Use backticks not vertical bars to denote variables in comments for /modules/audio_coding

Bug: webrtc:12338
Change-Id: I02613d9fca45d00e2477f334b7a0416e7912e26b
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227037
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34621}
diff --git a/modules/audio_coding/acm2/acm_receive_test.h b/modules/audio_coding/acm2/acm_receive_test.h
index 043092c..6349c63 100644
--- a/modules/audio_coding/acm2/acm_receive_test.h
+++ b/modules/audio_coding/acm2/acm_receive_test.h
@@ -71,8 +71,8 @@
   RTC_DISALLOW_COPY_AND_ASSIGN(AcmReceiveTestOldApi);
 };
 
-// This test toggles the output frequency every |toggle_period_ms|. The test
-// starts with |output_freq_hz_1|. Except for the toggling, it does the same
+// This test toggles the output frequency every `toggle_period_ms`. The test
+// starts with `output_freq_hz_1`. Except for the toggling, it does the same
 // thing as AcmReceiveTestOldApi.
 class AcmReceiveTestToggleOutputFreqOldApi : public AcmReceiveTestOldApi {
  public:
diff --git a/modules/audio_coding/acm2/acm_receiver.cc b/modules/audio_coding/acm2/acm_receiver.cc
index 80cb3c5..6d9211c 100644
--- a/modules/audio_coding/acm2/acm_receiver.cc
+++ b/modules/audio_coding/acm2/acm_receiver.cc
@@ -131,7 +131,7 @@
                                   /*num_channels=*/format->num_channels,
                                   /*sdp_format=*/std::move(format->sdp_format)};
     }
-  }  // |mutex_| is released.
+  }  // `mutex_` is released.
 
   if (neteq_->InsertPacket(rtp_header, incoming_payload) < 0) {
     RTC_LOG(LERROR) << "AcmReceiver::InsertPacket "
@@ -201,7 +201,7 @@
     // We might end up here ONLY if codec is changed.
   }
 
-  // Store current audio in |last_audio_buffer_| for next time.
+  // Store current audio in `last_audio_buffer_` for next time.
   memcpy(last_audio_buffer_.get(), audio_frame->data(),
          sizeof(int16_t) * audio_frame->samples_per_channel_ *
              audio_frame->num_channels_);
diff --git a/modules/audio_coding/acm2/acm_receiver.h b/modules/audio_coding/acm2/acm_receiver.h
index 19dc577..9963603 100644
--- a/modules/audio_coding/acm2/acm_receiver.h
+++ b/modules/audio_coding/acm2/acm_receiver.h
@@ -177,9 +177,9 @@
   // enabled then the maximum NACK list size is modified accordingly.
   //
   // If the sequence number of last received packet is N, the sequence numbers
-  // of NACK list are in the range of [N - |max_nack_list_size|, N).
+  // of NACK list are in the range of [N - `max_nack_list_size`, N).
   //
-  // |max_nack_list_size| should be positive (none zero) and less than or
+  // `max_nack_list_size` should be positive (none zero) and less than or
   // equal to |Nack::kNackListSizeLimit|. Otherwise, No change is applied and -1
   // is returned. 0 is returned at success.
   //
@@ -189,12 +189,12 @@
   void DisableNack();
 
   //
-  // Get a list of packets to be retransmitted. |round_trip_time_ms| is an
+  // Get a list of packets to be retransmitted. `round_trip_time_ms` is an
   // estimate of the round-trip-time (in milliseconds). Missing packets which
   // will be playout in a shorter time than the round-trip-time (with respect
   // to the time this API is called) will not be included in the list.
   //
-  // Negative |round_trip_time_ms| results is an error message and empty list
+  // Negative `round_trip_time_ms` results is an error message and empty list
   // is returned.
   //
   std::vector<uint16_t> GetNackList(int64_t round_trip_time_ms) const;
diff --git a/modules/audio_coding/acm2/audio_coding_module.cc b/modules/audio_coding/acm2/audio_coding_module.cc
index b5c0c3b..d629139 100644
--- a/modules/audio_coding/acm2/audio_coding_module.cc
+++ b/modules/audio_coding/acm2/audio_coding_module.cc
@@ -125,7 +125,7 @@
   int Add10MsDataInternal(const AudioFrame& audio_frame, InputData* input_data)
       RTC_EXCLUSIVE_LOCKS_REQUIRED(acm_mutex_);
 
-  // TODO(bugs.webrtc.org/10739): change |absolute_capture_timestamp_ms| to
+  // TODO(bugs.webrtc.org/10739): change `absolute_capture_timestamp_ms` to
   // int64_t when it always receives a valid value.
   int Encode(const InputData& input_data,
              absl::optional<int64_t> absolute_capture_timestamp_ms)
@@ -141,8 +141,8 @@
   //
   // in_frame: input audio-frame
   // ptr_out: pointer to output audio_frame. If no preprocessing is required
-  //          |ptr_out| will be pointing to |in_frame|, otherwise pointing to
-  //          |preprocess_frame_|.
+  //          `ptr_out` will be pointing to `in_frame`, otherwise pointing to
+  //          `preprocess_frame_`.
   //
   // Return value:
   //   -1: if encountering an error.
@@ -152,7 +152,7 @@
       RTC_EXCLUSIVE_LOCKS_REQUIRED(acm_mutex_);
 
   // Change required states after starting to receive the codec corresponding
-  // to |index|.
+  // to `index`.
   int UpdateUponReceivingCodec(int index);
 
   mutable Mutex acm_mutex_;
@@ -397,7 +397,7 @@
     // output data if needed.
     ReMixFrame(*ptr_frame, current_num_channels, &input_data->buffer);
 
-    // For pushing data to primary, point the |ptr_audio| to correct buffer.
+    // For pushing data to primary, point the `ptr_audio` to correct buffer.
     input_data->audio = input_data->buffer.data();
     RTC_DCHECK_GE(input_data->buffer.size(),
                   input_data->length_per_channel * input_data->audio_channel);
@@ -414,7 +414,7 @@
 // encoder is mono and input is stereo. In case of dual-streaming, both
 // encoders has to be mono for down-mix to take place.
 // |*ptr_out| will point to the pre-processed audio-frame. If no pre-processing
-// is required, |*ptr_out| points to |in_frame|.
+// is required, |*ptr_out| points to `in_frame`.
 // TODO(yujo): Make this more efficient for muted frames.
 int AudioCodingModuleImpl::PreprocessToAddData(const AudioFrame& in_frame,
                                                const AudioFrame** ptr_out) {
diff --git a/modules/audio_coding/acm2/audio_coding_module_unittest.cc b/modules/audio_coding/acm2/audio_coding_module_unittest.cc
index 7465456..a0a8854 100644
--- a/modules/audio_coding/acm2/audio_coding_module_unittest.cc
+++ b/modules/audio_coding/acm2/audio_coding_module_unittest.cc
@@ -342,7 +342,7 @@
 
 // Introduce this class to set different expectations on the number of encoded
 // bytes. This class expects all encoded packets to be 9 bytes (matching one
-// CNG SID frame) or 0 bytes. This test depends on |input_frame_| containing
+// CNG SID frame) or 0 bytes. This test depends on `input_frame_` containing
 // (near-)zero values. It also introduces a way to register comfort noise with
 // a custom payload type.
 class AudioCodingModuleTestWithComfortNoiseOldApi
@@ -593,7 +593,7 @@
       InsertAudio();
       ASSERT_LT(loop_counter++, 10);
     }
-    // Set |last_packet_number_| to one less that |num_calls| so that the packet
+    // Set `last_packet_number_` to one less that `num_calls` so that the packet
     // will be fetched in the next InsertPacket() call.
     last_packet_number_ = packet_cb_.num_calls() - 1;
 
@@ -617,7 +617,7 @@
     if (num_calls > last_packet_number_) {
       // Get the new payload out from the callback handler.
       // Note that since we swap buffers here instead of directly inserting
-      // a pointer to the data in |packet_cb_|, we avoid locking the callback
+      // a pointer to the data in `packet_cb_`, we avoid locking the callback
       // for the duration of the IncomingPacket() call.
       packet_cb_.SwapBuffers(&last_payload_vec_);
       ASSERT_GT(last_payload_vec_.size(), 0u);
@@ -1140,8 +1140,8 @@
   // Sets up the test::AcmSendTest object. Returns true on success, otherwise
   // false.
   bool SetUpSender(std::string input_file_name, int source_rate) {
-    // Note that |audio_source_| will loop forever. The test duration is set
-    // explicitly by |kTestDurationMs|.
+    // Note that `audio_source_` will loop forever. The test duration is set
+    // explicitly by `kTestDurationMs`.
     audio_source_.reset(new test::InputAudioFile(input_file_name));
     send_test_.reset(new test::AcmSendTestOldApi(audio_source_.get(),
                                                  source_rate, kTestDurationMs));
@@ -1243,7 +1243,7 @@
     VerifyPacket(packet.get());
     // TODO(henrik.lundin) Save the packet to file as well.
 
-    // Pass it on to the caller. The caller becomes the owner of |packet|.
+    // Pass it on to the caller. The caller becomes the owner of `packet`.
     return packet;
   }
 
@@ -1631,8 +1631,8 @@
   bool SetUpSender() {
     const std::string input_file_name =
         webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm");
-    // Note that |audio_source_| will loop forever. The test duration is set
-    // explicitly by |kTestDurationMs|.
+    // Note that `audio_source_` will loop forever. The test duration is set
+    // explicitly by `kTestDurationMs`.
     audio_source_.reset(new test::InputAudioFile(input_file_name));
     static const int kSourceRateHz = 32000;
     send_test_.reset(new test::AcmSendTestOldApi(
@@ -1859,7 +1859,7 @@
 
 // This test fixture is implemented to run ACM and change the desired output
 // frequency during the call. The input packets are simply PCM16b-wb encoded
-// payloads with a constant value of |kSampleValue|. The test fixture itself
+// payloads with a constant value of `kSampleValue`. The test fixture itself
 // acts as PacketSource in between the receive test class and the constant-
 // payload packet source class. The output is both written to file, and analyzed
 // in this test fixture.
diff --git a/modules/audio_coding/acm2/call_statistics.cc b/modules/audio_coding/acm2/call_statistics.cc
index e97e529..0aad594 100644
--- a/modules/audio_coding/acm2/call_statistics.cc
+++ b/modules/audio_coding/acm2/call_statistics.cc
@@ -44,7 +44,7 @@
       break;
     }
     case AudioFrame::kUndefined: {
-      // If the audio is decoded by NetEq, |kUndefined| is not an option.
+      // If the audio is decoded by NetEq, `kUndefined` is not an option.
       RTC_NOTREACHED();
     }
   }
diff --git a/modules/audio_coding/acm2/call_statistics.h b/modules/audio_coding/acm2/call_statistics.h
index 5d94ac4..a2db2a29 100644
--- a/modules/audio_coding/acm2/call_statistics.h
+++ b/modules/audio_coding/acm2/call_statistics.h
@@ -36,8 +36,8 @@
   CallStatistics() {}
   ~CallStatistics() {}
 
-  // Call this method to indicate that NetEq engaged in decoding. |speech_type|
-  // is the audio-type according to NetEq, and |muted| indicates if the decoded
+  // Call this method to indicate that NetEq engaged in decoding. `speech_type`
+  // is the audio-type according to NetEq, and `muted` indicates if the decoded
   // frame was produced in muted state.
   void DecodedByNetEq(AudioFrame::SpeechType speech_type, bool muted);