gstreamer/subprojects/gst-plugins-bad/gst-libs/gst/wayland/gstwlshmallocator.c
Robert Mader 8c3e33d494 gstwayland: Move reusable parts of the waylandsink into a library
In preparation for the new element `GstGtkWaylandSink`, move reusable
parts out of `GstWaylandSink` into the already exisiting but very
barebone library.

Notable changes include:
 - the `GstWaylandVideo` interface was dropped
 - support for `wl-shell` was dropped
 - lots of renaming in order to match established naming patterns
 - lots of code modernisations, reducing boilerplate
 - members were made private wherever possible

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2479>
2022-06-06 14:36:39 +02:00

235 lines
6.6 KiB
C

/* GStreamer Wayland Library
*
* Copyright (C) 2012 Intel Corporation
* Copyright (C) 2012 Sreerenj Balachandran <sreerenj.balachandran@intel.com>
* Copyright (C) 2014 Collabora Ltd.
*
* 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 "gstwlshmallocator.h"
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#define GST_CAT_DEFAULT gst_wl_shm_debug
GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);
G_DEFINE_TYPE_WITH_CODE (GstWlShmAllocator, gst_wl_shm_allocator,
GST_TYPE_FD_ALLOCATOR,
GST_DEBUG_CATEGORY_INIT (gst_wl_shm_debug, "wlshm", 0, "wlshm library");
);
static GstMemory *
gst_wl_shm_allocator_alloc (GstAllocator * allocator, gsize size,
GstAllocationParams * params)
{
GstWlShmAllocator *self = GST_WL_SHM_ALLOCATOR (allocator);
char filename[1024];
static int init = 0;
int fd;
GstMemory *mem;
GstMapInfo info;
/* TODO: make use of the allocation params, if necessary */
#ifdef HAVE_MEMFD_CREATE
fd = memfd_create ("gst-wayland-shm", MFD_CLOEXEC | MFD_ALLOW_SEALING);
if (fd >= 0) {
/* We can add this seal before calling posix_fallocate(), as
* the file is currently zero-sized anyway.
*
* There is also no need to check for the return value, we
* couldn't do anything with it anyway.
*/
fcntl (fd, F_ADD_SEALS, F_SEAL_SHRINK);
} else
#endif
{
/* allocate shm pool */
snprintf (filename, 1024, "%s/%s-%d-%s", g_get_user_runtime_dir (),
"wayland-shm", init++, "XXXXXX");
fd = g_mkstemp (filename);
if (fd < 0) {
GST_ERROR_OBJECT (self, "opening temp file %s failed: %s", filename,
strerror (errno));
return NULL;
}
unlink (filename);
}
if (ftruncate (fd, size) < 0) {
GST_ERROR_OBJECT (self, "ftruncate failed: %s", strerror (errno));
close (fd);
return NULL;
}
mem = gst_fd_allocator_alloc (allocator, fd, size,
GST_FD_MEMORY_FLAG_KEEP_MAPPED);
if (G_UNLIKELY (!mem)) {
GST_ERROR_OBJECT (self, "GstFdMemory allocation failed");
close (fd);
return NULL;
}
/* we need to map the memory in order to unlink the file without losing it */
if (!gst_memory_map (mem, &info, GST_MAP_READWRITE)) {
GST_ERROR_OBJECT (self, "GstFdMemory map failed");
close (fd);
return NULL;
}
/* unmap will not really munmap(), we just
* need it to release the miniobject lock */
gst_memory_unmap (mem, &info);
return mem;
}
static void
gst_wl_shm_allocator_class_init (GstWlShmAllocatorClass * klass)
{
GstAllocatorClass *alloc_class = (GstAllocatorClass *) klass;
alloc_class->alloc = GST_DEBUG_FUNCPTR (gst_wl_shm_allocator_alloc);
}
static void
gst_wl_shm_allocator_init (GstWlShmAllocator * self)
{
GstAllocator *alloc = GST_ALLOCATOR_CAST (self);
alloc->mem_type = GST_ALLOCATOR_WL_SHM;
GST_OBJECT_FLAG_UNSET (self, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC);
}
void
gst_wl_shm_allocator_init_once (void)
{
static gsize _init = 0;
if (g_once_init_enter (&_init)) {
GstAllocator *alloc;
alloc = g_object_new (GST_TYPE_WL_SHM_ALLOCATOR, NULL);
gst_object_ref_sink (alloc);
gst_allocator_register (GST_ALLOCATOR_WL_SHM, alloc);
g_once_init_leave (&_init, 1);
}
}
GstAllocator *
gst_wl_shm_allocator_get (void)
{
return gst_allocator_find (GST_ALLOCATOR_WL_SHM);
}
gboolean
gst_is_wl_shm_memory (GstMemory * mem)
{
return gst_memory_is_type (mem, GST_ALLOCATOR_WL_SHM);
}
static gboolean
gst_wl_shm_validate_video_info (const GstVideoInfo * vinfo)
{
gint height = GST_VIDEO_INFO_HEIGHT (vinfo);
gint base_stride = GST_VIDEO_INFO_PLANE_STRIDE (vinfo, 0);
gsize base_offs = GST_VIDEO_INFO_PLANE_OFFSET (vinfo, 0);
gint i;
gsize offs = 0;
for (i = 0; i < GST_VIDEO_INFO_N_PLANES (vinfo); i++) {
guint32 estride;
/* Overwrite the video info's stride and offset using the pitch calculcated
* by the kms driver. */
estride = gst_video_format_info_extrapolate_stride (vinfo->finfo, i,
base_stride);
if (estride != GST_VIDEO_INFO_PLANE_STRIDE (vinfo, i))
return FALSE;
if (GST_VIDEO_INFO_PLANE_OFFSET (vinfo, i) - base_offs != offs)
return FALSE;
/* Note that we cannot negotiate special padding betweem each planes,
* hence using the display height here. */
offs +=
estride * GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (vinfo->finfo, i, height);
}
if (vinfo->size < offs)
return FALSE;
return TRUE;
}
struct wl_buffer *
gst_wl_shm_memory_construct_wl_buffer (GstMemory * mem, GstWlDisplay * display,
const GstVideoInfo * info)
{
gint width, height, stride;
gsize offset, size, memsize, maxsize;
enum wl_shm_format format;
struct wl_shm_pool *wl_pool;
struct wl_buffer *wbuffer;
if (!gst_wl_shm_validate_video_info (info)) {
GST_DEBUG_OBJECT (display, "Unsupported strides and offsets.");
return NULL;
}
width = GST_VIDEO_INFO_WIDTH (info);
height = GST_VIDEO_INFO_HEIGHT (info);
stride = GST_VIDEO_INFO_PLANE_STRIDE (info, 0);
size = GST_VIDEO_INFO_SIZE (info);
format = gst_video_format_to_wl_shm_format (GST_VIDEO_INFO_FORMAT (info));
memsize = gst_memory_get_sizes (mem, &offset, &maxsize);
offset += GST_VIDEO_INFO_PLANE_OFFSET (info, 0);
g_return_val_if_fail (gst_is_fd_memory (mem), NULL);
g_return_val_if_fail (size <= memsize, NULL);
g_return_val_if_fail (gst_wl_display_check_format_for_shm (display,
GST_VIDEO_INFO_FORMAT (info)), NULL);
GST_DEBUG_OBJECT (display, "Creating wl_buffer from SHM of size %"
G_GSSIZE_FORMAT " (%d x %d, stride %d), format %s", size, width, height,
stride, gst_wl_shm_format_to_string (format));
wl_pool = wl_shm_create_pool (gst_wl_display_get_shm (display),
gst_fd_memory_get_fd (mem), memsize);
wbuffer = wl_shm_pool_create_buffer (wl_pool, offset, width, height, stride,
format);
wl_shm_pool_destroy (wl_pool);
return wbuffer;
}