Add use_v4lplugin flag to enable v4l2 library

third_party/v4l-utils/lib/include/libv4lconvert.h

+/*
+#             (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 __LIBV4LCONVERT_H
+#define __LIBV4LCONVERT_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 :( */
+
+#ifdef linux
+#include <sys/time.h>
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#endif
+
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#endif
+
+/* end broken header workaround includes */
+
+#include <linux/videodev2.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+#if HAVE_VISIBILITY
+#define LIBV4L_PUBLIC __attribute__ ((visibility("default")))
+#else
+#define LIBV4L_PUBLIC
+#endif
+
+struct libv4l_dev_ops;
+struct v4lconvert_data;
+
+LIBV4L_PUBLIC const struct libv4l_dev_ops *v4lconvert_get_default_dev_ops();
+
+LIBV4L_PUBLIC struct v4lconvert_data *v4lconvert_create(int fd);
+LIBV4L_PUBLIC struct v4lconvert_data *v4lconvert_create_with_dev_ops(int fd,
+                void *dev_ops_priv, const struct libv4l_dev_ops *dev_ops);
+LIBV4L_PUBLIC void v4lconvert_destroy(struct v4lconvert_data *data);
+
+/* When doing flipping / rotating / video-processing, only supported
+   destination formats can be used (as flipping / rotating / video-processing
+   is not supported on other formats). This function can be used to query
+   if that is the case. */
+LIBV4L_PUBLIC int v4lconvert_supported_dst_fmt_only(
+                struct v4lconvert_data *data);
+
+/* With regards to dest_fmt just like VIDIOC_TRY_FMT, except that the try
+   format will succeed and return the requested V4L2_PIX_FMT_foo in dest_fmt if
+   the cam has a format from which v4lconvert can convert to dest_fmt.
+   The real format to which the cam should be set is returned through src_fmt
+   when not NULL.
+   Note that just like the real VIDIOC_TRY_FMT this function will change the
+   dest_fmt when not supported. This includes changing it to a supported
+   destination format when trying a native format of the camera and
+   v4lconvert_supported_dst_fmt_only() returns true. */
+LIBV4L_PUBLIC int v4lconvert_try_format(struct v4lconvert_data *data,
+                struct v4l2_format *dest_fmt, /* in / out */
+                struct v4l2_format *src_fmt); /* out */
+
+/* Like VIDIOC_ENUM_FMT, but the emulated formats are added at the end of the
+   list, except if flipping / processing is active for the device, then only
+   supported destination formats are listed */
+LIBV4L_PUBLIC int v4lconvert_enum_fmt(struct v4lconvert_data *data,
+                struct v4l2_fmtdesc *fmt);
+
+/* Is conversion necessary or can the app use the data directly? */
+LIBV4L_PUBLIC int v4lconvert_needs_conversion(struct v4lconvert_data *data,
+                const struct v4l2_format *src_fmt,   /* in */
+                const struct v4l2_format *dest_fmt); /* in */
+
+/* This function does the following conversions:
+    - format conversion
+    - cropping
+   if enabled:
+    - processing (auto whitebalance, auto gain, gamma correction)
+    - horizontal/vertical flipping
+    - 90 degree (clockwise) rotation
+
+   NOTE: the last 3 steps are enabled/disabled depending on
+    - the internal device list
+    - the state of the (software emulated) image controls
+
+   Therefore this function should
+    - not be used when getting the frames from libv4l
+    - be called only once per frame
+   Otherwise this may result in unintended double conversions !
+
+   Returns the amount of bytes written to dest and -1 on error */
+LIBV4L_PUBLIC int v4lconvert_convert(struct v4lconvert_data *data,
+                const struct v4l2_format *src_fmt,  /* in */
+                const struct v4l2_format *dest_fmt, /* in */
+                unsigned char *src, int src_size, unsigned char *dest, int dest_size);
+
+/* get a string describing the last error */
+LIBV4L_PUBLIC const char *v4lconvert_get_error_message(struct v4lconvert_data *data);
+
+/* Just like VIDIOC_ENUM_FRAMESIZE, except that the framesizes of emulated
+   formats can be enumerated as well. */
+LIBV4L_PUBLIC int v4lconvert_enum_framesizes(struct v4lconvert_data *data,
+                struct v4l2_frmsizeenum *frmsize);
+
+/* Just like VIDIOC_ENUM_FRAMEINTERVALS, except that the intervals of emulated
+   formats can be enumerated as well. */
+LIBV4L_PUBLIC int v4lconvert_enum_frameintervals(struct v4lconvert_data *data,
+                struct v4l2_frmivalenum *frmival);
+
+/* Pass calls to query, get and set video controls to the libv4lcontrol class */
+LIBV4L_PUBLIC int v4lconvert_vidioc_queryctrl(struct v4lconvert_data *data,
+                void *arg);
+LIBV4L_PUBLIC int v4lconvert_vidioc_g_ctrl(struct v4lconvert_data *data,
+                void *arg);
+LIBV4L_PUBLIC int v4lconvert_vidioc_s_ctrl(struct v4lconvert_data *data,
+                void *arg);
+LIBV4L_PUBLIC int v4lconvert_vidioc_g_ext_ctrls(struct v4lconvert_data *data,
+                void *arg);
+LIBV4L_PUBLIC int v4lconvert_vidioc_try_ext_ctrls(struct v4lconvert_data *data,
+                void *arg);
+LIBV4L_PUBLIC int v4lconvert_vidioc_s_ext_ctrls(struct v4lconvert_data *data,
+                void *arg);
+
+/* Is the passed in pixelformat supported as destination format? */
+LIBV4L_PUBLIC int v4lconvert_supported_dst_format(unsigned int pixelformat);
+
+/* Get/set the no fps libv4lconvert uses to decide if a compressed format
+   must be used as src fmt to stay within the bus bandwidth */
+LIBV4L_PUBLIC int v4lconvert_get_fps(struct v4lconvert_data *data);
+LIBV4L_PUBLIC void v4lconvert_set_fps(struct v4lconvert_data *data, int fps);
+
+/* Fixup bytesperline and sizeimage for supported destination formats */
+LIBV4L_PUBLIC void v4lconvert_fixup_fmt(struct v4l2_format *fmt);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif