zcrana: Analysis of the averages of the short-term positive and...

In humlab-speech/superassp: A speech signal processing using various framworks using a wrassp-like interface

Analysis of the averages of the short-term positive and negative zero-crossing rates

Description

Analysis of the averages of the short-term positive and negative zero-crossing rates of the signal in listOfFiles using the libassp C library \insertCites5hsuperassp function. If toFile is TRUE, the results will be written to an output fil in the SSFF binary format, with the same name as the input file, but with an extension .zcr and with a track named 'ZCRHz'.

Usage

zcrana(
  listOfFiles = NULL,
  beginTime = 0,
  centerTime = FALSE,
  endTime = 0,
  windowShift = 5,
  windowSize = 25,
  toFile = TRUE,
  explicitExt = "zcr",
  outputDirectory = NULL,
  assertLossless = NULL,
  logToFile = FALSE,
  convertOverwrites = FALSE,
  keepConverted = FALSE,
  verbose = TRUE
)

Arguments

listOfFiles	vector of file paths to be processed by function
beginTime	the time point (in seconds) of the start of the analysed interval. A NULL or 0 is interpreted as the start of the signal file. If a vector of time points is supplied, the length of that vector needs to correspond with the length of listOfFiles.
centerTime	sets a single-frame analysis time point (in seconds). Overrides beginTime, endTime and windowShift parameters.
endTime	the time point (in seconds) of the end of the analysed interval. A NULL or 0 is interpreted as the end of the signal file. If a vector of time points is supplied, the length of that vector needs to correspond with the length of listOfFiles.
windowShift	the amount of time (in ms) that the analysis window will be shifted between analysis frames
windowSize	the analysis window size (in ms); overrides the effect of the effectiveLength parameter
toFile	Should the function write the results to a file, with the (default) file extension (TRUE) or returned as a list of AsspDataObj objects (FALSE)?
explicitExt	the file extension will be used when result files are written (toFile=TRUE), but the file extension can be set to something else using this function argument.
outputDirectory	directory in which output files are stored. Defaults to NULL which means that the result file will be stored in the same directory as the input file.
assertLossless	an optional list of file extensions that the user wants to assert contains losslessly encoded signals data.
logToFile	whether to log commands to a separate logfile in the outputDirectory. Logging will otherwise be in the function-specific logging namespace of logger and will be put wherever this namespace is defined to place its output. See logger::log_appender for details.
verbose	display verbose information about processing steps taken, as well as progress bars.

Details

Input signals not in a natively supported file format will be converted before the autocorrelation functions are computed. The conversion process will display warnings about input files that are not in known losslessly encoded formats.

The function is a re-write of the wrassp::zcrana function, but with media pre-conversion, better checking of preconditions such as the input file existance, structured logging, and the use of a more modern framework for user feedback.

The native file type of this function is "wav" files (in "pcm_s16le" format), SUNs "au", NIST, or CSL formats (kay or NSP extension). Input signal conversion, when needed, is done by libavcodec and the excellent av wrapper package.

Value

If toFile is FALSE, the function returns a list of AsspDataObj objects. If toFile is TRUE, the number (integer) of successfully processed and stored output files is returned.

Note

This function is not considered computationally expensive enough to require caching of results if applied to many signals. However, if the number of signals it will be applied to is very long, then caching of results may be warranted.

Author(s)

Raphael Winkelmann

Lasse Bombien

Fredrik Nylén

Examples

# get path to audio file
path2wav <- list.files(system.file("samples","sustained", package = "superassp"), pattern = glob2rx("a1.wav"), full.names = TRUE)

# calculate zcr values
res <- zcrana(path2wav, toFile=FALSE)

# plot zcr values
plot(seq(0,numRecs.AsspDataObj(res) - 1) / rate.AsspDataObj(res) +
      attr(res, 'startTime'),
    res[["ZCR[Hz]"]],
    type='l',
    xlab='time (s)',
    ylab='Zero Crossing Rates (Hz)')

humlab-speech/superassp documentation built on May 8, 2024, 2:27 p.m.