Add sender controlled playout delay limits

webrtc/modules/rtp_rtcp/source/playout_delay_oracle_unittest.cc

+/*
+ *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/modules/rtp_rtcp/source/playout_delay_oracle.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/logging.h"
+
+namespace webrtc {
+
+namespace {
+constexpr int kSsrc = 100;
+constexpr int kSequenceNumber = 100;
+constexpr int kMinPlayoutDelay = 0;
+constexpr int kMaxPlayoutDelay = 150;
+}  // namespace
+
+class PlayoutDelayOracleTest : public ::testing::Test {
+ protected:
+  void ReportRTCPFeedback(int ssrc, int seq_num) {
+    RTCPReportBlock report_block;
+    report_block.sourceSSRC = ssrc;
+    report_block.extendedHighSeqNum = seq_num;
+    report_blocks_.push_back(report_block);
+    playout_delay_oracle_.OnReceivedRtcpReportBlocks(report_blocks_);
+  }
+
+  ReportBlockList report_blocks_;
+  PlayoutDelayOracle playout_delay_oracle_;
+};
+
+TEST_F(PlayoutDelayOracleTest, DisabledByDefault) {
+  EXPECT_FALSE(playout_delay_oracle_.send_playout_delay());
+  EXPECT_EQ(playout_delay_oracle_.min_playout_delay_ms(), -1);
+  EXPECT_EQ(playout_delay_oracle_.max_playout_delay_ms(), -1);
+}
+
+TEST_F(PlayoutDelayOracleTest, SendPlayoutDelayUntilSeqNumberExceeds) {
+  PlayoutDelay playout_delay = {kMinPlayoutDelay, kMaxPlayoutDelay};
+  playout_delay_oracle_.UpdateRequest(kSsrc, playout_delay, kSequenceNumber);
+  EXPECT_TRUE(playout_delay_oracle_.send_playout_delay());
+  EXPECT_EQ(playout_delay_oracle_.min_playout_delay_ms(), kMinPlayoutDelay);
+  EXPECT_EQ(playout_delay_oracle_.max_playout_delay_ms(), kMaxPlayoutDelay);
+
+  // Oracle indicates playout delay should be sent if highest sequence number
+  // acked is lower than the sequence number of the first packet containing
+  // playout delay.
+  ReportRTCPFeedback(kSsrc, kSequenceNumber - 1);
+  EXPECT_TRUE(playout_delay_oracle_.send_playout_delay());
+
+  // An invalid ssrc feedback report is dropped by the oracle.
+  ReportRTCPFeedback(kSsrc + 1, kSequenceNumber + 1);
+  EXPECT_TRUE(playout_delay_oracle_.send_playout_delay());
+
+  // Oracle indicates playout delay should not be sent if sequence number
+  // acked on a matching ssrc indicates the receiver has received the playout
+  // delay values.
+  ReportRTCPFeedback(kSsrc, kSequenceNumber + 1);
+  EXPECT_FALSE(playout_delay_oracle_.send_playout_delay());
+}
+
+}  // namespace webrtc