csound [flags] orchfile scorefile

Csound is an environment in which a "scorefile" or external event sequence can invoke arbitrarily complex signal-processing "instruments" to produce sound. Audio may be displayed during its creation, and the resulting sound sent to an on-line audio device or to an intermediate soundfile for later playback. Csound is invoked by a single command, which induces three phases of action: Score sorting Orchestra translation and loading Sound generation (audio processing and synthesis).

Csound audio processing is supported by various score manipulation languages (SCOT, CSCORE, SCSORT, EXTRACT) and by soundfile analysis-synthesis methods including additive synthesis (ADSYN), linear predictive coding (LPC), and phase vocoding (PVOC).

There is no complete on-line manual, but man entries exist for the stand-alone analysis and scoring programs. More complete information can be found in the troff-able "Csound Reference Manual," which provides an overview, tutorial, details of behavior, and step-by-step examples.

csound is a command for passing an orchestra file and score file to the Csound environment to generate a soundfile. In the above SYNOPSIS, all flag arguments are optional with set defaults. Flags may appear either separately or bundled; those that take an argument will expect to find it either immediately following or as the next argument. Recognized flags are:

• -I Init-time processing only. Allocate and initialize all instrument events as per the score, but skip all Performance-time processing (no k-signals or a-signals, thus no amplitudes and no sound). Provides a fast validity check of all score pfields and instrument i-variables. Implies -n.
• -n No sound output, i.e. do all sound generation, but bypass audio output. This flag will override a -o flag.
• -i sfnam Input soundfile name or audio-device name. If this flag is present, sound will be continuously read from the named file or device, and will be available to all instruments containing an "in" unit. If no explicit path is given, the file will be sought in the user's sound directory (environment variable SFDIR); if sfnam is of the form path/name, the file will be sought in the 'path' directory. If sfnam is of the form /dev/name or stdin, sound will be read from there. The encoding format of an audio input file is self-defining, described by its soundfile header; if no header is present, the format is presumed the same as the generated output. The channel count and sampling rate of an audio input file must match that of the receiving Orchestra.
• -o sfnam Output soundfile name or audio-device name; the default name is "test". Csound writes continuously to a soundfile or device, unless prevented by a -n flag. If sfnam is omitted or contains no explicit path, sound will be written to the user's soundfile directory (environment variable SFDIR); if sfnam is of the form path/name, sound will be placed in the 'path' directory. If sfnam is of the form /dev/name or stdout, sound will be sent there.
• -b N Blocksize, in samples (not bytes), for the above sound I/O. Typically 512 samples per buffer. A larger number is more efficient, but small numbers reduce the delay in realtime performances.
• -h Do not write a soundfile header in the sound output stream.
• -c Write 8-bit signed-character sound samples.
• -a Write 8-bit alaw-encoded sound samples.
• -u Write 8-bit ulaw-encoded sound samples.
• -s Write 16-bit short_integer sound samples.
• -l Write 32-bit long_integer sound samples.
• -f Write single-precision floating-point sound samples. A float file cannot generally be played, but can be rescaled, or read by soundin and GEN01.
• -v Verbose translate and run. Prints details of orch translation and performance, enabling errors to be more clearly located.
• -m N Message level for standard (terminal) output. Takes the sum of 3 print control flags, turned on by the following values: 1 = note amplitude messages, 2 = samples out of range message, 4 = warning messages. The default value is m7 (all messages on).
• -d Suppress all display functions.
• -g Suppress graphics, and use ascii displays instead. If the user terminal supports graphic windows, display functions ordinarily appear in that form. This flag will invoke an alternate system, printing graphs in ascii characters--as would occur if the terminal did not support graphics.
• -S sname Interpret sname as a Scot scorefile, create a standard score file from it, then perform the result.
• -x xname Extract a portion of the sorted scorefile (or 'score.srt') according to the contents of xname (see Extract below).
• -B Beat mode. Use the uninterpreted Beats of score.srt for this performance. In this mode, the beat rate of score performance is controllable from within the orchestra by a tempo unit.
• -R indev Allow Realtime Line-oriented ascii-defined events via device indev to activate instruments of the Orchestra. E.g., the name stdin would enable an associated realtime process to initiate fully-specified score events through a pipe. The format of events is identical to that in an unsorted scorefile, except that pfield 3 (duration) is given in seconds and pfield 2 (start-time) is automatically set at event-time. A parallel score is optional.
• -M indev Allow MIDI invocation of the orchestra instruments via device indev, of the form /dev/midi or stdin. A parallel score is optional.

The orchfile is a collection of Instruments which are sequences of Csound statements invoking control-signal and audio-signal processing modules. A simple instrument might appear as follows:

                  instr        3
          k1        linseg        p4, p3, p4/10
          a1        oscil        k1, p5, 1
                  out           a1
                  endin
  

          f 1        0        256        10        1
          i 3        0        2        1000        440
          i 3        2        2        1000        522
          e
  

This feature will extract a segment of a "sorted numeric score" file according to instructions taken from a control file. The control file contains an instrument list and two time points, from and to, in the form: instruments 1 2 from 1:27.5 to 2:2

The component labels may be abbreviated as "i, f" and t. The time points denote the begininng and end of the extract in terms of: [section no.] : [beat no.]. Each of the three parts is also optional. The default values for missing "i, f" or t are: all instruments, begining of score, end of score.

extract reads an orchestra-readable score file and produces an orchestra-readable result. Comments, tabs and extra spaces are flushed, w and a statements are added and an f0 reflecting the extract length is appended to the output. Following an extract process, the abbreviated score will contain all function table statements, together with just those note statements that occur in the from-to interval specified. Notes lying completely in the interval will be unmodified; notes that lie only partly within will their p3 durations truncated as necessary. .SH Independent Preprocessing:

Although the result of all score preprocessing is retained in the file score.srt after orchestra performance (it exists as soon as score preprocessing has completed), the user may sometimes want to run these phases independently. The command scot filename will process the Scot formatted filename, and leave a "standard numeric score" result in a file named score for perusal or later processing. The command scscort < infile > outfile will put a numeric score infile through Carry, Tempo, and Sort preprocessing, leaving the result in outfile. Likewise extract, also normally invoked as part of the perf command, can be invoked as a standalone program: extract xfile < score.sort > score.extract This command expects an already sorted score. An unsorted score should first be sent through scsort then piped to the extract program: scsort < scorefile | extract xfile > score.extract

hetro(1Csound), lpcanal(1Csound), pvanal(1Csound), "The Csound Reference Manual"