/
online-endpoint.cc
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/
online-endpoint.cc
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// online2/online-endpoint.cc
// Copyright 2014 Johns Hopkins University (author: Daniel Povey)
// See ../../COPYING for clarification regarding multiple authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
// WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
// MERCHANTABLITY OR NON-INFRINGEMENT.
// See the Apache 2 License for the specific language governing permissions and
// limitations under the License.
#include "online2/online-endpoint.h"
#include "decoder/lattice-faster-online-decoder.h"
#include "decoder/grammar-fst.h"
namespace kaldi {
static bool RuleActivated(const OnlineEndpointRule &rule,
const std::string &rule_name,
BaseFloat trailing_silence,
BaseFloat relative_cost,
BaseFloat utterance_length) {
bool contains_nonsilence = (utterance_length > trailing_silence);
bool ans = (contains_nonsilence || !rule.must_contain_nonsilence) &&
trailing_silence >= rule.min_trailing_silence &&
relative_cost <= rule.max_relative_cost &&
utterance_length >= rule.min_utterance_length;
if (ans) {
KALDI_VLOG(2) << "Endpointing rule " << rule_name << " activated: "
<< (contains_nonsilence ? "true" : "false" ) << ','
<< trailing_silence << ',' << relative_cost << ','
<< utterance_length;
}
return ans;
}
bool EndpointDetected(const OnlineEndpointConfig &config,
int32 num_frames_decoded,
int32 trailing_silence_frames,
BaseFloat frame_shift_in_seconds,
BaseFloat final_relative_cost) {
KALDI_ASSERT(num_frames_decoded >= trailing_silence_frames);
BaseFloat utterance_length = num_frames_decoded * frame_shift_in_seconds,
trailing_silence = trailing_silence_frames * frame_shift_in_seconds;
if (RuleActivated(config.rule1, "rule1",
trailing_silence, final_relative_cost, utterance_length))
return true;
if (RuleActivated(config.rule2, "rule2",
trailing_silence, final_relative_cost, utterance_length))
return true;
if (RuleActivated(config.rule3, "rule3",
trailing_silence, final_relative_cost, utterance_length))
return true;
if (RuleActivated(config.rule4, "rule4",
trailing_silence, final_relative_cost, utterance_length))
return true;
if (RuleActivated(config.rule5, "rule5",
trailing_silence, final_relative_cost, utterance_length))
return true;
return false;
}
template <typename DEC>
int32 TrailingSilenceLength(const TransitionInformation &tmodel,
const std::string &silence_phones_str,
const DEC &decoder) {
std::vector<int32> silence_phones;
if (!SplitStringToIntegers(silence_phones_str, ":", false, &silence_phones))
KALDI_ERR << "Bad --silence-phones option in endpointing config: "
<< silence_phones_str;
std::sort(silence_phones.begin(), silence_phones.end());
KALDI_ASSERT(IsSortedAndUniq(silence_phones) &&
"Duplicates in --silence-phones option in endpointing config");
KALDI_ASSERT(!silence_phones.empty() &&
"Endpointing requires nonempty --endpoint.silence-phones option");
ConstIntegerSet<int32> silence_set(silence_phones);
bool use_final_probs = false;
typename DEC::BestPathIterator iter =
decoder.BestPathEnd(use_final_probs, NULL);
int32 num_silence_frames = 0;
while (!iter.Done()) { // we're going backwards in time from the most
// recently decoded frame...
LatticeArc arc;
iter = decoder.TraceBackBestPath(iter, &arc);
if (arc.ilabel != 0) {
int32 phone = tmodel.TransitionIdToPhone(arc.ilabel);
if (silence_set.count(phone) != 0) {
num_silence_frames++;
} else {
break; // stop counting as soon as we hit non-silence.
}
}
}
return num_silence_frames;
}
template <typename DEC>
bool EndpointDetected(
const OnlineEndpointConfig &config,
const TransitionInformation &tmodel,
BaseFloat frame_shift_in_seconds,
const DEC &decoder) {
if (decoder.NumFramesDecoded() == 0) return false;
BaseFloat final_relative_cost = decoder.FinalRelativeCost();
int32 num_frames_decoded = decoder.NumFramesDecoded(),
trailing_silence_frames = TrailingSilenceLength(tmodel,
config.silence_phones,
decoder);
return EndpointDetected(config, num_frames_decoded, trailing_silence_frames,
frame_shift_in_seconds, final_relative_cost);
}
// Instantiate EndpointDetected for the types we need.
// It will require TrailingSilenceLength so we don't have to instantiate that.
template
bool EndpointDetected<LatticeFasterOnlineDecoderTpl<fst::Fst<fst::StdArc> > >(
const OnlineEndpointConfig &config,
const TransitionInformation &tmodel,
BaseFloat frame_shift_in_seconds,
const LatticeFasterOnlineDecoderTpl<fst::Fst<fst::StdArc> > &decoder);
template
bool EndpointDetected<LatticeFasterOnlineDecoderTpl<fst::ConstGrammarFst > >(
const OnlineEndpointConfig &config,
const TransitionInformation &tmodel,
BaseFloat frame_shift_in_seconds,
const LatticeFasterOnlineDecoderTpl<fst::ConstGrammarFst > &decoder);
template
bool EndpointDetected<LatticeFasterOnlineDecoderTpl<fst::VectorGrammarFst > >(
const OnlineEndpointConfig &config,
const TransitionInformation &tmodel,
BaseFloat frame_shift_in_seconds,
const LatticeFasterOnlineDecoderTpl<fst::VectorGrammarFst > &decoder);
template
bool EndpointDetected<LatticeIncrementalOnlineDecoderTpl<fst::Fst<fst::StdArc> > >(
const OnlineEndpointConfig &config,
const TransitionInformation &tmodel,
BaseFloat frame_shift_in_seconds,
const LatticeIncrementalOnlineDecoderTpl<fst::Fst<fst::StdArc> > &decoder);
template
bool EndpointDetected<LatticeIncrementalOnlineDecoderTpl<fst::ConstGrammarFst > >(
const OnlineEndpointConfig &config,
const TransitionInformation &tmodel,
BaseFloat frame_shift_in_seconds,
const LatticeIncrementalOnlineDecoderTpl<fst::ConstGrammarFst > &decoder);
template
bool EndpointDetected<LatticeIncrementalOnlineDecoderTpl<fst::VectorGrammarFst > >(
const OnlineEndpointConfig &config,
const TransitionInformation &tmodel,
BaseFloat frame_shift_in_seconds,
const LatticeIncrementalOnlineDecoderTpl<fst::VectorGrammarFst > &decoder);
} // namespace kaldi