sys/applemedia/videotexturecache.m - mtk-gst-plugins-bad-debian - Git at Google

 /*
  * Copyright (C) 2010 Ole André Vadla Ravnås <oleavr@soundrop.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.
  */

 #ifdef HAVE_CONFIG_H
 #  include "config.h"
 #endif

 #if !HAVE_IOS
 #import <AppKit/AppKit.h>
 #include <gst/gl/cocoa/gstglcontext_cocoa.h>
 #include <gst/gl/gstglbufferpool.h>
 #include "iosurfacememory.h"
 #endif
 #include "videotexturecache.h"
 #include "coremediabuffer.h"
 #include "corevideobuffer.h"
 #include "vtutil.h"

 typedef struct _ContextThreadData
 {
   GstVideoTextureCache *cache;
   GstBuffer *input_buffer;
   GstBuffer *output_buffer;
 } ContextThreadData;

 GstVideoTextureCache *
 gst_video_texture_cache_new (GstGLContext * ctx)
 {
   g_return_val_if_fail (ctx != NULL, NULL);

   GstVideoTextureCache *cache = g_new0 (GstVideoTextureCache, 1);

   cache->ctx = gst_object_ref (ctx);
   gst_video_info_init (&cache->input_info);

 #if HAVE_IOS
   CFMutableDictionaryRef cache_attrs =
       CFDictionaryCreateMutable (NULL, 0, &kCFTypeDictionaryKeyCallBacks,
       &kCFTypeDictionaryValueCallBacks);
   CVOpenGLESTextureCacheCreate (kCFAllocatorDefault, (CFDictionaryRef) cache_attrs,
       (CVEAGLContext) gst_gl_context_get_gl_context (ctx), NULL, &cache->cache);
 #else
   gst_ios_surface_memory_init ();
 #if 0
   cache->pool = GST_BUFFER_POOL (gst_gl_buffer_pool_new (ctx));
 #endif
 #endif

   return cache;
 }

 void
 gst_video_texture_cache_free (GstVideoTextureCache * cache)
 {
   g_return_if_fail (cache != NULL);

 #if HAVE_IOS
   CFRelease (cache->cache); /* iOS has no "CVOpenGLESTextureCacheRelease" */
 #else
 #if 0
   gst_buffer_pool_set_active (cache->pool, FALSE);
   gst_object_unref (cache->pool);
 #endif
 #endif
   gst_object_unref (cache->ctx);
   if (cache->in_caps)
     gst_caps_unref (cache->in_caps);
   if (cache->out_caps)
     gst_caps_unref (cache->out_caps);
   g_free (cache);
 }

 void
 gst_video_texture_cache_set_format (GstVideoTextureCache * cache,
     GstVideoFormat in_format, GstCaps * out_caps)
 {
   GstCaps *in_caps;
   GstCapsFeatures *features;

   g_return_if_fail (gst_caps_is_fixed (out_caps));

   out_caps = gst_caps_copy (out_caps);
   features = gst_caps_get_features (out_caps, 0);
   gst_caps_features_add (features, GST_CAPS_FEATURE_MEMORY_GL_MEMORY);
   gst_video_info_from_caps (&cache->output_info, out_caps);

   in_caps = gst_caps_copy (out_caps);
   gst_caps_set_simple (in_caps, "format",
           G_TYPE_STRING, gst_video_format_to_string (in_format), NULL);
   features = gst_caps_get_features (in_caps, 0);
   gst_caps_features_add (features, GST_CAPS_FEATURE_MEMORY_GL_MEMORY);
   gst_video_info_from_caps (&cache->input_info, in_caps);

   if (cache->in_caps)
     gst_caps_unref (cache->in_caps);
   if (cache->out_caps)
     gst_caps_unref (cache->out_caps);
   cache->in_caps = in_caps;
   cache->out_caps = out_caps;

 #if 0
   GstStructure *config = gst_buffer_pool_get_config (cache->pool);
   gst_buffer_pool_config_set_params (config, cache->in_caps,
           GST_VIDEO_INFO_SIZE (&cache->input_info), 0, 0);
   gst_buffer_pool_config_set_allocator (config,
           gst_allocator_find (GST_IO_SURFACE_MEMORY_ALLOCATOR_NAME), NULL);
   gst_buffer_pool_config_add_option (config,
           GST_BUFFER_POOL_OPTION_GL_TEXTURE_TARGET_RECTANGLE);
   gst_buffer_pool_set_config (cache->pool, config);
   gst_buffer_pool_set_active (cache->pool, TRUE);
 #endif
 }

 static CVPixelBufferRef
 cv_pixel_buffer_from_gst_buffer (GstBuffer * buffer)
 {
   GstCoreMediaMeta *cm_meta =
       (GstCoreMediaMeta *) gst_buffer_get_meta (buffer,
       gst_core_media_meta_api_get_type ());
   GstCoreVideoMeta *cv_meta =
       (GstCoreVideoMeta *) gst_buffer_get_meta (buffer,
       gst_core_video_meta_api_get_type ());

   g_return_val_if_fail (cm_meta || cv_meta, NULL);

   return cm_meta ? cm_meta->pixel_buf : cv_meta->pixbuf;
 }

 #if HAVE_IOS
 static void
 _do_get_gl_buffer (GstGLContext * context, ContextThreadData * data)
 {
   CVOpenGLESTextureRef texture = NULL;
   GstVideoTextureCache *cache = data->cache;
   CVPixelBufferRef pixel_buf = cv_pixel_buffer_from_gst_buffer (data->input_buffer);
   GstGLTextureTarget gl_target;
   GstGLBaseMemoryAllocator *base_mem_alloc;
   GstGLVideoAllocationParams *params;
   GstBuffer *output_buffer;

   base_mem_alloc = GST_GL_BASE_MEMORY_ALLOCATOR (gst_gl_memory_allocator_get_default (cache->ctx));
   output_buffer = gst_buffer_new ();
   gst_buffer_copy_into (output_buffer, data->input_buffer, GST_BUFFER_COPY_ALL, 0, -1);

   switch (GST_VIDEO_INFO_FORMAT (&cache->input_info)) {
       case GST_VIDEO_FORMAT_BGRA:
         /* avfvideosrc does BGRA on iOS when doing GLMemory */
         if (CVOpenGLESTextureCacheCreateTextureFromImage (kCFAllocatorDefault,
               cache->cache, pixel_buf, NULL, GL_TEXTURE_2D, GL_RGBA,
               GST_VIDEO_INFO_WIDTH (&cache->input_info),
               GST_VIDEO_INFO_HEIGHT (&cache->input_info),
               GL_RGBA, GL_UNSIGNED_BYTE, 0, &texture) != kCVReturnSuccess)
           goto error;

         gl_target = gst_gl_texture_target_from_gl (CVOpenGLESTextureGetTarget (texture));
         params = gst_gl_video_allocation_params_new_wrapped_texture (cache->ctx,
             NULL, &cache->input_info, 0, NULL, gl_target,
             CVOpenGLESTextureGetName (texture), texture,
             (GDestroyNotify) CFRelease);

         gst_buffer_replace_memory (output_buffer, 0,
                 (GstMemory *) gst_gl_base_memory_alloc (base_mem_alloc,
                     (GstGLAllocationParams *) params));
         gst_gl_allocation_params_free ((GstGLAllocationParams *) params);
         break;
       case GST_VIDEO_FORMAT_NV12: {
         GstVideoGLTextureType textype;
         GLenum texifmt, texfmt;

         textype = gst_gl_texture_type_from_format (cache->ctx, GST_VIDEO_FORMAT_NV12, 0);
         texifmt = gst_gl_format_from_gl_texture_type (textype);
         texfmt = gst_gl_sized_gl_format_from_gl_format_type (cache->ctx, texifmt, GL_UNSIGNED_BYTE);

         /* vtdec does NV12 on iOS when doing GLMemory */
         if (CVOpenGLESTextureCacheCreateTextureFromImage (kCFAllocatorDefault,
               cache->cache, pixel_buf, NULL, GL_TEXTURE_2D, texifmt,
               GST_VIDEO_INFO_WIDTH (&cache->input_info),
               GST_VIDEO_INFO_HEIGHT (&cache->input_info),
               texfmt, GL_UNSIGNED_BYTE, 0, &texture) != kCVReturnSuccess)
           goto error;

         gl_target = gst_gl_texture_target_from_gl (CVOpenGLESTextureGetTarget (texture));
         params = gst_gl_video_allocation_params_new_wrapped_texture (cache->ctx,
             NULL, &cache->input_info, 0, NULL, gl_target,
             CVOpenGLESTextureGetName (texture), texture,
             (GDestroyNotify) CFRelease);

         gst_buffer_replace_memory (output_buffer, 0,
                 (GstMemory *) gst_gl_base_memory_alloc (base_mem_alloc,
                     (GstGLAllocationParams *) params));
         gst_gl_allocation_params_free ((GstGLAllocationParams *) params);

         textype = gst_gl_texture_type_from_format (cache->ctx, GST_VIDEO_FORMAT_NV12, 1);
         texifmt = gst_gl_format_from_gl_texture_type (textype);
         texfmt = gst_gl_sized_gl_format_from_gl_format_type (cache->ctx, texifmt, GL_UNSIGNED_BYTE);

         if (CVOpenGLESTextureCacheCreateTextureFromImage (kCFAllocatorDefault,
               cache->cache, pixel_buf, NULL, GL_TEXTURE_2D, texifmt,
               GST_VIDEO_INFO_WIDTH (&cache->input_info) / 2,
               GST_VIDEO_INFO_HEIGHT (&cache->input_info) / 2,
               texfmt, GL_UNSIGNED_BYTE, 1, &texture) != kCVReturnSuccess)
           goto error;

         gl_target = gst_gl_texture_target_from_gl (CVOpenGLESTextureGetTarget (texture));
         params = gst_gl_video_allocation_params_new_wrapped_texture (cache->ctx,
             NULL, &cache->input_info, 1, NULL, gl_target,
             CVOpenGLESTextureGetName (texture), texture,
             (GDestroyNotify) CFRelease);

         gst_buffer_replace_memory (output_buffer, 1,
                 (GstMemory *) gst_gl_base_memory_alloc (base_mem_alloc,
                     (GstGLAllocationParams *) params));
         gst_gl_allocation_params_free ((GstGLAllocationParams *) params);
         break;
       }
     default:
       g_warn_if_reached ();
       goto error;
   }

   gst_object_unref (base_mem_alloc);

   data->output_buffer = output_buffer;

   return;

 error:
   data->output_buffer = NULL;
 }
 #else /* !HAVE_IOS */
 static void
 _do_get_gl_buffer (GstGLContext * context, ContextThreadData * data)
 {
   GstVideoTextureCache *cache = data->cache;
   CVPixelBufferRef pixel_buf = cv_pixel_buffer_from_gst_buffer (data->input_buffer);
   IOSurfaceRef surface = CVPixelBufferGetIOSurface (pixel_buf);

   data->output_buffer = gst_buffer_new ();
   gst_buffer_copy_into (data->output_buffer, data->input_buffer, GST_BUFFER_COPY_ALL, 0, -1);
   for (int i = 0; i < GST_VIDEO_INFO_N_PLANES (&cache->input_info); i++) {
     GstIOSurfaceMemory *mem;

     CFRetain (pixel_buf);
     mem = gst_io_surface_memory_wrapped (cache->ctx,
             surface, GST_GL_TEXTURE_TARGET_RECTANGLE, &cache->input_info,
             i, NULL, pixel_buf, (GDestroyNotify) CFRelease);

     gst_buffer_replace_memory (data->output_buffer, i, (GstMemory *) mem);
   }
 }
 #endif

 GstBuffer *
 gst_video_texture_cache_get_gl_buffer (GstVideoTextureCache * cache,
         GstBuffer * cv_buffer)
 {
   ContextThreadData data = {cache, cv_buffer, NULL};

   gst_gl_context_thread_add (cache->ctx,
       (GstGLContextThreadFunc) _do_get_gl_buffer, &data);

   gst_buffer_unref (cv_buffer);

   return data.output_buffer;
 }
	/*
	* Copyright (C) 2010 Ole André Vadla Ravnås <oleavr@soundrop.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.
	*/

	#ifdef HAVE_CONFIG_H
	# include "config.h"
	#endif

	#if !HAVE_IOS
	#import <AppKit/AppKit.h>
	#include <gst/gl/cocoa/gstglcontext_cocoa.h>
	#include <gst/gl/gstglbufferpool.h>
	#include "iosurfacememory.h"
	#endif
	#include "videotexturecache.h"
	#include "coremediabuffer.h"
	#include "corevideobuffer.h"
	#include "vtutil.h"

	typedef struct _ContextThreadData
	{
	GstVideoTextureCache *cache;
	GstBuffer *input_buffer;
	GstBuffer *output_buffer;
	} ContextThreadData;

	GstVideoTextureCache *
	gst_video_texture_cache_new (GstGLContext * ctx)
	{
	g_return_val_if_fail (ctx != NULL, NULL);

	GstVideoTextureCache *cache = g_new0 (GstVideoTextureCache, 1);

	cache->ctx = gst_object_ref (ctx);
	gst_video_info_init (&cache->input_info);

	#if HAVE_IOS
	CFMutableDictionaryRef cache_attrs =
	CFDictionaryCreateMutable (NULL, 0, &kCFTypeDictionaryKeyCallBacks,
	&kCFTypeDictionaryValueCallBacks);
	CVOpenGLESTextureCacheCreate (kCFAllocatorDefault, (CFDictionaryRef) cache_attrs,
	(CVEAGLContext) gst_gl_context_get_gl_context (ctx), NULL, &cache->cache);
	#else
	gst_ios_surface_memory_init ();
	#if 0
	cache->pool = GST_BUFFER_POOL (gst_gl_buffer_pool_new (ctx));
	#endif
	#endif

	return cache;
	}

	void
	gst_video_texture_cache_free (GstVideoTextureCache * cache)
	{
	g_return_if_fail (cache != NULL);

	#if HAVE_IOS
	CFRelease (cache->cache); /* iOS has no "CVOpenGLESTextureCacheRelease" */
	#else
	#if 0
	gst_buffer_pool_set_active (cache->pool, FALSE);
	gst_object_unref (cache->pool);
	#endif
	#endif
	gst_object_unref (cache->ctx);
	if (cache->in_caps)
	gst_caps_unref (cache->in_caps);
	if (cache->out_caps)
	gst_caps_unref (cache->out_caps);
	g_free (cache);
	}

	void
	gst_video_texture_cache_set_format (GstVideoTextureCache * cache,
	GstVideoFormat in_format, GstCaps * out_caps)
	{
	GstCaps *in_caps;
	GstCapsFeatures *features;

	g_return_if_fail (gst_caps_is_fixed (out_caps));

	out_caps = gst_caps_copy (out_caps);
	features = gst_caps_get_features (out_caps, 0);
	gst_caps_features_add (features, GST_CAPS_FEATURE_MEMORY_GL_MEMORY);
	gst_video_info_from_caps (&cache->output_info, out_caps);

	in_caps = gst_caps_copy (out_caps);
	gst_caps_set_simple (in_caps, "format",
	G_TYPE_STRING, gst_video_format_to_string (in_format), NULL);
	features = gst_caps_get_features (in_caps, 0);
	gst_caps_features_add (features, GST_CAPS_FEATURE_MEMORY_GL_MEMORY);
	gst_video_info_from_caps (&cache->input_info, in_caps);

	if (cache->in_caps)
	gst_caps_unref (cache->in_caps);
	if (cache->out_caps)
	gst_caps_unref (cache->out_caps);
	cache->in_caps = in_caps;
	cache->out_caps = out_caps;

	#if 0
	GstStructure *config = gst_buffer_pool_get_config (cache->pool);
	gst_buffer_pool_config_set_params (config, cache->in_caps,
	GST_VIDEO_INFO_SIZE (&cache->input_info), 0, 0);
	gst_buffer_pool_config_set_allocator (config,
	gst_allocator_find (GST_IO_SURFACE_MEMORY_ALLOCATOR_NAME), NULL);
	gst_buffer_pool_config_add_option (config,
	GST_BUFFER_POOL_OPTION_GL_TEXTURE_TARGET_RECTANGLE);
	gst_buffer_pool_set_config (cache->pool, config);
	gst_buffer_pool_set_active (cache->pool, TRUE);
	#endif
	}

	static CVPixelBufferRef
	cv_pixel_buffer_from_gst_buffer (GstBuffer * buffer)
	{
	GstCoreMediaMeta *cm_meta =
	(GstCoreMediaMeta *) gst_buffer_get_meta (buffer,
	gst_core_media_meta_api_get_type ());
	GstCoreVideoMeta *cv_meta =
	(GstCoreVideoMeta *) gst_buffer_get_meta (buffer,
	gst_core_video_meta_api_get_type ());

	g_return_val_if_fail (cm_meta \|\| cv_meta, NULL);

	return cm_meta ? cm_meta->pixel_buf : cv_meta->pixbuf;
	}

	#if HAVE_IOS
	static void
	_do_get_gl_buffer (GstGLContext * context, ContextThreadData * data)
	{
	CVOpenGLESTextureRef texture = NULL;
	GstVideoTextureCache *cache = data->cache;
	CVPixelBufferRef pixel_buf = cv_pixel_buffer_from_gst_buffer (data->input_buffer);
	GstGLTextureTarget gl_target;
	GstGLBaseMemoryAllocator *base_mem_alloc;
	GstGLVideoAllocationParams *params;
	GstBuffer *output_buffer;

	base_mem_alloc = GST_GL_BASE_MEMORY_ALLOCATOR (gst_gl_memory_allocator_get_default (cache->ctx));
	output_buffer = gst_buffer_new ();
	gst_buffer_copy_into (output_buffer, data->input_buffer, GST_BUFFER_COPY_ALL, 0, -1);

	switch (GST_VIDEO_INFO_FORMAT (&cache->input_info)) {
	case GST_VIDEO_FORMAT_BGRA:
	/* avfvideosrc does BGRA on iOS when doing GLMemory */
	if (CVOpenGLESTextureCacheCreateTextureFromImage (kCFAllocatorDefault,
	cache->cache, pixel_buf, NULL, GL_TEXTURE_2D, GL_RGBA,
	GST_VIDEO_INFO_WIDTH (&cache->input_info),
	GST_VIDEO_INFO_HEIGHT (&cache->input_info),
	GL_RGBA, GL_UNSIGNED_BYTE, 0, &texture) != kCVReturnSuccess)
	goto error;

	gl_target = gst_gl_texture_target_from_gl (CVOpenGLESTextureGetTarget (texture));
	params = gst_gl_video_allocation_params_new_wrapped_texture (cache->ctx,
	NULL, &cache->input_info, 0, NULL, gl_target,
	CVOpenGLESTextureGetName (texture), texture,
	(GDestroyNotify) CFRelease);

	gst_buffer_replace_memory (output_buffer, 0,
	(GstMemory *) gst_gl_base_memory_alloc (base_mem_alloc,
	(GstGLAllocationParams *) params));
	gst_gl_allocation_params_free ((GstGLAllocationParams *) params);
	break;
	case GST_VIDEO_FORMAT_NV12: {
	GstVideoGLTextureType textype;
	GLenum texifmt, texfmt;

	textype = gst_gl_texture_type_from_format (cache->ctx, GST_VIDEO_FORMAT_NV12, 0);
	texifmt = gst_gl_format_from_gl_texture_type (textype);
	texfmt = gst_gl_sized_gl_format_from_gl_format_type (cache->ctx, texifmt, GL_UNSIGNED_BYTE);

	/* vtdec does NV12 on iOS when doing GLMemory */
	if (CVOpenGLESTextureCacheCreateTextureFromImage (kCFAllocatorDefault,
	cache->cache, pixel_buf, NULL, GL_TEXTURE_2D, texifmt,
	GST_VIDEO_INFO_WIDTH (&cache->input_info),
	GST_VIDEO_INFO_HEIGHT (&cache->input_info),
	texfmt, GL_UNSIGNED_BYTE, 0, &texture) != kCVReturnSuccess)
	goto error;

	gl_target = gst_gl_texture_target_from_gl (CVOpenGLESTextureGetTarget (texture));
	params = gst_gl_video_allocation_params_new_wrapped_texture (cache->ctx,
	NULL, &cache->input_info, 0, NULL, gl_target,
	CVOpenGLESTextureGetName (texture), texture,
	(GDestroyNotify) CFRelease);

	gst_buffer_replace_memory (output_buffer, 0,
	(GstMemory *) gst_gl_base_memory_alloc (base_mem_alloc,
	(GstGLAllocationParams *) params));
	gst_gl_allocation_params_free ((GstGLAllocationParams *) params);

	textype = gst_gl_texture_type_from_format (cache->ctx, GST_VIDEO_FORMAT_NV12, 1);
	texifmt = gst_gl_format_from_gl_texture_type (textype);
	texfmt = gst_gl_sized_gl_format_from_gl_format_type (cache->ctx, texifmt, GL_UNSIGNED_BYTE);

	if (CVOpenGLESTextureCacheCreateTextureFromImage (kCFAllocatorDefault,
	cache->cache, pixel_buf, NULL, GL_TEXTURE_2D, texifmt,
	GST_VIDEO_INFO_WIDTH (&cache->input_info) / 2,
	GST_VIDEO_INFO_HEIGHT (&cache->input_info) / 2,
	texfmt, GL_UNSIGNED_BYTE, 1, &texture) != kCVReturnSuccess)
	goto error;

	gl_target = gst_gl_texture_target_from_gl (CVOpenGLESTextureGetTarget (texture));
	params = gst_gl_video_allocation_params_new_wrapped_texture (cache->ctx,
	NULL, &cache->input_info, 1, NULL, gl_target,
	CVOpenGLESTextureGetName (texture), texture,
	(GDestroyNotify) CFRelease);

	gst_buffer_replace_memory (output_buffer, 1,
	(GstMemory *) gst_gl_base_memory_alloc (base_mem_alloc,
	(GstGLAllocationParams *) params));
	gst_gl_allocation_params_free ((GstGLAllocationParams *) params);
	break;
	}
	default:
	g_warn_if_reached ();
	goto error;
	}

	gst_object_unref (base_mem_alloc);

	data->output_buffer = output_buffer;

	return;

	error:
	data->output_buffer = NULL;
	}
	#else /* !HAVE_IOS */
	static void
	_do_get_gl_buffer (GstGLContext * context, ContextThreadData * data)
	{
	GstVideoTextureCache *cache = data->cache;
	CVPixelBufferRef pixel_buf = cv_pixel_buffer_from_gst_buffer (data->input_buffer);
	IOSurfaceRef surface = CVPixelBufferGetIOSurface (pixel_buf);

	data->output_buffer = gst_buffer_new ();
	gst_buffer_copy_into (data->output_buffer, data->input_buffer, GST_BUFFER_COPY_ALL, 0, -1);
	for (int i = 0; i < GST_VIDEO_INFO_N_PLANES (&cache->input_info); i++) {
	GstIOSurfaceMemory *mem;

	CFRetain (pixel_buf);
	mem = gst_io_surface_memory_wrapped (cache->ctx,
	surface, GST_GL_TEXTURE_TARGET_RECTANGLE, &cache->input_info,
	i, NULL, pixel_buf, (GDestroyNotify) CFRelease);

	gst_buffer_replace_memory (data->output_buffer, i, (GstMemory *) mem);
	}
	}
	#endif

	GstBuffer *
	gst_video_texture_cache_get_gl_buffer (GstVideoTextureCache * cache,
	GstBuffer * cv_buffer)
	{
	ContextThreadData data = {cache, cv_buffer, NULL};

	gst_gl_context_thread_add (cache->ctx,
	(GstGLContextThreadFunc) _do_get_gl_buffer, &data);

	gst_buffer_unref (cv_buffer);

	return data.output_buffer;
	}