online-nnet2-decoding.h
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// online2/online-nnet2-decoding.h
// 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.
#ifndef KALDI_ONLINE2_ONLINE_NNET2_DECODING_H_
#define KALDI_ONLINE2_ONLINE_NNET2_DECODING_H_
#include <string>
#include <vector>
#include <deque>
#include "matrix/matrix-lib.h"
#include "util/common-utils.h"
#include "base/kaldi-error.h"
#include "nnet2/online-nnet2-decodable.h"
#include "itf/online-feature-itf.h"
#include "online2/online-endpoint.h"
#include "decoder/lattice-faster-online-decoder.h"
#include "hmm/transition-model.h"
#include "hmm/posterior.h"
namespace kaldi {
/// @addtogroup onlinedecoding OnlineDecoding
/// @{
// This configuration class contains the configuration classes needed to create
// the class SingleUtteranceNnet2Decoder. The actual command line program
// requires other configs that it creates separately, and which are not included
// here: namely, OnlineNnet2FeaturePipelineConfig and OnlineEndpointConfig.
struct OnlineNnet2DecodingConfig {
LatticeFasterDecoderConfig decoder_opts;
nnet2::DecodableNnet2OnlineOptions decodable_opts;
OnlineNnet2DecodingConfig() { decodable_opts.acoustic_scale = 0.1; }
void Register(OptionsItf *opts) {
decoder_opts.Register(opts);
decodable_opts.Register(opts);
}
};
/**
You will instantiate this class when you want to decode a single
utterance using the online-decoding setup for neural nets.
*/
class SingleUtteranceNnet2Decoder {
public:
// Constructor. The feature_pipeline_ pointer is not owned in this
// class, it's owned externally.
SingleUtteranceNnet2Decoder(const OnlineNnet2DecodingConfig &config,
const TransitionModel &tmodel,
const nnet2::AmNnet &model,
const fst::Fst<fst::StdArc> &fst,
OnlineFeatureInterface *feature_pipeline);
/// advance the decoding as far as we can.
void AdvanceDecoding();
/// Finalizes the decoding. Cleans up and prunes remaining tokens, so the
/// GetLattice() call will return faster. You must not call this before
/// calling (TerminateDecoding() or InputIsFinished()) and then Wait().
void FinalizeDecoding();
int32 NumFramesDecoded() const;
/// Gets the lattice. The output lattice has any acoustic scaling in it
/// (which will typically be desirable in an online-decoding context); if you
/// want an un-scaled lattice, scale it using ScaleLattice() with the inverse
/// of the acoustic weight. "end_of_utterance" will be true if you want the
/// final-probs to be included.
void GetLattice(bool end_of_utterance,
CompactLattice *clat) const;
/// Outputs an FST corresponding to the single best path through the current
/// lattice. If "use_final_probs" is true AND we reached the final-state of
/// the graph then it will include those as final-probs, else it will treat
/// all final-probs as one.
void GetBestPath(bool end_of_utterance,
Lattice *best_path) const;
/// This function calls EndpointDetected from online-endpoint.h,
/// with the required arguments.
bool EndpointDetected(const OnlineEndpointConfig &config);
const LatticeFasterOnlineDecoder &Decoder() const { return decoder_; }
~SingleUtteranceNnet2Decoder() { }
private:
OnlineNnet2DecodingConfig config_;
OnlineFeatureInterface *feature_pipeline_;
const TransitionModel &tmodel_;
nnet2::DecodableNnet2Online decodable_;
LatticeFasterOnlineDecoder decoder_;
};
/// @} End of "addtogroup onlinedecoding"
} // namespace kaldi
#endif // KALDI_ONLINE2_ONLINE_NNET2_DECODING_H_