xref: /linux/Documentation/sound/cards/emu-mixer.rst (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
1==================================================
2E-MU Digital Audio System mixer / default DSP code
3==================================================
4
5This document covers the E-MU 0404/1010/1212/1616/1820 PCI/PCI-e/CardBus
6cards.
7
8These cards use regular EMU10K2 (SoundBlaster Audigy) chips, but with an
9alternative front-end geared towards semi-professional studio recording.
10
11This document is based on audigy-mixer.rst.
12
13
14Hardware compatibility
15======================
16
17The EMU10K2 chips have a very short capture FIFO, which makes recording
18unreliable if the card's PCI bus requests are not handled with the
19appropriate priority.
20This is the case on more modern motherboards, where the PCI bus is only a
21secondary peripheral, rather than the actual arbiter of device access.
22In particular, I got recording glitches during simultaneous playback on an
23Intel DP55 board (memory controller in the CPU), but had success with an
24Intel DP45 board (memory controller in the north bridge).
25
26The PCI Express variants of these cards (which have a PCI bridge on board,
27but are otherwise identical) may be less problematic.
28
29
30Driver capabilities
31===================
32
33This driver supports only 16-bit 44.1/48 kHz operation. The multi-channel
34device (see emu10k1-jack.rst) additionally supports 24-bit capture.
35
36A patchset to enhance the driver is available from `a GitHub repository
37<https://github.com/ossilator/linux/tree/ossis-emu10k1>`_.
38Its multi-channel device supports 24-bit for both playback and capture,
39and also supports full 88.2/96/176.4/192 kHz operation.
40It is not going to be upstreamed due to a fundamental disagreement about
41what constitutes a good user experience.
42
43
44Digital mixer controls
45======================
46
47Note that the controls work as attenuators: the maximum value is the neutral
48position leaving the signal unchanged. Note that if the same destination is
49mentioned in multiple controls, the signal is accumulated and can be clipped
50(set to maximal or minimal value without checking for overflow).
51
52Explanation of used abbreviations:
53
54DAC
55	digital to analog converter
56ADC
57	analog to digital converter
58LFE
59	low frequency effects (used as subwoofer signal)
60IEC958
61	S/PDIF
62FX-bus
63	the EMU10K2 chip has an effect bus containing 64 accumulators.
64	Each of the synthesizer voices can feed its output to these accumulators
65	and the DSP microcontroller can operate with the resulting sum.
66
67name='Clock Source',index=0
68---------------------------
69This control allows switching the word clock between interally generated
7044.1 or 48 kHz, or a number of external sources.
71
72Note: the sources for the 1616 CardBus card are unclear. Please report your
73findings.
74
75name='Clock Fallback',index=0
76-----------------------------
77This control determines the internal clock which the card switches to when
78the selected external clock source is/becomes invalid.
79
80name='DAC1 0202 14dB PAD',index=0, etc.
81---------------------------------------
82Output attenuation controls. Not available on 0404 cards.
83
84name='ADC1 14dB PAD 0202',index=0, etc.
85---------------------------------------
86Input attenuation controls. Not available on 0404 cards.
87
88name='Optical Output Mode',index=0
89----------------------------------
90Switches the TOSLINK output port between S/PDIF and ADAT.
91Not available on 0404 cards (fixed to S/PDIF).
92
93name='Optical Input Mode',index=0
94---------------------------------
95Switches the TOSLINK input port between S/PDIF and ADAT.
96Not available on 0404 cards (fixed to S/PDIF).
97
98name='PCM Front Playback Volume',index=0
99----------------------------------------
100This control is used to attenuate samples from left and right front PCM FX-bus
101accumulators. ALSA uses accumulators 8 and 9 for left and right front PCM
102samples for 5.1 playback. The result samples are forwarded to the DSP 0 & 1
103playback channels.
104
105name='PCM Surround Playback Volume',index=0
106-------------------------------------------
107This control is used to attenuate samples from left and right surround PCM FX-bus
108accumulators. ALSA uses accumulators 2 and 3 for left and right surround PCM
109samples for 5.1 playback. The result samples are forwarded to the DSP 2 & 3
110playback channels.
111
112name='PCM Side Playback Volume',index=0
113---------------------------------------
114This control is used to attenuate samples from left and right side PCM FX-bus
115accumulators. ALSA uses accumulators 14 and 15 for left and right side PCM
116samples for 7.1 playback. The result samples are forwarded to the DSP 6 & 7
117playback channels.
118
119name='PCM Center Playback Volume',index=0
120-----------------------------------------
121This control is used to attenuate samples from the center PCM FX-bus accumulator.
122ALSA uses accumulator 6 for center PCM samples for 5.1 playback. The result samples
123are forwarded to the DSP 4 playback channel.
124
125name='PCM LFE Playback Volume',index=0
126--------------------------------------
127This control is used to attenuate samples from the LFE PCM FX-bus accumulator.
128ALSA uses accumulator 7 for LFE PCM samples for 5.1 playback. The result samples
129are forwarded to the DSP 5 playback channel.
130
131name='PCM Playback Volume',index=0
132----------------------------------
133This control is used to attenuate samples from left and right PCM FX-bus
134accumulators. ALSA uses accumulators 0 and 1 for left and right PCM samples for
135stereo playback. The result samples are forwarded to the virtual stereo mixer.
136
137name='PCM Capture Volume',index=0
138---------------------------------
139This control is used to attenuate samples from left and right PCM FX-bus
140accumulators. ALSA uses accumulators 0 and 1 for left and right PCM.
141The result is forwarded to the standard capture PCM device.
142
143name='Music Playback Volume',index=0
144------------------------------------
145This control is used to attenuate samples from left and right MIDI FX-bus
146accumulators. ALSA uses accumulators 4 and 5 for left and right MIDI samples.
147The result samples are forwarded to the virtual stereo mixer.
148
149name='Music Capture Volume',index=0
150-----------------------------------
151These controls are used to attenuate samples from left and right MIDI FX-bus
152accumulator. ALSA uses accumulators 4 and 5 for left and right MIDI samples.
153The result is forwarded to the standard capture PCM device.
154
155name='Front Playback Volume',index=0
156------------------------------------
157This control is used to attenuate samples from the virtual stereo mixer.
158The result samples are forwarded to the DSP 0 & 1 playback channels.
159
160name='Surround Playback Volume',index=0
161---------------------------------------
162This control is used to attenuate samples from the virtual stereo mixer.
163The result samples are forwarded to the DSP 2 & 3 playback channels.
164
165name='Side Playback Volume',index=0
166-----------------------------------
167This control is used to attenuate samples from the virtual stereo mixer.
168The result samples are forwarded to the DSP 6 & 7 playback channels.
169
170name='Center Playback Volume',index=0
171-------------------------------------
172This control is used to attenuate samples from the virtual stereo mixer.
173The result samples are forwarded to the DSP 4 playback channel.
174
175name='LFE Playback Volume',index=0
176----------------------------------
177This control is used to attenuate samples from the virtual stereo mixer.
178The result samples are forwarded to the DSP 5 playback channel.
179
180name='Tone Control - Switch',index=0
181------------------------------------
182This control turns the tone control on or off. The samples forwarded to
183the DSP playback channels are affected.
184
185name='Tone Control - Bass',index=0
186----------------------------------
187This control sets the bass intensity. There is no neutral value!!
188When the tone control code is activated, the samples are always modified.
189The closest value to pure signal is 20.
190
191name='Tone Control - Treble',index=0
192------------------------------------
193This control sets the treble intensity. There is no neutral value!!
194When the tone control code is activated, the samples are always modified.
195The closest value to pure signal is 20.
196
197name='Master Playback Volume',index=0
198-------------------------------------
199This control is used to attenuate samples for all DSP playback channels.
200
201name='EMU Capture Volume',index=0
202----------------------------------
203This control is used to attenuate samples from the DSP 0 & 1 capture channels.
204The result is forwarded to the standard capture PCM device.
205
206name='DAC Left',index=0, etc.
207-----------------------------
208Select the source for the given physical audio output. These may be physical
209inputs, playback channels (DSP xx, specified as a decimal number), or silence.
210
211name='DSP x',index=0
212--------------------
213Select the source for the given capture channel (specified as a hexadecimal
214digit). Same options as for the physical audio outputs.
215
216
217PCM stream related controls
218===========================
219
220These controls are described in audigy-mixer.rst.
221
222
223MANUALS/PATENTS
224===============
225
226See sb-live-mixer.rst.
227