| | la_mettrie
Registered: Feb 2012
Posts: 21 |
Finding a good vibrato
On GoatTracker I've always had difficulties to find a suitable vibrato while I don't recall any problems like this when using PC trackers (IT, S3M).
Or have my ears just became more sensitive for a good vibrato???
I have let's say, values like 02 40 (speed 02 & depth 40), then I try something like 01 or 03 for speed (others feel inappropriate) and different values (from 10 to F0) for depth. But nothing seems to satisfy.
It seems those few GoatTracker SNG files which have been leaked use roughly similar range of vibrato values. This may suggest that using some totally different values won't help.
Are there further techniques to find more different kind of vibratos? Basically, what I feel is that there are no enough alternatives for different _speeds_. |
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| | cadaver
Registered: Feb 2002
Posts: 1154 |
Vibrato in S3M/XM/IT modules uses lookuptables (sine, triangle etc.) which can be stepped at a wide variety of speeds. C64 players, GT included usually generate a triangle wave frequency change programmatically, so they're limited to integer speeds (or more likely, only even integer speeds, if it's important that the vibrato stays in tune)
I guess there have to be some C64 playroutines which use a lookuptable for finer control, but can't remember which outright. |
| | la_mettrie
Registered: Feb 2012
Posts: 21 |
Okay, then I guess everybody else has problems too (but I'm not sure if you ppl have balls to admit it...)
Thanks for a quick answer |
| | Dane
Account closed
Registered: May 2002
Posts: 421 |
Yep, this always gives me a headache when modifying my player. I've tried everything from JCH's own note-calculated triangle wave to my own hardcoded triangle and even a lookuptable for precise control.
For different kinds of sounds I like to use different kinds of vibrato, I guess. |
| | la_mettrie
Registered: Feb 2012
Posts: 21 |
DRAX's "Gone" has some very impressive vibratos (on "solo part"). Not sure if all the C64 trackers can do that. |
| | Jammer
Registered: Nov 2002
Posts: 1292 |
The first thing you do is turning the RealtimeOptimization off. Without that forget about DRAXish vibratos :) |
| | CreaMD
Registered: Dec 2001
Posts: 3036 |
FKK, I wanna do something so sophisticated as that part around 1:00... lovely. Drax is good. Always loved his pop style. |
| | Hein
Registered: Apr 2004
Posts: 933 |
I publicly admit: same struggle for vibrato here. :)
you could try the note dependant vibrato in GT, if you haven't tried it yet:
Quoting readme.txt
3.4.4 Speedtable
...
For both vibrato and portamento, if XX has the high bit ($80) set, note
independent vibrato depth / portamento speed calculation is enabled, and YY
specifies the divisor (higher value -> lower result and more rastertime taken).
I've been working on my own player, which also uses a note dependant vibrato, but it's not defined as vibrato, but as a reference to a glissando table which enables me to increase/decrease vibrato depth/speed over time. I think the MoN player has this too. Maybe JCH has the same feature. Obviously this can be simulated the old protracker way in GT by placing the vibrato pointers on the track. Drax also uses extensive PW modulation in combination with vibrato on the accents, PW modulation may sound a bit like a 'tremolo'. |
| | CreaMD
Registered: Dec 2001
Posts: 3036 |
Hein, exactly, it's not just vibrato. |
| | Adam
Registered: Jul 2009
Posts: 321 |
Quoting franz_koopaOkay, then I guess everybody else has problems too (but I'm not sure if you ppl have balls to admit it...)
I guess some people do. I don't have any problems using vibrato no matter what tracker it is. I guess trying to find the right type of vibrato that fits with the overall speed and composition of the tune is the trickiest part but after years of making music with trackers you learn what sounds best, what doesn't and when to use it. |
| | Radiant
Registered: Sep 2004
Posts: 639 |
Tweak it until it sounds right. You've got space for hundreds of different vibratos in the speed table. |
| | Frantic
Registered: Mar 2003
Posts: 1629 |
Hey.. speaking of such things.. is there any C64 music player at all which implements portamento = sliding from note X to note Y in fixed speed, independently of which notes X and Y that are involved? I am pretty sure there is none, but I thought I should ask anyway. A bit off topic perhaps.. but still related to note independent freq calcs.
Note that it is possible to make use of a standard freq table with freqs for all the standard notes to get the offset for sub note steps of at least 16 step resolution (i.e. 16 subnotes, or fine tune steps, between each standard note) by picking the right values from the freq table. Makes it a lot easier to do freq stuff in fixed speed/"size" independently of which notes that are used. In fact, with just an additional subtraction, one can also get the above mentioned 16 steps not only between adjacents notes, but between any two notes, which could be used for portamento.
Another tip, which I haven't seen anyone else exploit: If you can live with note freq values that are rounded down (floored) rather than rounded the standard way, you can actually have partially overlapping tables for the hibyte and the lowbyte of the freq values. This one is a bit non-standard considering at what note is starts, but it illustrates the concept:
freq_hibyte: ;floored
.byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; oct0
.byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00 ; oct1
.byte $00,$00,$00,$00,$00,$00,$00,$00,$01,$01,$01,$01 ; oct2
.byte $01,$01,$01,$01,$01,$01,$01,$01,$02,$02,$02,$02 ; oct3
.byte $02,$02,$02,$03,$03,$03,$03,$03,$04,$04,$04,$04 ; oct4
.byte $05,$05,$05,$06,$06,$06,$07,$07,$08,$08,$09,$09 ; oct5
.byte $0a,$0a,$0b,$0c,$0d,$0d,$0e,$0f,$10,$11,$12,$13 ; oct6
.byte $14,$15,$17,$18,$1a,$1b,$1d,$1f,$20,$22,$24,$27 ; oct7
; .byte $29,$2b,$2e,$31,$34,$37,$3a,$3e,$41,$45,$49,$4e ; oct8
; .byte $52,$57,$5c,$62,$68,$6e,$75,$7c,$83,$8b,$93,$9c ; oct9
; .byte $a5,$af,$b9,$c4,$d0,$dc,$ea,$f8
freq_lobyte: ;floored as well
.byte $29,$2b,$2e,$31,$34,$37,$3a,$3e,$41,$45,$49,$4e ; oct0
.byte $52,$57,$5c,$62,$68,$6e,$75,$7c,$83,$8b,$93,$9c ; oct1
.byte $a5,$af,$b9,$c4,$d0,$dc,$ea,$f8,$06,$16,$26,$38 ; oct2
.byte $4b,$5e,$73,$89,$a1,$b9,$d4,$f0,$0d,$2c,$4d,$71 ; oct3
.byte $96,$bd,$e7,$13,$42,$73,$a8,$e0,$1b,$59,$9b,$e2 ; oct4
.byte $2c,$7b,$ce,$27,$84,$e7,$51,$c0,$36,$b3,$37,$c4 ; oct5
.byte $59,$f6,$9d,$4e,$09,$cf,$a2,$81,$6d,$67,$6f,$88 ; oct6
.byte $b2,$ed,$3a,$9c,$13,$9f,$44,$02,$da,$ce,$df,$11 ; oct7
.byte $64,$da,$75,$38,$26,$3f,$89,$04,$b4,$9c,$bf,$22 ; oct8
.byte $c8,$b4,$eb,$71,$4c,$7f,$12,$08,$68,$38,$7f,$45 ; oct9
.byte $90,$68,$d6,$e3,$98,$ff,$24,$10
Note how the lines which are commented away are identical with the first lines in the lowbyte table. Hence no need to duplicate these. |
| | Hermit
Registered: May 2008
Posts: 208 |
@Frantic:
SID-Wizard makes the slide/vibrato-amplitude values in SID note-dependent, so you get nearly the same audible slide-speed for notes in high/low octaves.
I use the frequency table as exponential table for multiplication, of course with lot of optimizations, so it's not kinda exact multiplication, but does the job.
Although, the slide-speed is only set on note-start, and isn't dependent on current pitch during the slide, but it's usually not a big issue for portamentos, they're local enough not to cause big audible difference...
I used the similarity of lo/high frequency tables in SID-Hacker 2.5 to detect the played notes from frequencies, otherwise it would have been impossible to look up on C64...
I used this fact in SID-Wizard as well, but don't remember from the top of my head if only for the Oscilloscope display or the player too...
To the topic: In my old attempt to create C64 player, HMTSYNTH, which is on the 3SID tracker disk (but unfinished, no load/save menu..) I used sine-table to create the vibrato and used normal multiplication, but i think there was no big difference to the easier-to-implement triangle vibrato.
On the other hand, the strict vibrato-speeds on C64 are limiting factors, such as the strict tempos for PAL timing... |
| | SIDWAVE
Account closed
Registered: Apr 2002
Posts: 2238 |
im not sure what youre asking frantic..
in SDI you can make any kinda slide you want, but you always have to set a speed. |
| | Hein
Registered: Apr 2004
Posts: 933 |
Frantic, that's what I'm using aswell, for calculations on the note-dependant glissandos and the PW modulation. It only wastes some extra memory on zero bytes.
pw_lookup_hi
.byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
.byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
.byte $00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00,$00
freq_table_hi
.byte $01,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01,$01
.byte $02,$02,$02,$02,$02,$02,$02,$03,$03,$03,$03,$03
.byte $04,$04,$04,$04,$05,$05,$05,$06,$06,$06,$07,$07
.byte $08,$08,$09,$09,$0a,$0a,$0b,$0c,$0d,$0d,$0e,$0f
.byte $10,$11,$12,$13,$14,$15,$17,$18,$1a,$1b,$1d,$1f
pw_lookup_lo
.byte $20,$22,$24,$27,$29,$2b,$2e,$31,$34,$37,$3a,$3e
.byte $41,$45,$49,$4e,$52,$57,$5c,$62,$68,$6e,$75,$7c
.byte $83,$8b,$93,$9c,$a5,$af,$b9,$c4,$d0,$dd,$ea,$f8
freq_table_lo
.byte $07,$17,$27,$39,$4b,$5f,$74,$8a,$a1,$ba,$d4,$f0
.byte $0e,$2d,$4e,$71,$96,$be,$e8,$14,$43,$74,$a9,$e1
.byte $1c,$5a,$9c,$e2,$2d,$7c,$cf,$28,$85,$e8,$52,$c1
.byte $37,$b4,$39,$c5,$5a,$f7,$9e,$4f,$0a,$d1,$a3,$82
.byte $6e,$68,$71,$8a,$b3,$ee,$3c,$9e,$15,$a2,$46,$04
.byte $dc,$d0,$e2,$14,$67,$dd,$79,$3c,$29,$44,$8d,$08
.byte $b8,$a1,$c5,$28,$cd,$ba,$f1,$78,$53,$87,$1a,$10
.byte $71,$42,$89,$4f,$9b,$74,$e2,$f0,$a6,$0e,$33,$20
I think I considered fixed steps for glides no matter how high the delta between de notes, but in the end I decided not to implement it. I think it's a choice between the two (fixed steps selection or manually set glide speed), else the player code will get too large (and possibly rastertime too) |
| | SIDWAVE
Account closed
Registered: Apr 2002
Posts: 2238 |
spend 30 secs to make the vibrato you want..
spend 5 mins to find out how to make it, makes all the difference.
try all: slow, fast, middle
play around with it, for no use, just to control it.
thats the way you learn what to do. |
| | HCL
Registered: Feb 2003
Posts: 717 |
..but how do those fancy Amiga and PC-trackers implement a proper vibrato then? Perhaps something like:
F(t) = F0 + ramp(t) * sin(speed * t); ??
..where ramp(t) is a simple envelope-function like step-function, ramp with/without amplitude limit, and possibly also decreasing ramp..
or perhaps it should rather be..
F(t) = (F0 * (1 + ramp(t))) * sin(speed * t);
Any suggestions? |
| | Magnar
Registered: Aug 2009
Posts: 60 |
HCL, it is a bit more easier to modify the playback of a sample when you have direct possibility to influence the xxx kHz it plays.
A simple sine function on the frequency to be played is all that is necessary for a vibrator function with sine curves.
However, compare that with real life vibration, is not the same. If I put my finger on a guitar and vibrate the note, it is not necessary same as a sine curve... It is actually more as a triangle. Or sometime, it is more like sine+triangle+some noise to it :) as the speed is not constantly the same of my finger movement.
Anyway, triangle vibrator seems just fine to me on C64.
|
| | Mixer
Registered: Apr 2008
Posts: 422 |
A guitar vibrato is done by stretching string sideways, its frequency is always above the base fret frequency. Some playroutines implement vibrato this way and forget the middle note frequency altogether.
The extended frqtable for "sub" frequencies that Frantic hinted of can take a bit more cycles on each call, but arpeggio, vibrato and slides become same operation - adding something to the base note extended frqtable index. In practice, the added index bits need some handling and that eat cycles.
An octave up is always 2x frq or one bit shift left, it is obvious that 8 ocaves jump makes 8 bits shift to a register value. I am pretty sure this type of extended table is in use somewhere as it is very old idea.
But: why not do an LFO? a block long sin table. Add two sines of different phases together. Then alter phase difference for amplitude changes and run the index faster or slower for speed. Every democoder can write such stuff blindfolded.
That LFO can be reused for filter and pwm so they do not need register specific up/down routines, just a loop calculating through all the needed "LFO"s and then pick values for registers or offset for the extended frq table index. I am sure some routines use this too already. (I've got some such old test routines somewhere as well)
Such stuff takes more cycles and memory for variables and sin table, and require bring new variables to initialize for each instrument - but it sounds very much like analogue synths do.
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| | SIDWAVE
Account closed
Registered: Apr 2002
Posts: 2238 |
Quote: ..but how do those fancy Amiga and PC-trackers implement a proper vibrato then? Perhaps something like:
F(t) = F0 + ramp(t) * sin(speed * t); ??
..where ramp(t) is a simple envelope-function like step-function, ramp with/without amplitude limit, and possibly also decreasing ramp..
or perhaps it should rather be..
F(t) = (F0 * (1 + ramp(t))) * sin(speed * t);
Any suggestions?
players dont do this because they are all built to conserve cpu, because you coders take it all for realtime 3d :)
so they way to do it, and works well, is to make the progressions you need and just spit them in like:
NOTE
---
---
--- start vibrato at depth/speed #1
---
---
--- start next progression of this, and so on.. |
| | Soren
Registered: Dec 2001
Posts: 547 |
Sidwave: nah.... vibratos don't need to take up a lot of rastertime. :)
I can fade up/down (depth) if I want to... doesn't take much.
and it is included in the vibrato program itself... you just need to tell the player where in a sequence to start it.
Ofcourse you can alter it during a note also.
Mine simply looks up values from extendeed freq tables. |
| | Frantic
Registered: Mar 2003
Posts: 1629 |
@Jeff: "Extended freqtables"... So you use freq tables which already include something like 8 or 16 (or whatever) subnote/finetune steps, or did I misunderstand? ...or did you simply refer to what I mentioned above = looking up values from a standard freq table, but with some more values in the beginning of the table? |
| | Magnar
Registered: Aug 2009
Posts: 60 |
This is how I do it for pulse, vibrator and filter sweeps:
lda puls
change1: cls
change2: adc pulsadd
change3: adc #$00
sta puls
sta $d402
and #$0f
sta $d403
cmp #$0b // sweep up to $0b
bcc !+
lda #$38
sta change1
lda #$ed
sta change2
lda #$e9
sta change3
jmp endsweep
!:
cmp #$04 // sweep down to $04
bcs endsweep
lda #$18
sta change1
lda #$6d
sta change2
lda #$69
sta change3
endsweep:
rts |
| | Mr. SID
Registered: Jan 2003
Posts: 422 |
Isn't one of the main problems that if you do the vibrato in frequency register space (i.e. $d400/$d401) the same depth would sound different at low octaves vs. high octaves. It has do be done in logarithmic scale to be correct for all pitches.
To me it feels like to do this properly you need a multiply to scale the vibrato sine amplitude to the correct frequency register range. I do this in Phasor Soundtrack HiFi because it sounded wrong doing it any other way. |
| | Frantic
Registered: Mar 2003
Posts: 1629 |
@MrSid: That is why we're talking about various ways of using the freq tables to ensure consistent vibrato across the octaves. |
| | Magnar
Registered: Aug 2009
Posts: 60 |
I believe Geir Tjelta and GRG has a solution for constant slide/vibrate sweep depths depending on where in the lower or higher end of the note scale the frequence is modified.
The SDI also comes with the whole player as a Turbo Assembler source, so it should be pretty easy to look it up. But I'm fine with my current sweeps in my player, so I'm sticking to it.
As a foot note, I still don't have a good PC editor ready as interface to my music player, so I am using Goattracker to avoid writing the music as assembler sources - it ease the flow of it all ;) |
| | Soren
Registered: Dec 2001
Posts: 547 |
Frantic: Just simple lookup. Looks somewhat similar to yours as far as I remember. :-) |
| | VIC
Registered: Aug 2003
Posts: 73 |
Here you go: http://www.amazon.com/Best-Vibrator-pleasure-pre-programmed-sti.. |
| | Hermit
Registered: May 2008
Posts: 208 |
That's it \o/ ;):) |
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