Convert channel counts to size_t.

webrtc/modules/audio_coding/acm2/audio_coding_module_impl.cc

 /*
  *  Copyright (c) 2012 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.
  */
 
@@ skipping 306 matching lines @@
   const AudioFrame* ptr_frame;
   // Perform a resampling, also down-mix if it is required and can be
   // performed before resampling (a down mix prior to resampling will take
   // place if both primary and secondary encoders are mono and input is in
   // stereo).
   if (PreprocessToAddData(audio_frame, &ptr_frame) < 0) {
     return -1;
   }
 
   // Check whether we need an up-mix or down-mix?
-  const int current_num_channels =
+  const size_t current_num_channels =
       rent_a_codec_.GetEncoderStack()->NumChannels();
   const bool same_num_channels =
       ptr_frame->num_channels_ == current_num_channels;
 
   if (!same_num_channels) {
     if (ptr_frame->num_channels_ == 1) {
       if (UpMix(*ptr_frame, WEBRTC_10MS_PCM_AUDIO, input_data->buffer) < 0)
         return -1;
     } else {
       if (DownMix(*ptr_frame, WEBRTC_10MS_PCM_AUDIO, input_data->buffer) < 0)
@@ skipping 244 matching lines @@
   WEBRTC_TRACE(webrtc::kTraceStream, webrtc::kTraceAudioCoding, id_,
                "PlayoutFrequency()");
   return receiver_.last_output_sample_rate_hz();
 }
 
 // Register possible receive codecs, can be called multiple times,
 // for codecs, CNG (NB, WB and SWB), DTMF, RED.
 int AudioCodingModuleImpl::RegisterReceiveCodec(const CodecInst& codec) {
   CriticalSectionScoped lock(acm_crit_sect_.get());
   RTC_DCHECK(receiver_initialized_);
-  if (codec.channels > 2 || codec.channels < 0) {
+  if (codec.channels > 2) {
     LOG_F(LS_ERROR) << "Unsupported number of channels: " << codec.channels;
     return -1;
   }
 
   auto codec_id =
       RentACodec::CodecIdByParams(codec.plname, codec.plfreq, codec.channels);
   if (!codec_id) {
     LOG_F(LS_ERROR) << "Wrong codec params to be registered as receive codec";
     return -1;
   }
@@ skipping 216 matching lines @@
   return receiver_.LeastRequiredDelayMs();
 }
 
 void AudioCodingModuleImpl::GetDecodingCallStatistics(
       AudioDecodingCallStats* call_stats) const {
   receiver_.GetDecodingCallStatistics(call_stats);
 }
 
 }  // namespace acm2
 }  // namespace webrtc