NAME

       aubioonset - a command line tool to extract musical onset times

SYNOPSIS

       aubioonset source
       aubioonset [[-i] source] [-o sink]
                  [-r rate] [-B win] [-H hop]
                  [-O method] [-t thres]
                  [-T time-format]
                  [-s sil] [-m] [-f]
                  [-j] [-N miditap-note] [-V miditap-velo]
                  [-v] [-h]

DESCRIPTION

       aubioonset  attempts  to  detect  onset  times, the beginning of discrete sound events, in
       audio signals.

       When started with an input source (-i/--input), the detected onset times are given on  the
       console, in seconds.

       When  started  without  an  input  source, or with the jack option (-j/--jack), aubioonset
       starts in jack mode.

OPTIONS

       This program follows the usual GNU command line syntax, with long  options  starting  with
       two dashes (--). A summary of options is included below.

       -i, --input source
              Run  analysis  on  this audio file. Most uncompressed and compressed are supported,
              depending on how aubio was built.

       -o, --output sink
              Save results in this file. The file will be created on the model of the input file.
              Onset times are marked by a short wood-block like sound.

       -r, --samplerate rate
              Fetch  the  input  source, resampled at the given sampling rate. The rate should be
              specified in Hertz as an integer. If 0, the sampling rate of  the  original  source
              will be used. Defaults to 0.

       -B, --bufsize win
              The  size  of  the  buffer  to  analyze,  that is the length of the window used for
              spectral and temporal computations. Defaults to 512.

       -H, --hopsize hop
              The number of samples between two consecutive analysis.  Defaults to 256.

       -O, --onset method
              The onset detection method to use. See ONSET METHODS below. Defaults to 'default'.

       -t, --onset-threshold thres
              Set the threshold value for the onset peak picking. Values  are  typically  in  the
              range [0.001, 0.900]. Lower threshold values imply more onsets detected. Increasing
              this threshold should reduce the number of incorrect detections. Defaults to 0.3.

       -M, --minioi value
              Set the minimum inter-onset interval, in seconds, the shortest interval between two
              consecutive onsets. Defaults to 0.020

       -s, --silence sil
              Set  the  silence  threshold,  in dB, under which the onset will not be detected. A
              value of -20.0 would eliminate most onsets but the loudest ones. A value  of  -90.0
              would select all onsets. Defaults to -90.0.

       -T, --timeformat format
              Set time format (samples, ms, seconds). Defaults to seconds.

       -m, --mix-input
              Mix source signal to the output signal before writing to sink.

       -f, --force-overwrite
              Overwrite output file if it already exists.

       -j, --jack
              Use  Jack  input/output.  You  will need a Jack connection controller to feed aubio
              some signal and listen to its output.

       -N, --miditap-note
              Override note value for MIDI tap. Defaults to 69.

       -V, --miditap-velop
              Override velocity value for MIDI tap. Defaults to 65.

       -h, --help
              Print a short help message and exit.

       -v, --verbose
              Be verbose.

ONSET METHODS

       Available methods are:

       default
              Default distance, currently hfc

       Default: 'default' (currently set to hfc)

       energy Energy based distance

       This function calculates the local energy of the input spectral frame.

       hfc    High-Frequency content

       This method computes the High Frequency Content (HFC) of the  input  spectral  frame.  The
       resulting function is efficient at detecting percussive onsets.

       Paul Masri. Computer modeling of Sound for Transformation and Synthesis of Musical Signal.
       PhD dissertation, University of Bristol, UK, 1996.

       complex
              Complex domain onset detection function

       This function uses information both in frequency and in phase to determine changes in  the
       spectral  content  that might correspond to musical onsets.  It is best suited for complex
       signals such as polyphonic recordings.

       Christopher Duxbury, Mike E. Davies, and Mark B. Sandler.
              Complex domain onset detection for musical signals. In Proceedings of  the  Digital
              Audio Effects Conference, DAFx-03, pages 90-93, London, UK, 2003.

       phase  Phase based onset detection function

       This  function uses information both in frequency and in phase to determine changes in the
       spectral content that might correspond to musical onsets. It is best  suited  for  complex
       signals such as polyphonic recordings.

       Juan-Pablo Bello, Mike P. Davies, and Mark B. Sandler.
              Phase-based  note  onset  detection  for  music signals. In Proceedings of the IEEE
              International Conference on Acoustics Speech and Signal Processing,  pages  441444,
              Hong-Kong, 2003.

       specdiff
              Spectral difference onset detection function

       Jonhatan Foote and Shingo Uchihashi. The beat spectrum: a new approach to rhythm analysis.
       In IEEE International Conference on Multimedia and Expo (ICME 2001), pages 881884,  Tokyo,
       Japan, August 2001.

       kl     Kulback-Liebler onset detection function

       Stephen  Hainsworth  and  Malcom  Macleod.  Onset  detection  in  music  audio signals. In
       Proceedings of the International Computer Music Conference (ICMC), Singapore, 2003.

       mkl    Modified Kulback-Liebler onset detection function

       Paul Brossier, ``Automatic annotation of musical audio for interactive systems'',  Chapter
       2,  Temporal  segmentation, PhD thesis, Centre for Digital music, Queen Mary University of
       London, London, UK, 2006.

       specflux
              Spectral flux

       Simon Dixon,  Onset  Detection  Revisited,  in  ``Proceedings  of  the  9th  International
       Conference on Digital Audio Effects'' (DAFx-06), Montreal, Canada, 2006.

SEE ALSO

       aubiopitch(1), aubiotrack(1), aubionotes(1), aubioquiet(1), aubiomfcc(1), and aubiocut(1).

AUTHOR

       This  manual  page was written by Paul Brossier <piem@aubio.org>. Permission is granted to
       copy, distribute and/or modify this document under the terms of  the  GNU  General  Public
       License  as published by the Free Software Foundation, either version 3 of the License, or
       (at your option) any later version.