VideoCaptureDeviceLinux: Add support for SPLANE+DMABUF V4L2 type capture

media/video/capture/linux/video_capture_device_factory_linux.cc

Index: media/video/capture/linux/video_capture_device_factory_linux.cc
diff --git a/media/video/capture/linux/video_capture_device_factory_linux.cc b/media/video/capture/linux/video_capture_device_factory_linux.cc
index 966e4f7b90b22f4fa4941755b8996b8a08686890..51746bb7a750de87788864c69e0fe4e7d65751bb 100644
--- a/media/video/capture/linux/video_capture_device_factory_linux.cc
+++ b/media/video/capture/linux/video_capture_device_factory_linux.cc
@@ -11,12 +11,14 @@
 #else
 #include <linux/videodev2.h>
 #endif
+#include <linux/version.h>
 #include <sys/ioctl.h>
 
 #include "base/files/file_enumerator.h"
 #include "base/files/scoped_file.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/strings/stringprintf.h"
+//#include "content/common/gpu/gpu_memory_buffer_factory.h"

[emircan, 2015/05/06 03:06:26]

Can be erased.

[mcasas, 2015/05/06 21:44:42]

Done.

 #if defined(OS_CHROMEOS)
 #include "media/video/capture/linux/video_capture_device_chromeos.h"
 #endif
@@ -183,11 +185,23 @@ void VideoCaptureDeviceFactoryLinux::GetDeviceNames(
          !(cap.capabilities & V4L2_CAP_VIDEO_OUTPUT) &&
          !(cap.capabilities & V4L2_CAP_VIDEO_OUTPUT_MPLANE)) &&
         HasUsableFormats(fd.get(), cap.capabilities)) {
-      device_names->push_back(VideoCaptureDevice::Name(
-          base::StringPrintf("%s", cap.card), unique_id,
+      VideoCaptureDevice::Name::CaptureApiType api_type =
           (cap.capabilities & V4L2_CAP_VIDEO_CAPTURE_MPLANE)
               ? VideoCaptureDevice::Name::V4L2_MULTI_PLANE
-              : VideoCaptureDevice::Name::V4L2_SINGLE_PLANE));
+              : VideoCaptureDevice::Name::V4L2_SINGLE_PLANE;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0)
+      // For SPLANE API, check if we support Dma-Buf based capture.
+      if (api_type == VideoCaptureDevice::Name::V4L2_SINGLE_PLANE) {
+        v4l2_requestbuffers r_buffer = {};
+        r_buffer.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+        r_buffer.memory = V4L2_MEMORY_DMABUF;
+        r_buffer.count = 1u;
+        if (HANDLE_EINTR(ioctl(fd.get(), VIDIOC_REQBUFS, &r_buffer)) >= 0)
+          api_type = VideoCaptureDevice::Name::V4L2_SINGLE_PLANE_DMABUF;
+      }

[emircan, 2015/05/06 03:06:26]

I think, we should also check if the usable "fourcc formats" returned by the
device, corresponds to the configurations supported by Gpu Memory Buffer
abstraction. 
https://code.google.com/p/chromium/codesearch#chromium/src/content/common/gpu...

[mcasas, 2015/05/06 21:44:42]

We still need to figure out indeed where to check
that the platform (not the V4L2) provides what we 
need, but my gut feeling is that it should go into 
the V4L2CaptureDelegate factory; here is all about
listing abstract capabilities.

+#endif
+      device_names->push_back(VideoCaptureDevice::Name(
+          base::StringPrintf("%s", cap.card), unique_id, api_type));
     }
   }
 }