nbest-scripts.1

这是一款很好用的工具包

.\" $Id: nbest-scripts.1,v 1.35 2006/07/29 18:42:28 stolcke Exp $
.TH nbest-scripts 1 "$Date: 2006/07/29 18:42:28 $" "SRILM Tools"
.SH NAME
nbest-scripts, combine-rover-controls, compare-sclite, compute-sclite, fix-ctm, merge-nbest, nbest-error, nbest-posteriors, nbest-rover, nbest-vocab, nbest2-to-nbest1, rescore-acoustic, rescore-decipher, rescore-reweight, sentid-to-sclite \- rescore and evaluate N-best lists
.SH SYNOPSIS
.B rescore-decipher 
.RB [ \-bytelog ]
.RB [ \-nodecipherlm ]
.RB [ \-multiwords ]
.RB [ \-pretty
.IR mapfile ]
.RB [ \-ngram-tool
.IR program ]
.RB [ \-filter
.IR command ]
.RB [ \-norescore ]
.RB [ \-lm-only ]
.RB [ \-count-oovs ]
.RB [ \-limit-vocab ]
.RB [ \-vocab-aliases
.IR mapfile ]
.RB [ \-fast ]
.I nbest-file-list
.I score-dir
.B \-lm 
\&...
.I lm-options
\&...
.br
.B rescore-acoustic
.IR old-nbest-dir | old-file-list
.I old-ac-weight
.I new-score-dir1
.I new-ac-weight1
\&...
.I new-nbest-dir
.RI [ max-nbest ]
.br
.B rescore-reweight
.RB [ \-multiwords ]
.IR score-dir | file-list
.RI [ lmw
.RI [ wtw
.RI [ "score-dir1 score-weight1"
\&...]
.RI [ max-nbest ]]]
.br
.B rescore-minimize-wer
.I score-dir
.RI [ lmw
.RI [ wtw
.RI [ max-nbest ]]]
.br
.B nbest2-to-nbest1
.RI [ nbest-file ]
.br
.B nbest-rover
[
.I sentid-list
|
.B -
]
.I control-file
[
.I posterior-file
[
.I nbest-lattice-options
] ]
.br
.B combine-rover-controls
[
.BI lambda= weights 
]
.I rover-control
[ ... ]
.br
.B nbest-posteriors
[
.BI weight= W
.BI lmw= lmw
.BI wtw= wtw
.BI postscale= S
.BI max_nbest= M
]
.I nbest-file
.br
.B merge-nbest
[
.BI max_nbest= M
.B multiwords=1
.B nopauses=1
]
.I nbest-file
\&...
.br
.B nbest-vocab
.RI [ nbest-list ...]
.br
.B nbest-error
.IR score-dir | file-list
.I refs
.RI [ nbest-lattice-option ...]
.br
.B sentid-to-sclite
.I hyps
.br
.B sentid-to-ctm
.I hyps
.br
.B fix-ctm
.I ctmfile
.br
.B compute-sclite
.B \-r
.I refs
.B \-h
.I hyps
[\c
.B \-h
.I hyps
\&...]
[\c
.B \-S
.I subset
\&...]
.RB [ \-multiwords | \-M ]
.RB [ \-noperiods ]
.RB [ \-R ]
.RB [ \-g
.IR glmfile ]
.RB [ \-H ]
.RB [ \-v ]
.RI [ sclite-options ...]
.br
.B compare-sclite
.B \-r
.I refs
.B \-h1
.I hyps1
.B \-h2
.I hyps2
[\c
.B \-S
.I subset\c
]
.RB [ \-multiwords | \-M ]
.RI [ sclite-options ...]
.SH DESCRIPTION
These scripts perform common tasks on N-best hypotheses in 
.BR nbest-format (5),
especially those needed for rescoring and extracting and evaluating
1-best hypotheses.
.PP
.B rescore-decipher
applies a language model implemented by 
.BR ngram (1)
to the N-best lists listed in
.IR nbest-file-list .
The N-best files may be in compressed format.
The rescored N-best lists are stored in directory
.IR score-dir .
All following arguments are passed to 
.BR ngram (1)
and are used to control the language model.
The following options are handled by 
.B rescore-decipher
itself:
.TP 20
.B \-bytelog 
causes scores to be output on the bytelog scale
(see 
.BR nbest-format (1)).
.TP
.B \-nodecipherlm
indicates that the recognizer language model is not being provided
(with
.BR \-decipher-lm ).
(This is only possible if the N-best lists are not in ``NBestList1.0'' format.)
.TP
.B \-multiwords
specifies that N-best lists contain words joined by underscores, which are
to be split into their component prior to rescoring.
.TP
.BI \-pretty " mapfile"
specifies a word mapping file that allows individual words to be globally
replaced by strings of zero or more other words, e.g., to remove vocabulary
mismatches between the input N-best lists and the rescoring LM.
The 
.I mapfile
contains one mapping per line, the first field specifying the word to be
replaced and subsequent fields forming the replacement string.
.TP
.BI \-ngram-tool " program"
specifies a non-standard
.I program
to perform the actual LM evaluation
(by default, 
.BR ngram (1)
is used).
Such a program must understand
.BR ngram 's
command-line options related to N-best rescoring.
.TP
.BI \-filter " command"
specifies a
.I command
that is used to filter the N-best hypotheses prior to
evaluating the language model.
This may be used for more general textual rewriting so that non-standard
LMs can be applied.
The output N-best lists will contain the filtered hypotheses.
.TP
.B \-norescore
causes N-best lists to be simply reformatted from one of the Decipher formats
into the SRILM N-best format, separating acoustic and LM scores, without
replacing the existing LM scores.
In this case only the 
.BR ngram (1)
options
.BR \-decipher-lmw
and 
.BR \-decipher-wtw
are relevant, and others are ignored.
.B \-norescore 
and 
.B \-filter
may be used together to perform textual rewriting of N-best lists.
.TP
.B \-lm-only
dumps out LM scores only, instead of complete N-best lists.
.TP
.BR \-count-oovs
writes the count of out-of-vocabulary and zero-probability words to
the output score files (instead of rescored N-best lists).
.TP
.B \-limit-vocab
saves memory by arranging for
.BR ngram (1) 
to load only those N-gram parameters that are relevant to the vocabulary
of the N-best lists to be rescored.
After determining the N-best vocabulary the 
.B \-limit-vocab
option is passed to 
.BR ngram (1).
.TP
.BI \-vocab-aliases " map"
declares that certain words are to be treated as alternative spellings 
of the same word for LM evaluation; see the same option for 
.BR ngram (1).
The 
.I map
is filtered of unused words when used in conjunction with
.BR \-limit-vocab ,
and then passed on to 
.BR ngram (1).
.TP
.B \-fast
performs rescoring using only functions built into
.BR ngram (1).
This avoids some computational and I/O overhead and therefore runs faster,
but the options
.BR \-filter ,
.BR \-pretty ,
and 
.B \-lm-only
are not supported, and 
.B \-nodecipherlm
is obligatory.
.PP
.B rescore-acoustic
replaces the acoustic scores in a set of N-best lists by a weighted 
combination of new scores.
The old N-best lists are given by either a directory
.I old-score-dir
or a filelist
.IR old-file-list ;
.I old-ac-weight
is the weight given to the old scores.
Directories containing the new scores are listed alternating with the
corresponding weights; each score directory must contain one 
file per waveform segment, each having the same file basenames as 
the original N-best lists.
The new scores should appear in a single column per file, one per line.
The N-best lists containing the new combined acoustic scores are written to 
.IR new-nbest-dir .
The optional
.I max-nbest
argument can be used to limit the length of the N-best lists output.
Also, When a new score file is encountered containing fewer than
.I max-nbest
lines, the missing scores are set to the lowest score encountered so far.
.PP
.B rescore-reweight
combines the scores in N-best lists with a set of weights and outputs
the 1-best hypotheses.
The N-best files are found in directory
.I score-dir
or listed in
.IR file-list .
Optional arguments set the language model weight
.I lmw
(default 8),
the word transition weight
.I wtw