| /* |
| # (C) 2008 Hans de Goede <hdegoede@redhat.com> |
| |
| # 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 Lesser 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., 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA |
| */ |
| |
| #ifndef __LIBV4L2_H |
| #define __LIBV4L2_H |
| |
| #include <stdio.h> |
| #include <unistd.h> |
| #include <stdint.h> |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif /* __cplusplus */ |
| |
| #if HAVE_VISIBILITY |
| #define LIBV4L_PUBLIC __attribute__ ((visibility("default"))) |
| #else |
| #define LIBV4L_PUBLIC |
| #endif |
| |
| /* Point this to a FILE opened for writing when you want to log error and |
| status messages to a file, when NULL errors will get send to stderr */ |
| LIBV4L_PUBLIC extern FILE *v4l2_log_file; |
| |
| /* Just like your regular open/close/etc, except that format conversion is |
| done if necessary when capturing. That is if you (try to) set a capture |
| format which is not supported by the cam, but is supported by libv4lconvert, |
| then the try_fmt / set_fmt will succeed as if the cam supports the format |
| and on dqbuf / read the data will be converted for you and returned in |
| the request format. enum_fmt will also report support for the formats to |
| which conversion is possible. |
| |
| Another difference is that you can make v4l2_read() calls even on devices |
| which do not support the regular read() method. |
| |
| Note the device name passed to v4l2_open must be of a video4linux2 device, |
| if it is anything else (including a video4linux1 device), v4l2_open will |
| fail. |
| |
| Note that the argument to v4l2_ioctl after the request must be a valid |
| memory address of structure of the appropriate type for the request (for |
| v4l2 requests which expect a structure address). Passing in NULL or an |
| invalid memory address will not lead to failure with errno being EFAULT, |
| as it would with a real ioctl, but will cause libv4l2 to break, and you |
| get to keep both pieces. |
| */ |
| |
| LIBV4L_PUBLIC int v4l2_open(const char *file, int oflag, ...); |
| LIBV4L_PUBLIC int v4l2_close(int fd); |
| LIBV4L_PUBLIC int v4l2_dup(int fd); |
| LIBV4L_PUBLIC int v4l2_ioctl(int fd, unsigned long int request, ...); |
| LIBV4L_PUBLIC ssize_t v4l2_read(int fd, void *buffer, size_t n); |
| LIBV4L_PUBLIC ssize_t v4l2_write(int fd, const void *buffer, size_t n); |
| LIBV4L_PUBLIC void *v4l2_mmap(void *start, size_t length, int prot, int flags, |
| int fd, int64_t offset); |
| LIBV4L_PUBLIC int v4l2_munmap(void *_start, size_t length); |
| |
| |
| /* Misc utility functions */ |
| |
| /* This function takes a value of 0 - 65535, and then scales that range to |
| the actual range of the given v4l control id, and then if the cid exists |
| and is not locked sets the cid to the scaled value. |
| |
| Normally returns 0, even if the cid did not exist or was locked, returns |
| non 0 when an other error occured. */ |
| LIBV4L_PUBLIC int v4l2_set_control(int fd, int cid, int value); |
| |
| /* This function returns a value of 0 - 65535, scaled to from the actual range |
| of the given v4l control id. When the cid does not exist, or could not be |
| accessed -1 is returned. */ |
| LIBV4L_PUBLIC int v4l2_get_control(int fd, int cid); |
| |
| |
| /* "low level" access functions, these functions allow somewhat lower level |
| access to libv4l2 (currently there only is v4l2_fd_open here) */ |
| |
| /* Flags for v4l2_fd_open's v4l2_flags argument */ |
| |
| /* Disable all format conversion done by libv4l2, this includes the software |
| whitebalance, gamma correction, flipping, etc. libv4lconvert does. Use this |
| if you want raw frame data, but still want the additional error checks and |
| the read() emulation libv4l2 offers. */ |
| #define V4L2_DISABLE_CONVERSION 0x01 |
| /* This flag is *OBSOLETE*, since version 0.5.98 libv4l *always* reports |
| emulated formats to ENUM_FMT, except when conversion is disabled. */ |
| #define V4L2_ENABLE_ENUM_FMT_EMULATION 0x02 |
| |
| /* v4l2_fd_open: open an already opened fd for further use through |
| v4l2lib and possibly modify libv4l2's default behavior through the |
| v4l2_flags argument. |
| |
| Returns fd on success, -1 if the fd is not suitable for use through libv4l2 |
| (note the fd is left open in this case). */ |
| LIBV4L_PUBLIC int v4l2_fd_open(int fd, int v4l2_flags); |
| |
| #ifdef __cplusplus |
| } |
| #endif /* __cplusplus */ |
| |
| #endif |