#include <online-decodable.h>

Inheritance diagram for OnlineDecodableDiagGmmScaled:

Collaboration diagram for OnlineDecodableDiagGmmScaled:

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Public Member Functions
	OnlineDecodableDiagGmmScaled (const AmDiagGmm &am, const TransitionModel &trans_model, const BaseFloat scale, OnlineFeatureMatrix *input_feats)

virtual BaseFloat	LogLikelihood (int32 frame, int32 index)
	Returns the log likelihood, which will be negated in the decoder. More...

virtual bool	IsLastFrame (int32 frame) const
	Returns true if this is the last frame. More...

virtual int32	NumIndices () const
	Indices are one-based! This is for compatibility with OpenFst. More...

Public Member Functions inherited from DecodableInterface
virtual int32	NumFramesReady () const
	The call NumFramesReady() will return the number of frames currently available for this decodable object. More...

virtual	~DecodableInterface ()

Private Member Functions
void	CacheFrame (int32 frame)

	KALDI_DISALLOW_COPY_AND_ASSIGN (OnlineDecodableDiagGmmScaled)

Private Attributes
OnlineFeatureMatrix *	features_

const AmDiagGmm &	ac_model_

BaseFloat	ac_scale_

const TransitionModel &	trans_model_

const int32	feat_dim_

Vector< BaseFloat >	cur_feats_

int32	cur_frame_

std::vector< std::pair< int32, BaseFloat > >	cache_

Detailed Description

Definition at line 35 of file online-decodable.h.

Constructor & Destructor Documentation

◆ OnlineDecodableDiagGmmScaled()

OnlineDecodableDiagGmmScaled	(	const AmDiagGmm &	am,
		const TransitionModel &	trans_model,
		const BaseFloat	scale,
		OnlineFeatureMatrix *	input_feats
	)

Definition at line 27 of file online-decodable.cc.

References OnlineDecodableDiagGmmScaled::cache_, OnlineFeatureMatrix::IsValidFrame(), KALDI_ERR, TransitionModel::NumPdfs(), and OnlineDecodableDiagGmmScaled::trans_model_.

                                                             :  
       features_(input_feats), ac_model_(am),
       ac_scale_(scale), trans_model_(trans_model),
       feat_dim_(input_feats->Dim()), cur_frame_(-1) {
   if (!input_feats->IsValidFrame(0)) {
     // It's not safe to throw from a constructor, so please check
     // this condition yourself before reaching this point in the code.
     KALDI_ERR << "Attempt to initialize decodable object with empty "
               << "input: please check this before the initializer!";
   }
   int32 num_pdfs = trans_model_.NumPdfs();
   cache_.resize(num_pdfs, std::pair<int32,BaseFloat>(-1, 0.0));
 }

Member Function Documentation

◆ CacheFrame()

void CacheFrame ( int32 frame )

private

Definition at line 43 of file online-decodable.cc.

References OnlineDecodableDiagGmmScaled::cur_feats_, OnlineDecodableDiagGmmScaled::cur_frame_, OnlineDecodableDiagGmmScaled::feat_dim_, OnlineDecodableDiagGmmScaled::features_, OnlineFeatureMatrix::GetFrame(), OnlineFeatureMatrix::IsValidFrame(), KALDI_ASSERT, and KALDI_ERR.

Referenced by OnlineDecodableDiagGmmScaled::LogLikelihood(), and OnlineDecodableDiagGmmScaled::NumIndices().

                                                          {
   KALDI_ASSERT(frame >= 0);
   cur_feats_.Resize(feat_dim_);
   if (!features_->IsValidFrame(frame))
     KALDI_ERR << "Request for invalid frame (you need to check IsLastFrame, or, "
               << "for frame zero, check that the input is valid.";
   cur_feats_.CopyFromVec(features_->GetFrame(frame));
   cur_frame_ = frame;
 }

◆ IsLastFrame()

bool IsLastFrame ( int32 frame ) const

virtual

Returns true if this is the last frame.

Frames are zero-based, so the first frame is zero. IsLastFrame(-1) will return false, unless the file is empty (which is a case that I'm not sure all the code will handle, so be careful). Caution: the behavior of this function in an online setting is being changed somewhat. In future it may return false in cases where we haven't yet decided to terminate decoding, but later true if we decide to terminate decoding. The plan in future is to rely more on NumFramesReady(), and in future, IsLastFrame() would always return false in an online-decoding setting, and would only return true in a decoding-from-matrix setting where we want to allow the last delta or LDA features to be flushed out for compatibility with the baseline setup.

Implements DecodableInterface.

Definition at line 66 of file online-decodable.cc.

References OnlineDecodableDiagGmmScaled::features_, and OnlineFeatureMatrix::IsValidFrame().

                                                                 {
   return !features_->IsValidFrame(frame+1);
 }

◆ KALDI_DISALLOW_COPY_AND_ASSIGN()

KALDI_DISALLOW_COPY_AND_ASSIGN ( OnlineDecodableDiagGmmScaled )

private

◆ LogLikelihood()

BaseFloat LogLikelihood	(	int32	frame,
		int32	index
	)

virtual

Returns the log likelihood, which will be negated in the decoder.

Implements DecodableInterface.

Definition at line 53 of file online-decodable.cc.

References OnlineDecodableDiagGmmScaled::ac_model_, OnlineDecodableDiagGmmScaled::ac_scale_, OnlineDecodableDiagGmmScaled::cache_, OnlineDecodableDiagGmmScaled::CacheFrame(), OnlineDecodableDiagGmmScaled::cur_feats_, OnlineDecodableDiagGmmScaled::cur_frame_, AmDiagGmm::LogLikelihood(), OnlineDecodableDiagGmmScaled::trans_model_, and TransitionModel::TransitionIdToPdf().

                                                                               {
   if (frame != cur_frame_)
     CacheFrame(frame);
   int32 pdf_id = trans_model_.TransitionIdToPdf(index);
   if (cache_[pdf_id].first == frame)
     return cache_[pdf_id].second;
   BaseFloat ans = ac_model_.LogLikelihood(pdf_id, cur_feats_) * ac_scale_;
   cache_[pdf_id].first = frame;
   cache_[pdf_id].second = ans;
   return ans;
 }