AudioDecoder: New method SampleRateHz, + implementations for our codecs

webrtc/modules/audio_coding/codecs/isac/audio_decoder_isac_t_impl.h

Index: webrtc/modules/audio_coding/codecs/isac/audio_decoder_isac_t_impl.h
diff --git a/webrtc/modules/audio_coding/codecs/isac/audio_decoder_isac_t_impl.h b/webrtc/modules/audio_coding/codecs/isac/audio_decoder_isac_t_impl.h
index 4998feac84bd866edc2b64f3f8b5fe9333782cc9..431632112ac7333bb3582409c2cdb8ce9d9199ae 100644
--- a/webrtc/modules/audio_coding/codecs/isac/audio_decoder_isac_t_impl.h
+++ b/webrtc/modules/audio_coding/codecs/isac/audio_decoder_isac_t_impl.h
@@ -19,12 +19,31 @@ namespace webrtc {
 
 template <typename T>
 AudioDecoderIsacT<T>::AudioDecoderIsacT()
-    : AudioDecoderIsacT(nullptr) {}
+    : AudioDecoderIsacT(rtc::Optional<int>(), nullptr) {}
 
 template <typename T>
 AudioDecoderIsacT<T>::AudioDecoderIsacT(
     const rtc::scoped_refptr<LockedIsacBandwidthInfo>& bwinfo)
-    : bwinfo_(bwinfo), decoder_sample_rate_hz_(-1) {
+    : AudioDecoderIsacT(rtc::Optional<int>(), bwinfo) {}
+
+template <typename T>
+AudioDecoderIsacT<T>::AudioDecoderIsacT(int sample_rate_hz)
+    : AudioDecoderIsacT(rtc::Optional<int>(sample_rate_hz), nullptr) {}
+
+template <typename T>
+AudioDecoderIsacT<T>::AudioDecoderIsacT(
+    int sample_rate_hz,
+    const rtc::scoped_refptr<LockedIsacBandwidthInfo>& bwinfo)
+    : AudioDecoderIsacT(rtc::Optional<int>(sample_rate_hz), bwinfo) {}
+
+template <typename T>
+AudioDecoderIsacT<T>::AudioDecoderIsacT(
+    rtc::Optional<int> sample_rate_hz,
+    const rtc::scoped_refptr<LockedIsacBandwidthInfo>& bwinfo)
+    : sample_rate_hz_(sample_rate_hz), bwinfo_(bwinfo) {
+  RTC_CHECK(!sample_rate_hz || *sample_rate_hz == 16000 ||
+            *sample_rate_hz == 32000)
+      << "Unsupported sample rate " << *sample_rate_hz;
   RTC_CHECK_EQ(0, T::Create(&isac_state_));
   T::DecoderInit(isac_state_);
   if (bwinfo_) {
@@ -32,6 +51,9 @@ AudioDecoderIsacT<T>::AudioDecoderIsacT(
     T::GetBandwidthInfo(isac_state_, &bi);
     bwinfo_->Set(bi);
   }
+  if (sample_rate_hz_) {
+    RTC_CHECK_EQ(0, T::SetDecSampRate(isac_state_, *sample_rate_hz_));
+  }
 }
 
 template <typename T>
@@ -45,11 +67,13 @@ int AudioDecoderIsacT<T>::DecodeInternal(const uint8_t* encoded,
                                          int sample_rate_hz,
                                          int16_t* decoded,
                                          SpeechType* speech_type) {
-  RTC_CHECK(sample_rate_hz == 16000 || sample_rate_hz == 32000)
-      << "Unsupported sample rate " << sample_rate_hz;
-  if (sample_rate_hz != decoder_sample_rate_hz_) {
-    RTC_CHECK_EQ(0, T::SetDecSampRate(isac_state_, sample_rate_hz));
-    decoder_sample_rate_hz_ = sample_rate_hz;
+  if (sample_rate_hz_) {
+    RTC_CHECK_EQ(*sample_rate_hz_, sample_rate_hz);
+  } else {
+    RTC_CHECK(sample_rate_hz == 16000 || sample_rate_hz == 32000)
+        << "Unsupported sample rate " << sample_rate_hz;
+    sample_rate_hz_ = rtc::Optional<int>(sample_rate_hz);
+    RTC_CHECK_EQ(0, T::SetDecSampRate(isac_state_, *sample_rate_hz_));
   }
   int16_t temp_type = 1;  // Default is speech.
   int ret =
@@ -96,6 +120,12 @@ int AudioDecoderIsacT<T>::ErrorCode() {
 }
 
 template <typename T>
+int AudioDecoderIsacT<T>::SampleRateHz() const {
+  RTC_CHECK(sample_rate_hz_) << "Sample rate not set yet!";
+  return *sample_rate_hz_;
+}
+
+template <typename T>
 size_t AudioDecoderIsacT<T>::Channels() const {
   return 1;
 }