V4L2 VDA/VEA: Use VIDIOC_G/S_SELECTION for accelerators

media/gpu/v4l2_video_decode_accelerator.cc

Index: media/gpu/v4l2_video_decode_accelerator.cc
diff --git a/media/gpu/v4l2_video_decode_accelerator.cc b/media/gpu/v4l2_video_decode_accelerator.cc
index d9e3384ffd6bc4e769f882c9b3f80d8a00547f34..3dd1733ee8b8c53ed7c68051cde0efdac4ad97f1 100644
--- a/media/gpu/v4l2_video_decode_accelerator.cc
+++ b/media/gpu/v4l2_video_decode_accelerator.cc
@@ -2110,17 +2110,31 @@ gfx::Size V4L2VideoDecodeAccelerator::GetVisibleSize(
     const gfx::Size& coded_size) {
   DCHECK(decoder_thread_.task_runner()->BelongsToCurrentThread());
 
-  struct v4l2_crop crop_arg;
-  memset(&crop_arg, 0, sizeof(crop_arg));
-  crop_arg.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+  struct v4l2_rect* ioctl_rect = NULL;

[wuchengli, 2017/06/29 07:55:22]

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

+  struct v4l2_selection selection_arg;
+  memset(&selection_arg, 0, sizeof(selection_arg));
+  selection_arg.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+  selection_arg.target = V4L2_SEL_TGT_COMPOSE;
 
-  if (device_->Ioctl(VIDIOC_G_CROP, &crop_arg) != 0) {
-    PLOGF(ERROR) << "ioctl() VIDIOC_G_CROP failed";
-    return coded_size;
+  if (device_->Ioctl(VIDIOC_G_SELECTION, &selection_arg) == 0) {
+    ioctl_rect = &selection_arg.r;
+  }

[wuchengli, 2017/06/29 07:55:22]

if (device_->Ioctl(VIDIOC_G_SELECTION, &selection_arg) == 0) {
} else {
  CROP
}

+
+  if (ioctl_rect == NULL) {
+    VLOGF(2) << "Fallback to VIDIOC_G_CROP";
+    struct v4l2_crop crop_arg;
+    memset(&crop_arg, 0, sizeof(crop_arg));
+    crop_arg.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE;
+
+    if (device_->Ioctl(VIDIOC_G_CROP, &crop_arg) != 0) {
+      PLOGF(ERROR) << "ioctl() VIDIOC_G_CROP failed";
+      return coded_size;
+    }
+    ioctl_rect = &crop_arg.c;
   }
 
-  gfx::Rect rect(crop_arg.c.left, crop_arg.c.top, crop_arg.c.width,
-                 crop_arg.c.height);
+  gfx::Rect rect(ioctl_rect->left, ioctl_rect->top, ioctl_rect->width,
+                 ioctl_rect->height);
   VLOGF(2) << "visible rectangle is " << rect.ToString();
   if (!gfx::Rect(coded_size).Contains(rect)) {
     DLOGF(ERROR) << "visible rectangle " << rect.ToString()