time2matlab manpage

COMMAND

time2matlab -- Convert a **kern score with performance timing into a matlab array.

The time2matlab command is used to prepare a Humdrum **kern score to be read into numerical analysis software such as octave, FreeMat, or matlab. The Humdrum file should contain **kern data representing the musical score as well as a **time spine which indicates the absolute time at which the notes occur in a performance. Here is a short example score: **time **kern **kern * * *M4/4 =3 =3 =3 1300 1CC 8c 1700 . 8c# 2400 . 4d 3000 . 4e 4000 . 4f =4 =4 =4 8000 1r 1g == == == *- *- *- Running the above score through time2matlab will generate the following data: %% Data column information: %%%col01: abstime (absolute time in milliseconds of note attack) %%%col02: duration (duration of note in ms based on score duration) %%%col03: note (MIDI note number of pitch) %%%col04: metlev (metric level: 1 = downbeat; 0 = beat; -1 = offbeat) %%%col05: measure (measure number in which note occurs) %%%col06: absbeat (absolute beat from starting beat at 0) %%%col07: trackno (track number of the note: e.g.: 1 = left hand; 2=right) 1300 6700 36 1 3 0 1 1300 400 60 1 3 0 2 1700 700 61 -1 3 0.5 2 2400 600 62 0 3 1 2 3000 1000 64 0 3 2 2 4000 4000 65 1 3 3 2 8000 16000 67 0 4 4 2

Text following a '%' character are comments which will be ignored when reading the data into matlab. The kern data is converted into a matrix (currently) with seven columns. Each row in the matrix represents one note in the score, and the columns contain information about the note:

1. Start time of the note. In the above example, the timings are intended to be in milliseconds, but you could also use seconds. In any case, the timing values as stored in the score will be used to generate the timing information in the output file, regardless of the time units used.
2. Duration of the note. This value subtracts the time at which the note ends in the score from the time that the note starts in the score. For example, the 1CC note in the first **kern spine starts at time index 1300 and ends at time index 8000 when a rest starts in that voice. Therefore, the duration of the 1CC note is 8000 - 1300 = 6700.
3. MIDI note number of the note's pitch.
4. Metric level of the note: less than zero means the note is on an off-beat (such as the c# on the 5th line of the input, or the third data line in the output for note number 61). A zero or higher in this column means that the note was played on a beat; and a value greater than zero (1) means that the note was played on the first beat of a measure.
5. Measure number in which the note occurs.
6. Absolute beat position of the note in reference to the start of the music.
7. Track number which indicates which data spine in the original data the note belongs. In this case there are two **kern spines: the first spine which contains 1CC is spine 1, and the next one to the right is spine 2. If the score contains piano music, the track number would typically mean that notes in track 1 are played by the left hand and notes in track 2 are played by the right hand. If the input music were an orchestral score, then the track number would indicate the different instruments of the orchestra.

The output data should be saved to a file ending in the extension .mat. This will allow you to read the data file into octave or matlab using the load command for further analysis in one of those programs. Below is an example of loading the file into octave via a file called output.mat and then displaying the contents of the variable called output which is created to store the data read from that file.

octave:1> load output octave:2> output output = Columns 1 through 5: 1.3000e+03 6.7000e+03 3.6000e+01 1.0000e+00 3.0000e+00 1.3000e+03 4.0000e+02 6.0000e+01 1.0000e+00 3.0000e+00 1.7000e+03 7.0000e+02 6.1000e+01 -1.0000e+00 3.0000e+00 2.4000e+03 6.0000e+02 6.2000e+01 0.0000e+00 3.0000e+00 3.0000e+03 1.0000e+03 6.4000e+01 0.0000e+00 3.0000e+00 4.0000e+03 4.0000e+03 6.5000e+01 1.0000e+00 3.0000e+00 8.0000e+03 1.6000e+04 6.7000e+01 0.0000e+00 4.0000e+00 Columns 6 and 7: 0.0000e+00 1.0000e+00 0.0000e+00 2.0000e+00 5.0000e-01 2.0000e+00 1.0000e+00 2.0000e+00 2.0000e+00 2.0000e+00 3.0000e+00 2.0000e+00 4.0000e+00 2.0000e+00

Use of time2matlab in the Mazurka Project

The output data from time2matlab is intended for use in Andrew Earis's Expression Algorithm program which takes an audio file and a data file containing estimated note positions generated as output from time2matlab. The Expression Algorithm then produces revised notes attack times based on an analysis of the contents of the audio file.

Example input data files can be found starting from this page. Links on that page point to preliminary performance data. Input files to time2matlab end in the extension .time, such as this one for a performance of Chopin's mazurka in C-sharp minor, Op. 63, No. 3 as performed by Richard Farrell in particular on the recording found on the CD label EMI Phoenixa CDM 7641362. This file contains the score for the mazurka music along with estimated timings of note attacks (not the exact timings of notes) in the performance. The timing data found in the first column of the .time score is ultimately generated from this file which marks the times of beats in the performance in the recording. This beat file was in turn created by tapping to the beats inside of the audio editor program called Sonic Visualiser, and saved as a text-based annotation file.

Example output data from the Expression Algorithm software is viewable on this webpage.

Extracting data without performance information

If you are only interested in durations based on the score rhythms and not from an actual performance of a file, you can use the gettime program to extract score-based timings rather than timings based on a performance.

gettime -sp input.krn > output.krn
input.krn	output.krn	time2matlab output.krn
**kern **kern *M4/4 *M4/4 =3 =3 1CC 8c . 8c# . 4d . 4e . 4f =4 =4 1r 1g == == *- *-	**time **kern **kern *u=sec * * *M4/4 *M4/4 *M4/4 =3 =3 =3 *MM60 *MM60 *MM60 0 1CC 8c 0.5 . 8c# 1 . 4d 2 . 4e 3 . 4f =4 =4 =4 4 1r 1g == == == *- *- *-	0 4 36 1 3 0 1 0 0.5 60 1 3 0 2 0.5 0.5 61 -1 3 0.5 2 1 1 62 0 3 1 2 2 1 64 0 3 2 2 3 1 65 1 3 3 2 4 4 67 0 4 4 2

By default, a tempo of 60 beats per minute will be used when extracting timing information. To use a different tempo, you can add tempo information into the file, such as *MM100 for 100 beats per minute:

gettime -sp input.krn > output.krn
input.krn	output.krn	time2matlab output.krn
**kern **kern *M4/4 *M4/4 *MM100 *MM100 =3 =3 1CC 8c . 8c# . 4d . 4e . 4f =4 =4 1r 1g == == *- *-	**time **kern **kern *u=sec * * *M4/4 *M4/4 *M4/4 *MM100 *MM100 *MM100 =3 =3 =3 0 1CC 8c 0.3 . 8c# 0.6 . 4d 1.2 . 4e 1.8 . 4f =4 =4 =4 2.4 1r 1g == == == *- *- *-	0 2.4 36 1 3 0 1 0 0.3 60 1 3 0 2 0.3 0.3 61 -1 3 0.5 2 0.6 0.6 62 0 3 1 2 1.2 0.6 64 0 3 2 2 1.8 0.6 65 1 3 3 2 2.4 2 67 0 4 4 2

Example usages of the time2matlab program are available on the time2matlab examples page.

Input arguments or piped data which are expected to be Humdrum files can also be web addresses. For example, if a program can process files like this:

       program file.krn

It can also read the data over the web:

       program http://www.some-computer.com/some-directory/file.krn

Piped data works in a somewhat similar manner:

       cat file.krn | program

is equivalent to a web file using ths form:

       echo http://www.some-computer.com/some-directory/file.krn | program

Besides the http:// protocol, there is another special resource indicator prefix called humdrum:// which downloads data from the kernscores website. For example, using the URI humdrum://brandenburg/bwv1046a.krn:

      program humdrum://brandenburg/bwv1046a.krn

will download the URL:

http://kern.humdrum.org/cgi-bin/ksdata?file=bwv1046a.krn&l=/brandenburg&format=kern
Which is found in the Musedata Bach Brandenburg Concerto collection.

This online-access of Humdrum data can also interface with the classical Humdrum Toolkit commands by using humcat to download the data from the kernscores website. For example, try the command pipeline:

      humcat humdrum://brandenburg/bwv1046a.krn | census -k

gettime, kern2melisma, kern2midi, kern2skini.

The compiled time2matlab program can be downloaded for the following platforms:
• Linux (i386 processors) (dynamically linked) compiled on 28 Jun 2012.
• Windows compiled on 29 Jun 2012.
• Mac OS X/i386 compiled on 13 Nov 2013.
• Mac OS X/PowerPC (version 10.2 and higher) compiled on 13 May 2009.

The source code for the program was last modified on 13 Dec 2005. Click here to go to the full source-code download page.