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Diffstat (limited to 'kaldi_io/src/kaldi/hmm/posterior.h')
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diff --git a/kaldi_io/src/kaldi/hmm/posterior.h b/kaldi_io/src/kaldi/hmm/posterior.h new file mode 100644 index 0000000..be73be9 --- /dev/null +++ b/kaldi_io/src/kaldi/hmm/posterior.h @@ -0,0 +1,214 @@ +// hmm/posterior.h + +// Copyright 2009-2011 Microsoft Corporation +// 2013-2014 Johns Hopkins University (author: Daniel Povey) +// 2014 Guoguo Chen + + +// 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_HMM_POSTERIOR_H_ +#define KALDI_HMM_POSTERIOR_H_ + +#include "base/kaldi-common.h" +#include "tree/context-dep.h" +#include "util/const-integer-set.h" +#include "util/kaldi-table.h" +#include "hmm/transition-model.h" + + +namespace kaldi { + + +/// \addtogroup posterior_group +/// @{ + +/// Posterior is a typedef for storing acoustic-state (actually, transition-id) +/// posteriors over an utterance. The "int32" is a transition-id, and the BaseFloat +/// is a probability (typically between zero and one). +typedef std::vector<std::vector<std::pair<int32, BaseFloat> > > Posterior; + +/// GaussPost is a typedef for storing Gaussian-level posteriors for an utterance. +/// the "int32" is a transition-id, and the Vector<BaseFloat> is a vector of +/// Gaussian posteriors. +/// WARNING: We changed "int32" from transition-id to pdf-id, and the change is +/// applied for all programs using GaussPost. This is for efficiency purpose. We +/// also changed the name slightly from GauPost to GaussPost to reduce the +/// chance that the change will go un-noticed in downstream code. +typedef std::vector<std::vector<std::pair<int32, Vector<BaseFloat> > > > GaussPost; + + +// PosteriorHolder is a holder for Posterior, which is +// std::vector<std::vector<std::pair<int32, BaseFloat> > > +// This is used for storing posteriors of transition id's for an +// utterance. +class PosteriorHolder { + public: + typedef Posterior T; + + PosteriorHolder() { } + + static bool Write(std::ostream &os, bool binary, const T &t); + + void Clear() { Posterior tmp; std::swap(tmp, t_); } + + // Reads into the holder. + bool Read(std::istream &is); + + // Kaldi objects always have the stream open in binary mode for + // reading. + static bool IsReadInBinary() { return true; } + + const T &Value() const { return t_; } + + private: + KALDI_DISALLOW_COPY_AND_ASSIGN(PosteriorHolder); + T t_; +}; + + +// GaussPostHolder is a holder for GaussPost, which is +// std::vector<std::vector<std::pair<int32, Vector<BaseFloat> > > > +// This is used for storing posteriors of transition id's for an +// utterance. +class GaussPostHolder { + public: + typedef GaussPost T; + + GaussPostHolder() { } + + static bool Write(std::ostream &os, bool binary, const T &t); + + void Clear() { GaussPost tmp; std::swap(tmp, t_); } + + // Reads into the holder. + bool Read(std::istream &is); + + // Kaldi objects always have the stream open in binary mode for + // reading. + static bool IsReadInBinary() { return true; } + + const T &Value() const { return t_; } + + private: + KALDI_DISALLOW_COPY_AND_ASSIGN(GaussPostHolder); + T t_; +}; + + +// Posterior is a typedef: vector<vector<pair<int32, BaseFloat> > >, +// representing posteriors over (typically) transition-ids for an +// utterance. +typedef TableWriter<PosteriorHolder> PosteriorWriter; +typedef SequentialTableReader<PosteriorHolder> SequentialPosteriorReader; +typedef RandomAccessTableReader<PosteriorHolder> RandomAccessPosteriorReader; + + +// typedef std::vector<std::vector<std::pair<int32, Vector<BaseFloat> > > > GaussPost; +typedef TableWriter<GaussPostHolder> GaussPostWriter; +typedef SequentialTableReader<GaussPostHolder> SequentialGaussPostReader; +typedef RandomAccessTableReader<GaussPostHolder> RandomAccessGaussPostReader; + + +/// Scales the BaseFloat (weight) element in the posterior entries. +void ScalePosterior(BaseFloat scale, Posterior *post); + +/// Returns the total of all the weights in "post". +BaseFloat TotalPosterior(const Posterior &post); + +/// Returns true if the two lists of pairs have no common .first element. +bool PosteriorEntriesAreDisjoint( + const std::vector<std::pair<int32, BaseFloat> > &post_elem1, + const std::vector<std::pair<int32, BaseFloat> > &post_elem2); + + +/// Merge two sets of posteriors, which must have the same length. If "merge" +/// is true, it will make a common entry whenever there are duplicated entries, +/// adding up the weights. If "drop_frames" is true, for frames where the +/// two sets of posteriors were originally disjoint, makes no entries for that +/// frame (relates to frame dropping, or drop_frames, see Vesely et al, ICASSP +/// 2013). Returns the number of frames for which the two posteriors were +/// disjoint (i.e. no common transition-ids or whatever index we are using). +int32 MergePosteriors(const Posterior &post1, + const Posterior &post2, + bool merge, + bool drop_frames, + Posterior *post); + +/// Given a vector of log-likelihoods (typically of Gaussians in a GMM +/// but could be of pdf-ids), a number gselect >= 1 and a minimum posterior +/// 0 <= min_post < 1, it gets the posterior for each element of log-likes +/// by applying Softmax(), then prunes the posteriors using "gselect" and +/// "min_post" (keeping at least one), and outputs the result into +/// "post_entry", sorted from greatest to least posterior. +/// Returns the total log-likelihood (the output of calling ApplySoftMax() +/// on a copy of log_likes). +BaseFloat VectorToPosteriorEntry( + const VectorBase<BaseFloat> &log_likes, + int32 num_gselect, + BaseFloat min_post, + std::vector<std::pair<int32, BaseFloat> > *post_entry); + +/// Convert an alignment to a posterior (with a scale of 1.0 on +/// each entry). +void AlignmentToPosterior(const std::vector<int32> &ali, + Posterior *post); + +/// Sorts posterior entries so that transition-ids with same pdf-id are next to +/// each other. +void SortPosteriorByPdfs(const TransitionModel &tmodel, + Posterior *post); + + +/// Converts a posterior over transition-ids to be a posterior +/// over pdf-ids. +void ConvertPosteriorToPdfs(const TransitionModel &tmodel, + const Posterior &post_in, + Posterior *post_out); + +/// Converts a posterior over transition-ids to be a posterior +/// over phones. +void ConvertPosteriorToPhones(const TransitionModel &tmodel, + const Posterior &post_in, + Posterior *post_out); + +/// Weight any silence phones in the posterior (i.e. any phones +/// in the set "silence_set" by scale "silence_scale". +/// The interface was changed in Feb 2014 to do the modification +/// "in-place" rather than having separate input and output. +void WeightSilencePost(const TransitionModel &trans_model, + const ConstIntegerSet<int32> &silence_set, + BaseFloat silence_scale, + Posterior *post); + +/// This is similar to WeightSilencePost, except that on each frame it +/// works out the amount by which the overall posterior would be reduced, +/// and scales down everything on that frame by the same amount. It +/// has the effect that frames that are mostly silence get down-weighted. +/// The interface was changed in Feb 2014 to do the modification +/// "in-place" rather than having separate input and output. +void WeightSilencePostDistributed(const TransitionModel &trans_model, + const ConstIntegerSet<int32> &silence_set, + BaseFloat silence_scale, + Posterior *post); + +/// @} end "addtogroup posterior_group" + + +} // end namespace kaldi + + +#endif |