Command-line Flags (by Category)

Listed below are the command line available in Csound5 organized by categories. Various platform implementations may not react the same way to different flags!

You can view the command line flags organized alphabetically in Command-line Flags (Alphabetically).

The format of a command is either:

csound [flags] [orchname] [scorename]

or

csound [flags] [csdfilename]

where the arguments are of 2 types: flags arguments (beginning with a -,-- or -+), and name arguments (such as filenames). Certain flag arguments take a following name or numeric argument. Flags that start with -- and -+ usually take an argument themselves using =.

Audio File Ouput

-3, --format=24bit

Use 24-bit audio samples.

-8, --format=uchar

Use 8-bit unsigned character audio samples.

-A, --aiff, --format=aiff

Write an AIFF format soundfile. Use with the -c, -s, -l, or -f flags.

-a, --format=alaw

Use a-law audio samples.

-c, --format=schar

Use 8-bit signed character audio samples.

-f, --format=float

Use single-format float audio samples (not playable on some systems, but can be read by -i, soundin and GEN01

--format=type

Set the audio file output format to one of the formats available in libsndfile. At present the list is aiff, au, avr, caf, flac, htk, ircam, mat4, mat5, nis, paf, pvf, raw, sd2, sds, svx, voc, w64, wav, wavex and xi. Can also be used as --format=type:format or --format=format:type to set both the file type (wav, aiff, etc.) and sample format (short, long, float, etc.) at the same time.

-h, --noheader

No header on output soundfile. Don't write a file header, just binary samples.

-i FILE, --input=FILE

Input soundfile name. If not a full pathname, the file will be sought first in the current directory, then in that given by the environment variable SSDIR (if defined), then by SFDIR. The name stdin will cause audio to be read from standard input.

The name devaudio or adc will request sound from the host audio input device. It is possible to select a device number by appending an integer value in the range 0 to 1023, or a device name separated by a : character. It depends on the host audio interface whether a device number or a name should be used. In the first case, an out of range number usually results in an error and listing the valid device numbers.

The audio coming in using -i can be received using opcodes like inch.

-J, --ircam, --format=ircam

Write an IRCAM format soundfile.

-K, --nopeaks

Do not generate any PEAK chunks.

-l, --format=long

Use long integer audio samples.

-n, --nosound

No sound. Do all processing, but bypass writing of sound to disk. This flag does not change the execution in any other way.

-o FILE, --output=FILE

Output soundfile name. If not a full pathname, the soundfile will be placed in the directory given by the environment variable SFDIR (if defined), else in the current directory. The name stdout will cause audio to be written to standard output, while null results in no sound output similarly to the -n flag. If no name is given, the default name will be test.

The name dac or devaudio (you can use -odac or -o dac) will request writing sound to the host audio output device. It is possible to select a device number by appending an integer value in the range 0 to 1023, or a device name separated by a : character. It depends on the host audio interface whether a device number or a name should be used. In the first case, an out of range number usually results in an error and listing the valid device numbers.

--ogg

Set output file format to ogg. (Csound 5.18 and later).

-R, --rewrite

Continually rewrite the header while writing the soundfile (WAV/AIFF).

-s, --format=short

Use short integer audio samples.

-u, --format=ulaw

Use u-law audio samples.

-W, --wave, --format=wave

Write a WAV format soundfile.

-Z, --dither

Switch on dithering of audio conversion from internal floating point to 32, 16 and 8-bit formats. The default form of the dither is triangular.

-Z, --dither--triangular, --dither--uniform

Switch on dithering of audio conversion from internal floating point to 32, 16 and 8-bit formats. In the case of -Z the next digit should be a 1 (for trangular) or a 2 (for uniform). The exact interpretation depends on the output system.

Output File Id tags

-+id_artist=string

(max. length = 200 characters) Artist tag in output soundfile (no spaces)

-+id_comment=string

(max. length = 200 characters) Comment tag in output soundfile (no spaces)

-+id_copyright=string

(max. length = 200 characters) Copyright tag in output soundfile (no spaces)

-+id_date=string

(max. length = 200 characters) Date tag in output soundfile (no spaces)

-+id_software=string

(max. length = 200 characters) Software tag in output soundfile (no spaces)

-+id_title=string

(max. length = 200 characters) Title tag in output soundfile (no spaces)

Realtime Audio Input/Output

-i adc[DEVICE], --input=adc[DEVICE]

The name devaudio or adc will request sound from the host audio input device. It is possible to select a device number by appending an integer value in the range 0 to 1023, or a device name separated by a : character (e.g. -iadc3, -iadc:hw:1,1). It depends on the host audio interface whether a device number or a name should be used. In the first case, an out of range number usually results in an error and listing the valid device numbers.

-o dac[DEVICE], --output=dac[DEVICE]

The name dac or devaudio (you can use -odac or -o dac) will request writing sound to the host audio output device. It is possible to select a device number by appending an integer value in the range 0 to 1023, or a device name separated by a : character (e.g. -odac3, -odac:hw:1,1). It depends on the host audio interface whether a device number or a name should be used. In the first case, an out of range number usually results in an error and listing the valid device numbers.

-+rtaudio=string

(max. length = 20 characters) Real time audio module name. The default is PortAudio (all platforms). Also available, depending on platform and build options: Linux: alsa, jack; Windows: mme; Mac OS X: CoreAudio. In addition, null can be used on all platforms, to disable the use of any real time audio plugin.

-+server=string

Pulseaudio server name.

-+output_stream=string

Pulseaudio output stream name.

-+input_stream=string

Pulseaudio input stream name.

-+jack_client=[client_name]

The client name used by Csound, defaults to 'csound5'. If multiple instances of Csound connect to the JACK server, different client names need to be used to avoid name conflicts. (Linux and Mac OS X only)

-+jack_inportname=[input port name prefix], -+jack_outportname=[output port name prefix]

Name prefix of Csound JACK input/output ports; the default is 'input' and 'output'. The actual port name is the channel number appended to the name prefix. (Linux and Mac OS X only)

Example: with the above default settings, a stereo orchestra will create these ports in full duplex operation:

csound5:input1              (record left)
csound5:input2              (record right)
csound5:output1             (playback left)
csound5:output2             (playback right)

MIDI File Input/Ouput

-F FILE, --midifile=FILE

Read MIDI events from MIDI file FILE. The file should have only one track in Csound versions 4.xx and earlier; this limitation is removed in Csound 5.00.

--midioutfile=FILENAME

Save MIDI output to a file (Csound 5.00 and later only).

-+mute_tracks=string

(max. length = 255 characters) Ignore events (other than tempo changes) in MIDI file tracks defined by pattern (for example, -+mute_tracks=00101 will mute the third and fifth tracks).

-+raw_controller_mode=boolean

Disable special handling of MIDI controllers like sustain pedal, all notes off etc., allowing the use of all the 128 controllers for any purpose. This will also set the initial value of all controllers to zero. Default: no.

-+skip_seconds=float

(min: 0) Start playback at the specified time (in seconds), skipping earlier events in the score and MIDI file.

-T, --terminate-on-midi

Terminate the performance when the end of MIDI file is reached.

MIDI Realtime Input/Ouput

-M DEVICE, --midi-device=DEVICE

Read MIDI events from device DEVICE. If using ALSA MIDI (-+rtmidi=alsa), devices are selected by name and not number. So, you need to use an option like -M hw:CARD,DEVICE where CARD and DEVICE are the card and device numbers (e.g. -M hw:1,0). In the case of PortMidi and MME, DEVICE should be a number, and if it is out of range, an error occurs and the valid device numbers are printed. When using PortMidi, you can use '-Ma' to enable all devices. This is also convenient when you don't have devices as it will not generate an error.

--midi-key=N

Route MIDI note on message key number to pfield N as MIDI value [0-127].

--midi-key-cps=N

Route MIDI note on message key number to pfield N as cycles per second.

--midi-key-oct=N

Route MIDI note on message key number to pfield N as linear octave.

--midi-key-pch=N

Route MIDI note on message key number to pfield N as oct.pch (pitch class).

--midi-velocity=N

Route MIDI note on message velocity number to pfield N as MIDI value [0-127].

--midi-velocity-amp=N

Route MIDI note on message velocity number to pfield N as amplitude [0-0dbFS].

--midioutfile=FILENAME

Save MIDI output to a file (Csound 5.00 and later only).

-+rtmidi=string

(max. length = 20 characters) Real time MIDI module name. Defaults to PortMidi, other options (depending on build options): Linux: alsa; Windows: mme, winmm. In addition, null can be used on all platforms, to disable the use of any real time MIDI plugin.

ALSA MIDI devices are selected by name and not number. So, you need to use an option like -M hw:CARD,DEVICE where CARD and DEVICE are the card and device numbers (e.g. -M hw:1,0).

-Q DEVICE

Enables MIDI OUT operations to device id DEVICE. This flag allows parallel MIDI OUT and DAC performance. Unfortunately the real-time timing implemented in Csound is completely managed by DAC buffer sample flow. So MIDI OUT operations can present some time irregularities. These irregularities can be reduced by using a lower value for the -b flag.

If using ALSA MIDI (-+rtmidi=alsa), devices are selected by name and not number. So, you need to use an option like -Q hw:CARD,DEVICE where CARD and DEVICE are the card and device numbers (e.g. -Q hw:1,0). In the case of PortMidi and MME, DEVICE should be a number, and if it is out of range, an error occurs and the valid device numbers are printed.

Display

--csd-line-nums=NUM

Determines how line numbers are counted and displayed for error messages when processing a Csound Unified Document file (.csd). This flag has no effect if separate orchestra and score files are used. (Csound 5.08 and later).

  • 0 = line numbers are relative to the beginning of the orchestra or score sections of the CSD

  • 1 = line numbers are relative to the beginning of the CSD file. This is the default as of Csound 5.08.

-d, --nodisplays

Suppress all displays. See -O if you want to save the log to a file.

--displays

Enables displays, reverting the effect of any previous -d flag.

-G, --postscriptdisplay

Suppress graphics, use PostScript displays instead.

-g, --asciidisplay

Suppress graphics, use ASCII displays instead.

-H#, --heartbeat=NUM

Print a heartbeat after each soundfile buffer write:

  • no NUM, a rotating bar.

  • NUM = 1, a rotating bar.

  • NUM = 2, a dot (.)

  • NUM = 3, filesize in seconds.

  • NUM = 4, sound a bell.

-m NUM, --messagelevel=NUM

Message level for standard (terminal) output. Takes the sum of any of the following values:

  • 1 = note amplitude messages

  • 2 = samples out of range message

  • 4 = warning messages

  • 128 = print benchmark information

And exactly one of these to select note amplitude format:

  • 0 = raw amplitudes, no colours

  • 32 = dB, no colors

  • 64 = dB, out of range highlighted with red

  • 96 = dB, all colors

  • 256 = raw, out of range highlighted with red

  • 512 = raw, all colours

The default is 135 (128+4+2+1), which means all messages, raw amplitude values, and printing elapsed time at the end of performance. The coloring of raw amplitudes was introduced in version 5.04

--m-amps=NUM

Message level for amplitudes on standard (terminal) output.

  • 0 = no note amplitude messages

  • 1 = note amplitude messages

--m-range=NUM

Message level for out of range messages on standard (terminal) output.

  • 0 = no samples out of range message

  • 1 = samples out of range message

--m-warnings=NUM

Message level for warnings on standard (terminal) output.

  • 0 = no warning messages

  • 1 = warning messages

--m-dB=NUM

Message level for amplitude format on standard (terminal) output.

  • 0 = absolute amplitude messages

  • 1 = dB amplitude messages

--m-colours=NUM

Message level for amplitude format on standard (terminal) output.

  • 0 = no colouring of amplitude messages

  • 1 = colouring of amplitude messages

--m-benchmarks=NUM

Message level for benchmark information on standard (terminal) output.

  • 0 = no benchnark numbers

  • 1 = print benchnark numbers

-+msg_color=boolean

Enable message attributes (colors etc.); might need to be disabled on some terminals which print strange characters instead of modifying text attributes. default: true.

-v, --verbose

Verbose translate and run. Prints details of orch translation and performance, enabling errors to be more clearly located.

-z NUM, --list-opcodesNUM

List opcodes in this version:

  • no NUM, just show names

  • NUM = 0, just show names

  • NUM = 1, show arguments to each opcode using the format <opname> <outargs> <inargs>

Performance Configuration and Control

-B NUM, --hardwarebufsamps=NUM

Number of audio sample-frames held in the DAC hardware buffer. This is a threshold on which software audio I/O (above) will wait before returning. A small number reduces audio I/O delay; but the value is often hardware limited, and small values will risk data lates. In the case of portaudio output (the default real-time output), the -B parameter (more precisely, -B / sr) is passed as the "suggested latency" value. Other than that, Csound has no control over how PortAudio interprets the parameter. The default is 1024 on Linux, 4096 on Mac OS X and 16384 on Windows.

-b NUM, --iobufsamps=NUM

Number of audio sample-frames per sound i/o software buffer. Large is efficient, but small will reduce audio I/O delay and improve the accuracy of the timing of real time events. The default is 256 on Linux, 1024 on MacOS X, and 4096 on Windows. In real-time performance, Csound waits on audio I/O on NUM boundaries. It also processes audio (and polls for other input like MIDI) on orchestra ksmps boundaries. The two can be made synchronous. For convenience, if NUM is negative, the effective value is ksmps * -NUM (audio synchronous with k-period boundaries). With NUM small (e.g. 1) polling is then frequent and also locked to fixed DAC sample boundaries.

Note: if both -iadc and -odac are used at the same time (full duplex real time audio), the -b option should be set to an integer multiple of ksmps.

-k NUM, --control-rate=NUM

Override the control rate (KR) supplied by the orchestra.

-L DEVICE, --score-in=DEVICE

Read line-oriented real-time score events from device DEVICE. The name stdin will permit score events to be typed at your terminal, or piped from another process. Each line-event is terminated by a carriage-return. Events are coded just like those in a standard numeric score, except that an event with p2=0 will be performed immediately, and an event with p2=T will be performed T seconds after arrival. Events can arrive at any time, and in any order. The score carry feature is legal here, as are held notes (p3 negative) and string arguments, but ramps and pp or np references are not.

[Note] Note

The -L flag is only valid on *NIX systems which have pipes. It doesn't work on Windows.

--omacro:XXX=YYY

Set orchestra macro XXX to value YYY

-r NUM, --sample-rate=NUM

Override the sampling rate (SR) supplied by the orchestra.

--sched

Linux only. Use real-time scheduling and lock memory. (Also requires -d and either -o dac or -o devaudio). See also --sched=N below.

--sched=N

Linux only. Same as --sched, but allows specifying a priority value: if N is positive (in the range 1 to 99) the scheduling policy SCHED_RR will be used with a priority of N; otherwise, SCHED_OTHER is used with the nice level set to N. Can also be used in the format --sched=N,MAXCPU,TIME to enable the use of a "watchdog" thread that terminates Csound if the average CPU usage exceeds MAXCPU percents over a peroid of TIME seconds (new in Csound 5.00).

--smacro:XXX=YYY

Set score macro XXX to value YYY

--strset

Csound 5. The --strset option allows setting strset string values from the command line, in the format '--strsetN=VALUE'. It is useful for passing parameters to the orchestra (e.g. file names).

-+skip_seconds=float

(min: 0) Start playback at the specified time (in seconds), skipping earlier events in the score and MIDI file.

-t NUM, --tempo=NUM

Use the uninterpreted beats of score.srt for this performance, and set the initial tempo at NUM beats per minute. When this flag is set, the tempo of score performance is also controllable from within the orchestra. WARNING: this mode of operation is experimental and may be unreliable.

Miscellaneous

-@ FILE

Provide an extended command-line in file FILE

-C, --cscore

Use Cscore processing of the scorefile.

--default-paths

Reenables adding of directory of CSD/ORC/SCO to search paths, if it has been disabled by a previous --no-default-paths (e.g. in .csoundrc).

-D, --defer-gen1

Defer GEN01 soundfile loads until performance time.

--env:NAME=VALUE

Set environment variable NAME to VALUE. Note: not all environment variables can be set this way, because some are read before parsing the command line. INCDIR, SADIR, SFDIR, and SSDIR are known to work.

--env:NAME+=VALUE

Append VALUE to ';' separated list of search paths in environment variable NAME (should be INCDIR, SADIR, SFDIR, or SSDIR). If a file is found in multiple directories, the last will be used.

--expression-opt

Since Csound 5. Turns on some optimizations in expressions:

  • Redundant assignment operations are eliminated whenever possible. This means that for example this line a1 = a2 + a3 will compile as a1 Add a2, a3 instead of #a0 Add a2, a3 a1 = #a0 saving a temporary variable and an opcode call. Less opcode calls result in reduced CPU usage (an average orchestra may compile about 10% faster with --expression-opt, but it depends largely on how many expressions are used, what the control rate is (see also below), etc.; thus, the difference may be less, but also much more).

  • number of a- and k-rate temporary variables is significantly reduced. This expression

    (a1 + a2 + a3 + a4)

    will compile as

    #a0 Add a1, a2
    #a0 Add #a0, a3
    #a0 Add #a0, a4       ; (the result is in #a0)

    instead of

    #a0 Add a1, a2
    #a1 Add #a0, a3
    #a2 Add #a1, a4       ; (the result is in #a2)

    The advantages of less temporary variables are:

    • less cache memory is used, which may improve performance of orchestras with many a-rate expressions and a low control rate (e.g. ksmps = 100)
    • large orchestras may load faster due to less different identifier names
    • index overflow errors (i.e. when messages like this Case2: indx=-56004 (ffff253c); (short)indx = 9532 (253c) are printed and odd behavior or a Csound crash occurs) may be fixed, because such errors are triggered by too many different (especially a-rate) variable names in a single instrument.

    Note that this optimization (due to technical reasons) is not performed on i-rate temporary variables.

[Warning] Warning

When --expression-opt is turned on, it is not allowed to use the i() function with an expression argument, and relying on the value of k-rate expressions at i-time is unsafe.

--help

Display on-line help message.

-I, --i-only

i-time only. Allocate and initialize all instruments as per the score, but skip all p-time processing (no k-signals or a-signals, and thus no amplitudes and no sound). Provides a fast validity check of the score pfields and orchestra i-variables. This option is exclusive of the --syntax-check-only flag.

-+ignore_csopts=integer

If set to 1, Csound will ignore all options specified in the csd file's CsOptions section. See Unified File Format for Orchestras and Scores.

-+max_str_len=integer

(min: 10, max: 10000) Maximum length of string variables + 1; defaults to 256 allowing a length of 255 characters. The length of string constants is not limited by this parameter.

-N, --notify

Notify (ring the bell) when score or MIDI track is done.

--no-default-paths

Disables adding of directory of CSD/ORC/SCO to search paths.

--no-expression-opt

Disables expression optimization.

-O FILE, --logfile=FILE

Log output to file FILE. If FILE is null (i.e. -O null or --logfile=null) all printing of messages to the console is disabled.

--opcode-lib=LIBNAME

Load plugin library LIBNAME.

--orc orcname

Set the argument as the orchestra file. Used when not score is required>. (Csound 5.18 and later).

--syntax-check-only

Causes Csound to exit immediately after the orchestra and score parsers finish checking the syntax of the input files and before the orchestra performs the score. This option is exclusive of the --i-only flag. (Csound 5.08 and later).

-t0, --keep-sorted-score

Prevents Csound from deleting the sorted score file, score.srt, upon exit.

-U UTILITY, --utility=UTILITY

Invoke the utility program UTILITY. Use any invalid name to list the available utilities.

-x FILE, --extract-score=FILE

Extract a portion of the sorted score, score.srt, using the extract file FILE (see Extract).