Removing unused Opus wrapper API: WebRTCOpus_DecodePlc.

Bug: None
Change-Id: I5b613b4c13ec5f6ad13d8430043d006f6d83c11f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/158671
Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org>
Commit-Queue: Minyue Li <minyue@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29664}
diff --git a/modules/audio_coding/codecs/opus/opus_fec_test.cc b/modules/audio_coding/codecs/opus/opus_fec_test.cc
index 1ab4d86..47e40c6 100644
--- a/modules/audio_coding/codecs/opus/opus_fec_test.cc
+++ b/modules/audio_coding/codecs/opus/opus_fec_test.cc
@@ -154,7 +154,8 @@
           WebRtcOpus_DecodeFec(opus_decoder_, &bit_stream_[0], encoded_bytes_,
                                &out_data_[0], &audio_type);
     } else {
-      value_1 = WebRtcOpus_DecodePlc(opus_decoder_, &out_data_[0], 1);
+      value_1 =
+          WebRtcOpus_Decode(opus_decoder_, NULL, 0, &out_data_[0], &audio_type);
     }
     EXPECT_EQ(static_cast<int>(block_length_sample_), value_1);
   }
diff --git a/modules/audio_coding/codecs/opus/opus_interface.cc b/modules/audio_coding/codecs/opus/opus_interface.cc
index 45eab2b..fc3d3ff 100644
--- a/modules/audio_coding/codecs/opus/opus_interface.cc
+++ b/modules/audio_coding/codecs/opus/opus_interface.cc
@@ -514,6 +514,29 @@
   return res;
 }
 
+static int DecodePlc(OpusDecInst* inst, int16_t* decoded) {
+  int16_t audio_type = 0;
+  int decoded_samples;
+  int plc_samples;
+
+  /* The number of samples we ask for is |number_of_lost_frames| times
+   * |prev_decoded_samples_|. Limit the number of samples to maximum
+   * |MaxFrameSizePerChannel()|. */
+  plc_samples = inst->prev_decoded_samples;
+  const int max_samples_per_channel =
+      MaxFrameSizePerChannel(inst->sample_rate_hz);
+  plc_samples = plc_samples <= max_samples_per_channel
+                    ? plc_samples
+                    : max_samples_per_channel;
+  decoded_samples =
+      DecodeNative(inst, NULL, 0, plc_samples, decoded, &audio_type, 0);
+  if (decoded_samples < 0) {
+    return -1;
+  }
+
+  return decoded_samples;
+}
+
 int WebRtcOpus_Decode(OpusDecInst* inst,
                       const uint8_t* encoded,
                       size_t encoded_bytes,
@@ -523,7 +546,7 @@
 
   if (encoded_bytes == 0) {
     *audio_type = DetermineAudioType(inst, encoded_bytes);
-    decoded_samples = WebRtcOpus_DecodePlc(inst, decoded, 1);
+    decoded_samples = DecodePlc(inst, decoded);
   } else {
     decoded_samples = DecodeNative(inst, encoded, encoded_bytes,
                                    MaxFrameSizePerChannel(inst->sample_rate_hz),
@@ -539,31 +562,6 @@
   return decoded_samples;
 }
 
-int WebRtcOpus_DecodePlc(OpusDecInst* inst,
-                         int16_t* decoded,
-                         int number_of_lost_frames) {
-  int16_t audio_type = 0;
-  int decoded_samples;
-  int plc_samples;
-
-  /* The number of samples we ask for is |number_of_lost_frames| times
-   * |prev_decoded_samples_|. Limit the number of samples to maximum
-   * |MaxFrameSizePerChannel()|. */
-  plc_samples = number_of_lost_frames * inst->prev_decoded_samples;
-  const int max_samples_per_channel =
-      MaxFrameSizePerChannel(inst->sample_rate_hz);
-  plc_samples = plc_samples <= max_samples_per_channel
-                    ? plc_samples
-                    : max_samples_per_channel;
-  decoded_samples =
-      DecodeNative(inst, NULL, 0, plc_samples, decoded, &audio_type, 0);
-  if (decoded_samples < 0) {
-    return -1;
-  }
-
-  return decoded_samples;
-}
-
 int WebRtcOpus_DecodeFec(OpusDecInst* inst,
                          const uint8_t* encoded,
                          size_t encoded_bytes,
diff --git a/modules/audio_coding/codecs/opus/opus_interface.h b/modules/audio_coding/codecs/opus/opus_interface.h
index cf95a69..ef62e0d 100644
--- a/modules/audio_coding/codecs/opus/opus_interface.h
+++ b/modules/audio_coding/codecs/opus/opus_interface.h
@@ -407,24 +407,6 @@
                       int16_t* audio_type);
 
 /****************************************************************************
- * WebRtcOpus_DecodePlc(...)
- *
- * This function processes PLC for opus frame(s).
- * Input:
- *        - inst                  : Decoder context
- *        - number_of_lost_frames : Number of PLC frames to produce
- *
- * Output:
- *        - decoded               : The decoded vector
- *
- * Return value                   : >0 - number of samples in decoded PLC vector
- *                                  -1 - Error
- */
-int WebRtcOpus_DecodePlc(OpusDecInst* inst,
-                         int16_t* decoded,
-                         int number_of_lost_frames);
-
-/****************************************************************************
  * WebRtcOpus_DecodeFec(...)
  *
  * This function decodes the FEC data from an Opus packet into one or more audio
diff --git a/modules/audio_coding/codecs/opus/opus_unittest.cc b/modules/audio_coding/codecs/opus/opus_unittest.cc
index f0f2ef0..10897fb 100644
--- a/modules/audio_coding/codecs/opus/opus_unittest.cc
+++ b/modules/audio_coding/codecs/opus/opus_unittest.cc
@@ -810,7 +810,7 @@
   // Call decoder PLC.
   int16_t* plc_buffer = new int16_t[decode_samples_per_channel * channels_];
   EXPECT_EQ(decode_samples_per_channel,
-            WebRtcOpus_DecodePlc(opus_decoder_, plc_buffer, 1));
+            WebRtcOpus_Decode(opus_decoder_, NULL, 0, plc_buffer, &audio_type));
 
   // Free memory.
   delete[] plc_buffer;