Merge pull request kaldi-asr#23 from david-ryan-snyder/xvector2

Xvector: another update to nnet3-xvector-compute

src/xvectorbin/nnet3-xvector-compute.cc

@@ -86,6 +86,7 @@ int main(int argc, char *argv[]) {
                 << "be true.";
     if (chunk_size == -1)
       chunk_size = xvector_period;
+
     KALDI_ASSERT(chunk_size > 0 && xvector_period > 0);
 
     std::string nnet_rxfilename = po.GetArg(1),
@@ -102,30 +103,42 @@ int main(int argc, char *argv[]) {
 
     int32 num_success = 0,
           num_fail = 0,
+          left_context,
+          right_context,
           xvector_dim = nnet.OutputDim("output");
+    ComputeSimpleNnetContext(nnet, &left_context, &right_context);
+    int32 min_chunk_size = left_context + right_context;
     int64 frame_count = 0;
 
     SequentialBaseFloatMatrixReader feat_reader(feat_rspecifier);
     for (; !feat_reader.Done(); feat_reader.Next()) {
       std::string utt = feat_reader.Key();
       const Matrix<BaseFloat> &feats (feat_reader.Value());
       int32 num_rows = feats.NumRows(),
-            feat_dim = feats.NumCols();
-      if (num_rows < chunk_size) {
-        KALDI_WARN << "The chunk-size is greater than the number of rows "
+            feat_dim = feats.NumCols(),
+            this_chunk_size = chunk_size;
+
+      if (num_rows < min_chunk_size) {
+        KALDI_WARN << "Minimum chunk size of " << min_chunk_size
+                   << " is greater than the number of rows "
                    << "in utterance: " << utt;
         num_fail++;
         continue;
+      } else if (num_rows < this_chunk_size) {
+        KALDI_LOG << "Chunk size of " << this_chunk_size << " is greater than "
+                  << "the number of rows in utterance: " << utt
+                  << ", using chunk size  of " << num_rows;
+        this_chunk_size = num_rows;
       }
 
-      int32 num_chunks = ceil((num_rows - chunk_size)
+      int32 num_chunks = ceil((num_rows - this_chunk_size)
             / static_cast<BaseFloat>(xvector_period)) + 1,
             num_xvectors = repeat ? num_rows : ceil(num_rows
             / static_cast<BaseFloat>(xvector_period));
 
       // The number of frames by which the last two chunks overlap.
       int32 overlap = std::max(0, (num_chunks - 1) * xvector_period
-                      - num_rows + chunk_size);
+                      - num_rows + this_chunk_size);
       BaseFloat total_chunk_weight = 0.0;
       Vector<BaseFloat> xvector_avg;
       Matrix<BaseFloat> xvector_mat;
@@ -140,11 +153,11 @@ int main(int argc, char *argv[]) {
       // Iterate over the feature chunks.
       for (int32 chunk_indx = 0; chunk_indx < num_chunks; chunk_indx++) {
         // If we're nearing the end of the input, we may need to shift the
-        // offset back so that we can get chunk_size frames of input to the
-        // nnet.
+        // offset back so that we can get this_chunk_size frames of input to
+        // the nnet.
         int32 offset = std::min(chunk_indx * xvector_period,
-                           num_rows - chunk_size);
-        SubMatrix<BaseFloat> sub_feats(feats, offset, chunk_size,
+                           num_rows - this_chunk_size);
+        SubMatrix<BaseFloat> sub_feats(feats, offset, this_chunk_size,
                                        0, feat_dim);
         Vector<BaseFloat> xvector(xvector_dim);
         nnet_computer.ComputeXvector(sub_feats, &xvector);
@@ -155,9 +168,9 @@ int main(int argc, char *argv[]) {
           // chunks, so that the overlapping portion isn't counted twice.
           BaseFloat weight;
           if (chunk_indx < num_chunks - 2)
-            weight = chunk_size;
+            weight = this_chunk_size;
           else
-            weight = chunk_size - 0.5 * overlap;
+            weight = this_chunk_size - 0.5 * overlap;
           total_chunk_weight += weight;
           xvector_avg.AddVec(weight, xvector);
         // Cases for outputting as a matrix: