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1 /* GStreamer Wayland video sink
2  *
3  * Copyright (C) 2012 Intel Corporation
4  * Copyright (C) 2012 Sreerenj Balachandran <sreerenj.balachandran@intel.com>
5  * Copyright (C) 2014 Collabora Ltd.
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Library General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Library General Public License for more details.
16  *
17  * You should have received a copy of the GNU Library General Public
18  * License along with this library; if not, write to the
19  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
20  * Boston, MA 02110-1301, USA.
21  */
22 
23 #include "wlshmallocator.h"
24 #include "wlvideoformat.h"
25 
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <errno.h>
30 #include <unistd.h>
31 #include <sys/mman.h>
32 #include <sys/types.h>
33 
34 GST_DEBUG_CATEGORY_EXTERN (gstwayland_debug);
35 #define GST_CAT_DEFAULT gstwayland_debug
36 
37 G_DEFINE_TYPE (GstWlShmAllocator, gst_wl_shm_allocator, GST_TYPE_FD_ALLOCATOR);
38 
39 static GstMemory *
gst_wl_shm_allocator_alloc(GstAllocator * allocator,gsize size,GstAllocationParams * params)40 gst_wl_shm_allocator_alloc (GstAllocator * allocator, gsize size,
41     GstAllocationParams * params)
42 {
43   GstWlShmAllocator *self = GST_WL_SHM_ALLOCATOR (allocator);
44   char filename[1024];
45   static int init = 0;
46   int fd;
47   GstMemory *mem;
48   GstMapInfo info;
49 
50   /* TODO: make use of the allocation params, if necessary */
51 
52 #ifdef HAVE_MEMFD_CREATE
53   fd = memfd_create ("gst-wayland-shm", MFD_CLOEXEC | MFD_ALLOW_SEALING);
54   if (fd >= 0) {
55     /* We can add this seal before calling posix_fallocate(), as
56      * the file is currently zero-sized anyway.
57      *
58      * There is also no need to check for the return value, we
59      * couldn't do anything with it anyway.
60      */
61     fcntl (fd, F_ADD_SEALS, F_SEAL_SHRINK);
62   } else
63 #endif
64   {
65     /* allocate shm pool */
66     snprintf (filename, 1024, "%s/%s-%d-%s", g_get_user_runtime_dir (),
67         "wayland-shm", init++, "XXXXXX");
68 
69     fd = g_mkstemp (filename);
70     if (fd < 0) {
71       GST_ERROR_OBJECT (self, "opening temp file %s failed: %s", filename,
72           strerror (errno));
73       return NULL;
74     }
75 
76     unlink (filename);
77   }
78 
79   if (ftruncate (fd, size) < 0) {
80     GST_ERROR_OBJECT (self, "ftruncate failed: %s", strerror (errno));
81     close (fd);
82     return NULL;
83   }
84 
85   mem = gst_fd_allocator_alloc (allocator, fd, size,
86       GST_FD_MEMORY_FLAG_KEEP_MAPPED);
87   if (G_UNLIKELY (!mem)) {
88     GST_ERROR_OBJECT (self, "GstFdMemory allocation failed");
89     close (fd);
90     return NULL;
91   }
92 
93   /* we need to map the memory in order to unlink the file without losing it */
94   if (!gst_memory_map (mem, &info, GST_MAP_READWRITE)) {
95     GST_ERROR_OBJECT (self, "GstFdMemory map failed");
96     close (fd);
97     return NULL;
98   }
99 
100   /* unmap will not really munmap(), we just
101    * need it to release the miniobject lock */
102   gst_memory_unmap (mem, &info);
103 
104   return mem;
105 }
106 
107 static void
gst_wl_shm_allocator_class_init(GstWlShmAllocatorClass * klass)108 gst_wl_shm_allocator_class_init (GstWlShmAllocatorClass * klass)
109 {
110   GstAllocatorClass *alloc_class = (GstAllocatorClass *) klass;
111 
112   alloc_class->alloc = GST_DEBUG_FUNCPTR (gst_wl_shm_allocator_alloc);
113 }
114 
115 static void
gst_wl_shm_allocator_init(GstWlShmAllocator * self)116 gst_wl_shm_allocator_init (GstWlShmAllocator * self)
117 {
118   GstAllocator *alloc = GST_ALLOCATOR_CAST (self);
119 
120   alloc->mem_type = GST_ALLOCATOR_WL_SHM;
121 
122   GST_OBJECT_FLAG_UNSET (self, GST_ALLOCATOR_FLAG_CUSTOM_ALLOC);
123 }
124 
125 void
gst_wl_shm_allocator_register(void)126 gst_wl_shm_allocator_register (void)
127 {
128   GstAllocator *alloc;
129 
130   alloc = g_object_new (GST_TYPE_WL_SHM_ALLOCATOR, NULL);
131   gst_object_ref_sink (alloc);
132   gst_allocator_register (GST_ALLOCATOR_WL_SHM, alloc);
133 }
134 
135 GstAllocator *
gst_wl_shm_allocator_get(void)136 gst_wl_shm_allocator_get (void)
137 {
138   return gst_allocator_find (GST_ALLOCATOR_WL_SHM);
139 }
140 
141 gboolean
gst_is_wl_shm_memory(GstMemory * mem)142 gst_is_wl_shm_memory (GstMemory * mem)
143 {
144   return gst_memory_is_type (mem, GST_ALLOCATOR_WL_SHM);
145 }
146 
147 /* Copied from gst_v4l2_object_extrapolate_stride() */
148 static gint
gst_wl_shm_extrapolate_stride(const GstVideoFormatInfo * finfo,gint plane,gint stride)149 gst_wl_shm_extrapolate_stride (const GstVideoFormatInfo * finfo, gint plane,
150     gint stride)
151 {
152   gint estride;
153 
154   switch (finfo->format) {
155     case GST_VIDEO_FORMAT_NV12:
156     case GST_VIDEO_FORMAT_NV12_64Z32:
157     case GST_VIDEO_FORMAT_NV21:
158     case GST_VIDEO_FORMAT_NV16:
159     case GST_VIDEO_FORMAT_NV61:
160     case GST_VIDEO_FORMAT_NV24:
161       estride = (plane == 0 ? 1 : 2) *
162           GST_VIDEO_FORMAT_INFO_SCALE_WIDTH (finfo, plane, stride);
163       break;
164     default:
165       estride = GST_VIDEO_FORMAT_INFO_SCALE_WIDTH (finfo, plane, stride);
166       break;
167   }
168 
169   return estride;
170 }
171 
172 static gboolean
gst_wl_shm_validate_video_info(const GstVideoInfo * vinfo)173 gst_wl_shm_validate_video_info (const GstVideoInfo * vinfo)
174 {
175   gint height = GST_VIDEO_INFO_HEIGHT (vinfo);
176   gint base_stride = GST_VIDEO_INFO_PLANE_STRIDE (vinfo, 0);
177   gsize base_offs = GST_VIDEO_INFO_PLANE_OFFSET (vinfo, 0);
178   gint i;
179   gsize offs = 0;
180 
181   for (i = 0; i < GST_VIDEO_INFO_N_PLANES (vinfo); i++) {
182     guint32 estride;
183 
184     /* Overwrite the video info's stride and offset using the pitch calculcated
185      * by the kms driver. */
186     estride = gst_wl_shm_extrapolate_stride (vinfo->finfo, i, base_stride);
187 
188     if (estride != GST_VIDEO_INFO_PLANE_STRIDE (vinfo, i))
189       return FALSE;
190 
191     if (GST_VIDEO_INFO_PLANE_OFFSET (vinfo, i) - base_offs != offs)
192       return FALSE;
193 
194     /* Note that we cannot negotiate special padding betweem each planes,
195      * hence using the display height here. */
196     offs +=
197         estride * GST_VIDEO_FORMAT_INFO_SCALE_HEIGHT (vinfo->finfo, i, height);
198   }
199 
200   if (vinfo->size < offs)
201     return FALSE;
202 
203   return TRUE;
204 }
205 
206 struct wl_buffer *
gst_wl_shm_memory_construct_wl_buffer(GstMemory * mem,GstWlDisplay * display,const GstVideoInfo * info)207 gst_wl_shm_memory_construct_wl_buffer (GstMemory * mem, GstWlDisplay * display,
208     const GstVideoInfo * info)
209 {
210   gint width, height, stride;
211   gsize offset, size, memsize, maxsize;
212   enum wl_shm_format format;
213   struct wl_shm_pool *wl_pool;
214   struct wl_buffer *wbuffer;
215 
216   if (!gst_wl_shm_validate_video_info (info)) {
217     GST_DEBUG_OBJECT (display, "Unsupported strides and offsets.");
218     return NULL;
219   }
220 
221   width = GST_VIDEO_INFO_WIDTH (info);
222   height = GST_VIDEO_INFO_HEIGHT (info);
223   stride = GST_VIDEO_INFO_PLANE_STRIDE (info, 0);
224   size = GST_VIDEO_INFO_SIZE (info);
225   format = gst_video_format_to_wl_shm_format (GST_VIDEO_INFO_FORMAT (info));
226 
227   memsize = gst_memory_get_sizes (mem, &offset, &maxsize);
228   offset += GST_VIDEO_INFO_PLANE_OFFSET (info, 0);
229 
230   g_return_val_if_fail (gst_is_fd_memory (mem), NULL);
231   g_return_val_if_fail (size <= memsize, NULL);
232   g_return_val_if_fail (gst_wl_display_check_format_for_shm (display,
233           GST_VIDEO_INFO_FORMAT (info)), NULL);
234 
235   GST_DEBUG_OBJECT (display, "Creating wl_buffer from SHM of size %"
236       G_GSSIZE_FORMAT " (%d x %d, stride %d), format %s", size, width, height,
237       stride, gst_wl_shm_format_to_string (format));
238 
239   wl_pool = wl_shm_create_pool (display->shm, gst_fd_memory_get_fd (mem),
240       memsize);
241   wbuffer = wl_shm_pool_create_buffer (wl_pool, offset, width, height, stride,
242       format);
243   wl_shm_pool_destroy (wl_pool);
244 
245   return wbuffer;
246 }
247