Android video capture: use new libyuv::Android420ToI420 API for format converting.

media/capture/video/android/video_capture_device_android.cc

Index: media/capture/video/android/video_capture_device_android.cc
diff --git a/media/capture/video/android/video_capture_device_android.cc b/media/capture/video/android/video_capture_device_android.cc
index 320976116830970cf156ff0ea1769fcd97447789..8b815c711899cf4baca2ee6cb8206d618fb27bc4 100644
--- a/media/capture/video/android/video_capture_device_android.cc
+++ b/media/capture/video/android/video_capture_device_android.cc
@@ -15,6 +15,7 @@
 #include "media/capture/video/android/photo_capabilities.h"
 #include "media/capture/video/android/video_capture_device_factory_android.h"
 #include "mojo/public/cpp/bindings/string.h"
+#include "third_party/libyuv/include/libyuv.h"
 
 using base::android::AttachCurrentThread;
 using base::android::CheckException;
@@ -231,6 +232,59 @@ void VideoCaptureDeviceAndroid::OnFrameAvailable(
   env->ReleaseByteArrayElements(data, buffer, JNI_ABORT);
 }
 
+void VideoCaptureDeviceAndroid::OnI420FrameAvailable(JNIEnv* env,
+                                                     jobject obj,
+                                                     jobject y_buffer,
+                                                     jint y_stride,
+                                                     jobject u_buffer,
+                                                     jobject v_buffer,
+                                                     jint uv_row_stride,
+                                                     jint uv_pixel_stride,
+                                                     jint width,
+                                                     jint height,
+                                                     jint rotation) {
+  base::TimeTicks current_time = base::TimeTicks::Now();

[mcasas, 2016/07/19 01:22:58]

nit: const

[braveyao, 2016/07/19 19:06:01]

Done.

+  if (!got_first_frame_) {
+    // Set aside one frame allowance for fluctuation.
+    expected_next_frame_time_ = current_time - frame_interval_;
+    first_ref_time_ = current_time;
+    got_first_frame_ = true;
+  }
+
+  uint8_t* const y_src =
+      reinterpret_cast<uint8_t*>(env->GetDirectBufferAddress(y_buffer));
+  CHECK(y_src);
+  uint8_t* const u_src =
+      reinterpret_cast<uint8_t*>(env->GetDirectBufferAddress(u_buffer));
+  CHECK(u_src);
+  uint8_t* const v_src =
+      reinterpret_cast<uint8_t*>(env->GetDirectBufferAddress(v_buffer));
+  CHECK(v_src);
+
+  const int y_plane_length = width * height;
+  const int uv_plane_length = y_plane_length / 4;
+  const int buffer_length = y_plane_length + uv_plane_length * 2;
+  std::unique_ptr<uint8_t> buffer;
+  buffer.reset(new uint8_t[buffer_length]);

[mcasas, 2016/07/19 01:22:58]

std::unique_ptr<uint8_t[]> buffer(new uint8_t[buffer_length]);

however, consider using an std::array instead.

[braveyao, 2016/07/19 19:06:01]

Done.

Maybe this comment is outdated,
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-dev/zvGR9Ke_kHs.
But it seems no one uses std::array in chromium at present. Leave it for now.

+
+  libyuv::Android420ToI420(y_src, y_stride, u_src, uv_row_stride, v_src,
+                           uv_row_stride, uv_pixel_stride, buffer.get(), width,
+                           buffer.get() + y_plane_length, width / 2,
+                           buffer.get() + y_plane_length + uv_plane_length,
+                           width / 2, width, height);
+
+  // Deliver the frame when it doesn't arrive too early.
+  if (expected_next_frame_time_ <= current_time) {
+    expected_next_frame_time_ += frame_interval_;
+
+    // TODO(qiangchen): Investigate how to get raw timestamp for Android,
+    // rather than using reference time to calculate timestamp.
+    client_->OnIncomingCapturedData(buffer.get(), buffer_length,
+                                    capture_format_, rotation, current_time,
+                                    current_time - first_ref_time_);
+  }
+}
+
 void VideoCaptureDeviceAndroid::OnError(JNIEnv* env,
                                         const JavaParamRef<jobject>& obj,
                                         const JavaParamRef<jstring>& message) {