NAME

       osscore - Open Sound Sytem core audio framework.

DESCRIPTION

       Open  Sound  System  core audio support psudo driver. This driver implements the core Open
       Sound System API for audio, midi, mixer and synth functions. This driver  also  implements
       the  OS  driver  interface as well as device configuration and setup.  More information on
       programming on the OSS API is avaialable at: http://manuals.opensound.com/

OPTIONS

       o ac97_recselect
              When set to 1 this option enables independent recording source  selection  for  the
              left  and  the  right  channel on AC97 devices. In this way it's possible to record
              audio streams so that  (for  example)  the  left  channel  signal  comes  from  the
              microphone  and  the right channel signal from line-in. However when this option is
              enabled it's only possible to select the recording source by using a fully OSS  4.0
              compatible  mixer program such as ossxmix.  Default: 0 - recording source is common
              to both channels.

       o ac97_amplifier
              When set to 1 this option enables the speaker power amplifier feature of AC97 codec
              (if available).  Some boards have this inverted, so this feature can be disabled by
              setting this option to 0.  Affects all AC97 based  audio  devices  in  the  system.
              Default: -1=autodetect correct setting.

       o cooked_enable
              By default OSS will let applications to use sampling rates and formats that are not
              supported by the hardware.  Instead OSS performs the necessary  format  conversions
              in  software.  Applications  that  don't  tolerate this kind of conversions usually
              disable them by using features of the  OSS  API  (SNDCTL_DSP_COOKEDMODE).  If  this
              option  is  set  to  0  then  the  format  conversions  will  be  disabled  for all
              applications and devices unless the application explicitly enables them.   Default:
              1 - conversions are enabled.  This option should not be changed without very strong
              reasons.

       o detect_trace
              Internal debugging (do not change). Default: 0

       o dma_buffsize
              By default OSS will allocate audio DMA buffers with some system  dependent  default
              size  (usually  64k  but  sometimes smaller). It is possible to change this default
              allocation by setting this option. Value of 0 means that the default size  will  be
              used.  Value  between 16 and 128 (kilobytes) can be used if the default size is not
              suitable for some reason.  Default: 0 - system  dependent  buffsize.   This  option
              mustn't be changed unless it's absolutely necessary.

       o max_intrate
              Set  the maximum number of interrupts per second.  A value of 0 means the number is
              unlimited.  Default: 100 interrupts per  second  which  equals  to  about  10  msec
              minimum latencies.

       o vmix_disabled
              The virtual mixer subsystem can be disabled by setting this configuration option to
              1.  Default: 0 - virtual mixer is enabled.

       o vmix_loopdevs
              Optionally the virtual mixer subsystem can create special  loopback  audio  devices
              that can be used to record the output mix sent to the device. This option tells how
              many loopback devices will be created (0, 1 or 2).  If  there  are  multiple  audio
              devices  in  the  system  the  all  of  them  will have the same number of loopback
              devices.  Default: 0 - no loopback devices are created.   This  setting  should  be
              left to 0 unless there are specific reasons to enable the loopback devices.

       o vmix_no_autoattach
              By default (0) the low level drivers for most sound cards will automatically attach
              virtual mixer (vmix) to the primary audio devices of the cards.  In some situations
              it  may  be  necessary  to  attach  virtual  mixer using nonstandard parameters. If
              vmix_no_autoattach is set to 1 then user can use vmixctl attach command  to  attach
              virtual mixer manually to the device(s).  Default: 0 - Automatically attach virtual
              mixer.

       o excl_policy
              The O_EXCL open() flag can be used by programs to bypass the virtual mixer. Setting
              excl_policy  to 1 or 2 makes OSS ignore O_EXCL.  A setting of 1 ignores O_EXCL from
              all but root processes, while a setting of 2 always ignores O_EXCL.  Default:  0  -
              Do not ignore O_EXCL.

       o mixer_muted
              By  default  OSS  will  set  most volume controls to audible level.  If this causes
              problems then it's possible to ask OSS to set the levels to zero when  the  drivers
              are loaded. However the levels saved with the savemixer utility will get loaded few
              moments later when all OSS drivers have been started. Note that just  some  of  the
              OSS drivers honor this setting.  Values: 0 (default) - Use audible volumes, 1 - Set
              volumes to low.

FILES

       /usr/lib/oss/conf/osscore.conf Device configuration file

AUTHOR

       4Front Technologies

                                         23 January 2023                               osscore(7)