linux/Documentation/sound/alsa/emu10k1-jack.txt
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   1This document is a guide to using the emu10k1 based devices with JACK for low
   2latency, multichannel recording functionality.  All of my recent work to allow
   3Linux users to use the full capabilities of their hardware has been inspired 
   4by the kX Project.  Without their work I never would have discovered the true
   5power of this hardware.
   6
   7        http://www.kxproject.com
   8                                                - Lee Revell, 2005.03.30
   9
  10Low latency, multichannel audio with JACK and the emu10k1/emu10k2
  11-----------------------------------------------------------------
  12
  13Until recently, emu10k1 users on Linux did not have access to the same low
  14latency, multichannel features offered by the "kX ASIO" feature of their
  15Windows driver.  As of ALSA 1.0.9 this is no more!
  16
  17For those unfamiliar with kX ASIO, this consists of 16 capture and 16 playback
  18channels.  With a post 2.6.9 Linux kernel, latencies down to 64 (1.33 ms) or
  19even 32 (0.66ms) frames should work well.
  20
  21The configuration is slightly more involved than on Windows, as you have to
  22select the correct device for JACK to use.  Actually, for qjackctl users it's
  23fairly self explanatory - select Duplex, then for capture and playback select
  24the multichannel devices, set the in and out channels to 16, and the sample
  25rate to 48000Hz.  The command line looks like this:
  26
  27/usr/local/bin/jackd -R -dalsa -r48000 -p64 -n2 -D -Chw:0,2 -Phw:0,3 -S
  28
  29This will give you 16 input ports and 16 output ports.
  30
  31The 16 output ports map onto the 16 FX buses (or the first 16 of 64, for the
  32Audigy).  The mapping from FX bus to physical output is described in
  33SB-Live-mixer.txt (or Audigy-mixer.txt).
  34
  35The 16 input ports are connected to the 16 physical inputs.  Contrary to
  36popular belief, all emu10k1 cards are multichannel cards.  Which of these
  37input channels have physical inputs connected to them depends on the card
  38model.  Trial and error is highly recommended; the pinout diagrams
  39for the card have been reverse engineered by some enterprising kX users and are 
  40available on the internet.  Meterbridge is helpful here, and the kX forums are
  41packed with useful information.
  42
  43Each input port will either correspond to a digital (SPDIF) input, an analog
  44input, or nothing.  The one exception is the SBLive! 5.1.  On these devices,
  45the second and third input ports are wired to the center/LFE output.  You will
  46still see 16 capture channels, but only 14 are available for recording inputs.
  47
  48This chart, borrowed from kxfxlib/da_asio51.cpp, describes the mapping of JACK
  49ports to FXBUS2 (multitrack recording input) and EXTOUT (physical output)
  50channels.
  51
  52/*JACK (& ASIO) mappings on 10k1 5.1 SBLive cards:
  53--------------------------------------------
  54JACK            Epilog          FXBUS2(nr)
  55--------------------------------------------
  56capture_1       asio14          FXBUS2(0xe)
  57capture_2       asio15          FXBUS2(0xf)
  58capture_3       asio0           FXBUS2(0x0)     
  59~capture_4      Center          EXTOUT(0x11)    // mapped to by Center
  60~capture_5      LFE             EXTOUT(0x12)    // mapped to by LFE
  61capture_6       asio3           FXBUS2(0x3)
  62capture_7       asio4           FXBUS2(0x4)
  63capture_8       asio5           FXBUS2(0x5)
  64capture_9       asio6           FXBUS2(0x6)
  65capture_10      asio7           FXBUS2(0x7)
  66capture_11      asio8           FXBUS2(0x8)
  67capture_12      asio9           FXBUS2(0x9)
  68capture_13      asio10          FXBUS2(0xa)
  69capture_14      asio11          FXBUS2(0xb)
  70capture_15      asio12          FXBUS2(0xc)
  71capture_16      asio13          FXBUS2(0xd)
  72*/
  73
  74TODO: describe use of ld10k1/qlo10k1 in conjunction with JACK
  75