Class: DevAudio (private in SoundStream

• Inheritance
• Description
• Class protocol
  • default values
  • queries
• Instance protocol
  • misc
  • open & close
  • private
  • queries
  • reading
  • writing

Inheritance:

   Object
   |
   +--Stream
      |
      +--PeekableStream
         |
         +--PositionableStream
            |
            +--WriteStream
               |
               +--ReadWriteStream
                  |
                  +--ExternalStream
                     |
                     +--FileStream
                        |
                        +--SoundStream
                           |
                           +--SoundStream::DevAudio

Package:

stx:libbasic2

Category:

Streams-External

Owner:

SoundStream

Description:

interface to /dev/audio (sun, hpux, linux, ...)

Class protocol:

 defaultSampleRate

minimum, supported by all audio systems

 isSupported

SoundStream::DevAudio isSupported
SoundStream::PortAudio isSupported

Instance protocol:

 dumpSettings

debugging interface - dump the current settings

Usage example(s):

self writing dumpSettings; close

 flush

wait until all sound has been played

 closeFile

a stream has been collected - close the file

 openWithMode: aMode attributes: attributeSpec

normally not reached

 initialize

initialize for least common mode

 resetSoundCard

debugging interface - reset the soundCard

Usage example(s):

self writing resetSoundCard; dumpSettings; close

 setAudioFormat: aSymbol

set the format of the audio data as specified by aSymbol.
Returns true if sucessful - may fail with some formats on many sound devices.

Usage example(s):

self writing dumpSettings; close self writing setAudioFormat:#'MU_LAW'; close self writing setAudioFormat:#'U8'; dumpSettings; close self writing setAudioFormat:#'MPEG'; dumpSettings; close

 setChannels: nChannels

set the number of channels (1 -> mono; 2 -> stereo).
Returns true if sucessful - may fail with many sound devices.

Usage example(s):

self writing setChannels:2; dumpSettings; close self writing setChannels:2; setSampleRate:10000; dumpSettings; close self writing setChannels:2; setSampleRate:40000; dumpSettings; close

 setFragmentSize: blockSize

set the soundDriver's fragmentSize

 setSampleRate: hz

set the sample rate

Usage example(s):

self writing setSampleRate:10000; dumpSettings; close self writing setSampleRate:1000; dumpSettings; close self writing setSampleRate:8000; dumpSettings; close

 supportedAudioFormats

return a collection of supported audio formats.
possibly returned symbols are:
U8 unsigned 8bit samples
S8 signed 8bit samples
U16 unsigned 16bit samples in native format
U16_LE unsigned 16bit big endian samples
U16_BE unsigned 16bit big endian samples
S16 signed 16bit little endian samples in native format
S16_LE signed 16bit little endian samples
S16_BE signed 16bit big endian samples
S24 signed 24bit little endian samples in native format
S24_LE signed 24bit little endian samples
S24_BE signed 24bit big endian samples
S32 signed 32bit little endian samples in native format
S32_LE signed 32bit little endian samples
S32_BE signed 32bit big endian samples
F16 float samples
F32 float samples
MPEG audio mpeg encoded
MU_LAW u-law encoded 8bit samples
A_LAW a-law encoded 8bit samples
IMA_ADPCM adpcm encoded
the set of returned symbols depends on the underlying sound hardware.

Usage example(s):

|s formats| s := self writing. formats := s supportedAudioFormats. s close. formats

 nextBytes: count into: anObject startingAt: start

read the next count bytes into an object and return the number of
bytes read or nil on error.
Use with ByteArrays only.

 nextPutBytes: count from: anObject startingAt: start

write count bytes from an object starting at index start.
return the number of bytes written or nil on error.
Redefined, since IRIS audio library cannot be used with stdio.
(at least I don't know). Use with ByteArrays only.