Provided by: oss4-base_4.2-build2005-2ubuntu1_amd64 bug


       oss_madi - RME HDSP MADI and AES32 audio driver


       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.


       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

       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.


       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.


       ·  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).


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


       4Front Technologies

                                         05 February 2012                             oss_madi(7)