NAME

       osscore - Open Sound System 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 available 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

                                                11 February 2015                                      osscore(7)