gstreamer/subprojects/gst-plugins-base/gst-libs/gst/gl/egl/gsteglimagecache.c
Philipp Zabel f18d6fcb40 glupload/egl: Extract EGL image cache and make it public
Extract the EGLImage cache from gstglupload.c, place it in a separate
source file gsteglimagecache.c, and make the API public, so it can be
reused by the gldownload element.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6792>
2024-11-28 15:25:28 -05:00

201 lines
5.6 KiB
C

/*
* GStreamer
* Copyright (C) 2024 Pengutronix, Philipp Zabel <graphics@pengutronix.de>
*
* 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
#include "gsteglimage.h"
#include "gsteglimage_private.h"
#include "gsteglimagecache.h"
struct _GstEGLImageCacheEntry
{
GstEGLImage *eglimage[GST_VIDEO_MAX_PLANES];
};
struct _GstEGLImageCache
{
gint ref_count;
GHashTable *hash_table; /* for GstMemory -> GstEGLImageCacheEntry lookup */
GMutex lock; /* protects hash_table */
};
/**
* gst_egl_image_cache_ref:
* @cache: a #GstEGLImageCache.
*
* Increases the refcount of the given image cache by one.
*
* Returns: (transfer full): @cache
*
* Since: 1.26
*/
GstEGLImageCache *
gst_egl_image_cache_ref (GstEGLImageCache * cache)
{
g_atomic_int_inc (&cache->ref_count);
return cache;
}
/**
* gst_egl_image_cache_unref:
* @cache: (transfer full): a #GstEGLImageCache.
*
* Decreases the refcount of the image cache. If the refcount reaches 0, the
* image cache will be freed and all cached images will be unreffed.
*
* Since: 1.26
*/
void
gst_egl_image_cache_unref (GstEGLImageCache * cache)
{
if (g_atomic_int_dec_and_test (&cache->ref_count)) {
g_hash_table_unref (cache->hash_table);
g_mutex_clear (&cache->lock);
g_free (cache);
}
}
static void
gst_egl_image_cache_entry_remove (GstEGLImageCache * cache, GstMiniObject * mem)
{
g_mutex_lock (&cache->lock);
g_hash_table_remove (cache->hash_table, mem);
g_mutex_unlock (&cache->lock);
gst_egl_image_cache_unref (cache);
}
static GstEGLImageCacheEntry *
gst_egl_image_cache_entry_add (GstEGLImageCache * cache, GstMemory * mem)
{
GstEGLImageCacheEntry *cache_entry;
cache_entry = g_new0 (GstEGLImageCacheEntry, 1);
gst_egl_image_cache_ref (cache);
gst_mini_object_weak_ref (GST_MINI_OBJECT (mem),
(GstMiniObjectNotify) gst_egl_image_cache_entry_remove, cache);
g_mutex_lock (&cache->lock);
g_hash_table_insert (cache->hash_table, mem, cache_entry);
g_mutex_unlock (&cache->lock);
return cache_entry;
}
/*
* Called with the cache lock taken.
*/
static void
gst_egl_image_cache_entry_free (GstEGLImageCacheEntry * cache_entry)
{
gint i;
for (i = 0; i < GST_VIDEO_MAX_PLANES; i++) {
if (cache_entry->eglimage[i])
gst_egl_image_unref (cache_entry->eglimage[i]);
}
g_free (cache_entry);
}
/**
* gst_egl_image_cache_lookup:
* @cache: a #GstEGLImageCache.
* @mem: a #GstMemory to look a cached #GetEGLImage up for
* @plane: the plane to select which cached #GstEGLImage to look up for @mem
* @previous_mem:
* @cache_entry:
*
* Looks up a @cache_entry for @mem if mem is different from @previous_mem.
* If @mem is the same as @previous_mem, the costly lookup is skipped and the
* provided (previous) @cache_entry is used instead. In this case, @cache_entry
* must have been returned by a previous call of @gst_egl_image_cache_lookup
* with the same @mem.
*
* Returns: (nullable): a cached #GstEGLImage for @mem and @plane or %NULL.
* @previous_mem is set to @mem.
*
* Since: 1.26
*/
GstEGLImage *
gst_egl_image_cache_lookup (GstEGLImageCache * cache, GstMemory * mem,
gint plane, GstMemory ** previous_mem, GstEGLImageCacheEntry ** cache_entry)
{
if (mem != *previous_mem) {
g_mutex_lock (&cache->lock);
*cache_entry = g_hash_table_lookup (cache->hash_table, mem);
g_mutex_unlock (&cache->lock);
*previous_mem = mem;
}
if (*cache_entry)
return (*cache_entry)->eglimage[plane];
return NULL;
}
/**
* gst_egl_image_cache_store:
* @cache: a #GstEGLImageCache.
* @mem: a #GstMemory to store @eglimage for
* @plane: the plane slot to store @eglimage in
* @eglimage: a #GstEGLImage to be cached for @mem and @plane
* @cache_entry: a #GstEGLImageCacheEntry looked up for @mem, or %NULL
*
* Creates a new cache_entry for mem if no cache_entry is provided.
* Stores the eglimage for the given plane in the cache_entry. If an
* existing cache entry is provided, it must be returned by a
* @gst_egl_image_cache_lookup call with the same @mem.
*
* Since: 1.26
*/
void
gst_egl_image_cache_store (GstEGLImageCache * cache, GstMemory * mem,
gint plane, GstEGLImage * eglimage, GstEGLImageCacheEntry ** cache_entry)
{
if (!(*cache_entry))
*cache_entry = gst_egl_image_cache_entry_add (cache, mem);
(*cache_entry)->eglimage[plane] = eglimage;
}
/**
* gst_egl_image_cache_new:
*
* Creates an EGL image cache that holds references to EGL images
* until the cache is freed. Each cache entry can be looked up by
* GstMemory and holds one or more EGL images derived from it.
*
* Returns: (nullable): an empty #GstEGLImageCache or %NULL on failure
*
* Since: 1.26
*/
GstEGLImageCache *
gst_egl_image_cache_new (void)
{
GstEGLImageCache *cache;
cache = g_new0 (GstEGLImageCache, 1);
cache->ref_count = 1;
cache->hash_table = g_hash_table_new_full (g_direct_hash, g_direct_equal,
NULL, (GDestroyNotify) gst_egl_image_cache_entry_free);
g_mutex_init (&cache->lock);
return cache;
}