WAVE File Format (WAV)

8.12

WAVE File Format (WAV)🔗ℹ

(require binary-class/wave)

package: binary-class-riff

This module provides utilities for reading and writing WAVE files.

Some of the more advanced features of the format are not implemented; let me know if you need them!

1 Reading and Writing🔗ℹ

procedure
(read-wave [in]) → wave?
in : input-port? = (current-input-port)

Reads WAVE data from in and returns it.

procedure
(write-wave wav [out]) → void?
wav : wave?
out : output-port? = (current-output-port)

Writes the WAVE object wav to out.

2 Utilities🔗ℹ

procedure
(wave? v) → boolean?
v : any/c

Predicate for WAVE data. Equivalent to (and (is-a? v riff:list%) (bytes=? #"WAVE" (get-field type v))).

procedure
(wave-bits wav) → exact-positive-integer?
wav : wave?

Returns the number of bits per sample of wav.

procedure
(wave-channels wav) → exact-positive-integer?
wav : wave?

Returns the number of channels in wav.

procedure
(wave-sample-rate wav) → exact-positive-integer?
wav : wave?

Returns the sample rate of wav.

procedure
(wave-format wav) → (is-a?/c wave:format%)
wav : wave?

Returns the format chunk of wav. An exception will be raised if none is found.

procedure
(in-wave-channel wav ch) → sequence?
wav : wave?
ch : exact-nonnegative-integer?

Returns a sequence consisting of the samples of channel number ch in wav.

procedure
(in-wave wav) → sequence?
wav : wave?

Returns a sequence consisting of the samples of wav. Each element of the sequence has as many values as there are channels.

3 Binary Classes🔗ℹ

class
wave:format% : class?

superclass: riff%

A type representing the WAVE format chunk.

constructor
(new wave:format%
    [format-tag format-tag]
    [channels channels]
    [samples-per-sec samples-per-sec]
    [avg-bytes-per-sec avg-bytes-per-sec]
    [block-align block-align]
    [bits-per-sample bits-per-sample])
→ (is-a?/c wave:format%)
  format-tag : exact-nonnegative-integer?
  channels : exact-positive-integer?
  samples-per-sec : exact-positive-integer?
  avg-bytes-per-sec : exact-positive-integer?
  block-align : exact-positive-integer?
  bits-per-sample : exact-positive-integer?

class
wave:format:extensible% : class?

superclass: wave:format%

Represents extensible format data.

constructor
(new wave:format:extensible%
    [extension-size extension-size]
    ...superclass-args...)
→ (is-a?/c wave:format:extensible%)
  extension-size : exact-nonnegative-integer?

class
wave:format:extended% : class?

superclass: wave:format:extensible%

Represents extended format data.

constructor
(new wave:format:extended%
    [valid-bits-per-sample valid-bits-per-sample]
    [channel-mask channel-mask]
    [sub-format sub-format]
    ...superclass-args...)
→ (is-a?/c wave:format:extended%)
  valid-bits-per-sample : exact-nonnegative-integer?
  channel-mask : exact-nonnegative-integer?
  sub-format : bytes?