now supports different sample rates

src/Makefile

 all:
 
-KALDI_ROOT?=~/tools/kaldi-online
+KALDI_ROOT?=/home/tanel/tools/kaldi-online
 
 ifeq ("$(wildcard $(KALDI_ROOT)/src/kaldi.mk)","")
 $(error Cannot find Kaldi's makefile $(KALDI_ROOT)/src/kaldi.mk. \
-Specify Kaldi's root directory using KALDI_ROOT when issuing make, e.g.: `KALDI_ROOT=~/tools/kaldi-trunk make` )
+Specify Kaldi's root directory using KALDI_ROOT when issuing make, e.g.: `KALDI_ROOT=/home/tanel/tools/kaldi-trunk make` )
 endif
 
 include $(KALDI_ROOT)/src/kaldi.mk

src/gstkaldinnet2onlinedecoder.cc

@@ -78,7 +78,7 @@ enum {
 /* the capabilities of the inputs and outputs.
  *
  */
-static GstStaticPadTemplate sink_factory =
+static GstStaticPadTemplate sink_template =
 GST_STATIC_PAD_TEMPLATE("sink",
     GST_PAD_SINK,
     GST_PAD_ALWAYS,
@@ -86,9 +86,9 @@ GST_STATIC_PAD_TEMPLATE("sink",
         "audio/x-raw, "
         "format = (string) S16LE, "
         "channels = (int) 1, "
-        "rate = (int) 16000 "));
+        "rate = (int) [ 1, MAX ]"));
 
-static GstStaticPadTemplate src_factory =
+static GstStaticPadTemplate src_template =
 GST_STATIC_PAD_TEMPLATE("src",
     GST_PAD_SRC,
     GST_PAD_ALWAYS,
@@ -121,6 +121,8 @@ static GstFlowReturn gst_kaldinnet2onlinedecoder_chain(GstPad * pad,
 static GstStateChangeReturn gst_kaldinnet2onlinedecoder_change_state(
     GstElement *element, GstStateChange transition);
 
+static gboolean gst_kaldinnet2onlinedecoder_query (GstPad *pad, GstObject * parent, GstQuery * query);
+
 static void gst_kaldinnet2onlinedecoder_finalize(GObject * object);
 
 /* GObject vmethod implementations */
@@ -191,10 +193,11 @@ static void gst_kaldinnet2onlinedecoder_class_init(
       gstelement_class, "KaldiNNet2OnlineDecoder", "Speech/Audio",
       "Convert speech to text", "Tanel Alumae <tanel.alumae@phon.ioc.ee>");
 
+
   gst_element_class_add_pad_template(gstelement_class,
-                                     gst_static_pad_template_get(&src_factory));
+                                     gst_static_pad_template_get(&src_template));
   gst_element_class_add_pad_template(
-      gstelement_class, gst_static_pad_template_get(&sink_factory));
+      gstelement_class, gst_static_pad_template_get(&sink_template));
 }
 
 /* initialize the new element
@@ -211,17 +214,21 @@ static void gst_kaldinnet2onlinedecoder_init(
   double tmp_double;
   std::string tmp_string;
 
-  filter->sinkpad = gst_pad_new_from_static_template(&sink_factory, "sink");
+  filter->sinkpad = NULL;
+
+  filter->sinkpad = gst_pad_new_from_static_template(&sink_template, "sink");
   gst_pad_set_event_function(
       filter->sinkpad,
       GST_DEBUG_FUNCPTR(gst_kaldinnet2onlinedecoder_sink_event));
   gst_pad_set_chain_function(
       filter->sinkpad, GST_DEBUG_FUNCPTR(gst_kaldinnet2onlinedecoder_chain));
+  gst_pad_set_query_function(
+      filter->sinkpad, GST_DEBUG_FUNCPTR(gst_kaldinnet2onlinedecoder_query));
 
-  gst_pad_use_fixed_caps(filter->sinkpad);
   gst_element_add_pad(GST_ELEMENT(filter), filter->sinkpad);
 
-  filter->srcpad = gst_pad_new_from_static_template(&src_factory, "src");
+
+  filter->srcpad = gst_pad_new_from_static_template(&src_template, "src");
   gst_pad_use_fixed_caps(filter->srcpad);
   gst_element_add_pad(GST_ELEMENT(filter), filter->srcpad);
 
@@ -240,6 +247,10 @@ static void gst_kaldinnet2onlinedecoder_init(
   filter->feature_config->Register(filter->simple_options);
   filter->nnet2_decoding_config->Register(filter->simple_options);
 
+  // will be set later
+  filter->feature_info = NULL;
+  filter->sample_rate = 0;
+
   // init properties from various Kaldi Opts
   GstElementClass * klass = GST_ELEMENT_GET_CLASS(filter);
 
@@ -316,7 +327,6 @@ static void gst_kaldinnet2onlinedecoder_init(
     }
     i += 1;
   }
-
 }
 
 static void gst_kaldinnet2onlinedecoder_set_property(GObject * object,
@@ -533,7 +543,7 @@ static void gst_kaldinnet2onlinedecoder_loop(
   BaseFloat chunk_length_secs = 0.05;
   BaseFloat traceback_period_secs = 1.0;
 
-  int32 chunk_length = int32(16000 * chunk_length_secs);
+  int32 chunk_length = int32(filter->sample_rate * chunk_length_secs);
 
   bool more_data = true;
   while (more_data) {
@@ -556,7 +566,7 @@ static void gst_kaldinnet2onlinedecoder_loop(
     while (true) {
       more_data = filter->audio_source->Read(&wave_part);
       //GST_DEBUG_OBJECT(filter,  "Read %d samples", wave_part.Dim());
-      feature_pipeline.AcceptWaveform(16000, wave_part);
+      feature_pipeline.AcceptWaveform(filter->sample_rate, wave_part);
       //GST_DEBUG_OBJECT(filter,  "Advancing decoding..");
       if (!more_data) {
         feature_pipeline.InputFinished();
@@ -600,6 +610,73 @@ static void gst_kaldinnet2onlinedecoder_loop(
 
 /* GstElement vmethod implementations */
 
+static gboolean
+gst_kaldinnet2onlinedecoder_query (GstPad *pad, GstObject * parent, GstQuery * query) {
+  gboolean ret;
+  Gstkaldinnet2onlinedecoder *filter;
+
+  filter = GST_KALDINNET2ONLINEDECODER(parent);
+
+  switch (GST_QUERY_TYPE (query)) {
+    case GST_QUERY_CAPS: {
+      if (filter->feature_info == NULL) {
+        filter->feature_info = new OnlineNnet2FeaturePipelineInfo(*(filter->feature_config));
+        filter->sample_rate = (int) filter->feature_info->mfcc_opts.frame_opts.samp_freq;
+      }
+      GstCaps *new_caps = gst_caps_new_simple ("audio/x-raw",
+            "format", G_TYPE_STRING, "S16LE",
+            "rate", G_TYPE_INT, filter->sample_rate,
+            "channels", G_TYPE_INT, 1, NULL);
+
+
+//      GstPad *otherpad;
+//      GstCaps *temp, *caps, *filt, *tcaps;
+//      gint i;
+//
+//      otherpad = (pad == filter->srcpad) ? filter->sinkpad :
+//                                           filter->srcpad;
+//      caps = gst_pad_get_allowed_caps (otherpad);
+//
+//      gst_query_parse_caps (query, &filt);
+//
+//      /* We support *any* samplerate, indifferent from the samplerate
+//       * supported by the linked elements on both sides. */
+//      for (i = 0; i < gst_caps_get_size (caps); i++) {
+//        GstStructure *structure = gst_caps_get_structure (caps, i);
+//
+//        gst_structure_remove_field (structure, "rate");
+//      }
+//
+//      /* make sure we only return results that intersect our
+//       * padtemplate */
+//      tcaps = gst_pad_get_pad_template_caps (pad);
+//      if (tcaps) {
+//        temp = gst_caps_intersect (caps, tcaps);
+//        gst_caps_unref (caps);
+//        gst_caps_unref (tcaps);
+//        caps = temp;
+//      }
+//      /* filter against the query filter when needed */
+//      if (filt) {
+//        temp = gst_caps_intersect (caps, filt);
+//        gst_caps_unref (caps);
+//        caps = temp;
+//      }
+      GST_DEBUG_OBJECT (filter, "Setting caps query result: %" GST_PTR_FORMAT, new_caps);
+      gst_query_set_caps_result (query, new_caps);
+      gst_caps_unref (new_caps);
+      ret = TRUE;
+      break;
+    }
+    default:
+      ret = gst_pad_query_default (pad, parent, query);
+      break;
+  }
+  return ret;
+}
+
+
+
 /* this function handles sink events */
 static gboolean gst_kaldinnet2onlinedecoder_sink_event(GstPad * pad,
                                                        GstObject * parent,
@@ -647,9 +724,8 @@ static gboolean gst_kaldinnet2onlinedecoder_sink_event(GstPad * pad,
 static GstFlowReturn gst_kaldinnet2onlinedecoder_chain(GstPad * pad,
                                                        GstObject * parent,
                                                        GstBuffer * buf) {
-  Gstkaldinnet2onlinedecoder *filter;
+  Gstkaldinnet2onlinedecoder *filter = GST_KALDINNET2ONLINEDECODER(parent);
 
-  filter = GST_KALDINNET2ONLINEDECODER(parent);
 
   if (G_UNLIKELY(!filter->audio_source))
     goto not_negotiated;
@@ -669,15 +745,21 @@ static GstFlowReturn gst_kaldinnet2onlinedecoder_chain(GstPad * pad,
   }
 }
 
-static bool gst_kaldinnet2onlinedecoder_allocate(
+
+static bool
+gst_kaldinnet2onlinedecoder_allocate(
     Gstkaldinnet2onlinedecoder * filter) {
-  if (!filter->feature_info) {
+  if (!filter->decode_fst) {
     GST_INFO_OBJECT(filter, "Loading Kaldi models and feature extractor");
 
     filter->audio_source = new GstBufferSource();
 
-    filter->feature_info = new OnlineNnet2FeaturePipelineInfo(
-        *(filter->feature_config));
+    if (filter->feature_info == NULL) {
+      filter->feature_info = new OnlineNnet2FeaturePipelineInfo(*(filter->feature_config));
+      filter->sample_rate = (int) filter->feature_info->mfcc_opts.frame_opts.samp_freq;
+    }
+
+    filter->sample_rate = (int) filter->feature_info->mfcc_opts.frame_opts.samp_freq;
 
     filter->trans_model = new TransitionModel();
     filter->nnet = new nnet2::AmNnet();
@@ -710,6 +792,7 @@ static bool gst_kaldinnet2onlinedecoder_deallocate(
 
 static GstStateChangeReturn gst_kaldinnet2onlinedecoder_change_state(
     GstElement *element, GstStateChange transition) {
+
   GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
   Gstkaldinnet2onlinedecoder *filter = GST_KALDINNET2ONLINEDECODER(element);
 

src/gstkaldinnet2onlinedecoder.h

@@ -84,6 +84,8 @@ struct _Gstkaldinnet2onlinedecoder
 
   GstPad *sinkpad, *srcpad;
 
+  GstCaps *sink_caps;
+
   gboolean silent;
   gboolean do_endpointing;
   GstBufferSource *audio_source;
@@ -102,6 +104,7 @@ struct _Gstkaldinnet2onlinedecoder
   nnet2::AmNnet *nnet;
   fst::Fst<fst::StdArc> *decode_fst;
   fst::SymbolTable *word_syms;
+  int sample_rate;
 };
 
 struct _Gstkaldinnet2onlinedecoderClass