Module spro24dsp

Expand description

Protocol specific to Focusrite Saffire Pro 24 DSP.

The module includes structure, enumeration, and trait and its implementation for protocol defined by Focusrite for Saffire Pro 24 DSP.

§Diagram of internal signal flow for Saffire Pro 24 DSP.

I note that optical input interface is available exclusively for ADAT input and S/PDIF input.


XLR input 1 ------+---------+
Phone input 1-----+         |
                            |
XLR input 2 ------+---------+
Phone input 2 ----+         |
                            +------------------> analog-input-1/2
Phone input 3/4 -------------------------------> analog-input-3/4
Phone input 5/6 -------------------------------> analog-input-5/6
Coaxial input 1/2 -----------------------------> spdif-input-1/2
Optical input --------------or-----------------> spdif-input-3/4
                            +------------------> adat-input-1..8

                         ++=============++
analog-input-1/2 ------> ||   46 x 46   || ----> analog-output-1/2
analog-input-3/4 ------> ||   router    || ----> analog-output-3/4
analog-input-5/6 ------> ||   up to     || ----> analog-output-5/6
spdif-input-1/2 -------> || 128 entries || ----> spdif-output-1/2
spdif-input-3/4 -------> ||             ||
adat-input-1/2 --------> ||             ||
adat-input-3/4 --------> ||             ||
adat-input-5/6 --------> ||             ||
adat-input-7/8 --------> ||             ||
                         ||             ||
stream-input-1/2 ------> ||             || ----> stream-output-1/2
stream-input-3/4 ------> ||             || ----> stream-output-3/4
stream-input-5/6 ------> ||             || ----> stream-output-5/6
stream-input-7/8 ------> ||             || ----> stream-output-7/8
                         ||             || ----> stream-output-9/10
                         ||             || ----> stream-output-11/12
                         ||             || ----> stream-output-13/14
                         ||             || ----> stream-output-15/16
                         ||             ||
mixer-output-1/2 ------> ||             || ----> mixer-input-1/2
mixer-output-3/4 ------> ||             || ----> mixer-input-3/4
mixer-output-5/6 ------> ||             || ----> mixer-input-5/6
mixer-output-7/8 ------> ||             || ----> mixer-input-7/8
mixer-output-9/10 -----> ||             || ----> mixer-input-9/10
mixer-output-11/12 ----> ||             || ----> mixer-input-11/12
mixer-output-13/14 ----> ||             || ----> mixer-input-13/14
mixer-output-15/16 ----> ||             || ----> mixer-input-15/16
                         ||             || ----> mixer-input-17/18
                         ||             ||
ch-strip-output-1/2 ---> ||             || ----> ch-strip-input-1/2
reverb-output-1/2 -----> ||             || ----> reverb-input-1/2
                         ++=============++

                         ++=============++
mixer-input-1/2 -------> ||             || ----> mixer-output-1/2
mixer-input-3/4 -------> ||             || ----> mixer-output-3/4
mixer-input-5/6 -------> ||             || ----> mixer-output-5/6
mixer-input-7/8 -------> ||    mixer    || ----> mixer-output-7/8
mixer-input-9/10 ------> ||             || ----> mixer-output-9/10
mixer-input-11/12 -----> ||   18 x 16   || ----> mixer-output-10/12
mixer-input-13/14 -----> ||             || ----> mixer-output-12/14
mixer-input-15/16 -----> ||             || ----> mixer-output-14/16
mixer-input-17/18 -----> ||             ||
                         ++=============++

                         ++=============++
                         ||             || ----> Phone output 1/2
                         ||             ||
analog-output-1/2 -----> ||   output    || --+-> Phone output 3/4
analog-output-3/4 -----> ||             ||   +-> Headphone output 1/2
analog-output-5/6 -----> ||   group     ||
                         ||             || --+-> Phone output 5/6
                         ||             ||   +-> Headphone output 3/4
                         ++=============++

                         ++=============++
                         ||  equalizer  ||
ch-strip-input-1/2 ----> ||      &      || ----> ch-strip-output-1/2
                         || compressor  ||
                         ++=============++

                         ++=============++
reverb-input-1/2 ------> ||   reverb    || ----> reverb-output-1/2
                         ++=============++

§Data layout in TCAT application section for DSP effect

The offset of TCAT application section is 0x6dd4. Any change by write transaction is firstly effective when software message is written to 0x5ec.

§Data Layout for DSP effect

0x000: DSP enable/disable (sw msg: 0x1c)
0x008: flags for channel strip effects (sw msg: 0x05)
- 0x00000001: ch 0 equalizer enable
- 0x00010000: ch 1 equalizer enable
- 0x00000002: ch 0 compressor enable
- 0x00020000: ch 1 compressor enable
- 0x00000004: ch 0 equalizer after compressor
- 0x00040000: ch 1 equalizer after compressor

blk 0	blk 2	blk 4	blk 6	count	purpose	sw msg
0x120	0x230	0x340	0x450	6 quads	ch 0 comp	0x06
0x138	0x248	0x358	0x468	2 quads	ch 0/ch 1 eq output	0z09
0x140	0x250	0x360	0x470	5 quads	ch 0 eq low freq filter	0x0c
0x154	0x264	0x374	0x484	5 quads	ch 0 eq low-middle freq filter	0x0f
0x168	0x278	0x388	0x498	5 quads	ch 0 eq high-middle freq filter	0x12
0x17c	0x28c	0x39c	0x4ac	5 quads	ch 0 eq high freq filter	0x15
0x190	0x2a0	0x3b0	0x4c0	6 quads	ch 0 reverb	0x1a

blk 1	blk 3	blk 5	blk 7	count	purpose	sw msg
0x1a8	0x2b8	0x3c8	0x4d8	6 quads	ch 1 comp	0x07
0x1c0	0x2d0	0x3e0	0x4f0	2 quads	ch 0/ch 1 eq output	0x0a
0x1c8	0x2d8	0x3e8	0x4f8	5 quads	ch 1 eq low freq filter	0x0d
0x1dc	0x2ec	0x3fc	0x50c	5 quads	ch 1 eq low-middle freq filter	0x10
0x1f0	0x300	0x410	0x520	5 quads	ch 1 eq high-middle freq filter	0x13
0x204	0x314	0x424	0x534	5 quads	ch 1 eq high freq filter	0x16
0x218	0x328	0x438	0x548	6 quads	ch 1 reverb	0x1a

§Compressor coefficients (6 quadlets)

Actually change to block 2 is effective.

quad	purpose	min value	max value	min repr	max repr
0	unknown	0x3f800000	0x3f800000	-	-
1	output volume	0x00000000	0x42800000	-36.0 dB	+36.0 dB
2	threshold	0xbfa00000	0x00000000	-80.0 dB	0.0 dB
3	ratio	0x3d000000	0x3f000000	1.1:1	inf:1
4	attack	0xbf800000	0xbf700000	2ms	100ms
5	release	0x3f700000	0x3f800000	100ms	3s

§Equalizer output coefficients (2 quadlets)

Actually change to block 2 is effective.

quad	purpose	min value	max value	min repr	max repr
0	left volume	0x00000000	0x3f800000	-36.0 dB	+36.0 dB
1	right volume	0x00000000	0x3f800000	-36.0 dB	+36.0 dB

§Equalizer coefficients (5 quadlets)

Actually change to block 2 is effective.

quad	purpose	min value	max value	min repr	max repr
0	unknown	-	-	-	-
1	unknown	-	-	-	-
2	unknown	-	-	-	-
3	unknown	-	-	-	-
4	unknown	-	-	-	-

§Reverb coefficients (6 quadlets)

Actually change to block 3 is effective.

quad	purpose	min value	max value	min repr	max repr
0	room size	0x00000000	0x3f800000	0 %	100 %
1	air	0x00000000	0x3f800000	100 %	0 %
2	enabled	0x00000000	0x3f800000	false	true
3	disabled	0x00000000	0x3f800000	false	true
4	pre filter value	0x00000000	0x3f800000	5.0	0.0
5	pre filter sign	0x00000000	0x3f800000	negative	positive

Structs§

SPro24DspProtocol: Protocol implementation specific to Saffire Pro 24 DSP.
Spro24DspCompressorState: State of compressor effect.
Spro24DspEffectGeneralParams: General parameters of DSP effects.
Spro24DspEqualizerFrequencyBandState: Coefficients per frequency band.
Spro24DspEqualizerState: State of equalizer effect.
Spro24DspReverbState: State of reverb effect.