extensions/browser/api/webcam_private/v4l2_webcam.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "extensions/browser/api/webcam_private/v4l2_webcam.h"
   6
   7 #include <fcntl.h>
   8 #include <linux/uvcvideo.h>
   9 #include <linux/videodev2.h>
  10 #include <stdio.h>
  11 #include <sys/ioctl.h>
  12 #include <unistd.h>
  13
  14 #include "base/posix/eintr_wrapper.h"
  15
  16 #define V4L2_CID_PAN_SPEED (V4L2_CID_CAMERA_CLASS_BASE+32)
  17 #define V4L2_CID_TILT_SPEED (V4L2_CID_CAMERA_CLASS_BASE+33)
  18 #define V4L2_CID_PANTILT_CMD (V4L2_CID_CAMERA_CLASS_BASE+34)
  19
  20 // GUID of the Extension Unit for Logitech CC3300e motor control:
  21 // {212de5ff-3080-2c4e-82d9-f587d00540bd}
  22 #define UVC_GUID_LOGITECH_CC3000E_MOTORS          \
  23  {0x21, 0x2d, 0xe5, 0xff, 0x30, 0x80, 0x2c, 0x4e, \
  24   0x82, 0xd9, 0xf5, 0x87, 0xd0, 0x05, 0x40, 0xbd}
  25
  26 #define LOGITECH_MOTORCONTROL_PANTILT_CMD 2
  27
  28 namespace {
  29 const int kLogitechMenuIndexGoHome = 2;
  30
  31 const uvc_menu_info kLogitechCmdMenu[] = {
  32   {1, "Set Preset"}, {2, "Get Preset"}, {3, "Go Home"}
  33 };
  34
  35 const uvc_xu_control_mapping kLogitechCmdMapping = {
  36   V4L2_CID_PANTILT_CMD,
  37   "Pan/Tilt Go",
  38   UVC_GUID_LOGITECH_CC3000E_MOTORS,
  39   LOGITECH_MOTORCONTROL_PANTILT_CMD,
  40   8,
  41   0,
  42   V4L2_CTRL_TYPE_MENU,
  43   UVC_CTRL_DATA_TYPE_ENUM,
  44   const_cast<uvc_menu_info*>(&kLogitechCmdMenu[0]),
  45   arraysize(kLogitechCmdMenu),
  46 };
  47 }  // namespace
  48
  49 namespace extensions {
  50
  51 V4L2Webcam::V4L2Webcam(const std::string& device_id) : device_id_(device_id) {
  52 }
  53
  54 V4L2Webcam::~V4L2Webcam() {
  55 }
  56
  57 bool V4L2Webcam::Open() {
  58   fd_.reset(HANDLE_EINTR(open(device_id_.c_str(), 0)));
  59   return fd_.is_valid();
  60 }
  61
  62 bool V4L2Webcam::EnsureLogitechCommandsMapped() {
  63   int res =
  64       HANDLE_EINTR(ioctl(fd_.get(), UVCIOC_CTRL_MAP, &kLogitechCmdMapping));
  65   // If mapping is successful or it's already mapped, this is a Logitech
  66   // camera.
  67   // NOTE: On success, occasionally EFAULT is returned.  On a real error,
  68   // ENOMEM, EPERM, EINVAL, or EOVERFLOW should be returned.
  69   return res >= 0 || errno == EEXIST || errno == EFAULT;
  70 }
  71
  72 bool V4L2Webcam::SetWebcamParameter(int fd, uint32_t control_id, int value) {
  73   struct v4l2_control v4l2_ctrl = {control_id, value};
  74   int res = HANDLE_EINTR(ioctl(fd, VIDIOC_S_CTRL, &v4l2_ctrl)) >= 0;
  75   return res >= 0;
  76 }
  77
  78 bool V4L2Webcam::GetWebcamParameter(int fd, uint32_t control_id, int* value) {
  79   struct v4l2_control v4l2_ctrl = {control_id};
  80
  81   if (HANDLE_EINTR(ioctl(fd, VIDIOC_G_CTRL, &v4l2_ctrl)))
  82     return false;
  83
  84   *value = v4l2_ctrl.value;
  85   return true;
  86 }
  87
  88 void V4L2Webcam::Reset(bool pan, bool tilt, bool zoom) {
  89   if (pan || tilt) {
  90     if (EnsureLogitechCommandsMapped()) {
  91       SetWebcamParameter(fd_.get(), V4L2_CID_PANTILT_CMD,
  92                          kLogitechMenuIndexGoHome);
  93     } else {
  94       if (pan) {
  95         struct v4l2_control v4l2_ctrl = {V4L2_CID_PAN_RESET};
  96         HANDLE_EINTR(ioctl(fd_.get(), VIDIOC_S_CTRL, &v4l2_ctrl));
  97       }
  98
  99       if (tilt) {
 100         struct v4l2_control v4l2_ctrl = {V4L2_CID_TILT_RESET};
 101         HANDLE_EINTR(ioctl(fd_.get(), VIDIOC_S_CTRL, &v4l2_ctrl));
 102       }
 103     }
 104   }
 105
 106   if (zoom) {
 107     const int kDefaultZoom = 100;
 108     SetWebcamParameter(fd_.get(), V4L2_CID_ZOOM_ABSOLUTE, kDefaultZoom);
 109   }
 110 }
 111
 112 bool V4L2Webcam::GetPan(int* value) {
 113   return GetWebcamParameter(fd_.get(), V4L2_CID_PAN_ABSOLUTE, value);
 114 }
 115
 116 bool V4L2Webcam::GetTilt(int* value) {
 117   return GetWebcamParameter(fd_.get(), V4L2_CID_TILT_ABSOLUTE, value);
 118 }
 119
 120 bool V4L2Webcam::GetZoom(int* value) {
 121   return GetWebcamParameter(fd_.get(), V4L2_CID_ZOOM_ABSOLUTE, value);
 122 }
 123
 124 bool V4L2Webcam::SetPan(int value) {
 125   return SetWebcamParameter(fd_.get(), V4L2_CID_PAN_ABSOLUTE, value);
 126 }
 127
 128 bool V4L2Webcam::SetTilt(int value) {
 129   return SetWebcamParameter(fd_.get(), V4L2_CID_TILT_ABSOLUTE, value);
 130 }
 131
 132 bool V4L2Webcam::SetZoom(int value) {
 133   return SetWebcamParameter(fd_.get(), V4L2_CID_ZOOM_ABSOLUTE, value);
 134 }
 135
 136 bool V4L2Webcam::SetPanDirection(PanDirection direction) {
 137   int direction_value = 0;
 138   switch (direction) {
 139     case PAN_STOP:
 140       direction_value = 0;
 141       break;
 142
 143     case PAN_RIGHT:
 144       direction_value = 1;
 145       break;
 146
 147     case PAN_LEFT:
 148       direction_value = -1;
 149       break;
 150   }
 151   return SetWebcamParameter(fd_.get(), V4L2_CID_PAN_SPEED, direction_value);
 152 }
 153
 154 bool V4L2Webcam::SetTiltDirection(TiltDirection direction) {
 155   int direction_value = 0;
 156   switch (direction) {
 157     case TILT_STOP:
 158       direction_value = 0;
 159       break;
 160
 161     case TILT_UP:
 162       direction_value = 1;
 163       break;
 164
 165     case TILT_DOWN:
 166       direction_value = -1;
 167       break;
 168   }
 169   return SetWebcamParameter(fd_.get(), V4L2_CID_TILT_SPEED, direction_value);
 170 }
 171
 172 }  // namespace extensions