Linux video capture: rotate image if V4L2_IN_ST_VFLIP is set

media/video/capture/linux/video_capture_device_linux.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/video/capture/linux/video_capture_device_linux.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #if defined(OS_OPENBSD)
 #include <sys/videoio.h>
@@ skipping 232 matching lines @@
          0) {
     best = std::find(v4l2_formats.begin(), best, fmtdesc.pixelformat);
     fmtdesc.index++;
   }
 
   if (best == v4l2_formats.end()) {
     SetErrorState("Failed to find a supported camera format.");
     return;
   }
 
+  // Check sensor orientation.
+  struct v4l2_input first_input;
+  first_input.index = 0;  // First input type.
+  if (HANDLE_EINTR(ioctl(device_fd_.get(),
+                         VIDIOC_ENUMINPUT, &first_input)) == 0) {
+    struct v4l2_input second_input;
+    second_input.index = 1;
+    if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_ENUMINPUT,
+                           &second_input)) < 0) {
+      // Only one input type
+      if (first_input.status & V4L2_IN_ST_VFLIP) {
+        DVLOG(1) << "Sensor is flipped vertically, rotating 180 deg.";
+        if (!(first_input.status & V4L2_IN_ST_HFLIP)) {
+          DVLOG(1) << "Sensor is only flipped vertically, "
+                      "image will be mirrored";
+        }
+        SetRotation(180);
+      }
+    } else {
+      // More than one input type, don't try to fix sensor orientation.
+      DVLOG(1) << "Video capture device has more than one input type";
+    }
+  } else {
+    DVLOG(1) << "Failed to enumerate video input";
+  }
+
   // Set format and frame size now.
   v4l2_format video_fmt;
   memset(&video_fmt, 0, sizeof(v4l2_format));
   video_fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
   video_fmt.fmt.pix.sizeimage = 0;
   video_fmt.fmt.pix.width = width;
   video_fmt.fmt.pix.height = height;
   video_fmt.fmt.pix.pixelformat = *best;
 
   if (HANDLE_EINTR(ioctl(device_fd_.get(), VIDIOC_S_FMT, &video_fmt)) < 0) {
@@ skipping 242 matching lines @@
 }
 
 void VideoCaptureDeviceLinux::SetErrorState(const std::string& reason) {
   DCHECK(!v4l2_thread_.IsRunning() ||
          v4l2_thread_.message_loop() == base::MessageLoop::current());
   state_ = kError;
   client_->OnError(reason);
 }
 
 }  // namespace media