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diff --git a/Documentation/sound/cards/emu-mixer.rst b/Documentation/sound/cards/emu-mixer.rst new file mode 100644 index 000000000000..d87a6338d3d8 --- /dev/null +++ b/Documentation/sound/cards/emu-mixer.rst @@ -0,0 +1,226 @@ +================================================== +E-MU Digital Audio System mixer / default DSP code +================================================== + +This document covers the E-MU 0404/1010/1212/1616/1820 PCI/PCI-e/CardBus +cards. + +These cards use regular EMU10K2 (SoundBlaster Audigy) chips, but with an +alternative front-end geared towards semi-professional studio recording. + +This document is based on audigy-mixer.rst. + + +Hardware compatibility +====================== + +The EMU10K2 chips have a very short capture FIFO, which makes recording +unreliable if the card's PCI bus requests are not handled with the +appropriate priority. +This is the case on more modern motherboards, where the PCI bus is only a +secondary peripheral, rather than the actual arbiter of device access. +In particular, I got recording glitches during simultaneous playback on an +Intel DP55 board (memory controller in the CPU), but had success with an +Intel DP45 board (memory controller in the north bridge). + +The PCI Express variants of these cards (which have a PCI bridge on board, +but are otherwise identical) may be less problematic. + + +Driver capabilities +=================== + +This driver supports only 16-bit 44.1/48 kHz operation. The multi-channel +device (see emu10k1-jack.rst) additionally supports 24-bit capture. + +A patchset to enhance the driver is available from `a GitHub repository +<https://github.com/ossilator/linux/tree/ossis-emu10k1>`_. +Its multi-channel device supports 24-bit for both playback and capture, +and also supports full 88.2/96/176.4/192 kHz operation. +It is not going to be upstreamed due to a fundamental disagreement about +what constitutes a good user experience. + + +Digital mixer controls +====================== + +Note that the controls work as attenuators: the maximum value is the neutral +position leaving the signal unchanged. Note that if the same destination is +mentioned in multiple controls, the signal is accumulated and can be clipped +(set to maximal or minimal value without checking for overflow). + +Explanation of used abbreviations: + +DAC + digital to analog converter +ADC + analog to digital converter +LFE + low frequency effects (used as subwoofer signal) +IEC958 + S/PDIF +FX-bus + the EMU10K2 chip has an effect bus containing 64 accumulators. + Each of the synthesizer voices can feed its output to these accumulators + and the DSP microcontroller can operate with the resulting sum. + +name='Clock Source',index=0 +--------------------------- +This control allows switching the word clock between interally generated +44.1 or 48 kHz, or a number of external sources. + +Note: the sources for the 1616 CardBus card are unclear. Please report your +findings. + +name='Clock Fallback',index=0 +----------------------------- +This control determines the internal clock which the card switches to when +the selected external clock source is/becomes invalid. + +name='DAC1 0202 14dB PAD',index=0, etc. +--------------------------------------- +Output attenuation controls. Not available on 0404 cards. + +name='ADC1 14dB PAD 0202',index=0, etc. +--------------------------------------- +Input attenuation controls. Not available on 0404 cards. + +name='Optical Output Mode',index=0 +---------------------------------- +Switches the TOSLINK output port between S/PDIF and ADAT. +Not available on 0404 cards (fixed to S/PDIF). + +name='Optical Input Mode',index=0 +--------------------------------- +Switches the TOSLINK input port between S/PDIF and ADAT. +Not available on 0404 cards (fixed to S/PDIF). + +name='PCM Front Playback Volume',index=0 +---------------------------------------- +This control is used to attenuate samples from left and right front PCM FX-bus +accumulators. ALSA uses accumulators 8 and 9 for left and right front PCM +samples for 5.1 playback. The result samples are forwarded to the DSP 0 & 1 +playback channels. + +name='PCM Surround Playback Volume',index=0 +------------------------------------------- +This control is used to attenuate samples from left and right surround PCM FX-bus +accumulators. ALSA uses accumulators 2 and 3 for left and right surround PCM +samples for 5.1 playback. The result samples are forwarded to the DSP 2 & 3 +playback channels. + +name='PCM Side Playback Volume',index=0 +--------------------------------------- +This control is used to attenuate samples from left and right side PCM FX-bus +accumulators. ALSA uses accumulators 14 and 15 for left and right side PCM +samples for 7.1 playback. The result samples are forwarded to the DSP 6 & 7 +playback channels. + +name='PCM Center Playback Volume',index=0 +----------------------------------------- +This control is used to attenuate samples from the center PCM FX-bus accumulator. +ALSA uses accumulator 6 for center PCM samples for 5.1 playback. The result samples +are forwarded to the DSP 4 playback channel. + +name='PCM LFE Playback Volume',index=0 +-------------------------------------- +This control is used to attenuate samples from the LFE PCM FX-bus accumulator. +ALSA uses accumulator 7 for LFE PCM samples for 5.1 playback. The result samples +are forwarded to the DSP 5 playback channel. + +name='PCM Playback Volume',index=0 +---------------------------------- +This control is used to attenuate samples from left and right PCM FX-bus +accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples for +stereo playback. The result samples are forwarded to the virtual stereo mixer. + +name='PCM Capture Volume',index=0 +--------------------------------- +This control is used to attenuate samples from left and right PCM FX-bus +accumulators. ALSA uses accumulators 0 and 1 for left and right PCM. +The result is forwarded to the standard capture PCM device. + +name='Music Playback Volume',index=0 +------------------------------------ +This control is used to attenuate samples from left and right MIDI FX-bus +accumulators. ALSA uses accumulators 4 and 5 for left and right MIDI samples. +The result samples are forwarded to the virtual stereo mixer. + +name='Music Capture Volume',index=0 +----------------------------------- +These controls are used to attenuate samples from left and right MIDI FX-bus +accumulator. ALSA uses accumulators 4 and 5 for left and right MIDI samples. +The result is forwarded to the standard capture PCM device. + +name='Front Playback Volume',index=0 +------------------------------------ +This control is used to attenuate samples from the virtual stereo mixer. +The result samples are forwarded to the DSP 0 & 1 playback channels. + +name='Surround Playback Volume',index=0 +--------------------------------------- +This control is used to attenuate samples from the virtual stereo mixer. +The result samples are forwarded to the DSP 2 & 3 playback channels. + +name='Side Playback Volume',index=0 +----------------------------------- +This control is used to attenuate samples from the virtual stereo mixer. +The result samples are forwarded to the DSP 6 & 7 playback channels. + +name='Center Playback Volume',index=0 +------------------------------------- +This control is used to attenuate samples from the virtual stereo mixer. +The result samples are forwarded to the DSP 4 playback channel. + +name='LFE Playback Volume',index=0 +---------------------------------- +This control is used to attenuate samples from the virtual stereo mixer. +The result samples are forwarded to the DSP 5 playback channel. + +name='Tone Control - Switch',index=0 +------------------------------------ +This control turns the tone control on or off. The samples forwarded to +the DSP playback channels are affected. + +name='Tone Control - Bass',index=0 +---------------------------------- +This control sets the bass intensity. There is no neutral value!! +When the tone control code is activated, the samples are always modified. +The closest value to pure signal is 20. + +name='Tone Control - Treble',index=0 +------------------------------------ +This control sets the treble intensity. There is no neutral value!! +When the tone control code is activated, the samples are always modified. +The closest value to pure signal is 20. + +name='Master Playback Volume',index=0 +------------------------------------- +This control is used to attenuate samples for all DSP playback channels. + +name='EMU Capture Volume',index=0 +---------------------------------- +This control is used to attenuate samples from the DSP 0 & 1 capture channels. +The result is forwarded to the standard capture PCM device. + +name='DAC Left',index=0, etc. +----------------------------- +Select the source for the given physical audio output. These may be physical +inputs, playback channels (DSP xx, specified as a decimal number), or silence. + +name='DSP x',index=0 +-------------------- +Select the source for the given capture channel (specified as a hexadecimal +digit). Same options as for the physical audio outputs. + + +PCM stream related controls +=========================== + +These controls are described in audigy-mixer.rst. + + +MANUALS/PATENTS +=============== + +See sb-live-mixer.rst. |