Reland "Change buffer level filter to store current level in number of samples."

This is a reland of 87977dd06e702ed517f26235c12e37bd927527c7

Original change's description:
> Change buffer level filter to store current level in number of samples.
> 
> The buffer level should not be converted back and forth between samples and packets in case of variable packet lengths.
> 
> Bug: webrtc:10736
> Change-Id: Ia08dcfac3d8104dc79fbad0704a5f6f12a050a01
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/142178
> Reviewed-by: Minyue Li <minyue@webrtc.org>
> Commit-Queue: Jakob Ivarsson <jakobi@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#28368}

Bug: webrtc:10736
Change-Id: I1ff603e65cdd31c7429f36b035dcc00a17b68f3b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/143787
Commit-Queue: Minyue Li <minyue@webrtc.org>
Reviewed-by: Minyue Li <minyue@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28393}
diff --git a/modules/audio_coding/acm2/audio_coding_module_unittest.cc b/modules/audio_coding/acm2/audio_coding_module_unittest.cc
index c95091f..f30deed 100644
--- a/modules/audio_coding/acm2/audio_coding_module_unittest.cc
+++ b/modules/audio_coding/acm2/audio_coding_module_unittest.cc
@@ -994,35 +994,35 @@
 #if (defined(WEBRTC_CODEC_ISAC) || defined(WEBRTC_CODEC_ISACFX)) && \
     defined(WEBRTC_CODEC_ILBC)
 TEST_F(AcmReceiverBitExactnessOldApi, 8kHzOutput) {
-  Run(8000, PlatformChecksum("bcfbe2e89b4317b22e29557168edf187",
-                             "af15addb648cf7f032d6415672365fb3",
-                             "54a0008eb79537dee1d8fdaa5bc29f4b",
+  Run(8000, PlatformChecksum("73e82368b90b0708bd970da1f357f71d",
+                             "e777abcc66fccf8e86ac18450ad8b23c",
+                             "5a668d4075a39cd07a2db82ec3bf19ba",
                              "4598140b5e4f7ee66c5adad609e65a3e",
-                             "3155d7f2593a3276986f36221a61783c"));
+                             "99d17cc50d41232a4f96c976231cb59b"));
 }
 
 TEST_F(AcmReceiverBitExactnessOldApi, 16kHzOutput) {
-  Run(16000, PlatformChecksum("1737deef193e6c90e139ce82b7361ae4",
-                              "9e2a9f7728c71d6559ce3a32d2b10a5d",
-                              "114958862099142ac78b12100c21cb8d",
+  Run(16000, PlatformChecksum("f0b9d6961c243a3397b0bb95191b189b",
+                              "c73877b73a7ae2687eabc88de3d3f5bc",
+                              "70d24360be8290abbd0e56c38f83cdef",
                               "f2aad418af974a3b1694d5ae5cc2c3c7",
-                              "af2889a5ca84fb40c9aa209b9318ee7a"));
+                              "564b1b5d2d9bcace5285623cd9822b57"));
 }
 
 TEST_F(AcmReceiverBitExactnessOldApi, 32kHzOutput) {
-  Run(32000, PlatformChecksum("1bf40ff024c6aa5b832d1d242c29cb3b",
-                              "3c9690cd136e9ecd1b26a22f70fe1d5c",
-                              "a1a3a01d8e25fcd11f1cedcd02e968b8",
+  Run(32000, PlatformChecksum("881a799ad91f845b1cd833e4e42d1791",
+                              "90e478af57f11bcf678b72ed1ba87765",
+                              "774657761e20fdec6d325d7d4b4101a7",
                               "100869c8dcde51346c2073e52a272d98",
-                              "33695077e9ec6bca80819ce2ba263a78"));
+                              "4b77795ba2581097dc8e4db6e6a3a921"));
 }
 
 TEST_F(AcmReceiverBitExactnessOldApi, 48kHzOutput) {
-  Run(48000, PlatformChecksum("bf92db1e502deff5adf6fd2e6ab9a2e5",
-                              "c37b110ab50d87620972daee5d1eaf31",
-                              "5d55b68be7bcf39b60fcc74519363fb4",
+  Run(48000, PlatformChecksum("991b729aef7f08eca75d4c9ece848264",
+                              "0334f53d4e96156edc302e46ff5cfaec",
+                              "a578705020fe94ebde31b27d61035299",
                               "bd44bf97e7899186532f91235cef444d",
-                              "32eec738698ffe62b9777d6a349cd596"));
+                              "c0d4185eacde6cd470c1a2ce4cd45318"));
 }
 
 TEST_F(AcmReceiverBitExactnessOldApi, 48kHzOutputExternalDecoder) {
@@ -1105,11 +1105,11 @@
   rtc::scoped_refptr<rtc::RefCountedObject<ADFactory>> factory(
       new rtc::RefCountedObject<ADFactory>);
   Run(48000,
-      PlatformChecksum("bf92db1e502deff5adf6fd2e6ab9a2e5",
-                       "c37b110ab50d87620972daee5d1eaf31",
-                       "5d55b68be7bcf39b60fcc74519363fb4",
+      PlatformChecksum("991b729aef7f08eca75d4c9ece848264",
+                       "0334f53d4e96156edc302e46ff5cfaec",
+                       "a578705020fe94ebde31b27d61035299",
                        "bd44bf97e7899186532f91235cef444d",
-                       "32eec738698ffe62b9777d6a349cd596"),
+                       "c0d4185eacde6cd470c1a2ce4cd45318"),
       factory, [](AudioCodingModule* acm) {
         acm->SetReceiveCodecs({{0, {"MockPCMu", 8000, 1}},
                                {103, {"ISAC", 16000, 1}},
@@ -1328,7 +1328,7 @@
   Run(AcmReceiverBitExactnessOldApi::PlatformChecksum(
           "2c9cb15d4ed55b5a0cadd04883bc73b0",
           "9336a9b993cbd8a751f0e8958e66c89c",
-          "bd4682225f7c4ad5f2049f6769713ac2",
+          "5c2eb46199994506236f68b2c8e51b0d",
           "343f1f42be0607c61e6516aece424609",
           "2c9cb15d4ed55b5a0cadd04883bc73b0"),
       AcmReceiverBitExactnessOldApi::PlatformChecksum(
@@ -1343,11 +1343,11 @@
 TEST_F(AcmSenderBitExactnessOldApi, IsacWb60ms) {
   ASSERT_NO_FATAL_FAILURE(SetUpTest("ISAC", 16000, 1, 103, 960, 960));
   Run(AcmReceiverBitExactnessOldApi::PlatformChecksum(
-          "1ad29139a04782a33daad8c2b9b35875",
-          "14d63c5f08127d280e722e3191b73bdd",
-          "edcf26694c289e3d9691faf79b74f09f",
+          "f59760fa000991ee5fa81f2e607db254",
+          "986aa16d7097a26e32e212e39ec58517",
+          "9a81e467eb1485f84aca796f8ea65011",
           "ef75e900e6f375e3061163c53fd09a63",
-          "1ad29139a04782a33daad8c2b9b35875"),
+          "f59760fa000991ee5fa81f2e607db254"),
       AcmReceiverBitExactnessOldApi::PlatformChecksum(
           "9e0a0ab743ad987b55b8e14802769c56",
           "ebe04a819d3a9d83a83a17f271e1139a",
diff --git a/modules/audio_coding/neteq/buffer_level_filter.cc b/modules/audio_coding/neteq/buffer_level_filter.cc
index 2f96618..0d75a47 100644
--- a/modules/audio_coding/neteq/buffer_level_filter.cc
+++ b/modules/audio_coding/neteq/buffer_level_filter.cc
@@ -26,32 +26,22 @@
   level_factor_ = 253;
 }
 
-void BufferLevelFilter::Update(size_t buffer_size_packets,
-                               int time_stretched_samples,
-                               size_t packet_len_samples) {
+void BufferLevelFilter::Update(size_t buffer_size_samples,
+                               int time_stretched_samples) {
   // Filter:
   // |filtered_current_level_| = |level_factor_| * |filtered_current_level_| +
-  //                            (1 - |level_factor_|) * |buffer_size_packets|
+  //                            (1 - |level_factor_|) * |buffer_size_samples|
   // |level_factor_| and |filtered_current_level_| are in Q8.
-  // |buffer_size_packets| is in Q0.
+  // |buffer_size_samples| is in Q0.
   filtered_current_level_ =
       ((level_factor_ * filtered_current_level_) >> 8) +
-      ((256 - level_factor_) * rtc::dchecked_cast<int>(buffer_size_packets));
+      ((256 - level_factor_) * rtc::dchecked_cast<int>(buffer_size_samples));
 
-  // Account for time-scale operations (accelerate and pre-emptive expand).
-  if (time_stretched_samples && packet_len_samples > 0) {
-    // Time-scaling has been performed since last filter update. Subtract the
-    // value of |time_stretched_samples| from |filtered_current_level_| after
-    // converting |time_stretched_samples| from samples to packets in Q8.
-    // Make sure that the filtered value remains non-negative.
-
-    int64_t time_stretched_packets =
-        (int64_t{time_stretched_samples} * (1 << 8)) /
-        rtc::dchecked_cast<int64_t>(packet_len_samples);
-
-    filtered_current_level_ = rtc::saturated_cast<int>(
-        std::max<int64_t>(0, filtered_current_level_ - time_stretched_packets));
-  }
+  // Account for time-scale operations (accelerate and pre-emptive expand) and
+  // make sure that the filtered value remains non-negative.
+  filtered_current_level_ = rtc::saturated_cast<int>(std::max<int64_t>(
+      0,
+      filtered_current_level_ - (int64_t{time_stretched_samples} * (1 << 8))));
 }
 
 void BufferLevelFilter::SetTargetBufferLevel(int target_buffer_level) {
@@ -66,8 +56,4 @@
   }
 }
 
-int BufferLevelFilter::filtered_current_level() const {
-  return filtered_current_level_;
-}
-
 }  // namespace webrtc
diff --git a/modules/audio_coding/neteq/buffer_level_filter.h b/modules/audio_coding/neteq/buffer_level_filter.h
index 83388fb..6dd4249 100644
--- a/modules/audio_coding/neteq/buffer_level_filter.h
+++ b/modules/audio_coding/neteq/buffer_level_filter.h
@@ -24,20 +24,20 @@
   virtual void Reset();
 
   // Updates the filter. Current buffer size is |buffer_size_packets| (Q0).
-  // If |time_stretched_samples| is non-zero, the value is converted to the
-  // corresponding number of packets, and is subtracted from the filtered
-  // value (thus bypassing the filter operation). |packet_len_samples| is the
-  // number of audio samples carried in each incoming packet.
-  virtual void Update(size_t buffer_size_packets,
-                      int time_stretched_samples,
-                      size_t packet_len_samples);
+  // |time_stretched_samples| is subtracted from the filtered value (thus
+  // bypassing the filter operation).
+  virtual void Update(size_t buffer_size_samples, int time_stretched_samples);
 
-  // Set the current target buffer level (obtained from
+  // Set the current target buffer level in number of packets (obtained from
   // DelayManager::base_target_level()). Used to select the appropriate
   // filter coefficient.
-  virtual void SetTargetBufferLevel(int target_buffer_level);
+  virtual void SetTargetBufferLevel(int target_buffer_level_packets);
 
-  virtual int filtered_current_level() const;
+  // Returns filtered current level in number of samples.
+  virtual int filtered_current_level() const {
+    // Round to nearest whole sample.
+    return (filtered_current_level_ + (1 << 7)) >> 8;
+  }
 
  private:
   int level_factor_;  // Filter factor for the buffer level filter in Q8.
diff --git a/modules/audio_coding/neteq/buffer_level_filter_unittest.cc b/modules/audio_coding/neteq/buffer_level_filter_unittest.cc
index 1f12e73..bc42595 100644
--- a/modules/audio_coding/neteq/buffer_level_filter_unittest.cc
+++ b/modules/audio_coding/neteq/buffer_level_filter_unittest.cc
@@ -35,18 +35,17 @@
       ss << "times = " << times << ", value = " << value;
       SCOPED_TRACE(ss.str());  // Print out the parameter values on failure.
       for (int i = 0; i < times; ++i) {
-        filter.Update(value, 0 /* time_stretched_samples */,
-                      160 /* packet_len_samples */);
+        filter.Update(value, 0 /* time_stretched_samples */);
       }
       // Expect the filtered value to be (theoretically)
       // (1 - (251/256) ^ |times|) * |value|.
       double expected_value_double = (1 - pow(251.0 / 256.0, times)) * value;
       int expected_value = static_cast<int>(expected_value_double);
-      // filtered_current_level() returns the value in Q8.
+
       // The actual value may differ slightly from the expected value due to
       // intermediate-stage rounding errors in the filter implementation.
       // This is why we have to use EXPECT_NEAR with a tolerance of +/-1.
-      EXPECT_NEAR(expected_value, filter.filtered_current_level() >> 8, 1);
+      EXPECT_NEAR(expected_value, filter.filtered_current_level(), 1);
     }
   }
 }
@@ -60,38 +59,32 @@
 
   filter.SetTargetBufferLevel(3);  // Makes filter coefficient 252/256.
   for (int i = 0; i < kTimes; ++i) {
-    filter.Update(kValue, 0 /* time_stretched_samples */,
-                  160 /* packet_len_samples */);
+    filter.Update(kValue, 0 /* time_stretched_samples */);
   }
   // Expect the filtered value to be
   // (1 - (252/256) ^ |kTimes|) * |kValue|.
-  int expected_value = 14;
-  // filtered_current_level() returns the value in Q8.
-  EXPECT_EQ(expected_value, filter.filtered_current_level() >> 8);
+  int expected_value = 15;
+  EXPECT_EQ(expected_value, filter.filtered_current_level());
 
   filter.Reset();
   filter.SetTargetBufferLevel(7);  // Makes filter coefficient 253/256.
   for (int i = 0; i < kTimes; ++i) {
-    filter.Update(kValue, 0 /* time_stretched_samples */,
-                  160 /* packet_len_samples */);
+    filter.Update(kValue, 0 /* time_stretched_samples */);
   }
   // Expect the filtered value to be
   // (1 - (253/256) ^ |kTimes|) * |kValue|.
   expected_value = 11;
-  // filtered_current_level() returns the value in Q8.
-  EXPECT_EQ(expected_value, filter.filtered_current_level() >> 8);
+  EXPECT_EQ(expected_value, filter.filtered_current_level());
 
   filter.Reset();
   filter.SetTargetBufferLevel(8);  // Makes filter coefficient 254/256.
   for (int i = 0; i < kTimes; ++i) {
-    filter.Update(kValue, 0 /* time_stretched_samples */,
-                  160 /* packet_len_samples */);
+    filter.Update(kValue, 0 /* time_stretched_samples */);
   }
   // Expect the filtered value to be
   // (1 - (254/256) ^ |kTimes|) * |kValue|.
-  expected_value = 7;
-  // filtered_current_level() returns the value in Q8.
-  EXPECT_EQ(expected_value, filter.filtered_current_level() >> 8);
+  expected_value = 8;
+  EXPECT_EQ(expected_value, filter.filtered_current_level());
 }
 
 TEST(BufferLevelFilter, TimeStretchedSamples) {
@@ -100,62 +93,24 @@
   // Update 10 times with value 100.
   const int kTimes = 10;
   const int kValue = 100;
-  const int kPacketSizeSamples = 160;
-  const int kNumPacketsStretched = 2;
-  const int kTimeStretchedSamples = kNumPacketsStretched * kPacketSizeSamples;
+  const int kTimeStretchedSamples = 3;
   for (int i = 0; i < kTimes; ++i) {
-    // Packet size set to 0. Do not expect the parameter
-    // |kTimeStretchedSamples| to have any effect.
-    filter.Update(kValue, kTimeStretchedSamples, 0 /* packet_len_samples */);
+    filter.Update(kValue, 0);
   }
   // Expect the filtered value to be
   // (1 - (251/256) ^ |kTimes|) * |kValue|.
-  const int kExpectedValue = 17;
-  // filtered_current_level() returns the value in Q8.
-  EXPECT_EQ(kExpectedValue, filter.filtered_current_level() >> 8);
+  const int kExpectedValue = 18;
+  EXPECT_EQ(kExpectedValue, filter.filtered_current_level());
 
   // Update filter again, now with non-zero value for packet length.
   // Set the current filtered value to be the input, in order to isolate the
   // impact of |kTimeStretchedSamples|.
-  filter.Update(filter.filtered_current_level() >> 8, kTimeStretchedSamples,
-                kPacketSizeSamples);
-  EXPECT_EQ(kExpectedValue - kNumPacketsStretched,
-            filter.filtered_current_level() >> 8);
+  filter.Update(filter.filtered_current_level(), kTimeStretchedSamples);
+  EXPECT_EQ(kExpectedValue - kTimeStretchedSamples,
+            filter.filtered_current_level());
   // Try negative value and verify that we come back to the previous result.
-  filter.Update(filter.filtered_current_level() >> 8, -kTimeStretchedSamples,
-                kPacketSizeSamples);
-  EXPECT_EQ(kExpectedValue, filter.filtered_current_level() >> 8);
-}
-
-TEST(BufferLevelFilter, TimeStretchedSamplesNegativeUnevenFrames) {
-  BufferLevelFilter filter;
-  filter.SetTargetBufferLevel(1);  // Makes filter coefficient 251/256.
-  // Update 10 times with value 100.
-  const int kTimes = 10;
-  const int kValue = 100;
-  const int kPacketSizeSamples = 160;
-  const int kTimeStretchedSamples = -3.1415 * kPacketSizeSamples;
-  for (int i = 0; i < kTimes; ++i) {
-    // Packet size set to 0. Do not expect the parameter
-    // |kTimeStretchedSamples| to have any effect.
-    filter.Update(kValue, kTimeStretchedSamples, 0 /* packet_len_samples */);
-  }
-  // Expect the filtered value to be
-  // (1 - (251/256) ^ |kTimes|) * |kValue|.
-  const int kExpectedValue = 17;
-  // filtered_current_level() returns the value in Q8.
-  EXPECT_EQ(kExpectedValue, filter.filtered_current_level() >> 8);
-
-  // Update filter again, now with non-zero value for packet length.
-  // Set the current filtered value to be the input, in order to isolate the
-  // impact of |kTimeStretchedSamples|.
-  filter.Update(filter.filtered_current_level() >> 8, kTimeStretchedSamples,
-                kPacketSizeSamples);
-  EXPECT_EQ(21, filter.filtered_current_level() >> 8);
-  // Try negative value and verify that we come back to the previous result.
-  filter.Update(filter.filtered_current_level() >> 8, -kTimeStretchedSamples,
-                kPacketSizeSamples);
-  EXPECT_EQ(kExpectedValue, filter.filtered_current_level() >> 8);
+  filter.Update(filter.filtered_current_level(), -kTimeStretchedSamples);
+  EXPECT_EQ(kExpectedValue, filter.filtered_current_level());
 }
 
 }  // namespace webrtc
diff --git a/modules/audio_coding/neteq/decision_logic.cc b/modules/audio_coding/neteq/decision_logic.cc
index 40e421d..f9f420a 100644
--- a/modules/audio_coding/neteq/decision_logic.cc
+++ b/modules/audio_coding/neteq/decision_logic.cc
@@ -113,11 +113,9 @@
     cng_state_ = kCngInternalOn;
   }
 
-  const size_t samples_left =
-      sync_buffer.FutureLength() - expand.overlap_length();
   // TODO(jakobi): Use buffer span instead of num samples.
   const size_t cur_size_samples =
-      samples_left + packet_buffer_.NumSamplesInBuffer(decoder_frame_length);
+      packet_buffer_.NumSamplesInBuffer(decoder_frame_length);
 
   prev_time_scale_ =
       prev_time_scale_ && (prev_mode == kModeAccelerateSuccess ||
@@ -175,8 +173,7 @@
   // if the mute factor is low enough (otherwise the expansion was short enough
   // to not be noticable).
   // Note that the MuteFactor is in Q14, so a value of 16384 corresponds to 1.
-  size_t current_span =
-      samples_left + packet_buffer_.GetSpanSamples(decoder_frame_length);
+  size_t current_span = packet_buffer_.GetSpanSamples(decoder_frame_length);
   if ((prev_mode == kModeExpand || prev_mode == kModeCodecPlc) &&
       expand.MuteFactor(0) < 16384 / 2 &&
       current_span < static_cast<size_t>(delay_manager_->TargetLevel() *
@@ -193,9 +190,9 @@
     return ExpectedPacketAvailable(prev_mode, play_dtmf);
   } else if (!PacketBuffer::IsObsoleteTimestamp(
                  available_timestamp, target_timestamp, five_seconds_samples)) {
-    return FuturePacketAvailable(
-        sync_buffer, expand, decoder_frame_length, prev_mode, target_timestamp,
-        available_timestamp, play_dtmf, generated_noise_samples);
+    return FuturePacketAvailable(decoder_frame_length, prev_mode,
+                                 target_timestamp, available_timestamp,
+                                 play_dtmf, generated_noise_samples);
   } else {
     // This implies that available_timestamp < target_timestamp, which can
     // happen when a new stream or codec is received. Signal for a reset.
@@ -215,19 +212,13 @@
   buffer_level_filter_->SetTargetBufferLevel(
       delay_manager_->base_target_level());
 
-  size_t buffer_size_packets = 0;
-  if (packet_length_samples_ > 0) {
-    // Calculate size in packets.
-    buffer_size_packets = buffer_size_samples / packet_length_samples_;
-  }
   int sample_memory_local = 0;
   if (prev_time_scale_) {
     sample_memory_local = sample_memory_;
     timescale_countdown_ = tick_timer_->GetNewCountdown(kMinTimescaleInterval);
   }
 
-  buffer_level_filter_->Update(buffer_size_packets, sample_memory_local,
-                               packet_length_samples_);
+  buffer_level_filter_->Update(buffer_size_samples, sample_memory_local);
   prev_time_scale_ = false;
 }
 
@@ -283,15 +274,22 @@
 Operations DecisionLogic::ExpectedPacketAvailable(Modes prev_mode,
                                                   bool play_dtmf) {
   if (!disallow_time_stretching_ && prev_mode != kModeExpand && !play_dtmf) {
-    // Check criterion for time-stretching.
+    // Check criterion for time-stretching. The values are in number of packets
+    // in Q8.
     int low_limit, high_limit;
     delay_manager_->BufferLimits(&low_limit, &high_limit);
-    if (buffer_level_filter_->filtered_current_level() >= high_limit << 2)
+    int buffer_level_packets = 0;
+    if (packet_length_samples_ > 0) {
+      buffer_level_packets =
+          ((1 << 8) * buffer_level_filter_->filtered_current_level()) /
+          packet_length_samples_;
+    }
+    if (buffer_level_packets >= high_limit << 2)
       return kFastAccelerate;
     if (TimescaleAllowed()) {
-      if (buffer_level_filter_->filtered_current_level() >= high_limit)
+      if (buffer_level_packets >= high_limit)
         return kAccelerate;
-      if (buffer_level_filter_->filtered_current_level() < low_limit)
+      if (buffer_level_packets < low_limit)
         return kPreemptiveExpand;
     }
   }
@@ -299,8 +297,6 @@
 }
 
 Operations DecisionLogic::FuturePacketAvailable(
-    const SyncBuffer& sync_buffer,
-    const Expand& expand,
     size_t decoder_frame_length,
     Modes prev_mode,
     uint32_t target_timestamp,
@@ -327,10 +323,8 @@
     return kNormal;
   }
 
-  const size_t samples_left =
-      sync_buffer.FutureLength() - expand.overlap_length();
   const size_t cur_size_samples =
-      samples_left + packet_buffer_.NumPacketsInBuffer() * decoder_frame_length;
+      packet_buffer_.NumPacketsInBuffer() * decoder_frame_length;
 
   // If previous was comfort noise, then no merge is needed.
   if (prev_mode == kModeRfc3389Cng || prev_mode == kModeCodecInternalCng) {
@@ -365,8 +359,13 @@
 }
 
 bool DecisionLogic::UnderTargetLevel() const {
-  return buffer_level_filter_->filtered_current_level() <=
-         delay_manager_->TargetLevel();
+  int buffer_level_packets = 0;
+  if (packet_length_samples_ > 0) {
+    buffer_level_packets =
+        ((1 << 8) * buffer_level_filter_->filtered_current_level()) /
+        packet_length_samples_;
+  }
+  return buffer_level_packets <= delay_manager_->TargetLevel();
 }
 
 bool DecisionLogic::ReinitAfterExpands(uint32_t timestamp_leap) const {
diff --git a/modules/audio_coding/neteq/decision_logic.h b/modules/audio_coding/neteq/decision_logic.h
index 2414e8c..49020b0 100644
--- a/modules/audio_coding/neteq/decision_logic.h
+++ b/modules/audio_coding/neteq/decision_logic.h
@@ -134,9 +134,7 @@
 
   // Returns the operation to do given that the expected packet is not
   // available, but a packet further into the future is at hand.
-  Operations FuturePacketAvailable(const SyncBuffer& sync_buffer,
-                                   const Expand& expand,
-                                   size_t decoder_frame_length,
+  Operations FuturePacketAvailable(size_t decoder_frame_length,
                                    Modes prev_mode,
                                    uint32_t target_timestamp,
                                    uint32_t available_timestamp,
diff --git a/modules/audio_coding/neteq/mock/mock_buffer_level_filter.h b/modules/audio_coding/neteq/mock/mock_buffer_level_filter.h
index bf9fd59..031195c 100644
--- a/modules/audio_coding/neteq/mock/mock_buffer_level_filter.h
+++ b/modules/audio_coding/neteq/mock/mock_buffer_level_filter.h
@@ -22,10 +22,8 @@
   virtual ~MockBufferLevelFilter() { Die(); }
   MOCK_METHOD0(Die, void());
   MOCK_METHOD0(Reset, void());
-  MOCK_METHOD3(Update,
-               void(size_t buffer_size_packets,
-                    int time_stretched_samples,
-                    size_t packet_len_samples));
+  MOCK_METHOD2(Update,
+               void(size_t buffer_size_samples, int time_stretched_samples));
   MOCK_METHOD1(SetTargetBufferLevel, void(int target_buffer_level));
   MOCK_CONST_METHOD0(filtered_current_level, int());
 };
diff --git a/modules/audio_coding/neteq/neteq_impl.cc b/modules/audio_coding/neteq/neteq_impl.cc
index ad6becc..82ec18d 100644
--- a/modules/audio_coding/neteq/neteq_impl.cc
+++ b/modules/audio_coding/neteq/neteq_impl.cc
@@ -310,18 +310,12 @@
 
 int NetEqImpl::FilteredCurrentDelayMs() const {
   rtc::CritScope lock(&crit_sect_);
-  // Calculate the filtered packet buffer level in samples. The value from
-  // |buffer_level_filter_| is in number of packets, represented in Q8.
-  const size_t packet_buffer_samples =
-      (buffer_level_filter_->filtered_current_level() *
-       decoder_frame_length_) >>
-      8;
   // Sum up the filtered packet buffer level with the future length of the sync
-  // buffer, and divide the sum by the sample rate.
-  const size_t delay_samples =
-      packet_buffer_samples + sync_buffer_->FutureLength();
+  // buffer.
+  const int delay_samples = buffer_level_filter_->filtered_current_level() +
+                            sync_buffer_->FutureLength();
   // The division below will truncate. The return value is in ms.
-  return static_cast<int>(delay_samples) / rtc::CheckedDivExact(fs_hz_, 1000);
+  return delay_samples / rtc::CheckedDivExact(fs_hz_, 1000);
 }
 
 int NetEqImpl::NetworkStatistics(NetEqNetworkStatistics* stats) {
diff --git a/modules/audio_coding/neteq/neteq_unittest.cc b/modules/audio_coding/neteq/neteq_unittest.cc
index 6c67ca8..a89d248 100644
--- a/modules/audio_coding/neteq/neteq_unittest.cc
+++ b/modules/audio_coding/neteq/neteq_unittest.cc
@@ -458,16 +458,16 @@
       webrtc::test::ResourcePath("audio_coding/neteq_universal_new", "rtp");
 
   const std::string output_checksum =
-      PlatformChecksum("9652cee1d6771a9cbfda821ae1bbdb41b0dd4dee",
-                       "54a7e32f163663c0af35bf70bf45cefc24ad62ef", "not used",
-                       "9652cee1d6771a9cbfda821ae1bbdb41b0dd4dee",
-                       "79496b0a1ef0a3824f3ee04789748a461bed643f");
+      PlatformChecksum("998be2e5a707e636af0b6298f54bedfabe72aae1",
+                       "61e238ece4cd3b67d66a0b7047e06b20607dcb79", "not used",
+                       "998be2e5a707e636af0b6298f54bedfabe72aae1",
+                       "4116ac2a6e75baac3194b712d6fabe28b384275e");
 
   const std::string network_stats_checksum =
-      PlatformChecksum("c59b1f9f282b6d8733cdff975e3c150ca4a47d51",
-                       "bca95e565996a4ffd6e2ac15736e08843bdca93b", "not used",
-                       "c59b1f9f282b6d8733cdff975e3c150ca4a47d51",
-                       "c59b1f9f282b6d8733cdff975e3c150ca4a47d51");
+      PlatformChecksum("3689c9f0ab9e50cefab3e44c37c3d7aa0de82ca4",
+                       "0a596217fccd8d90eff7d1666b8cc63143eeda12", "not used",
+                       "3689c9f0ab9e50cefab3e44c37c3d7aa0de82ca4",
+                       "3689c9f0ab9e50cefab3e44c37c3d7aa0de82ca4");
 
   DecodeAndCompare(input_rtp_file, output_checksum, network_stats_checksum,
                    FLAG_gen_ref);
@@ -486,17 +486,17 @@
   // Checksum depends on libopus being compiled with or without SSE.
   const std::string maybe_sse =
       "14a63b3c7b925c82296be4bafc71bec85f2915c2|"
-      "2c05677daa968d6c68b92adf4affb7cd9bb4d363";
+      "eb0b68bddcac00fc85403df64f83126f8ea9bc93";
   const std::string output_checksum = PlatformChecksum(
-      maybe_sse, "b7b7ed802b0e18ee416973bf3b9ae98599b0181d",
-      "5876e52dda90d5ca433c3726555b907b97c86374", maybe_sse, maybe_sse);
+      maybe_sse, "f95f2a220c9ca5d60b81c4653d46e0de2bee159f",
+      "6f288a03d34958f62496f18fa85655593eef4dbe", maybe_sse, maybe_sse);
 
   const std::string network_stats_checksum =
-      PlatformChecksum("adb3272498e436d1c019cbfd71610e9510c54497",
-                       "fa935a91abc7291db47428a2d7c5361b98713a92",
-                       "42106aa5267300f709f63737707ef07afd9dac61",
-                       "adb3272498e436d1c019cbfd71610e9510c54497",
-                       "adb3272498e436d1c019cbfd71610e9510c54497");
+      PlatformChecksum("0b3d34baffaf651812ffaf06ea1b5ce45ea1c47a",
+                       "a71dce66c7bea85ba22d4e29a5298f606f810444",
+                       "7c64e1e915bace7c4bf583484efd64eaf234552f",
+                       "0b3d34baffaf651812ffaf06ea1b5ce45ea1c47a",
+                       "0b3d34baffaf651812ffaf06ea1b5ce45ea1c47a");
 
   DecodeAndCompare(input_rtp_file, output_checksum, network_stats_checksum,
                    FLAG_gen_ref);
@@ -796,7 +796,7 @@
   const double kDriftFactor = 1000.0 / (1000.0 + 25.0);
   const double kNetworkFreezeTimeMs = 5000.0;
   const bool kGetAudioDuringFreezeRecovery = false;
-  const int kDelayToleranceMs = 50;
+  const int kDelayToleranceMs = 60;
   const int kMaxTimeToSpeechMs = 200;
   LongCngWithClockDrift(kDriftFactor, kNetworkFreezeTimeMs,
                         kGetAudioDuringFreezeRecovery, kDelayToleranceMs,