sfrecord~ Reference

Record to audio file on disk



Use the sfrecord~ object to record and save MSP output as an audio file.


Save an audio file containing 'real world' sound and/or sound created in MSP


number-of-input-channels [int]


Sets the number of input channels, which determines the number of inlets that the sfrecord~ object will have. The maximum number of channels is 64, and the default is 1. The audio file created will have the same number of channels as this argument. Whether you can actually record the maximum number of channels is dependent on the speed of your processor and hard disk.

buffer-size [int]


An optional second argument sets the buffer size. The defult value is 20160.


bitdepth [int]

Bits Per Sample

dither [int] (default: 0)

Enable triangular dithering when writing PCM (integer) files. Possible values:

0 = 'Off' ( Apply no dithering when writing PCM files )
1 = 'Dither' ( Apply triangular dither (TPDF) when writing PCM files )
2 = 'Dither + Noise Shaping' ( Apply triangular dither (TPDF) with noise shaping when writing PCM files )

nchans [int]

Sets the number of channels for the audio file to be recorded (1-64). The default is 1.

quantization [int] (default: 0)

Select the quantization rule when writing PCM (integer) files. Possible values:

0 = 'Round' ( Round when quantizing to integer values. )
1 = 'Floor' ( Floor when quantizing to integer values. )

resample [float]

Upsamples or downsamples the file. Sample rates are expressed as floating-point values - 1.0 is the current sampling rate, 0.5 is half the current, 2.0 is twice the current sample rate, etc.

sortloop [int] (default: 0)

When the sortloop attribute is on, a recording made with the loop message will be re-ordered so that the beginning of the file is the beginning of the most recent recording. If sortloop is off (default), the beginning of the recording will likely be somewhere in the middle of the resulting audio file.

Common Box Attributes




recording-start/stop-flag (0 or nonzero) [int]
In left inlet: If a file has been opened with the open message, a non-zero value begins recording, and 0 stops recording and closes the file. sfrecord~ requires another open message to record again if a 0 has been sent.

Recording may also stop spontaneously if there is an error, such as running out of space on your hard disk.



length (milliseconds) [float]
In left inlet: If a file has been opened with the open message, the word loop, followed by a length in milliseconds, begins a recording that captures the most recent audio in the specified amount of time. The recording will stop when the sfrecord~ object receives 0 in its left inlet.



file-type [symbol]
filename [symbol]
In left inlet: Opens a file for recording. By default, the file type is AIFF, but sfrecord~ also supports WAVE, OGG, FLAC, and Raw Data. The word open, without an argument, brings up a standard Save As dialog allowing you to choose a filename. The optional symbols aiff, wave, ogg, flac, or raw specify the file format (which can also be set in the Save As dialog with a Format pop-up menu). If open is followed by a second symbol, it creates a file in the current default volume. An existing file with the same name will be overwritten. The format symbol (e.g., aiff) can follow the optional filename argument. If only one argument is given to the open message, which is a filename, the file type is determined from the file extension (e.g., "open test.wav" sets the file type to wave).


Outputs cryptic status information about the progress of the recording.



recording-time [float]
In left inlet: If a file has been opened with the open message, the word record, followed by a time in milliseconds, begins recording for the specified amount of time. The recording can be stopped before it reaches the end by sending sfrecord~ a 0 to its left inlet.



sample-type [symbol]
byte-swap-flag [int]
In left inlet: The word samptype, followed by a symbol, specifies the sample type to use when recording the audio file. The following types of sample data are supported:

int8: 8-bit integer
int16: 16-bit integer
int24: 24-bit integer
int32: 32-bit integer
float32: 32-bit floating-point
float64: 64-bit floating-point
mulaw: 8-bit "mu"-law encoding
alaw: 8-bit a-law encoding
The optional second argument, a 0 or 1, specifies whether or not byte-swapping should be used, which is only useful when writing a 'raw' audio file.


Each inlet of sfrecord~ accepts a signal which is recorded to a channel of an audio file when recording is turned on.



The time, in milliseconds, since recording of the file began. If recording has stopped, the signal value will remain at the length of the last recording until a new recording is started.

See Also

Name Description
MSP Sampling Tutorial 6: Record and Play Audio Files MSP Sampling Tutorial 6: Record and Play Audio Files