V4L2 VDA/VEA: Use VIDIOC_G/S_SELECTION for accelerators

media/gpu/v4l2_video_encode_accelerator.cc

Index: media/gpu/v4l2_video_encode_accelerator.cc
diff --git a/media/gpu/v4l2_video_encode_accelerator.cc b/media/gpu/v4l2_video_encode_accelerator.cc
index b09b6420a3f14c576831fb43f7ccf520b578eea7..99647613b0230277836d48fae30631869811489a 100644
--- a/media/gpu/v4l2_video_encode_accelerator.cc
+++ b/media/gpu/v4l2_video_encode_accelerator.cc
@@ -1081,19 +1081,39 @@ bool V4L2VideoEncodeAccelerator::SetFormats(VideoPixelFormat input_format,
   if (!NegotiateInputFormat(input_format))
     return false;
 
+  struct v4l2_rect ioctl_rect;

[wuchengli, 2017/06/29 07:55:23]

s/ioctl_rect/visible_rect/. It's more readable.

+  ioctl_rect.left = 0;
+  ioctl_rect.top = 0;
+  ioctl_rect.width = visible_size_.width();
+  ioctl_rect.height = visible_size_.height();
+
+  struct v4l2_selection selection_arg;
+  memset(&selection_arg, 0, sizeof(selection_arg));
+  selection_arg.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
+  selection_arg.target = V4L2_SEL_TGT_CROP;
+  selection_arg.r = ioctl_rect;
+
   struct v4l2_crop crop;
   memset(&crop, 0, sizeof(crop));
   crop.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;
-  crop.c.left = 0;
-  crop.c.top = 0;
-  crop.c.width = visible_size_.width();
-  crop.c.height = visible_size_.height();
-  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_S_CROP, &crop);
+
+  if (device_->Ioctl(VIDIOC_S_SELECTION, &selection_arg) != 0) {

[wuchengli, 2017/06/29 07:55:23]

if (device_->Ioctl(VIDIOC_S_SELECTION, &selection_arg) == 0) {
  G_SELECTION
} else {
  S_CROP
  G_CROP
}

We don't need to support the case of one selection and one crop. A driver should
either support selection and crop. They don't mix and match.

+    VLOG(2) << "Fallback to VIDIOC_S_CROP";

[wuchengli, 2017/06/29 07:55:23]

DVLOG

+    crop.c = ioctl_rect;
+    IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_S_CROP, &crop);
+  }
 
   // The width and height might be adjusted by driver.
   // Need to read it back and set to visible_size_.
-  IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_G_CROP, &crop);
-  visible_size_.SetSize(crop.c.width, crop.c.height);
+  if (device_->Ioctl(VIDIOC_G_SELECTION, &selection_arg) == 0) {
+    ioctl_rect = selection_arg.r;
+  }
+  else {
+    VLOG(2) << "Fallback to VIDIOC_G_CROP";

[wuchengli, 2017/06/29 07:55:23]

DVLOG

+    IOCTL_OR_ERROR_RETURN_FALSE(VIDIOC_G_CROP, &crop);
+    ioctl_rect = crop.c;
+  }
+  visible_size_.SetSize(ioctl_rect.width, ioctl_rect.height);
   DVLOG(3) << "After adjusted by driver, visible_size_="
            << visible_size_.ToString();