Fix CaptureMjpeg test may fail on devices that cannot capture MJPEG.

media/video/capture/video_capture_device_unittest.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 "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/run_loop.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/test/test_timeouts.h"
@@ skipping 110 matching lines @@
     run_loop_->QuitClosure().Run();
   }
 
   void WaitForCapturedFrame() {
     run_loop_.reset(new base::RunLoop());
     run_loop_->Run();
   }
 
   const VideoCaptureFormat& last_format() const { return last_format_; }
 
+  scoped_ptr<VideoCaptureDevice::Name> GetRquestedPixelFormatDeviceName(

[Ami GONE FROM CHROMIUM, 2014/04/07 17:14:17]

typo: GetRquestedPixelFormatDeviceName

[Ami GONE FROM CHROMIUM, 2014/04/07 17:14:17]

This function's name is a bit convoluted, and "requested" doesn't seem to be
adding value.  WDYT of GetFirstDeviceNameSupportingPixelFormat() and
"pixel_format" for the param?

[yuli, 2014/04/08 07:42:54]

Done.

+      const VideoPixelFormat& requested_pixel_format) {
+    VideoCaptureDevice::GetDeviceNames(&names_);
+    if (!names_.size()) {
+      DVLOG(1) << "No camera available.";
+      return scoped_ptr<VideoCaptureDevice::Name>();
+    }
+    VideoCaptureFormats supported_formats;
+    VideoCaptureDevice::Names::iterator names_iterator;
+    for (names_iterator = names_.begin(); names_iterator != names_.end();
+         ++names_iterator) {
+      VideoCaptureDevice::GetDeviceSupportedFormats(*names_iterator,

[Ami GONE FROM CHROMIUM, 2014/04/07 17:14:17]

This doesn't specify that it clears its output argument, so you should move
l.138 to l.142 (inside the loop) or else clear it explicitly).

[yuli, 2014/04/08 07:42:54]

Done.

+                                                    &supported_formats);
+      VideoCaptureFormats::iterator formats_iterator;
+      for (formats_iterator = supported_formats.begin();
+           formats_iterator != supported_formats.end(); ++formats_iterator) {
+        if (formats_iterator->pixel_format == requested_pixel_format) {
+          return scoped_ptr<VideoCaptureDevice::Name>(
+              new VideoCaptureDevice::Name(*names_iterator));
+        }
+      }
+    }
+    DVLOG(1) << "No camera can capture the requested pixel format.";

[Ami GONE FROM CHROMIUM, 2014/04/07 17:14:17]

DVLOG(1) << "No camera can capture " << requested_pixel_format;

[yuli, 2014/04/08 07:42:54]

Done.

+    return scoped_ptr<VideoCaptureDevice::Name>();
+  }
+
 #if defined(OS_WIN)
   base::win::ScopedCOMInitializer initialize_com_;
 #endif
   VideoCaptureDevice::Names names_;
   scoped_ptr<base::MessageLoop> loop_;
   scoped_ptr<base::RunLoop> run_loop_;
   scoped_ptr<MockClient> client_;
   VideoCaptureFormat last_format_;
 };
 
@@ skipping 184 matching lines @@
   device->AllocateAndStart(capture_params, client_.PassAs<Client>());
   WaitForCapturedFrame();
   EXPECT_EQ(last_format().frame_size.width(), 640);
   EXPECT_EQ(last_format().frame_size.height(), 480);
   EXPECT_EQ(last_format().frame_rate, 30);
   device->StopAndDeAllocate();
 }
 
 // Start the camera in 720p to capture MJPEG instead of a raw format.
 TEST_F(VideoCaptureDeviceTest, MAYBE_CaptureMjpeg) {
-  VideoCaptureDevice::GetDeviceNames(&names_);
-  if (!names_.size()) {
-    DVLOG(1) << "No camera available. Exiting test.";
+  scoped_ptr<VideoCaptureDevice::Name> name = GetRquestedPixelFormatDeviceName(
+      PIXEL_FORMAT_MJPEG);
+  if (name.get() == NULL) {
+    DVLOG(1) << "No camera supports MJPEG format. Exiting test.";
     return;
   }
-  scoped_ptr<VideoCaptureDevice> device(
-      VideoCaptureDevice::Create(names_.front()));
+  scoped_ptr<VideoCaptureDevice> device(VideoCaptureDevice::Create(*name));
   ASSERT_TRUE(device.get() != NULL);
 
   EXPECT_CALL(*client_, OnErr())
       .Times(0);
 
   VideoCaptureParams capture_params;
   capture_params.requested_format.frame_size.SetSize(1280, 720);
   capture_params.requested_format.frame_rate = 30;
   capture_params.requested_format.pixel_format = PIXEL_FORMAT_MJPEG;
   capture_params.allow_resolution_change = false;
   device->AllocateAndStart(capture_params, client_.PassAs<Client>());
   // Get captured video frames.
   WaitForCapturedFrame();
   // Verify we get MJPEG from the device. Not all devices can capture 1280x720
   // @ 30 fps, so we don't care about the exact resolution we get.
   EXPECT_EQ(last_format().pixel_format, PIXEL_FORMAT_MJPEG);
   device->StopAndDeAllocate();
 }
 
 TEST_F(VideoCaptureDeviceTest, GetDeviceSupportedFormats) {
-  VideoCaptureDevice::GetDeviceNames(&names_);
-  if (!names_.size()) {
-    DVLOG(1) << "No camera available. Exiting test.";
-    return;
-  }
-  VideoCaptureFormats supported_formats;
-  VideoCaptureDevice::Names::iterator names_iterator;
-  for (names_iterator = names_.begin(); names_iterator != names_.end();
-       ++names_iterator) {
-    VideoCaptureDevice::GetDeviceSupportedFormats(*names_iterator,
-                                                  &supported_formats);
-    // Nothing to test here since we cannot forecast the hardware capabilities.
-  }
+  // Use PIXEL_FORMAT_MAX to iterate all device names for testing
+  // GetDeviceSupportedFormats().
+  scoped_ptr<VideoCaptureDevice::Name> name = GetRquestedPixelFormatDeviceName(
+      PIXEL_FORMAT_MAX);
+  // Verify no camera returned for PIXEL_FORMAT_MAX. Nothing else to test here
+  // since we cannot forecast the hardware capabilities.
+  ASSERT_TRUE(name.get() == NULL);
 }
 
 TEST_F(VideoCaptureDeviceTest, FakeCaptureVariableResolution) {
   VideoCaptureDevice::Names names;
 
   FakeVideoCaptureDevice::GetDeviceNames(&names);
   VideoCaptureParams capture_params;
   capture_params.requested_format.frame_size.SetSize(640, 480);
   capture_params.requested_format.frame_rate = 30;
   capture_params.requested_format.pixel_format = PIXEL_FORMAT_I420;
@@ skipping 40 matching lines @@
     EXPECT_EQ(supported_formats[1].pixel_format, media::PIXEL_FORMAT_I420);
     EXPECT_GE(supported_formats[1].frame_rate, 20);
     EXPECT_EQ(supported_formats[2].frame_size.width(), 1280);
     EXPECT_EQ(supported_formats[2].frame_size.height(), 720);
     EXPECT_EQ(supported_formats[2].pixel_format, media::PIXEL_FORMAT_I420);
     EXPECT_GE(supported_formats[2].frame_rate, 20);
   }
 }
 
 };  // namespace media