Remove dead code

webrtc/api/audio_codecs/ilbc/audio_encoder_ilbc.cc

 /*
  *  Copyright (c) 2017 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/api/audio_codecs/ilbc/audio_encoder_ilbc.h"
 
 #include <memory>
 #include <vector>
 
+#include "webrtc/common_types.h"
 #include "webrtc/modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.h"
 #include "webrtc/rtc_base/ptr_util.h"
 #include "webrtc/rtc_base/safe_conversions.h"
+#include "webrtc/rtc_base/safe_minmax.h"
+#include "webrtc/rtc_base/string_to_number.h"
 
 namespace webrtc {
 namespace {
 int GetIlbcBitrate(int ptime) {
   switch (ptime) {
     case 20:
     case 40:
       // 38 bytes per frame of 20 ms => 15200 bits/s.
       return 15200;
     case 30:
     case 60:
       // 50 bytes per frame of 30 ms => (approx) 13333 bits/s.
       return 13333;
     default:
       FATAL();
   }
 }
 }  // namespace
 
 rtc::Optional<AudioEncoderIlbcConfig> AudioEncoderIlbc::SdpToConfig(
     const SdpAudioFormat& format) {
-  return AudioEncoderIlbcImpl::SdpToConfig(format);
+  if (STR_CASE_CMP(format.name.c_str(), "ILBC") != 0 ||
+      format.clockrate_hz != 8000 || format.num_channels != 1) {
+    return rtc::Optional<AudioEncoderIlbcConfig>();
+  }
+
+  AudioEncoderIlbcConfig config;
+  auto ptime_iter = format.parameters.find("ptime");
+  if (ptime_iter != format.parameters.end()) {
+    auto ptime = rtc::StringToNumber<int>(ptime_iter->second);
+    if (ptime && *ptime > 0) {
+      const int whole_packets = *ptime / 10;
+      config.frame_size_ms = rtc::SafeClamp<int>(whole_packets * 10, 20, 60);
+    }
+  }
+  return config.IsOk() ? rtc::Optional<AudioEncoderIlbcConfig>(config)
+                       : rtc::Optional<AudioEncoderIlbcConfig>();
 }
 
 void AudioEncoderIlbc::AppendSupportedEncoders(
     std::vector<AudioCodecSpec>* specs) {
   const SdpAudioFormat fmt = {"ILBC", 8000, 1};
   const AudioCodecInfo info = QueryAudioEncoder(*SdpToConfig(fmt));
   specs->push_back({fmt, info});
 }
 
 AudioCodecInfo AudioEncoderIlbc::QueryAudioEncoder(
     const AudioEncoderIlbcConfig& config) {
   RTC_DCHECK(config.IsOk());
   return {8000, 1, GetIlbcBitrate(config.frame_size_ms)};
 }
 
 std::unique_ptr<AudioEncoder> AudioEncoderIlbc::MakeAudioEncoder(
     const AudioEncoderIlbcConfig& config,
     int payload_type) {
   RTC_DCHECK(config.IsOk());
   return rtc::MakeUnique<AudioEncoderIlbcImpl>(config, payload_type);
 }
 
 }  // namespace webrtc