1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
/*
# open/close/ioctl/mmap/munmap library call wrapper doing format conversion
# for v4l2 applications which want to be able to simply capture bgr24 / yuv420
# from v4l2 devices with more exotic frame formats.
# (C) 2008 Hans de Goede <j.w.r.degoede@hhs.nl>
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdarg.h>
#include <stdlib.h>
#include <syscall.h>
#include <fcntl.h>
#include <string.h>
/* These headers are not needed by us, but by linux/videodev2.h,
which is broken on some systems and doesn't include them itself :( */
#include <sys/time.h>
#include <asm/types.h>
#include <linux/ioctl.h>
/* end broken header workaround includes */
#include <linux/videodev2.h>
#include <libv4l2.h>
/* Check that open/read/mmap is not a define */
#if defined open || defined read || defined mmap
#error open/read/mmap is a prepocessor macro !!
#endif
int open (const char *file, int oflag, ...)
{
int fd;
struct v4l2_capability cap;
/* original open code */
if (oflag & O_CREAT)
{
va_list ap;
mode_t mode;
va_start (ap, oflag);
mode = va_arg (ap, mode_t);
fd = syscall(SYS_open, file, oflag, mode);
va_end(ap);
} else
fd = syscall(SYS_open, file, oflag);
/* end of original open code */
if (fd == -1)
return fd;
/* check if we're opening a video4linux2 device */
if (strncmp(file, "/dev/video", 10))
return fd;
/* check that this is an v4l2 device, libv4l2 only supports v4l2 devices */
if (syscall(SYS_ioctl, fd, VIDIOC_QUERYCAP, &cap))
return fd;
/* libv4l2 only adds functionality to capture capable devices */
if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE))
return fd;
/* Try to Register with libv4l2 (in case of failure pass the fd to the
application as is) */
v4l2_fd_open(fd, V4L2_ENABLE_ENUM_FMT_EMULATION);
return fd;
}
int close(int fd)
{
return v4l2_close(fd);
}
int dup(int fd)
{
return v4l2_dup(fd);
}
int ioctl (int fd, unsigned long int request, ...)
{
void *arg;
va_list ap;
va_start (ap, request);
arg = va_arg (ap, void *);
va_end (ap);
return v4l2_ioctl (fd, request, arg);
}
ssize_t read (int fd, void* buffer, size_t n)
{
return v4l2_read (fd, buffer, n);
}
void mmap(void *start, size_t length, int prot, int flags, int fd,
off_t offset)
{
return v4l2_mmap(start, length, prot, flags, fd, offset);
}
int munmap(void *start, size_t length)
{
return v4l2_munmap(start, length);
}
|
