Add C++ runtime for Tele-AI/TeleSpeech-ASR (#970)

sherpa-onnx/csrc/features.h

@@ -18,7 +18,10 @@ struct FeatureExtractorConfig {
   // the sampling rate of the input waveform, we will do resampling inside.
   int32_t sampling_rate = 16000;
 
-  // Feature dimension
+  // num_mel_bins
+  //
+  // Note: for mfcc, this value is also for num_mel_bins.
+  // The actual feature dimension is actuall num_ceps
   int32_t feature_dim = 80;
 
   // minimal frequency for Mel-filterbank, in Hz
@@ -69,6 +72,12 @@ struct FeatureExtractorConfig {
   // for details
   std::string nemo_normalize_type;
 
+  // for MFCC
+  int32_t num_ceps = 13;
+  bool use_energy = true;
+
+  bool is_mfcc = false;
+
   std::string ToString() const;
 
   void Register(ParseOptions *po);