media/capture: Adding WebmMuxer class and unittests

media/capture/webm_muxer_unittest.cc

+// Copyright 2015 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/location.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "media/capture/webm_muxer.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using ::testing::_;
+using ::testing::AtLeast;
+using ::testing::Mock;
+using ::testing::WithArgs;
+
+namespace media {
+
+// Dummy interface class to be able to MOCK its only function below.
+class EventHandlerInterface {
+ public:
+  virtual void WriteCallback(const char* data, size_t len) = 0;
+  virtual ~EventHandlerInterface() {}
+};
+
+class WebmMuxerTest : public testing::Test, public EventHandlerInterface {
+ public:
+  WebmMuxerTest()
+      : webm_muxer_(base::Bind(&WebmMuxerTest::WriteCallback,
+                               base::Unretained(this))),
+        last_encoded_length_(0),
+        accumulated_position_(0) {
+    EXPECT_EQ(webm_muxer_.Position(), 0);
+    EXPECT_FALSE(webm_muxer_.Seekable());
+    EXPECT_EQ(webm_muxer_.segment_.mode(), mkvmuxer::Segment::kLive);
+  }
+
+  MOCK_METHOD2(WriteCallback, void(const char* data, size_t len));
+
+  void SaveEncodedDataLen(size_t len) {
+    last_encoded_length_ = len;
+    accumulated_position_ += len;
+  }
+
+  mkvmuxer::int64 GetWebmMuxerPosition() const {
+    return webm_muxer_.Position();
+  }
+
+  const mkvmuxer::Segment& GetWebmMuxerSegment() const {
+    return webm_muxer_.segment_;
+  }
+
+  mkvmuxer::int32 WebmMuxerWrite(const void* buf, mkvmuxer::uint32 len) {
+    return webm_muxer_.Write(buf, len);
+  }
+
+  WebmMuxer webm_muxer_;
+
+  size_t last_encoded_length_;
+  int64_t accumulated_position_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(WebmMuxerTest);
+};
+
+// Checks that AddVideoTrack adds a Track.
+TEST_F(WebmMuxerTest, AddVideoTrack) {
+  const uint64_t track_number = webm_muxer_.AddVideoTrack(gfx::Size(320, 240),
+                                                          30.0f);
+  EXPECT_TRUE(GetWebmMuxerSegment().GetTrackByNumber(track_number));
+}
+
+// Checks that the WriteCallback is called with appropriate params when
+// WebmMuxer::Write() method is called.
+TEST_F(WebmMuxerTest, Write) {
+  const char encoded_data[] = "abcdefghijklmnopqrstuvwxyz";
+  const int encoded_len = arraysize(encoded_data);
+
+  EXPECT_CALL(*this, WriteCallback(encoded_data, encoded_len));
+  WebmMuxerWrite(encoded_data, encoded_len);
+
+  EXPECT_EQ(GetWebmMuxerPosition(), encoded_len);
+}
+
+// This test sends two frames and checks that the WriteCallback is called with
+// appropriate params in both cases.
+TEST_F(WebmMuxerTest, OnEncodedVideoNormalFrames) {
+  const uint8_t encoded_data[] = "abcdefghijklmnopqrstuvwxyz";
+  const uint64_t track_number = webm_muxer_.AddVideoTrack(gfx::Size(320, 240),
+                                                          30.0f);
+
+  EXPECT_CALL(*this, WriteCallback(_, _))
+      .Times(AtLeast(1))
+      .WillRepeatedly(WithArgs<1>(
+          Invoke(this, &WebmMuxerTest::SaveEncodedDataLen)));
+  webm_muxer_.OnEncodedVideo(track_number,
+                             encoded_data,
+                             arraysize(encoded_data),
+                             base::TimeDelta::FromMicroseconds(0),
+                             false  /* keyframe */);
+
+  // First time around WriteCallback() is pinged a number of times to write the
+  // Matroska header, but at the end it dumps |encoded_data|.
+  EXPECT_EQ(last_encoded_length_, arraysize(encoded_data));
+  EXPECT_EQ(GetWebmMuxerPosition(), accumulated_position_);
+  EXPECT_GE(GetWebmMuxerPosition(),
+            static_cast<int64_t>(last_encoded_length_));
+
+  const int64_t begin_of_second_block = accumulated_position_;
+  EXPECT_CALL(*this, WriteCallback(_, _))
+      .Times(AtLeast(1))
+      .WillRepeatedly(WithArgs<1>(
+          Invoke(this, &WebmMuxerTest::SaveEncodedDataLen)));
+  webm_muxer_.OnEncodedVideo(track_number,
+                             encoded_data,
+                             arraysize(encoded_data),
+                             base::TimeDelta::FromMicroseconds(1),
+                             false  /* keyframe */);
+
+  // The second time around the callbacks should include a SimpleBlock header,
+  // namely the track index, a timestamp and a flags byte, for a total of 6B.
+  EXPECT_EQ(last_encoded_length_, arraysize(encoded_data));
+  EXPECT_EQ(GetWebmMuxerPosition(), accumulated_position_);
+  const uint32_t kSimpleBlockSize = 6u;
+  EXPECT_EQ(static_cast<int64_t>(begin_of_second_block + kSimpleBlockSize +
+                                 arraysize(encoded_data)),
+            accumulated_position_);
+}
+
+}  // namespace media