, guint prop_id,
260 GValue * value, GParamSpec * pspec)
262 GstGLTestSrc *src = GST_GL_TEST_SRC (object);
266 g_value_set_enum (value, src->set_pattern);
268 case PROP_TIMESTAMP_OFFSET:
269 g_value_set_int64 (value, src->timestamp_offset);
272 g_value_set_boolean (value, gst_base_src_is_live (GST_BASE_SRC (src)));
275 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
281 gst_gl_test_src_setcaps (GstBaseSrc * bsrc, GstCaps * caps)
283 GstGLTestSrc *gltestsrc = GST_GL_TEST_SRC (bsrc);
285 GST_DEBUG ("setcaps");
287 if (!gst_video_info_from_caps (&gltestsrc->out_info, caps))
290 gltestsrc->negotiated = TRUE;
292 gst_caps_replace (&gltestsrc->out_caps, caps);
299 GST_WARNING ("wrong caps");
305 gst_gl_test_src_set_context (GstElement * element, GstContext * context)
307 GstGLTestSrc *src = GST_GL_TEST_SRC (element);
309 gst_gl_handle_set_context (element, context, &src->display,
310 &src->other_context);
313 gst_gl_display_filter_gl_api (src->display, SUPPORTED_GL_APIS);
315 GST_ELEMENT_CLASS (parent_class)->set_context (element, context);
319 gst_gl_test_src_query (GstBaseSrc * bsrc, GstQuery * query)
321 gboolean res = FALSE;
324 src = GST_GL_TEST_SRC (bsrc);
326 switch (GST_QUERY_TYPE (query)) {
327 case GST_QUERY_CONTEXT:
329 const gchar *context_type;
330 GstContext *context, *old_context;
332 res = gst_gl_handle_context_query ((GstElement *) src, query,
333 &src->display, &src->other_context);
335 gst_gl_display_filter_gl_api (src->display, SUPPORTED_GL_APIS);
337 gst_query_parse_context_type (query, &context_type);
339 if (g_strcmp0 (context_type, "gst.gl.local_context") == 0) {
342 gst_query_parse_context (query, &old_context);
345 context = gst_context_copy (old_context);
347 context = gst_context_new ("gst.gl.local_context", FALSE);
349 s = gst_context_writable_structure (context);
350 gst_structure_set (s, "context", GST_TYPE_GL_CONTEXT, src->context,
352 gst_query_set_context (query, context);
353 gst_context_unref (context);
355 res = src->context != NULL;
357 GST_LOG_OBJECT (src, "context query of type %s %i", context_type, res);
364 case GST_QUERY_CONVERT:
366 GstFormat src_fmt, dest_fmt;
367 gint64 src_val, dest_val;
369 gst_query_parse_convert (query, &src_fmt, &src_val, &dest_fmt, &dest_val);
371 gst_video_info_convert (&src->out_info, src_fmt, src_val, dest_fmt,
373 gst_query_set_convert (query, src_fmt, src_val, dest_fmt, dest_val);
381 return GST_BASE_SRC_CLASS (parent_class)->query (bsrc, query);
385 gst_gl_test_src_get_times (GstBaseSrc * basesrc, GstBuffer * buffer,
386 GstClockTime * start, GstClockTime * end)
388 /* for live sources, sync on the timestamp of the buffer */
389 if (gst_base_src_is_live (basesrc)) {
390 GstClockTime timestamp = GST_BUFFER_TIMESTAMP (buffer);
392 if (GST_CLOCK_TIME_IS_VALID (timestamp)) {
393 /* get duration to calculate end time */
394 GstClockTime duration = GST_BUFFER_DURATION (buffer);
396 if (GST_CLOCK_TIME_IS_VALID (duration))
397 *end = timestamp + duration;
407 gst_gl_test_src_do_seek (GstBaseSrc * bsrc, GstSegment * segment)
412 src = GST_GL_TEST_SRC (bsrc);
414 segment->time = segment->start;
415 time = segment->position;
417 /* now move to the time indicated */
418 if (src->out_info.fps_n) {
419 src->n_frames = gst_util_uint64_scale (time,
420 src->out_info.fps_n, src->out_info.fps_d * GST_SECOND);
424 if (src->out_info.fps_n) {
425 src->running_time = gst_util_uint64_scale (src->n_frames,
426 src->out_info.fps_d * GST_SECOND, src->out_info.fps_n);
428 /* FIXME : Not sure what to set here */
429 src->running_time = 0;
432 g_return_val_if_fail (src->running_time <= time, FALSE);
438 gst_gl_test_src_is_seekable (GstBaseSrc * psrc)
440 /* we're seekable... */
445 gst_gl_test_src_init_shader (GstGLTestSrc * gltestsrc)
447 if (gst_gl_context_get_gl_api (gltestsrc->context)) {
448 /* blocking call, wait until the opengl thread has compiled the shader */
449 // if (gltestsrc->vertex_src == NULL)
451 // return gst_gl_context_gen_shader (gltestsrc->context, gltestsrc->vertex_src,
452 // gltestsrc->fragment_src, &gltestsrc->shader);
458 _fill_gl (GstGLContext * context, GstGLTestSrc * src)
460 src->gl_result = gst_gl_framebuffer_draw_to_texture (src->fbo, src->out_tex,
461 gst_gl_test_src_callback, src);
465 gst_gl_test_src_fill (GstPushSrc * psrc, GstBuffer * buffer)
467 GstGLTestSrc *src = GST_GL_TEST_SRC (psrc);
468 GstClockTime next_time;
469 GstVideoFrame out_frame;
470 GstGLSyncMeta *sync_meta;
472 if (G_UNLIKELY (!src->negotiated || !src->context))
475 /* 0 framerate and we are at the second frame, eos */
476 if (G_UNLIKELY (GST_VIDEO_INFO_FPS_N (&src->out_info) == 0
477 && src->n_frames == 1))
480 if (!gst_video_frame_map (&out_frame, &src->out_info, buffer,
481 GST_MAP_WRITE | GST_MAP_GL)) {
482 return GST_FLOW_NOT_NEGOTIATED;
485 src->out_tex = (GstGLMemory *) out_frame.map[0].memory;
487 gst_gl_context_thread_add (src->context, (GstGLContextThreadFunc) _fill_gl,
489 if (!src->gl_result) {
490 gst_video_frame_unmap (&out_frame);
493 gst_video_frame_unmap (&out_frame);
497 sync_meta = gst_buffer_get_gl_sync_meta (buffer);
499 gst_gl_sync_meta_set_sync_point (sync_meta, src->context);
501 GST_BUFFER_TIMESTAMP (buffer) = src->timestamp_offset + src->running_time;
502 GST_BUFFER_OFFSET (buffer) = src->n_frames;
504 GST_BUFFER_OFFSET_END (buffer) = src->n_frames;
505 if (src->out_info.fps_n) {
506 next_time = gst_util_uint64_scale_int (src->n_frames * GST_SECOND,
507 src->out_info.fps_d, src->out_info.fps_n);
508 GST_BUFFER_DURATION (buffer) = next_time - src->running_time;
510 next_time = src->timestamp_offset;
511 /* NONE means forever */
512 GST_BUFFER_DURATION (buffer) = GST_CLOCK_TIME_NONE;
515 src->running_time = next_time;
521 GST_ELEMENT_ERROR (src, RESOURCE, NOT_FOUND, (_("failed to draw pattern")),
522 (_("A GL error occured")));
523 return GST_FLOW_NOT_NEGOTIATED;
527 GST_ELEMENT_ERROR (src, CORE, NEGOTIATION, (NULL),
528 (_("format wasn't negotiated before get function")));
529 return GST_FLOW_NOT_NEGOTIATED;
533 GST_DEBUG_OBJECT (src, "eos: 0 framerate, frame %d", (gint) src->n_frames);
539 gst_gl_test_src_start (GstBaseSrc * basesrc)
541 GstGLTestSrc *src = GST_GL_TEST_SRC (basesrc);
543 if (!gst_gl_ensure_element_data (src, &src->display, &src->other_context))
546 gst_gl_display_filter_gl_api (src->display, SUPPORTED_GL_APIS);
548 src->running_time = 0;
550 src->negotiated = FALSE;
556 gst_gl_test_src_stop (GstBaseSrc * basesrc)
558 GstGLTestSrc *src = GST_GL_TEST_SRC (basesrc);
560 gst_caps_replace (&src->out_caps, NULL);
564 gst_object_unref (src->shader);
569 gst_object_unref (src->fbo);
572 gst_object_unref (src->context);
577 src->src_funcs->free (src->src_impl);
578 src->src_impl = NULL;
585 _find_local_gl_context (GstGLTestSrc * src)
589 const GstStructure *s;
594 query = gst_query_new_context ("gst.gl.local_context");
595 if (!src->context && gst_gl_run_query (GST_ELEMENT (src), query, GST_PAD_SRC)) {
596 gst_query_parse_context (query, &context);
598 s = gst_context_get_structure (context);
599 gst_structure_get (s, "context", GST_TYPE_GL_CONTEXT, &src->context,
604 && gst_gl_run_query (GST_ELEMENT (src), query, GST_PAD_SINK)) {
605 gst_query_parse_context (query, &context);
607 s = gst_context_get_structure (context);
608 gst_structure_get (s, "context", GST_TYPE_GL_CONTEXT, &src->context,
613 GST_DEBUG_OBJECT (src, "found local context %p", src->context);
615 gst_query_unref (query);
624 _src_generate_fbo_gl (GstGLContext * context, GstGLTestSrc * src)
626 src->fbo = gst_gl_framebuffer_new_with_default_depth (src->context,
627 GST_VIDEO_INFO_WIDTH (&src->out_info),
628 GST_VIDEO_INFO_HEIGHT (&src->out_info));
632 gst_gl_test_src_decide_allocation (GstBaseSrc * basesrc, GstQuery * query)
634 GstGLTestSrc *src = GST_GL_TEST_SRC (basesrc);
635 GstBufferPool *pool = NULL;
636 GstStructure *config;
638 guint min, max, size;
639 gboolean update_pool;
640 GError *error = NULL;
642 if (!gst_gl_ensure_element_data (src, &src->display, &src->other_context))
645 gst_gl_display_filter_gl_api (src->display, SUPPORTED_GL_APIS);
647 _find_local_gl_context (src);
650 GST_OBJECT_LOCK (src->display);
653 gst_object_unref (src->context);
656 /* just get a GL context. we don't care */
658 gst_gl_display_get_gl_context_for_thread (src->display, NULL);
660 if (!gst_gl_display_create_context (src->display, src->other_context,
661 &src->context, &error)) {
662 GST_OBJECT_UNLOCK (src->display);
666 } while (!gst_gl_display_add_context (src->display, src->context));
667 GST_OBJECT_UNLOCK (src->display);
670 if ((gst_gl_context_get_gl_api (src->context) & SUPPORTED_GL_APIS) == 0)
671 goto unsupported_gl_api;
673 gst_gl_context_thread_add (src->context,
674 (GstGLContextThreadFunc) _src_generate_fbo_gl, src);
678 gst_query_parse_allocation (query, &caps, NULL);
680 if (gst_query_get_n_allocation_pools (query) > 0) {
681 gst_query_parse_nth_allocation_pool (query, 0, &pool, &size, &min, &max);
687 gst_video_info_init (&vinfo);
688 gst_video_info_from_caps (&vinfo, caps);
694 if (!pool || !GST_IS_GL_BUFFER_POOL (pool)) {
695 /* can't use this pool */
697 gst_object_unref (pool);
698 pool = gst_gl_buffer_pool_new (src->context);
700 config = gst_buffer_pool_get_config (pool);
702 gst_buffer_pool_config_set_params (config, caps, size, min, max);
703 gst_buffer_pool_config_add_option (config, GST_BUFFER_POOL_OPTION_VIDEO_META);
704 if (gst_query_find_allocation_meta (query, GST_GL_SYNC_META_API_TYPE, NULL))
705 gst_buffer_pool_config_add_option (config,
706 GST_BUFFER_POOL_OPTION_GL_SYNC_META);
707 gst_buffer_pool_config_add_option (config,
708 GST_BUFFER_POOL_OPTION_VIDEO_GL_TEXTURE_UPLOAD_META);
710 gst_buffer_pool_set_config (pool, config);
713 gst_query_set_nth_allocation_pool (query, 0, pool, size, min, max);
715 gst_query_add_allocation_pool (query, pool, size, min, max);
717 gst_gl_test_src_init_shader (src);
719 gst_object_unref (pool);
725 GstGLAPI gl_api = gst_gl_context_get_gl_api (src->context);
726 gchar *gl_api_str = gst_gl_api_to_string (gl_api);
727 gchar *supported_gl_api_str = gst_gl_api_to_string (SUPPORTED_GL_APIS);
728 GST_ELEMENT_ERROR (src, RESOURCE, BUSY,
729 ("GL API's not compatible context: %s supported: %s", gl_api_str,
730 supported_gl_api_str), (NULL));
732 g_free (supported_gl_api_str);
738 GST_ELEMENT_ERROR (src, RESOURCE, NOT_FOUND, ("%s", error->message),
740 g_clear_error (&error);
742 gst_object_unref (src->context);
749 gst_gl_test_src_callback (gpointer stuff)
751 GstGLTestSrc *src = GST_GL_TEST_SRC (stuff);
752 const struct SrcFuncs *funcs;
754 funcs = src->src_funcs;
756 if (!funcs || src->set_pattern != src->active_pattern) {
757 if (src->src_impl && funcs)
758 funcs->free (src->src_impl);
759 src->src_funcs = funcs =
760 gst_gl_test_src_get_src_funcs_for_pattern (src->set_pattern);
762 GST_ERROR_OBJECT (src, "Could not find an implementation of the "
763 "requested pattern");
766 src->src_impl = funcs->new (src);
767 if (!(src->gl_result =
768 funcs->init (src->src_impl, src->context, &src->out_info))) {
769 GST_ERROR_OBJECT (src, "Failed to initialize pattern");
772 src->active_pattern = src->set_pattern;
775 return funcs->fill_bound_fbo (src->src_impl);
778 static GstStateChangeReturn
779 gst_gl_test_src_change_state (GstElement * element, GstStateChange transition)
781 GstGLTestSrc *src = GST_GL_TEST_SRC (element);
782 GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
784 GST_DEBUG_OBJECT (src, "changing state: %s => %s",
785 gst_element_state_get_name (GST_STATE_TRANSITION_CURRENT (transition)),
786 gst_element_state_get_name (GST_STATE_TRANSITION_NEXT (transition)));
788 switch (transition) {
789 case GST_STATE_CHANGE_NULL_TO_READY:
790 if (!gst_gl_ensure_element_data (element, &src->display,
791 &src->other_context))
792 return GST_STATE_CHANGE_FAILURE;
794 gst_gl_display_filter_gl_api (src->display, SUPPORTED_GL_APIS);
800 ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
801 if (ret == GST_STATE_CHANGE_FAILURE)
804 switch (transition) {
805 case GST_STATE_CHANGE_READY_TO_NULL:
806 if (src->other_context) {
807 gst_object_unref (src->other_context);
808 src->other_context = NULL;
812 gst_object_unref (src->display);