Implement V4l2 Allocator

This goal of this allocator is mainly to allow tracking the memory.
Currently, when a buffer memory has been modified, the buffer and it's
memory is disposed and lost until the stream is restarted.

sys/v4l2/Makefile.am

@@ -3,6 +3,7 @@ plugin_LTLIBRARIES = libgstvideo4linux2.la
 include $(top_srcdir)/common/gst-glib-gen.mak
 
 libgstvideo4linux2_la_SOURCES = gstv4l2.c \
+				gstv4l2allocator.c \
 				gstv4l2colorbalance.c \
 				gstv4l2devicemonitor.c \
 				gstv4l2object.c \
@@ -43,6 +44,7 @@ noinst_HEADERS = \
 	ext/v4l2-common.h \
 	ext/v4l2-controls.h \
 	ext/videodev2.h \
+	gstv4l2allocator.h \
 	gstv4l2bufferpool.h \
 	gstv4l2colorbalance.h \
 	gstv4l2devicemonitor.h \

sys/v4l2/gstv4l2allocator.h

+/*
+ * Copyright (C) 2014 Collabora Ltd.
+ *     Author: Nicolas Dufresne <nicolas.dufresne@collabora.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.
+ *
+ */
+
+
+#ifndef __GST_V4L2_ALLOCATOR_H__
+#define __GST_V4L2_ALLOCATOR_H__
+
+#include "ext/videodev2.h"
+#include <gst/gst.h>
+#include <gst/gstatomicqueue.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_V4L2_ALLOCATOR                 (gst_v4l2_allocator_get_type())
+#define GST_IS_V4L2_ALLOCATOR(obj)              (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_V4L2_ALLOCATOR))
+#define GST_IS_V4L2_ALLOCATOR_CLASS(klass)      (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_V4L2_ALLOCATOR))
+#define GST_V4L2_ALLOCATOR_GET_CLASS(obj)       (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_V4L2_ALLOCATOR, GstV4l2AllocatorClass))
+#define GST_V4L2_ALLOCATOR(obj)                 (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_V4L2_ALLOCATOR, GstV4l2Allocator))
+#define GST_V4L2_ALLOCATOR_CLASS(klass)         (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_V4L2_ALLOCATOR, GstV4l2AllocatorClass))
+#define GST_V4L2_ALLOCATOR_CAST(obj)            ((GstV4l2Allocator *)(obj))
+
+#define GST_V4L2_ALLOCATOR_CAN_REQUEST(obj,type) \
+        (GST_OBJECT_FLAG_IS_SET (obj, GST_V4L2_ALLOCATOR_FLAG_ ## type ## _REQBUFS))
+#define GST_V4L2_ALLOCATOR_CAN_ALLOCATE(obj,type) \
+        (GST_OBJECT_FLAG_IS_SET (obj, GST_V4L2_ALLOCATOR_FLAG_ ## type ## _CREATE_BUF))
+
+typedef struct _GstV4l2Allocator GstV4l2Allocator;
+typedef struct _GstV4l2AllocatorClass GstV4l2AllocatorClass;
+typedef struct _GstV4l2MemoryGroup GstV4l2MemoryGroup;
+typedef struct _GstV4l2Memory GstV4l2Memory;
+typedef enum _GstV4l2Capabilities GstV4l2Capabilities;
+typedef enum _GstV4l2Return GstV4l2Return;
+
+enum _GstV4l2AllocatorFlags
+{
+  GST_V4L2_ALLOCATOR_FLAG_MMAP_REQBUF        = (GST_ALLOCATOR_FLAG_LAST << 0),
+  GST_V4L2_ALLOCATOR_FLAG_MMAP_CREATE_BUF    = (GST_ALLOCATOR_FLAG_LAST << 1),
+  GST_V4L2_ALLOCATOR_FLAG_USERPTR_REQBUF     = (GST_ALLOCATOR_FLAG_LAST << 2),
+  GST_V4L2_ALLOCATOR_FLAG_USERPTR_CREATE_BUF = (GST_ALLOCATOR_FLAG_LAST << 3),
+  GST_V4L2_ALLOCATOR_FLAG_DMABUF_REQBUF      = (GST_ALLOCATOR_FLAG_LAST << 4),
+  GST_V4L2_ALLOCATOR_FLAG_DMABUF_CREATE_BUF  = (GST_ALLOCATOR_FLAG_LAST << 5),
+};
+
+enum _GstV4l2Return
+{
+  GST_V4L2_OK = 0,
+  GST_V4L2_ERROR = -1,
+  GST_V4L2_BUSY = -2
+};
+
+struct _GstV4l2Memory
+{
+  GstMemory mem;
+  gint plane;
+  GstV4l2MemoryGroup *group;
+  gpointer data;
+};
+
+struct _GstV4l2MemoryGroup
+{
+  gint n_mem;
+  GstMemory * mem[VIDEO_MAX_PLANES];
+  gint mems_allocated;
+  struct v4l2_buffer buffer;
+  struct v4l2_plane planes[VIDEO_MAX_PLANES];
+};
+
+struct _GstV4l2Allocator
+{
+  GstAllocator parent;
+  gint video_fd;
+  guint32 count;
+  guint32 type;
+  guint32 memory;
+  struct v4l2_format format;
+  gboolean can_allocate;
+  gboolean active;
+
+  GstV4l2MemoryGroup * groups[VIDEO_MAX_FRAME];
+  GstAtomicQueue *free_queue;
+  GstAtomicQueue *pending_queue;
+
+};
+
+struct _GstV4l2AllocatorClass {
+  GstAllocatorClass parent_class;
+};
+
+GType gst_v4l2_allocator_get_type(void);
+
+gboolean             gst_is_v4l2_memory                (GstMemory * mem);
+
+gboolean             gst_v4l2_allocator_is_active      (GstV4l2Allocator * allocator);
+
+guint                gst_v4l2_allocator_get_size       (GstV4l2Allocator * allocator);
+
+GstV4l2Allocator*    gst_v4l2_allocator_new            (GstObject *parent, gint video_fd,
+                                                        struct v4l2_format * format);
+
+guint                gst_v4l2_allocator_start          (GstV4l2Allocator * allocator,
+                                                        guint32 count, guint32 memory);
+
+gboolean             gst_v4l2_allocator_stop           (GstV4l2Allocator * allocator);
+
+GstV4l2MemoryGroup*  gst_v4l2_allocator_alloc_mmap     (GstV4l2Allocator * allocator);
+
+void                 gst_v4l2_allocator_flush          (GstV4l2Allocator * allocator);
+
+gboolean             gst_v4l2_allocator_qbuf           (GstV4l2Allocator * allocator,
+                                                        GstV4l2MemoryGroup * group);
+
+GstV4l2MemoryGroup*  gst_v4l2_allocator_dqbuf          (GstV4l2Allocator * allocator);
+
+void                 gst_v4l2_allocator_reset_size     (GstV4l2Allocator * allocator,
+                                                        GstV4l2MemoryGroup * group);
+
+G_END_DECLS
+
+#endif /* __GST_V4L2_ALLOCATOR_H__ */

sys/v4l2/v4l2_calls.h

@@ -29,8 +29,10 @@
 #ifdef HAVE_LIBV4L2
 #  include <libv4l2.h>
 #else
-#  include <sys/ioctl.h>
 #  include <linux/videodev2.h>
+#  include <sys/ioctl.h>
+#  include <sys/mman.h>
+#  include <unistd.h>
 #  define v4l2_fd_open(fd, flags) (fd)
 #  define v4l2_close    close
 #  define v4l2_dup      dup