oss_madi(7) OSS Devices oss_madi(7)
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
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.
By default this parameter is set to 2 which means that a device file will be cre‐
ated 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.
13 November 2019 oss_madi(7)