OfflineSession Class

OfflineSession Class#

class csoundengine.offline.OfflineSession(sr=None, nchnls=2, ksmps=None, a4=None, priorities=None, numAudioBuses=1000, numControlBuses=10000, dynamicArgsPerInstr=16, dynamicArgsSlots=None)[source]#

An OfflineSession is used when rendering offline.

In most cases an OfflineSession is a drop-in replacement of a Session when rendering offline (see makeRenderer()).

Instruments with higher priority are assured to be evaluated later in the chain. Instruments within a given priority are evaluated in the order they are defined (first defined is evaluated first)

Parameters:

sr (int | None) – the sampling rate. If not given, the value in the config is used (see config[‘rec_sr’])
nchnls (int) – number of channels.
ksmps (int | None) – csound ksmps. If not given, the value in the config is used (see config[‘ksmps’])
a4 (float | None) – reference frequency. (see config[‘A4’])
priorities (int | None) – max. number of priority groups. This will determine how long an effect chain can be
numAudioBuses – max. number of audio buses. This is the max. number of simultaneous events using an audio bus. To disable bus support use 0 and set numControlBuses also to 0
numControlBuses – the number of control buses.

Example

from csoundengine import *
session = OfflineSession(sr=44100, nchnls=2)

session.defInstr('saw', r'''
  kmidi = p5
  outch 1, oscili:a(0.1, mtof:k(kfreq))
''')

score = [('saw', 0,   2, 60),
         ('saw', 1.5, 4, 67),
         ('saw', 1.5, 4, 67.1)]
events = [session.sched(ev[0], delay=ev[1], dur=ev[2], args=ev[3:])
          for ev in score]

# offline events can be modified just like real-time events
events[0].automate('kmidi', pairs=[0, 60, 2, 59])
events[1].set(3, 'kmidi', 67.2)
session.render("out.wav")

Attributes:

`sr`	Samplerate
`nchnls`	Number of output channels
`ksmps`	Samples per cycle
`a4`	Reference frequency
`scheduledEvents`	All events scheduled in this session, mapps token to event
`renderedJobs`	A stack of rendered jobs
`csd`	Csd structure for this session (see `Csd`
`controlArgsPerInstr`	The maximum number of dynamic controls per instr
`instrs`	Maps instr name to Instr instance
`numPriorities`	Number of priorities in this session
`soundfileRegistry`	A dict mapping soundfile paths to their corresponding TableProxy

Methods:

`renderMode`()	The render mode of this Renderer, one of 'online', 'offline'
`initChannel`(channel[, value, kind, mode])	Create a channel and, optionally set its initial value
`setChannel`(channel, value[, delay])	Set the value of a software channel
`commitInstrument`(instrname[, priority])	Create concrete instrument at the given priority.
`registerInstr`(instr)	Register an Instr to be used in this session
`defInstr`(name, body[, args, init, priority, ...])	Create an `Instr` and register it with this session
`registeredInstrs`()	Returns a dict (instrname: Instr) with all registered Instrs
`getInstr`(name)	Find a registered Instr, by name
`includeFile`(path)	Add an #include clause to this offline renderer
`addGlobalCode`(code[, unique])	Add global code
`schedEvent`(event)	Schedule the given event
`sched`(instrname[, delay, dur, args, ...])	Schedule an event
`unsched`(event, delay)	Stop a scheduled event
`hasBusSupport`()	Returns True if this Engine was started with bus suppor
`assignBus`([kind, value, persist])	Assign a bus
`setCsoundOptions`(*options)	Set any command line options to use by all render operations
`renderDuration`()	Returns the actual duration of the rendered score, considering an end marker
`scoreTimeRange`()	Returns a tuple (score start time, score end time)
`setEndMarker`(time)	Set the end marker for the score
`render`([outfile, endtime, encoding, wait, ...])	Render to a soundfile
`lastRenderJob`()	Returns the last RenderJob spawned by `OfflineSession.render()`
`lastRenderedSoundfile`()	Returns the path of the last rendered soundfile, or None if no jobs were rendered
`writeCsd`(outfile)	Generate the csd project for this renderer, write it to outfile
`generateCsdString`()	Returns the csd as a string
`getEventById`(eventid)	Retrieve a scheduled event by its eventid
`getEventsByP1`(p1)	Retrieve all scheduled events which have the given p1
`strSet`(s[, index])	Set a string in this renderer.
`makeTable`([data, size, tabnum, sr, delay, ...])	Create a table with given data or an empty table of the given size
`readSoundfile`([path, chan, skiptime, delay, ...])	Add code to this offline renderer to load a soundfile
`playSample`(source[, delay, dur, chan, gain, ...])	Play a table or a soundfile
`automate`(event, param, pairs[, mode, delay, ...])	Automate a parameter of a scheduled event
`playPartials`(source[, delay, dur, speed, ...])	Play a packed spectrum

sr#: Samplerate

nchnls#: Number of output channels

ksmps#: Samples per cycle

a4#: Reference frequency

scheduledEvents: dict[int, SchedEvent]#: All events scheduled in this session, mapps token to event

renderedJobs: list[RenderJob]#: A stack of rendered jobs

csd#: Csd structure for this session (see Csd

controlArgsPerInstr#: The maximum number of dynamic controls per instr

instrs: dict[str, Instr]#: Maps instr name to Instr instance

numPriorities: int#: Number of priorities in this session

soundfileRegistry: dict[str, TableProxy]#: A dict mapping soundfile paths to their corresponding TableProxy

renderMode()[source]#

The render mode of this Renderer, one of ‘online’, ‘offline’

Return type:: str

initChannel(channel, value=None, kind='', mode='rw')[source]#

Create a channel and, optionally set its initial value

Parameters:

channel (str) – the name of the channel
value (float | str | None) – the initial value of the channel, will also determine the type (k, S)
kind – One of ‘k’, ‘S’, ‘a’. Leave unset to auto determine the channel type.
mode – r for read, w for write, rw for both.

Note

the mode determines the communication direction between csound and a host when running csound via its api. For offline rendering and when using channels for internal communication this is irrelevant

setChannel(channel, value, delay=0.0)[source]#

Set the value of a software channel

Parameters:

channel (str) – the name of the channel
value (float | str) – the new value, should match the type of the channel. Audio channels are not allowed offline
delay – when to perform the operation. A delay of 0 will generate a chnset instruction at the instr0 level

Return type:

None

commitInstrument(instrname, priority=1)[source]#

Create concrete instrument at the given priority.

Returns the instr number

Parameters:

instrname (str) – the name of the previously defined instrument to commit
priority – the priority of this version, will define the order of execution (higher priority is evaluated later)

Return type:

int

Returns:

The instr number (as in “instr xx … endin” in a csound orc)

registerInstr(instr)[source]#

Register an Instr to be used in this session

Parameters:: instr (Instr) – the insturment to register
Return type:: bool
Returns:: true if the instrument was registered, False if it was already registered in the current form

Example

>>> from csoundengine import *
>>> session = OfflineSession(sr=44100, nchnls=2)
>>> instrs = [
... Instr('vco', r'''
...   |kmidi=60|
...   outch 1, vco2:a(0.1, mtof:k(kmidi))
...   '''),
... Instr('sine', r'''
...   |kmidi=60|
...   outch 1, oscili:a(0.1, mtof:k(kmidi))
... ''')]
>>> for instr in instrs:
...     instr.register(session)   # This will call .registerInstr
>>> session.sched('vco', dur=4, kmidi=67)
>>> session.sched('sine', 2, dur=3, kmidi=68)
>>> session.render('out.wav')

defInstr(name, body, args=None, init='', priority=None, doc='', includes=None, aliases=None, useDynamicPfields=None, **kws)[source]#

Create an Instr and register it with this session

Parameters:

name (str) – the name of the created instr
body (str) – the body of the instrument. It can have named pfields (see example) or a table declaration
args (dict[str, float | str] | None) – args: pfields with their default values. Only needed if not using inline args
init (str) – init (global) code needed by this instr (read soundfiles, load soundfonts, etc)
priority (int | None) – has no effect for offline rendering, only here to maintain the same interface with Session
doc (str) – documentation describing what this instr does
includes (list[str] | None) – list of files to be included in order for this instr to work
aliases (dict[str, str] | None) – a dict mapping arg names to real argument names.
useDynamicPfields (bool | None) – if True, use pfields to implement dynamic arguments (arguments given as k-variables). Otherwise dynamic args are implemented as named controls, using a big global table
kws – any keywords are passed on to the Instr constructor. See the documentation of Instr for more information.

Return type:

Instr

Returns:

the created Instr. If needed, this instr can be registered at any other session

Example

>>> from csoundengine import *
>>> session = OfflineSession()
# An Instr with named pfields
>>> session.defInstr('synth', '''
... |ibus, kamp=0.5, kmidi=60|
... kfreq = mtof:k(lag:k(kmidi, 1))
... a0 vco2 kamp, kfreq
... a0 *= linsegr:a(0, 0.1, 1, 0.1, 0)
... busout ibus, a0
... ''')
# An instr with named table args
>>> session.defInstr('filter', '''
... {ibus=0, kcutoff=1000, kresonance=0.9}
... a0 = busin(ibus)
... a0 = moogladder2(a0, kcutoff, kresonance)
... outch 1, a0
... ''')

>>> bus = session.assignBus()
>>> event = session.sched('synth', 0, dur=10, ibus=bus, kmidi=67)
>>> event.set(kmidi=60, delay=2)  # This will set the kmidi param

>>> filt = session.sched('filter', 0, dur=event.dur, priority=event.priority+1,
...                       args={'ibus': bus, 'kcutoff': 1000})
>>> filt.automate('kcutoff', [3, 1000, 6, 200, 10, 4000])

registeredInstrs()[source]#

Returns a dict (instrname: Instr) with all registered Instrs

Return type:: dict[str, Instr]

getInstr(name)[source]#

Find a registered Instr, by name

Returns None if no such Instr was registered

Return type:: Instr | None

includeFile(path)[source]#

Add an #include clause to this offline renderer

Parameters:: path (str) – the path to the include file
Return type:: None

addGlobalCode(code, unique=False)[source]#

Add global code

This can be used to add resources, define global variables, define udos, etc

Parameters:

code (str) – the code to add. This must be valid orc code
unique – if True, code which is already added will be skipped.

Return type:

None

Example

>>> from csoundengine import *
>>> session = OfflineSession(...)
>>> session.addGlobalCode("giMelody[] fillarray 60, 62, 64, 65, 67, 69, 71")

schedEvent(event)[source]#

Schedule the given event

Return type:: SchedEvent

sched(instrname, delay=0.0, dur=-1.0, *pfields, args=None, priority=1, whenfinished=None, relative=True, name='', **kwargs)[source]#

Schedule an event

Parameters:

instrname (str) – the name of the already registered instrument
priority – determines the order of execution. 1 to the number of priorities defined at creation time. Priority can be negative: a priority of -1 equals to setting the priority to the highest priority, -2 would be the second highest, etc.
delay – time offset
dur – duration of this event. -1: endless
args (Union[Sequence[float | str], dict[str, float], None]) – pfields beginning with p5 (p1: instrnum, p2: delay, p3: duration, p4: reserved)
whenfinished (Optional[Callable]) – not relevant in the context of offline rendering
relative – not relevant for offline rendering
kwargs – any named argument passed to the instr

Return type:

SchedEvent

Returns:

a ScoreEvent, holding the csound event (p1, start, dur, args)

Example

>>> from csoundengine import *
>>> session = OfflineSession(sr=44100, nchnls=2)
>>> instrs = [
... Instr('vco', r'''
...   |kmidi=60|
...   outch 1, vco2:a(0.1, mtof:k(kmidi))
...   '''),
... Instr('sine', r'''
...   |kamp=0.1, kmidi=60|
...   outch 1, oscili:a(kamp, mtof:k(kmidi))
... ''')]
>>> for instr in instrs:
...     session.registerInstr(instr)
>>> session.sched('vco', dur=4, kmidi=67)
>>> session.sched('sine', 2, dur=3, kmidi=68)
>>> session.render('out.wav')

unsched(event, delay)[source]#

Stop a scheduled event

This schedule the stop of a playing event. The event can be an indefinite event (dur=-1) or it can be used to stop an event before its actual end

Parameters:

event (int | float | SchedEvent) – the event to stop
delay (float) – when to stop the given event

Return type:

None

hasBusSupport()[source]#: Returns True if this Engine was started with bus suppor

assignBus(kind='', value=None, persist=False)[source]#

Assign a bus

Parameters:

kind – the bus kind, one of ‘audio’ or ‘control’. The value, if given, will determine the kind if kind is left unset
value – an initial value for the bus, only valid for control buses
persist – if True, the bus exists until it is manually released. Otherwise the bus exists as long as it is unused and remains alive as long as there are instruments using it

Return type:

Bus

Example

from csoundengine import *
r = OfflineSession()

r.defInstr('sender', r'''
  ibus = p5
  ifreqbus = p6
  kfreq = busin:k(ifreqbus)
  asig vco2 0.1, kfreq
  busout(ibus, asig)
''')

r.defInstr('receiver', r'''
  ibus  = p5
  kgain = p6
  asig = busin:a(ibus)
  asig *= a(kgain)
  outch 1, asig
''')

bus = r.assignBus('audio')
freqbus = s.assignBus(value=880)
chain = [r.sched('sender', ibus=bus.token, ifreqbus=freqbus.token),
         r.sched('receiver', priority=2, ibus=bus.token, kgain=0.5)]

# Make a glissando
freqbus.automate((0, 880, 5, 440))

setCsoundOptions(*options)[source]#

Set any command line options to use by all render operations

Options can also be set while calling OfflineSession.render()

Parameters:: *options (str) – any option will be passed directly to csound when rendering
Return type:: None

Examples

>>> from csoundengine.offline import OfflineSession
>>> renderer = OfflineSession()
>>> instr = Instr("sine", ...)
>>> renderer.registerInstr(instr)
>>> renderer.sched("sine", ...)
>>> renderer.setCsoundOptions("--omacro:MYMACRO=foo")
>>> renderer.render("outfile.wav")

renderDuration()[source]#

Returns the actual duration of the rendered score, considering an end marker

Return type:: float
Returns:: the duration of the render, in seconds

See also

OfflineSession.render()

lastRenderedSoundfile()[source]#

Returns the path of the last rendered soundfile, or None if no jobs were rendered

Return type:: str | None

writeCsd(outfile)[source]#

Generate the csd project for this renderer, write it to outfile

Parameters:: outfile (str) – the path of the generated csd
Return type:: None

If this csd includes any datafiles (tables with data exceeding the limit to include the data ‘inline’) or soundfiles defined relative to the csd, these datafiles are written to a subfolder with the name {outfile}.assets, where outfile is the outfile given as argument

For example, if we call writeCsd as renderer.writeCsd('~/foo/myproj.csd') , any datafiles will be saved in '~/foo/myproj.assets' and referenced with relative paths as 'myproj.assets/datafile.gen23' or 'myproj.assets/mysnd.wav'

generateCsdString()[source]#

Returns the csd as a string

Return type:: str
Returns:: the csd as str

getEventById(eventid)[source]#

Retrieve a scheduled event by its eventid

Parameters:: eventid (int) – the event id, as returned by sched
Return type:: SchedEvent | None
Returns:: the ScoreEvent if it exists, or None

getEventsByP1(p1)[source]#

Retrieve all scheduled events which have the given p1

Parameters:: p1 (float) – the p1 of the scheduled event. This can be a fractional value
Return type:: list[SchedEvent]
Returns:: a list of all scheduled events with the given p1

strSet(s, index=None)[source]#

Set a string in this renderer.

The string can be retrieved in any instrument via strget. The index is determined by the Renderer itself, and it is guaranteed that calling strSet with the same string will result in the same index

Parameters:

s (str) – the string to set
index (int | None) – if given, it will force the renderer to use this index.

Return type:

int

Returns:

the string id. This can be passed to any instrument to retrieve the given string via the opcode “strget”

makeTable(data=None, size=0, tabnum=0, sr=0, delay=0.0, unique=True)[source]#

Create a table with given data or an empty table of the given size

Parameters:

data (ndarray | list[float] | None) – the data of the table. Use None if the table should be empty
size (int | tuple[int, int]) – if not data is given, sets the size of the empty table created. To create a multichannel table, use a tuple (frames, numchannels), where the actual size is frames * numchannels
tabnum (int) – 0 to self assign a table number
sr (int) – the samplerate of the data, if applicable.
delay (float) – when to create this table
unique – if True, create a table even if a table exists with the same data.

Return type:

TableProxy

Returns:

a TableProxy

readSoundfile(path='?', chan=0, skiptime=0.0, delay=0.0, force=False)[source]#

Add code to this offline renderer to load a soundfile

Parameters:

path – the path of the soundfile to load. Use ‘?’ to select a file using a GUI dialog
chan (int) – the channel to read, or 0 to read all channels
delay (float) – moment in the score to read this soundfile
skiptime (float) – skip this time at the beginning of the soundfile
force – if True, add the soundfile to this renderer even if the same soundfile has already been added

Return type:

TableProxy

Returns:

a TableProxy, representing the table holding the soundfile

playSample(source, delay=0.0, dur=0.0, chan=1, gain=1.0, speed=1.0, loop=False, pan=0.5, skip=0.0, fade=None, crossfade=0.02)[source]#

Play a table or a soundfile

Adds an instrument definition and an event to play the given table as sound (assumes that the table was allocated via readSoundFile() or any other GEN1 ftgen)

Parameters:

source (int | str | TableProxy | tuple[ndarray, int]) – the table number to play, a TableProxy, the path of a soundfile or a tuple (numpy array, sr). Use ‘?’ to select a file using a GUI dialog
delay – when to start playback
chan – the channel to output to. If the sample is stereo/multichannel, this indicates the first of a set of consecutive channels to output to.
loop – if True, sound will loop
speed – the speed to play at
pan – a value between 0-1. -1=default, which is 0 for mono, 0.5 for stereo. For multichannel samples panning is not taken into account at the moment
gain – apply a gain to playback
fade (float | tuple[float, float] | None) – fade-in / fade-out ramp, in seconds
skip – playback does not start at the beginning of the table but at starttime
dur – duration of playback. -1=indefinite duration, will stop at the end of the sample if no looping was set; 0=definite duration, the event is scheduled with dur=sampledur/speed. Do not use this if you plan to modify or modulate the playback speed.
crossfade – if looping, this indicates the length of the crossfade

Return type:

SchedEvent

automate(event, param, pairs, mode='linear', delay=None, overtake=False)[source]#

Automate a parameter of a scheduled event

Parameters:

event (SchedEvent) – the event to automate, as returned by sched
param (str) – the name of the parameter to automate. The instr should have a corresponding line of the sort “kparam = pn”. Call ScoreEvent.dynamicParams() to query the set of accepted parameters
pairs (Union[Sequence[float], ndarray]) – the automateion data as a flat list [t0, y0, t1, y1, ...], where the times are relative to the start of the automation event
mode – one of “linear”, “cos”, “smooth”, “exp=xx” (see interp1d)
delay (float | None) – start time of the automation event. If None is given, the start time of the automated event will be used.
overtake – if True, the first value is not used, the current value for the given parameter is used in its place.

Return type:

float

playPartials(source, delay=0.0, dur=-1, speed=1.0, freqscale=1.0, gain=1.0, bwscale=1.0, loop=False, chan=1, start=0.0, stop=0.0, minfreq=0, maxfreq=0, maxpolyphony=50, gaussian=False, interpfreq=True, interposcil=True, position=0.0)[source]#

Play a packed spectrum

A packed spectrum is a 2D numpy array representing a fixed set of oscillators. After partial tracking analysis, all partials are arranged into such a matrix where each row represents the state of all oscillators over time.

The loristrck packge is needed for both partial-tracking analysis and packing. It can be installed via pip install loristrck (see gesellkammer/loristrck). This is an optional dependency

Parameters:

source (int | str | TableProxy | ndarray) – a table number, tableproxy, path to a .mtx or .sdif file, or a numpy array containing the partials data
delay – when to start the playback
dur – duration of the synth (-1 will play indefinitely if looping or until the end of the last partial or the end of the selection
speed – speed of playback (does not affect pitch)
loop – if True, loop the selection or the entire spectrum
chan – channel to send the output to
start – start of the time selection
stop – stop of the time selection (0 to play until the end)
minfreq – lowest frequency to play
maxfreq – highest frequency to play
gaussian – if True, use gaussian noise for residual resynthesis
interpfreq – if True, interpolate frequency between cycles
interposcil – if True, use linear interpolation for the oscillators
maxpolyphony – if a sdif is passed, compress the partials to max. this number of simultaneous oscillators
position – pan position
freqscale – frequency scaling factor
gain – playback gain
bwscale – bandwidth scaling factor

Return type:

SchedEvent

Returns:

the playing Synth

Example

>>> import loristrck as lt
>>> import csoundengine as ce
>>> samples, sr = lt.util.sndread("/path/to/soundfile")
>>> partials = lt.analyze(samples, sr, resolution=50)
>>> lt.util.partials_save_matrix(partials, outfile='packed.mtx')
>>> session = ce.Engine().session()
>>> session.playPartials(source='packed.mtx', speed=0.5)

OfflineSession Class

Contents

OfflineSession Class#