The short-time Fourier analysis window allows access to the pvanal soundfile utility. This program (documented in the Csound manual) computes and outputs a set of short-time Fourier transform frames which can be used for resynthesis with the Csound pvoc opcode.

The following controls are present in the window:

Sound Input File

The name of the file containing the sound to be analyzed. For realtime input, enter either adc or devaudio.
NOTE: Realtime sound input is only available when the Csound Server is running.
This is a mandatory entry field.

Analysis Output File

The name of the generated file containing the resulting data.
This is a mandatory entry field.

Transcript

If this entry field contains a filename, all messages printed during analysis are logged and written to the named file.

Verbose Output

If a file name is given in this entry field, a (voluminous) textual form of the program's output will be written to it.

Sample Rate

If present, indicates the sample rate of the sound input file. If omitted, the sample rate in the sound file's header is used. For headerless files, analysis assumes a default sample rate of 10000Hz.

Channel Number

Selects one of the channels in the sound input file. Default is channel 1.

Begin Time

Offset (in seconds) from the start of the input file to the start of the segment to be analyzed.

Duration

Length (in seconds) of the analyzed segment of the input file. If this parameter is omitted, analysis proceeds to the end of the file.

Frame Size

The number of samples in each analyzed frame. Must be one of the powers of two between 16 and 16384, inclusive. If the frame is too short or too long, acoustic artifacts may occur during resynthesis; see the Csound manual for details.
The default value for this field depends on the sample rate; it is the smallest power of two that will result in a frame length of at least 20ms.

Window Overlap

The number of analysis frames in which a given sample occurs. Low values may cause distortion during resynthesis; high values increase analysis time and the size of the output file.
This option is mutually exclusive with the following one.

Hop Size

The offset in samples between successive analysis frames; the converse of the window overlap factor.
This option is mutually exclusive with the preceding one.

Graphical Displays

Selecting this option causes the analyzed waveforms to be displayed as they are being processed.
NOTE: This option is only available when the Csound Server is running.

Analyze

Clicking on this button (when enabled) starts analysis using the given parameters.

Abort

Clicking on this button (when enabled) causes a running analysis to be aborted.