NAME

       oss_madi - RME HDSP MADI and AES32 audio driver

DESCRIPTION

       Open Sound System driver for RME HDSP MADI and AES32 audio interfaces.

       This  driver  has  been  developed for RME HDSP MADI but it also supports HDSP AES32. The driver has been
       tested under Linux and Solaris under x86 and Sparc.

       The internal engine of the card supports 64 playback channels and 64 recording channels. Only  the  first
       channels are connected to the actual input and output ports of the card.

       The  mixer  section  of  the  card  has recording level settings for all inputs.  There is also an output
       mixer. Each output channel has mixer sliders for corresponding  input  channel  and  corresponding  audio
       playback channel.

       There  is a full 64x(64+64) mixing matrix supported by the hardware. For the time being this mixer matrix
       cannot be accessed directly by the applications. However  support  for  the  SNDCTL_MIX_MATRIX_WRITE  and
       SNDCTL_MIX_MATRIX_READ ioctl calls can be added in the future.

DEVICE FILES

       By  default  the  driver  will create input and output device files for each 32 stereo pairs. This can be
       changed by editing the settings in oss_madi.conf (see below).

       The application can set the devices to use 1, 2, 4, 8, 16, 32 or 64 channels.  The device file being used
       selects the first channel slot within the available channels. For example pcm0  and  pcmin0  sill  select
       channel  0. Equally well pcm1 and pcmin1 will select channel slot 2 (assuming that madi_devsize option is
       set to 2). The first device (pcm0 and pcmin0) can be set to use up  to  64  channels.  The  last  devices
       (pcm31  and  pcmin31)  only  support  1  or  2  channel  mode.   The  other  device files support channel
       configurations where the last channel doesn't exceed the number  of  total  channels  (madi_maxchannels).
       Also  the  driver  will not let two device files to share any of the channels with some other open device
       file.

       This channel allocation mechanism gives maximum flexibility to the user.  It  is  possible  to  use  some
       output  channels by multi channel application while the others are available for other applications. This
       works as long the channel allocations by different applications don't overlap.

OPTIONS

       o madi_maxchannels
              Number of channels supported by the driver. The default is 64 which  is  also  the  maximum.  This
              parameter can be set to a lower value if full 64 channels are not required. With less channels the
              mixer/control panel interface will require less space on screen.

       o madi_devsize
              By  default  this  parameter  is  set to 2 which means that a device file will be created for each
              stereo channel pair. Possible values are 1, 2, 4, 8, 16, 32 or 64.

LIMITATIONS

       •  The current driver doesn't support all control panel features of the card.  For example sampling  rate
          is fixed to 48 kHz. More features will be added on contract.

       •  Use of mmap() is and will not be supported.

       •  Virtual mixer is not supported (yet).

FILES

       /etc/oss4/conf/oss_madi.conf
              Device configuration file.

AUTHOR

       4Front Technologies

                                                11 February 2015                                     oss_madi(7)