pfile is a binary file format that is used in ASR for storing feature vectors and their corresponding labels. This file format is sometimes also called ICSI feature file archive format. But this file format cannot be used for ASR only, but also for many other ML tasks.
The file consists of a fixed length ascii header followed by zero or more variable length binary sections. Each parameter in the header has a name and a list of zero or more value strings. The programmer's interface to pfiles (see param.h and pfile.h) allows each parameter value to be interpreted as integer, float, string, arrays, distributed vector, matrix, mapping tables, etc.
Some special parameter names are associated with a section in the binary part of the pfile. The value strings for these parameters give the size and offset (from the end of the header) of the binary section.
A binary section can be used as a one dimensional sequence of values, or as a sequence of fixed length rows in a two dimensional matrix.
Some parameters are automatically added by the pfile command. For example, pfile_header is a parameter that contains the length and version number of the header.
Source: old-site.clsp.jhu.edu/ws96/ris/man/pfile.doc
pfile_utils
pfile_utils is a toolset to manage pfiles. It is part of the
SPRACHcore software package.
The project is located at
code.google.com/p/pfile-utilities
and seems to be in version 0.51 by now. The code is written in C++.
pfile_info gives general information about the file:
$ pfile_info all.pfile
all.pfile
9581 sentences, 3158027 frames, 1 label(s), 42 features
pfile_create
You can call pfile_create like this:
$ ./pfile_create -i - -f 1 -l 1 -o output.pfile
0 0 1 1
0 1 2 0
0 2 1 1
0 3 1 1
0 4 42 4
1 0 0 0
1 1 1337 0
1 2 2 2
2 0 3 3
You can end the input with Ctrl + D.
The numbers are:
[sentence-nr] [frame-nr] [feature 1] [feature 2] ... [feature n] [label 1] [label 2] ... [label n]
where the option -f defines the number of features and -l defines the number
of labels. Please note that within one sentence, the number of frames has to be
increasing by exactly one. One sentence can have an arbitrary number of
frames, but as soon as you make another sentence, you need to increase this
number by exactly one.