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5.7.2 Esignal Format Parameter Files

  The default for parameter files is native HTK format. However, HTK tools also support the Entropic Esignal format for both input and output. Esignal replaces the Entropic ESPS file format. To ensure compatibility Entropic provides conversion programs from ESPS to ESIG and vice versa.

To indicate that a source file is in Esignal format the configuration variable SOURCEFORMAT  should be set to ESIG. Alternatively, -F ESIG  can be specified as a command-line option. To generate Esignal format output files, the configuration variable TARGETFORMAT should be set to ESIG or the command line option -O ESIG should be set.

ESIG files consist of three parts: a preamble, a sequence of field specifications called the field list and a sequence of records. The preamble and the field list together constitute the header. The preamble is purely ASCII. Currently it consists of 6 information items that are all terminated by a new line. The information in the preamble is the following:

 
		line 1		- identification of the file format

line 2 - version of the file format

line 3 - architecture (ASCII, EDR1, EDR2, machine name)

line 4 - preamble size (48 bytes)

line 5 - total header size

line 6 - record size

All ESIG files that are output by HTK programs contain the following global fields:
commandLine
the command-line used to generate the file;
recordFreq
a double value that indicates the sample frequency in Herz;
startTime
a double value that indicates a time at which the first sample is presumed to be starting;
parmKind
a character string that indicates the full type of parameters in the file, e.g: MFCC_E_D.
source_1
if the input file was an ESIG file this field includes the header items in the input file.

After that there are field specifiers for the records. The first specifier is for the basekind of the parameters, e.g: MFCC. Then for each available qualifier there are additional specifiers. Possible specifiers are:
 
		zeroc

energy

delta

delta_zeroc

delta_energy

accs

accs_zeroc

accs_energy

  The data segments of the ESIG files have exactly the same format as the the corresponding HTK files. This format was described in the previous section.

HTK can only input parameter files that have a valid parameter kind as value of the header field parmKind. If this field does not exist or if the value of this field does not contain a valid parameter kind, the file is rejected. After the header has been read the file is treated as an HTK file.


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Next: 5.8 Waveform File Formats Up: 5.7 Storage of Parameter Files Previous: 5.7.1 HTK Format Parameter Files

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