From e78a50867a6cc733bf2b2a34be7a942cd1758495 Mon Sep 17 00:00:00 2001
From: Amit Beka <amit.beka@gmail.com>
Date: Tue, 25 Nov 2014 18:06:34 +0200
Subject: [PATCH] add inverse-scale property
When decoding the input, the output lattice is scaled using the acoustic
scale parameter. When 'inverse-scale' is set to TRUE, the lattice is
re-scaled back (inverse the acoustic scale) before the hypothesis is
extracted.
This behavior is common when playing with different scales after the
decoding phase.
Signed-off-by: Amit Beka <amit.beka@gmail.com>
---
src/gstkaldinnet2onlinedecoder.cc | 26 +++++++++++++++++++++++++-
src/gstkaldinnet2onlinedecoder.h | 1 +
2 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/src/gstkaldinnet2onlinedecoder.cc b/src/gstkaldinnet2onlinedecoder.cc
index 3a7455e..6c8749e 100644
--- a/src/gstkaldinnet2onlinedecoder.cc
+++ b/src/gstkaldinnet2onlinedecoder.cc
@@ -70,6 +70,7 @@ enum {
PROP_WORD_SYMS,
PROP_DO_ENDPOINTING,
PROP_ADAPTATION_STATE,
+ PROP_INVERSE_SCALE,
PROP_LAST
};
@@ -185,6 +186,15 @@ static void gst_kaldinnet2onlinedecoder_class_init(
"",
(GParamFlags) G_PARAM_READWRITE));
+ g_object_class_install_property(
+ gobject_class,
+ PROP_INVERSE_SCALE,
+ g_param_spec_boolean(
+ "inverse-scale", "If true, inverse acoustic scale in lattice",
+ "If true, inverse the acoustic scaling of the output lattice",
+ FALSE,
+ (GParamFlags) G_PARAM_READWRITE));
+
gst_kaldinnet2onlinedecoder_signals[PARTIAL_RESULT_SIGNAL] = g_signal_new(
"partial-result", G_TYPE_FROM_CLASS(klass), G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET(Gstkaldinnet2onlinedecoderClass, partial_result),
@@ -260,6 +270,7 @@ static void gst_kaldinnet2onlinedecoder_init(
filter->feature_info = NULL;
filter->sample_rate = 0;
filter->decoding = false;
+ filter->inverse_scale = FALSE;
// init properties from various Kaldi Opts
GstElementClass * klass = GST_ELEMENT_GET_CLASS(filter);
@@ -366,6 +377,9 @@ static void gst_kaldinnet2onlinedecoder_set_property(GObject * object,
case PROP_DO_ENDPOINTING:
filter->do_endpointing = g_value_get_boolean(value);
break;
+ case PROP_INVERSE_SCALE:
+ filter->inverse_scale = g_value_get_boolean(value);
+ break;
case PROP_ADAPTATION_STATE:
{
if (G_VALUE_HOLDS_STRING(value)) {
@@ -463,6 +477,9 @@ static void gst_kaldinnet2onlinedecoder_get_property(GObject * object,
case PROP_DO_ENDPOINTING:
g_value_set_boolean(value, filter->do_endpointing);
break;
+ case PROP_INVERSE_SCALE:
+ g_value_set_boolean(value, filter->inverse_scale);
+ break;
case PROP_ADAPTATION_STATE:
string_stream.clear();
if (filter->adaptation_state) {
@@ -513,13 +530,20 @@ static void gst_kaldinnet2onlinedecoder_get_property(GObject * object,
}
static void gst_kaldinnet2onlinedecoder_final_result(
- Gstkaldinnet2onlinedecoder * filter, const CompactLattice &clat,
+ Gstkaldinnet2onlinedecoder * filter, CompactLattice &clat,
int64 *tot_num_frames, double *tot_like, guint *num_words) {
if (clat.NumStates() == 0) {
KALDI_WARN<< "Empty lattice.";
return;
}
CompactLattice best_path_clat;
+
+ if (filter->inverse_scale) {
+ BaseFloat inv_acoustic_scale = 1.0 / filter->nnet2_decoding_config->
+ decodable_opts.acoustic_scale;
+ fst::ScaleLattice(fst::AcousticLatticeScale(inv_acoustic_scale), &clat);
+ }
+
CompactLatticeShortestPath(clat, &best_path_clat);
Lattice best_path_lat;
diff --git a/src/gstkaldinnet2onlinedecoder.h b/src/gstkaldinnet2onlinedecoder.h
index ef02fae..a1bb9d2 100644
--- a/src/gstkaldinnet2onlinedecoder.h
+++ b/src/gstkaldinnet2onlinedecoder.h
@@ -60,6 +60,7 @@ struct _Gstkaldinnet2onlinedecoder {
gboolean silent;
gboolean do_endpointing;
+ gboolean inverse_scale;
GstBufferSource *audio_source;
gchar* model_rspecifier;
--
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