Multi frequency DTMF support - receiver side

webrtc/modules/audio_coding/neteq/decoder_database.h

Index: webrtc/modules/audio_coding/neteq/decoder_database.h
diff --git a/webrtc/modules/audio_coding/neteq/decoder_database.h b/webrtc/modules/audio_coding/neteq/decoder_database.h
index 6e172600b7b304bd50fb303709324009887e4109..83789daa919028eccddb6d2734094994d12c5e9a 100644
--- a/webrtc/modules/audio_coding/neteq/decoder_database.h
+++ b/webrtc/modules/audio_coding/neteq/decoder_database.h
@@ -62,6 +62,10 @@ class DecoderDatabase {
     void DropDecoder() const { decoder_.reset(); }
 
     int SampleRateHz() const {
+      if (IsDtmf()) {
+        // DTMF has a 1:1 mapping between clock rate and sample rate.
+        return audio_format_.clockrate_hz;
+      }
       const AudioDecoder* decoder = GetDecoder();
       RTC_DCHECK_EQ(1, !!decoder + !!cng_decoder_);
       return decoder ? decoder->SampleRateHz() : cng_decoder_->sample_rate_hz;