380 строки
9.2 KiB
ReStructuredText
380 строки
9.2 KiB
ReStructuredText
=======================================
|
|
Software Interface ALSA-DSP MADI Driver
|
|
=======================================
|
|
|
|
(translated from German, so no good English ;-),
|
|
|
|
2004 - winfried ritsch
|
|
|
|
|
|
Full functionality has been added to the driver. Since some of
|
|
the Controls and startup-options are ALSA-Standard and only the
|
|
special Controls are described and discussed below.
|
|
|
|
|
|
Hardware functionality
|
|
======================
|
|
|
|
Audio transmission
|
|
------------------
|
|
|
|
* number of channels -- depends on transmission mode
|
|
|
|
The number of channels chosen is from 1..Nmax. The reason to
|
|
use for a lower number of channels is only resource allocation,
|
|
since unused DMA channels are disabled and less memory is
|
|
allocated. So also the throughput of the PCI system can be
|
|
scaled. (Only important for low performance boards).
|
|
|
|
* Single Speed -- 1..64 channels
|
|
|
|
.. note::
|
|
(Note: Choosing the 56channel mode for transmission or as
|
|
receiver, only 56 are transmitted/received over the MADI, but
|
|
all 64 channels are available for the mixer, so channel count
|
|
for the driver)
|
|
|
|
* Double Speed -- 1..32 channels
|
|
|
|
.. note::
|
|
Note: Choosing the 56-channel mode for
|
|
transmission/receive-mode , only 28 are transmitted/received
|
|
over the MADI, but all 32 channels are available for the mixer,
|
|
so channel count for the driver
|
|
|
|
|
|
* Quad Speed -- 1..16 channels
|
|
|
|
.. note::
|
|
Choosing the 56-channel mode for
|
|
transmission/receive-mode , only 14 are transmitted/received
|
|
over the MADI, but all 16 channels are available for the mixer,
|
|
so channel count for the driver
|
|
|
|
* Format -- signed 32 Bit Little Endian (SNDRV_PCM_FMTBIT_S32_LE)
|
|
|
|
* Sample Rates --
|
|
|
|
Single Speed -- 32000, 44100, 48000
|
|
|
|
Double Speed -- 64000, 88200, 96000 (untested)
|
|
|
|
Quad Speed -- 128000, 176400, 192000 (untested)
|
|
|
|
* access-mode -- MMAP (memory mapped), Not interleaved (PCM_NON-INTERLEAVED)
|
|
|
|
* buffer-sizes -- 64,128,256,512,1024,2048,8192 Samples
|
|
|
|
* fragments -- 2
|
|
|
|
* Hardware-pointer -- 2 Modi
|
|
|
|
|
|
The Card supports the readout of the actual Buffer-pointer,
|
|
where DMA reads/writes. Since of the bulk mode of PCI it is only
|
|
64 Byte accurate. SO it is not really usable for the
|
|
ALSA-mid-level functions (here the buffer-ID gives a better
|
|
result), but if MMAP is used by the application. Therefore it
|
|
can be configured at load-time with the parameter
|
|
precise-pointer.
|
|
|
|
|
|
.. hint::
|
|
(Hint: Experimenting I found that the pointer is maximum 64 to
|
|
large never to small. So if you subtract 64 you always have a
|
|
safe pointer for writing, which is used on this mode inside
|
|
ALSA. In theory now you can get now a latency as low as 16
|
|
Samples, which is a quarter of the interrupt possibilities.)
|
|
|
|
* Precise Pointer -- off
|
|
interrupt used for pointer-calculation
|
|
|
|
* Precise Pointer -- on
|
|
hardware pointer used.
|
|
|
|
Controller
|
|
----------
|
|
|
|
Since DSP-MADI-Mixer has 8152 Fader, it does not make sense to
|
|
use the standard mixer-controls, since this would break most of
|
|
(especially graphic) ALSA-Mixer GUIs. So Mixer control has be
|
|
provided by a 2-dimensional controller using the
|
|
hwdep-interface.
|
|
|
|
Also all 128+256 Peak and RMS-Meter can be accessed via the
|
|
hwdep-interface. Since it could be a performance problem always
|
|
copying and converting Peak and RMS-Levels even if you just need
|
|
one, I decided to export the hardware structure, so that of
|
|
needed some driver-guru can implement a memory-mapping of mixer
|
|
or peak-meters over ioctl, or also to do only copying and no
|
|
conversion. A test-application shows the usage of the controller.
|
|
|
|
* Latency Controls --- not implemented !!!
|
|
|
|
.. note::
|
|
Note: Within the windows-driver the latency is accessible of a
|
|
control-panel, but buffer-sizes are controlled with ALSA from
|
|
hwparams-calls and should not be changed in run-state, I did not
|
|
implement it here.
|
|
|
|
|
|
* System Clock -- suspended !!!!
|
|
|
|
* Name -- "System Clock Mode"
|
|
|
|
* Access -- Read Write
|
|
|
|
* Values -- "Master" "Slave"
|
|
|
|
.. note::
|
|
!!!! This is a hardware-function but is in conflict with the
|
|
Clock-source controller, which is a kind of ALSA-standard. I
|
|
makes sense to set the card to a special mode (master at some
|
|
frequency or slave), since even not using an Audio-application
|
|
a studio should have working synchronisations setup. So use
|
|
Clock-source-controller instead !!!!
|
|
|
|
* Clock Source
|
|
|
|
* Name -- "Sample Clock Source"
|
|
|
|
* Access -- Read Write
|
|
|
|
* Values -- "AutoSync", "Internal 32.0 kHz", "Internal 44.1 kHz",
|
|
"Internal 48.0 kHz", "Internal 64.0 kHz", "Internal 88.2 kHz",
|
|
"Internal 96.0 kHz"
|
|
|
|
Choose between Master at a specific Frequency and so also the
|
|
Speed-mode or Slave (Autosync). Also see "Preferred Sync Ref"
|
|
|
|
.. warning::
|
|
!!!! This is no pure hardware function but was implemented by
|
|
ALSA by some ALSA-drivers before, so I use it also. !!!
|
|
|
|
|
|
* Preferred Sync Ref
|
|
|
|
* Name -- "Preferred Sync Reference"
|
|
|
|
* Access -- Read Write
|
|
|
|
* Values -- "Word" "MADI"
|
|
|
|
|
|
Within the Auto-sync-Mode the preferred Sync Source can be
|
|
chosen. If it is not available another is used if possible.
|
|
|
|
.. note::
|
|
Note: Since MADI has a much higher bit-rate than word-clock, the
|
|
card should synchronise better in MADI Mode. But since the
|
|
RME-PLL is very good, there are almost no problems with
|
|
word-clock too. I never found a difference.
|
|
|
|
|
|
* TX 64 channel
|
|
|
|
* Name -- "TX 64 channels mode"
|
|
|
|
* Access -- Read Write
|
|
|
|
* Values -- 0 1
|
|
|
|
Using 64-channel-modus (1) or 56-channel-modus for
|
|
MADI-transmission (0).
|
|
|
|
|
|
.. note::
|
|
Note: This control is for output only. Input-mode is detected
|
|
automatically from hardware sending MADI.
|
|
|
|
|
|
* Clear TMS
|
|
|
|
* Name -- "Clear Track Marker"
|
|
|
|
* Access -- Read Write
|
|
|
|
* Values -- 0 1
|
|
|
|
|
|
Don't use to lower 5 Audio-bits on AES as additional Bits.
|
|
|
|
|
|
* Safe Mode oder Auto Input
|
|
|
|
* Name -- "Safe Mode"
|
|
|
|
* Access -- Read Write
|
|
|
|
* Values -- 0 1 (default on)
|
|
|
|
If on (1), then if either the optical or coaxial connection
|
|
has a failure, there is a takeover to the working one, with no
|
|
sample failure. Its only useful if you use the second as a
|
|
backup connection.
|
|
|
|
* Input
|
|
|
|
* Name -- "Input Select"
|
|
|
|
* Access -- Read Write
|
|
|
|
* Values -- optical coaxial
|
|
|
|
|
|
Choosing the Input, optical or coaxial. If Safe-mode is active,
|
|
this is the preferred Input.
|
|
|
|
Mixer
|
|
-----
|
|
|
|
* Mixer
|
|
|
|
* Name -- "Mixer"
|
|
|
|
* Access -- Read Write
|
|
|
|
* Values - <channel-number 0-127> <Value 0-65535>
|
|
|
|
|
|
Here as a first value the channel-index is taken to get/set the
|
|
corresponding mixer channel, where 0-63 are the input to output
|
|
fader and 64-127 the playback to outputs fader. Value 0
|
|
is channel muted 0 and 32768 an amplification of 1.
|
|
|
|
* Chn 1-64
|
|
|
|
fast mixer for the ALSA-mixer utils. The diagonal of the
|
|
mixer-matrix is implemented from playback to output.
|
|
|
|
|
|
* Line Out
|
|
|
|
* Name -- "Line Out"
|
|
|
|
* Access -- Read Write
|
|
|
|
* Values -- 0 1
|
|
|
|
Switching on and off the analog out, which has nothing to do
|
|
with mixing or routing. the analog outs reflects channel 63,64.
|
|
|
|
|
|
Information (only read access)
|
|
------------------------------
|
|
|
|
* Sample Rate
|
|
|
|
* Name -- "System Sample Rate"
|
|
|
|
* Access -- Read-only
|
|
|
|
getting the sample rate.
|
|
|
|
|
|
* External Rate measured
|
|
|
|
* Name -- "External Rate"
|
|
|
|
* Access -- Read only
|
|
|
|
|
|
Should be "Autosync Rate", but Name used is
|
|
ALSA-Scheme. External Sample frequency liked used on Autosync is
|
|
reported.
|
|
|
|
|
|
* MADI Sync Status
|
|
|
|
* Name -- "MADI Sync Lock Status"
|
|
|
|
* Access -- Read
|
|
|
|
* Values -- 0,1,2
|
|
|
|
MADI-Input is 0=Unlocked, 1=Locked, or 2=Synced.
|
|
|
|
|
|
* Word Clock Sync Status
|
|
|
|
* Name -- "Word Clock Lock Status"
|
|
|
|
* Access -- Read
|
|
|
|
* Values -- 0,1,2
|
|
|
|
Word Clock Input is 0=Unlocked, 1=Locked, or 2=Synced.
|
|
|
|
* AutoSync
|
|
|
|
* Name -- "AutoSync Reference"
|
|
|
|
* Access -- Read
|
|
|
|
* Values -- "WordClock", "MADI", "None"
|
|
|
|
Sync-Reference is either "WordClock", "MADI" or none.
|
|
|
|
* RX 64ch --- noch nicht implementiert
|
|
|
|
MADI-Receiver is in 64 channel mode oder 56 channel mode.
|
|
|
|
|
|
* AB_inp --- not tested
|
|
|
|
Used input for Auto-Input.
|
|
|
|
|
|
* actual Buffer Position --- not implemented
|
|
|
|
!!! this is a ALSA internal function, so no control is used !!!
|
|
|
|
|
|
|
|
Calling Parameter
|
|
=================
|
|
|
|
* index int array (min = 1, max = 8)
|
|
|
|
Index value for RME HDSPM interface. card-index within ALSA
|
|
|
|
note: ALSA-standard
|
|
|
|
* id string array (min = 1, max = 8)
|
|
|
|
ID string for RME HDSPM interface.
|
|
|
|
note: ALSA-standard
|
|
|
|
* enable int array (min = 1, max = 8)
|
|
|
|
Enable/disable specific HDSPM sound-cards.
|
|
|
|
note: ALSA-standard
|
|
|
|
* precise_ptr int array (min = 1, max = 8)
|
|
|
|
Enable precise pointer, or disable.
|
|
|
|
.. note::
|
|
note: Use only when the application supports this (which is a special case).
|
|
|
|
* line_outs_monitor int array (min = 1, max = 8)
|
|
|
|
Send playback streams to analog outs by default.
|
|
|
|
.. note::
|
|
note: each playback channel is mixed to the same numbered output
|
|
channel (routed). This is against the ALSA-convention, where all
|
|
channels have to be muted on after loading the driver, but was
|
|
used before on other cards, so i historically use it again)
|
|
|
|
|
|
|
|
* enable_monitor int array (min = 1, max = 8)
|
|
|
|
Enable Analog Out on Channel 63/64 by default.
|
|
|
|
.. note ::
|
|
note: here the analog output is enabled (but not routed).
|