AudioCodingModule: Specify decoders using SdpAudioFormat

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 ebea7e89a8dba495eb983c1f92cc0c153d07a724..07c3471a86244627da71ff7e7399c872b973ada4 100644
--- a/webrtc/modules/audio_coding/neteq/decoder_database.cc
+++ b/webrtc/modules/audio_coding/neteq/decoder_database.cc
@@ -85,7 +85,12 @@ bool DecoderDatabase::DecoderInfo::IsType(const std::string& name) const {
 rtc::Optional<DecoderDatabase::DecoderInfo::CngDecoder>
 DecoderDatabase::DecoderInfo::CngDecoder::Create(const SdpAudioFormat& format) {
   if (STR_CASE_CMP(format.name.c_str(), "CN") == 0) {
-    return rtc::Optional<CngDecoder>({format.clockrate_hz});
+    // CN has a 1:1 RTP clock rate to sample rate ratio.
+    const int sample_rate_hz = format.clockrate_hz;
+    RTC_DCHECK(sample_rate_hz == 8000 || sample_rate_hz == 16000 ||
+               sample_rate_hz == 32000 || sample_rate_hz == 48000);
+    return rtc::Optional<DecoderDatabase::DecoderInfo::CngDecoder>(
+        {sample_rate_hz});
   } else {
     return rtc::Optional<CngDecoder>();
   }
@@ -141,6 +146,20 @@ int DecoderDatabase::RegisterPayload(uint8_t rtp_payload_type,
   return kOK;
 }
 
+int DecoderDatabase::RegisterPayload(int rtp_payload_type,
+                                     const SdpAudioFormat& audio_format) {
+  if (rtp_payload_type < 0 || rtp_payload_type > 0x7f) {
+    return kInvalidRtpPayloadType;
+  }
+  const auto ret = decoders_.insert(std::make_pair(
+      rtp_payload_type, DecoderInfo(audio_format, decoder_factory_.get())));
+  if (ret.second == false) {
+    // Database already contains a decoder with type |rtp_payload_type|.
+    return kDecoderExists;
+  }
+  return kOK;
+}
+
 int DecoderDatabase::InsertExternal(uint8_t rtp_payload_type,
                                     NetEqDecoder codec_type,
                                     const std::string& codec_name,