Move CNG and RED management into the Rent-A-Codec

webrtc/modules/audio_coding/main/acm2/rent_a_codec_unittest.cc

 /*
  *  Copyright (c) 2015 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 "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/arraysize.h"
+#include "webrtc/modules/audio_coding/codecs/mock/mock_audio_encoder.h"
 #include "webrtc/modules/audio_coding/main/acm2/rent_a_codec.h"
 
 namespace webrtc {
 namespace acm2 {
 
+using ::testing::Return;
+
+namespace {
+const int kDataLengthSamples = 80;
+const int kPacketSizeSamples = 2 * kDataLengthSamples;
+const int16_t kZeroData[kDataLengthSamples] = {0};
+const CodecInst kDefaultCodecInst = {0, "pcmu", 8000, kPacketSizeSamples,
+                                     1, 64000};
+const int kCngPt = 13;
+}  // namespace
+
+class RentACodecTestF : public ::testing::Test {
+ protected:
+  void CreateCodec() {
+    speech_encoder_ = rent_a_codec_.RentEncoder(kDefaultCodecInst);
+    ASSERT_TRUE(speech_encoder_);
+    encoder_ = rent_a_codec_.RentEncoderStack(
+        speech_encoder_, rtc::Optional<RentACodec::CngConfig>(
+                             RentACodec::CngConfig{kCngPt, VADNormal}),
+        rtc::Optional<int>());
+  }
+
+  void EncodeAndVerify(size_t expected_out_length,
+                       uint32_t expected_timestamp,
+                       int expected_payload_type,
+                       int expected_send_even_if_empty) {
+    uint8_t out[kPacketSizeSamples];
+    AudioEncoder::EncodedInfo encoded_info;
+    encoded_info =
+        encoder_->Encode(timestamp_, kZeroData, kPacketSizeSamples, out);
+    timestamp_ += kDataLengthSamples;
+    EXPECT_TRUE(encoded_info.redundant.empty());
+    EXPECT_EQ(expected_out_length, encoded_info.encoded_bytes);
+    EXPECT_EQ(expected_timestamp, encoded_info.encoded_timestamp);
+    if (expected_payload_type >= 0)
+      EXPECT_EQ(expected_payload_type, encoded_info.payload_type);
+    if (expected_send_even_if_empty >= 0)
+      EXPECT_EQ(static_cast<bool>(expected_send_even_if_empty),
+                encoded_info.send_even_if_empty);
+  }
+
+  RentACodec rent_a_codec_;
+  AudioEncoder* speech_encoder_ = nullptr;
+  AudioEncoder* encoder_ = nullptr;
+  uint32_t timestamp_ = 0;
+};
+
+// This test verifies that CNG frames are delivered as expected. Since the frame
+// size is set to 20 ms, we expect the first encode call to produce no output
+// (which is signaled as 0 bytes output of type kNoEncoding). The next encode
+// call should produce one SID frame of 9 bytes. The third call should not
+// result in any output (just like the first one). The fourth and final encode
+// call should produce an "empty frame", which is like no output, but with
+// AudioEncoder::EncodedInfo::send_even_if_empty set to true. (The reason to
+// produce an empty frame is to drive sending of DTMF packets in the RTP/RTCP
+// module.)
+TEST_F(RentACodecTestF, VerifyCngFrames) {
+  CreateCodec();
+  uint32_t expected_timestamp = timestamp_;
+  // Verify no frame.
+  {
+    SCOPED_TRACE("First encoding");
+    EncodeAndVerify(0, expected_timestamp, -1, -1);
+  }
+
+  // Verify SID frame delivered.
+  {
+    SCOPED_TRACE("Second encoding");
+    EncodeAndVerify(9, expected_timestamp, kCngPt, 1);
+  }
+
+  // Verify no frame.
+  {
+    SCOPED_TRACE("Third encoding");
+    EncodeAndVerify(0, expected_timestamp, -1, -1);
+  }
+
+  // Verify NoEncoding.
+  expected_timestamp += 2 * kDataLengthSamples;
+  {
+    SCOPED_TRACE("Fourth encoding");
+    EncodeAndVerify(0, expected_timestamp, kCngPt, 1);
+  }
+}
+
+TEST(RentACodecTest, ExternalEncoder) {
+  MockAudioEncoder external_encoder;
+  RentACodec rac;
+  EXPECT_EQ(&external_encoder,
+            rac.RentEncoderStack(&external_encoder,
+                                 rtc::Optional<RentACodec::CngConfig>(),
+                                 rtc::Optional<int>()));
+  const int kSampleRateHz = 8000;
+  const int kPacketSizeSamples = kSampleRateHz / 100;
+  int16_t audio[kPacketSizeSamples] = {0};
+  uint8_t encoded[kPacketSizeSamples];
+  AudioEncoder::EncodedInfo info;
+  EXPECT_CALL(external_encoder, SampleRateHz())
+      .WillRepeatedly(Return(kSampleRateHz));
+  EXPECT_CALL(external_encoder, NumChannels()).WillRepeatedly(Return(1));
+
+  {
+    ::testing::InSequence s;
+    info.encoded_timestamp = 0;
+    EXPECT_CALL(external_encoder,
+                EncodeInternal(0, rtc::ArrayView<const int16_t>(audio),
+                               arraysize(encoded), encoded))
+        .WillOnce(Return(info));
+    EXPECT_CALL(external_encoder, Mark("A"));
+    EXPECT_CALL(external_encoder, Mark("B"));
+    info.encoded_timestamp = 2;
+    EXPECT_CALL(external_encoder,
+                EncodeInternal(2, rtc::ArrayView<const int16_t>(audio),
+                               arraysize(encoded), encoded))
+        .WillOnce(Return(info));
+    EXPECT_CALL(external_encoder, Die());
+  }
+
+  info = rac.GetEncoderStack()->Encode(0, audio, arraysize(encoded), encoded);
+  EXPECT_EQ(0u, info.encoded_timestamp);
+  external_encoder.Mark("A");
+
+  // Change to internal encoder.
+  CodecInst codec_inst = kDefaultCodecInst;
+  codec_inst.pacsize = kPacketSizeSamples;
+  AudioEncoder* enc = rac.RentEncoder(codec_inst);
+  ASSERT_TRUE(enc);
+  EXPECT_EQ(enc,
+            rac.RentEncoderStack(enc, rtc::Optional<RentACodec::CngConfig>(),
+                                 rtc::Optional<int>()));
+
+  // Don't expect any more calls to the external encoder.
+  info = rac.GetEncoderStack()->Encode(1, audio, arraysize(encoded), encoded);
+  external_encoder.Mark("B");
+
+  // Change back to external encoder again.
+  EXPECT_EQ(&external_encoder,
+            rac.RentEncoderStack(&external_encoder,
+                                 rtc::Optional<RentACodec::CngConfig>(),
+                                 rtc::Optional<int>()));
+  info = rac.GetEncoderStack()->Encode(2, audio, arraysize(encoded), encoded);
+  EXPECT_EQ(2u, info.encoded_timestamp);
+}
+
+// Verify that the speech encoder's Reset method is called when CNG or RED
+// (or both) are switched on, but not when they're switched off.
+void TestCngAndRedResetSpeechEncoder(bool use_cng, bool use_red) {
+  MockAudioEncoder speech_encoder;
+  EXPECT_CALL(speech_encoder, NumChannels()).WillRepeatedly(Return(1));
+  EXPECT_CALL(speech_encoder, Max10MsFramesInAPacket())
+      .WillRepeatedly(Return(2));
+  EXPECT_CALL(speech_encoder, SampleRateHz()).WillRepeatedly(Return(8000));
+  {
+    ::testing::InSequence s;
+    EXPECT_CALL(speech_encoder, Mark("disabled"));
+    EXPECT_CALL(speech_encoder, Mark("enabled"));
+    if (use_cng || use_red)
+      EXPECT_CALL(speech_encoder, Reset());
+    EXPECT_CALL(speech_encoder, Die());
+  }
+
+  auto cng_cfg = use_cng ? rtc::Optional<RentACodec::CngConfig>(
+                               RentACodec::CngConfig{17, VADNormal})
+                         : rtc::Optional<RentACodec::CngConfig>();
+  auto red_pt = use_red ? rtc::Optional<int>(19) : rtc::Optional<int>();
+  speech_encoder.Mark("disabled");
+  RentACodec rac;
+  rac.RentEncoderStack(&speech_encoder, rtc::Optional<RentACodec::CngConfig>(),
+                       rtc::Optional<int>());
+  speech_encoder.Mark("enabled");
+  rac.RentEncoderStack(&speech_encoder, cng_cfg, red_pt);
+}
+
+TEST(RentACodecTest, CngResetsSpeechEncoder) {
+  TestCngAndRedResetSpeechEncoder(true, false);
+}
+
+TEST(RentACodecTest, RedResetsSpeechEncoder) {
+  TestCngAndRedResetSpeechEncoder(false, true);
+}
+
+TEST(RentACodecTest, CngAndRedResetsSpeechEncoder) {
+  TestCngAndRedResetSpeechEncoder(true, true);
+}
+
+TEST(RentACodecTest, NoCngAndRedNoSpeechEncoderReset) {
+  TestCngAndRedResetSpeechEncoder(false, false);
+}
+
 TEST(RentACodecTest, RentEncoderError) {
   const CodecInst codec_inst = {
       0, "Robert'); DROP TABLE Students;", 8000, 160, 1, 64000};
   RentACodec rent_a_codec;
   EXPECT_FALSE(rent_a_codec.RentEncoder(codec_inst));
 }
 
 }  // namespace acm2
 }  // namespace webrtc