DecoderDatabase::IsComfortNoise: Improved efficiency.

webrtc/modules/audio_coding/neteq/decoder_database.cc

Index: webrtc/modules/audio_coding/neteq/decoder_database.cc
diff --git a/webrtc/modules/audio_coding/neteq/decoder_database.cc b/webrtc/modules/audio_coding/neteq/decoder_database.cc
index c163bbdbf3d5ad862470e299f741729ffbc4f518..845b2adaef7071ae040978d2d9efa76904c252a1 100644
--- a/webrtc/modules/audio_coding/neteq/decoder_database.cc
+++ b/webrtc/modules/audio_coding/neteq/decoder_database.cc
@@ -169,14 +169,16 @@ bool DecoderDatabase::IsType(uint8_t rtp_payload_type,
 }
 
 bool DecoderDatabase::IsComfortNoise(uint8_t rtp_payload_type) const {
-  if (IsType(rtp_payload_type, NetEqDecoder::kDecoderCNGnb) ||
-      IsType(rtp_payload_type, NetEqDecoder::kDecoderCNGwb) ||
-      IsType(rtp_payload_type, NetEqDecoder::kDecoderCNGswb32kHz) ||
-      IsType(rtp_payload_type, NetEqDecoder::kDecoderCNGswb48kHz)) {
-    return true;
-  } else {
+  DecoderMap::const_iterator it = decoders_.find(rtp_payload_type);
+  if (it == decoders_.end()) {
+    // Decoder not found.
     return false;
   }

[kwiberg-webrtc, 2016/04/27 12:16:34]

Suggestion for future improvement: If we're having performance problems with a
map whose keys are 7-bit integers, replacing the balanced binary tree with a
128-element array could be a big win.

+  const auto& type = it->second.codec_type;
+  return type == NetEqDecoder::kDecoderCNGnb
+      || type == NetEqDecoder::kDecoderCNGwb
+      || type == NetEqDecoder::kDecoderCNGswb32kHz
+      || type == NetEqDecoder::kDecoderCNGswb48kHz;
 }
 
 bool DecoderDatabase::IsDtmf(uint8_t rtp_payload_type) const {