/ 
Audio-OSS-0.0501
River stage zero No dependents
++
 / Audio::OSS
Author image David Huggins-Daines

NAME

Audio::OSS - pure-perl interface to OSS (open sound system) audio devices

SYNOPSIS

  use Audio::OSS qw(:funcs :formats :mixer);

  my $dsp = IO::Handle->new("</dev/dsp") or die "open failed: $!";
  dsp_reset($dsp) or die "reset failed: $!";

  my $mask = get_supported_formats($dsp);
  if ($mask & AFMT_S16_LE) {
    set_fmt($dsp, AFMT_S16_LE) or die set format failed: $!";
  }
  my $current_format = set_fmt($dsp, AFMT_QUERY);

  my $sps_actual = set_sps($dsp, 16000);

  set_fragment($dsp, $fragshift, $nfrags);
  my ($frags_avail, $frags_total, $fragsize, $bytes_avail)
      = get_outbuf_info($dsp);
  my ($bytes, $blocks, $dma_ptr) = get_outbuf_ptr($dsp);

  my $mixer = IO::Handle->new("</dev/mixer") or die "open failed: $!";
  my $miclevel = mixer_read($mixer, SOUND_MIXER_MIC);

DESCRIPTION

Audio::OSS is a pure Perl interface to the Open Sound System, as used on Linux, FreeBSD, and other Unix systems.

It provides a procedural interface based around filehandles opened on the audio device (usually /dev/dsp* for PCM audio).

It also defines constants for various ioctl calls and other things based on the OSS system header files, so you don't have to rely on .ph files that may or may be correct or even present on your system.

Currently, only the PCM audio input and output functions are supported. Mixer support is likely in the future, sequencer support less likely.

EXPORTS

The main exports of Audio::OSS are rubber, tea, and tractor parts.

Seriously, though, nothing is exported by default. However, there are three export tags which cover the vast majority of things you might conceivably want, and which exist on most systems. These are:

:funcs

This tag imports the following functions, which perform various operations on the PCM audio device:

  dsp_sync
  dsp_reset
  dsp_get_caps
  set_sps
  set_fmt
  set_stereo
  get_supported_fmts
  set_fragment
  get_outbuf_ptr
  get_inbuf_ptr
  get_outbuf_info
  get_inbuf_info
  mixer_read_devmask
  mixer_read_recmask
  mixer_read_stereodevs
  mixer_read_caps
  mixer_read
  mixer_write

Some functions are exported only if the underlying support for them exists on your operating system, namely:

  get_mixer_info
:formats

This tag imports the following constants, which correspond to arguments to the set_fmt and bits in the return value from get_supported_fmts:

  AFMT_QUERY
  AFMT_S16_NE
  AFMT_S16_LE
  AFMT_S16_BE
  AFMT_U16_LE
  AFMT_U16_BE
  AFMT_U8
  AFMT_MU_LAW
  AFMT_A_LAW
:caps

This tag imports the following constants, which correspond to bits in the return value from dsp_get_caps:

  DSP_CAP_REVISION
  DSP_CAP_DUPLEX
  DSP_CAP_REALTIME
  DSP_CAP_BATCH
  DSP_CAP_COPROC
  DSP_CAP_TRIGGER
  DSP_CAP_MMAP
  DSP_CAP_MULTI
  DSP_CAP_BIND
:mixer

This tag imports the following constants, which are used in mixer operations:

  SOUND_MIXER_NRDEVICES
  SOUND_MIXER_VOLUME
  SOUND_MIXER_BASS
  SOUND_MIXER_TREBLE
  SOUND_MIXER_SYNTH
  SOUND_MIXER_PCM
  SOUND_MIXER_SPEAKER
  SOUND_MIXER_LINE
  SOUND_MIXER_MIC
  SOUND_MIXER_CD
  SOUND_MIXER_IMIX
  SOUND_MIXER_ALTPCM
  SOUND_MIXER_RECLEV
  SOUND_MIXER_IGAIN
  SOUND_MIXER_OGAIN
  SOUND_MIXER_LINE1
  SOUND_MIXER_LINE2
  SOUND_MIXER_LINE3
  SOUND_MIXER_DIGITAL1
  SOUND_MIXER_DIGITAL2
  SOUND_MIXER_DIGITAL3
  SOUND_MIXER_PHONEIN
  SOUND_MIXER_PHONEOUT
  SOUND_MIXER_VIDEO
  SOUND_MIXER_RADIO
  SOUND_MIXER_MONITOR
  SOUND_MIXER_NONE
  SOUND_ONOFF_MIN
  SOUND_ONOFF_MAX

  SOUND_MIXER_RECSRC
  SOUND_MIXER_DEVMASK
  SOUND_MIXER_RECMASK
  SOUND_MIXER_CAPS
  SOUND_CAP_EXCL_INPUT
  SOUND_MIXER_STEREODEVS
  SOUND_MIXER_OUTSRC
  SOUND_MIXER_OUTMASK

The full list of constants and functions which can be imported from this module follows. Note that not all of these may be available on your system. When you build this module, the Makefile.PL will try to find them all, leaving out any that fail. To some extent, these are documented in the system header files, specifically <sys/soundcard.h> or <linux/soundcard.h>.

  SNDCTL_DSP_RESET
  SNDCTL_DSP_SYNC
  SNDCTL_DSP_SPEED
  SNDCTL_DSP_STEREO
  SNDCTL_DSP_GETBLKSIZE
  SNDCTL_DSP_SAMPLESIZE
  SNDCTL_DSP_CHANNELS
  SNDCTL_DSP_POST
  SNDCTL_DSP_SUBDIVIDE
  SNDCTL_DSP_SETFRAGMENT
  SNDCTL_DSP_GETOSPACE
  SNDCTL_DSP_GETISPACE
  SNDCTL_DSP_NONBLOCK
  SNDCTL_DSP_GETCAPS
  SNDCTL_DSP_GETFMTS
  SNDCTL_DSP_SETFMT
  SNDCTL_DSP_GETTRIGGER
  SNDCTL_DSP_SETTRIGGER
  SNDCTL_DSP_GETIPTR
  SNDCTL_DSP_GETOPTR
  SNDCTL_DSP_MAPINBUF
  SNDCTL_DSP_MAPOUTBUF
  SNDCTL_DSP_SETSYNCRO
  SNDCTL_DSP_SETDUPLEX
  SNDCTL_DSP_GETODELAY

  SNDCTL_DSP_GETCHANNELMASK
  SNDCTL_DSP_BIND_CHANNEL
  SNDCTL_DSP_PROFILE

  SOUND_PCM_READ_RATE
  SOUND_PCM_READ_CHANNELS
  SOUND_PCM_READ_BITS
  SOUND_PCM_READ_FILTER

  SOUND_MIXER_READ_VOLUME
  SOUND_MIXER_READ_BASS
  SOUND_MIXER_READ_TREBLE
  SOUND_MIXER_READ_SYNTH
  SOUND_MIXER_READ_PCM
  SOUND_MIXER_READ_SPEAKER
  SOUND_MIXER_READ_LINE
  SOUND_MIXER_READ_MIC
  SOUND_MIXER_READ_CD
  SOUND_MIXER_READ_IMIX
  SOUND_MIXER_READ_ALTPCM
  SOUND_MIXER_READ_RECLEV
  SOUND_MIXER_READ_IGAIN
  SOUND_MIXER_READ_OGAIN
  SOUND_MIXER_READ_LINE1
  SOUND_MIXER_READ_LINE2
  SOUND_MIXER_READ_LINE3
  SOUND_MIXER_READ_RECSRC
  SOUND_MIXER_READ_DEVMASK
  SOUND_MIXER_READ_RECMASK
  SOUND_MIXER_READ_STEREODEVS
  SOUND_MIXER_READ_CAPS

  SOUND_MIXER_WRITE_VOLUME
  SOUND_MIXER_WRITE_BASS
  SOUND_MIXER_WRITE_TREBLE
  SOUND_MIXER_WRITE_SYNTH
  SOUND_MIXER_WRITE_PCM
  SOUND_MIXER_WRITE_SPEAKER
  SOUND_MIXER_WRITE_LINE
  SOUND_MIXER_WRITE_MIC
  SOUND_MIXER_WRITE_CD
  SOUND_MIXER_WRITE_IMIX
  SOUND_MIXER_WRITE_ALTPCM
  SOUND_MIXER_WRITE_RECLEV
  SOUND_MIXER_WRITE_IGAIN
  SOUND_MIXER_WRITE_OGAIN
  SOUND_MIXER_WRITE_LINE1
  SOUND_MIXER_WRITE_LINE2
  SOUND_MIXER_WRITE_LINE3
  SOUND_MIXER_WRITE_RECSRC
  SOUND_MIXER_WRITE_DEVMASK
  SOUND_MIXER_WRITE_RECMASK

  SOUND_MIXER_INFO
  SOUND_MIXER_AGC
  SOUND_MIXER_3DSE
  SOUND_MIXER_PRIVATE1
  SOUND_MIXER_PRIVATE2
  SOUND_MIXER_PRIVATE3
  SOUND_MIXER_PRIVATE4
  SOUND_MIXER_PRIVATE5
  SOUND_MIXER_GETLEVELS
  SOUND_MIXER_SETLEVELS

  OSS_GETVERSION

  AFMT_QUERY
  AFMT_MU_LAW
  AFMT_A_LAW
  AFMT_IMA_ADPCM
  AFMT_U8
  AFMT_S16_LE
  AFMT_S16_BE
  AFMT_S16_NE
  AFMT_S8
  AFMT_U16_LE
  AFMT_U16_BE
  AFMT_MPEG
  AFMT_AC3

  DSP_CAP_REVISION
  DSP_CAP_DUPLEX
  DSP_CAP_REALTIME
  DSP_CAP_BATCH
  DSP_CAP_COPROC
  DSP_CAP_TRIGGER
  DSP_CAP_MMAP
  DSP_CAP_MULTI
  DSP_CAP_BIND

  PCM_ENABLE_INPUT
  PCM_ENABLE_OUTPUT

  DSP_BIND_QUERY
  DSP_BIND_FRONT
  DSP_BIND_SURR
  DSP_BIND_CENTER_LFE
  DSP_BIND_HANDSET
  DSP_BIND_MIC
  DSP_BIND_MODEM1
  DSP_BIND_MODEM2
  DSP_BIND_I2S
  DSP_BIND_SPDIF

  APF_NORMAL
  APF_NETWORK
  APF_CPUINTENS

BUGS

The Makefile.PL is pretty slow, and could be optimized to check more than one constant at once, or all of them at once, even.

There is no object oriented interface (this is a feature, in my opinion).

The documentation is lacking, but then, that's also true for OSS itself.

AUTHOR

David Huggins-Daines <dhd@cepstral.com>

SEE ALSO

perl(1), /usr/include/sys/soundcard.h