[src] Fix to older online decoding code in online/ (OnlineFeInput; was broken by commit cc2469e). (kaldi-asr#3025)

Author: jdieguez

src/online/online-feat-input.h

@@ -31,6 +31,7 @@
 
 #include "online-audio-source.h"
 #include "feat/feature-functions.h"
+#include "feat/feature-window.h"
 
 namespace kaldi {
 
@@ -275,7 +276,8 @@ class OnlineFeInput : public OnlineFeatInputItf {
   // "frame_size" - frame extraction window size in audio samples
   // "frame_shift" - feature frame width in audio samples
   OnlineFeInput(OnlineAudioSourceItf *au_src, E *fe,
-                const int32 frame_size, const int32 frame_shift);
+                const int32 frame_size, const int32 frame_shift,
+                const bool snip_edges = true);
 
   virtual int32 Dim() const { return extractor_->Dim(); }
 
@@ -287,15 +289,26 @@ class OnlineFeInput : public OnlineFeatInputItf {
   const int32 frame_size_;
   const int32 frame_shift_;
   Vector<BaseFloat> wave_; // the samples to be passed for extraction
+  Vector<BaseFloat> wave_remainder_; // the samples remained from the previous
+                                     // feature batch
+  FrameExtractionOptions frame_opts_;
 
   KALDI_DISALLOW_COPY_AND_ASSIGN(OnlineFeInput);
 };
 
 template<class E>
 OnlineFeInput<E>::OnlineFeInput(OnlineAudioSourceItf *au_src, E *fe,
-                                   int32 frame_size, int32 frame_shift)
+                                int32 frame_size, int32 frame_shift,
+                                bool snip_edges)
     : source_(au_src), extractor_(fe),
-      frame_size_(frame_size), frame_shift_(frame_shift) {}
+      frame_size_(frame_size), frame_shift_(frame_shift) {
+      // we need a FrameExtractionOptions to call NumFrames()
+      // 1000 is just a fake sample rate which equates ms and samples
+      frame_opts_.samp_freq = 1000;
+      frame_opts_.frame_shift_ms = frame_shift;
+      frame_opts_.frame_length_ms = frame_size;
+      frame_opts_.snip_edges = snip_edges;
+}
 
 template<class E> bool
 OnlineFeInput<E>::Compute(Matrix<BaseFloat> *output) {
@@ -311,11 +324,26 @@ OnlineFeInput<E>::Compute(Matrix<BaseFloat> *output) {
 
   bool ans = source_->Read(&read_samples);
 
+  Vector<BaseFloat> all_samples(wave_remainder_.Dim() + read_samples.Dim());
+  all_samples.Range(0, wave_remainder_.Dim()).CopyFromVec(wave_remainder_);
+  all_samples.Range(wave_remainder_.Dim(), read_samples.Dim()).
+      CopyFromVec(read_samples);
+
   // Extract the features
-  if (read_samples.Dim() >= frame_size_) {
-    extractor_->Compute(read_samples, 1.0, output);
+  if (all_samples.Dim() >= frame_size_) {
+    // extract waveform remainder before calling Compute()
+    int32 num_frames = NumFrames(all_samples.Dim(), frame_opts_);
+    // offset is the amount at the start that has been extracted.
+    int32 offset = num_frames * frame_shift_;
+    int32 remaining_len = all_samples.Dim() - offset;
+    wave_remainder_.Resize(remaining_len);
+    KALDI_ASSERT(remaining_len >= 0);
+    if (remaining_len > 0)
+      wave_remainder_.CopyFromVec(SubVector<BaseFloat>(all_samples, offset, remaining_len));
+    extractor_->Compute(all_samples, 1.0, output);
   } else {
     output->Resize(0, 0);
+    wave_remainder_ = all_samples;
   }
 
   return ans;