Cycling 74 » Topic: Continiously recording into buffer

Continiously recording into buffer

hmarstra — Thu, 21 Jan 2010 10:50:27 +0000

I would like to record continiously into a 2 minute buffer (from the record~objekt?) When the buffer is full I want it to continue to record by deleting the oldest material. In this way the buffer should always contain the latest 2 minutes of the performance.
Can this be done and is buffer~and record~ the right objects to use? IS there some knd of message I can send to buffer?

(The next step should be to save the latest 2 minutes (the entire buffer) when I hit some button. But this I think I can manage)

Re: Continiously recording into buffer

Patrick Delges — Thu, 21 Jan 2010 11:20:57 +0000

record~ has a loop recording mode. So when the record head reaches the end of the buffer, it will start from the beginning. So you get a circular buffer.
The beginning of your olr recorded sound is just afer the recording position: you get it using record~‘s outlet (* 120000 in ms, with a 2mn buffer).

Last time I tried, I think this loop mode worked only as long as the recording zone was the whole buffer (so if you set the max recording point to some value, record~ won’t loop at that value even if loop mode is set). In that case , you can use poke~ driven for instance by a phasor~.

Re: Continiously recording into buffer

AlexHarker — Thu, 21 Jan 2010 17:55:04 +0000

If you do use poke~ (and I’ve done this to create a double circular buffer where you can always read the last N ms or samples in one contiguous block) – I would suggest that count~ would be a better object to drive it with than a phasor~ as it is specifically designed for counting in integers once per sample, whereas phasor~ is not, and you could possibly experience issues with phasor~ due to float round-off errors…..

Re: Continiously recording into buffer

maaaxit — Thu, 21 Jan 2010 17:56:55 +0000

Another approach here, using tapin and tapout and recording a buffer when you need it.
I don’t know if it’s is really what you need, but you can try it.

– Pasted Max Patch, click to expand. –

Re: Continiously recording into buffer

hmarstra — Thu, 21 Jan 2010 19:16:19 +0000

Re: Continiously recording into buffer

hmarstra — Thu, 21 Jan 2010 19:40:37 +0000

To Patrick
It sounds like loop gives this kind of order “11 12 13 14 5 6 7 8 9 10″ (14 beeing the newest material and 5 beeing the oldest)
First you fill up the buffer with “1 2 3 4 5 6 7 8 9 10″
Then you start overwriting “11 12 13 14 …..
This gives a strange jump in the recording from “14″ to “5″

I would like to somehow maintain the chronology so that the order was always “1 2 3 4 5 6 7 8 9 10) It shoud record till it reaches the end of the buffer and then continiously erase material from the beginning and move old material gradually towards the beginning of the buffer and ad new material to the end of the buffer.

what about the append command for record~

“Last time I tried, I think this loop mode worked only as long as the recording zone was the whole buffer”
I guess in my case the record will use the whole buffer so this is not an issue. Or did I misunderstand?

——
To Patrick/ AlexHarker

Poke~ sounds promising. For some reason the poke~ objekt doesnt show up. I will look into it

——

To maaxit

This sounds also interesting, but Im guessing that I would have to wait for the recording to happen from the point when I initialize the recordprosess. So If I want 5 mins of recorded material I would have to wait those 5 min before the prosess is compleated

Im using unfortunatly using max 4.5 so is there any chance of posting tew patch in an older format (perhaps this is an option in the text format of max 5) Or post a screenshot?

Henrik

Re: Continiously recording into buffer

Patrick Delges — Thu, 21 Jan 2010 20:43:23 +0000

Alex, you’re right about count~; when I wrote “for instance”, it was because I had this in mind but I’m currently working on a difficult looping system where phasor~ was unfortunately much more adapted than count~:-)

hmarsta, to get the right order you need to play the buffer from the last recorded position, wrap around at the end of the buffer to start reading from the beginning and stop after 2 minutes. That’s the idea of a circular buffer.
As you will indeed use the whole buffer, my warning about loop mode is indeed useless for you :-)

Re: Continiously recording into buffer

hmarstra — Fri, 22 Jan 2010 08:03:19 +0000

found poke

Re: Continiously recording into buffer

hmarstra — Fri, 22 Jan 2010 08:38:24 +0000

Patrick: Im having differculties getting the exact details of your explanation. (Havent use poke or count before) Gratefull if someone have energy to post a quick patch (in some readable format: screenshot, old max format) …… :)

Re: Continiously recording into buffer

AlexHarker — Fri, 22 Jan 2010 13:09:43 +0000

This was what I did:

#P window setfont “Sans Serif” 9.;
#P window linecount 1;
#P newex 36 165 140 196617 buffer~ Circ_Buffer 120000;
#N comlet Input;
#P inlet 36 41 15 0;
#N comlet Write Postion (ms);
#P outlet 324 198 15 0;
#N comlet Write Position (samps);
#P outlet 235 198 15 0;
#P newex 235 134 64 196617 snapshot~ 5;
#P newex 268 170 66 196617 sampstoms~;
#P newex 135 135 93 196617 poke~ Circ_Buffer;
#B color 5;
#P newex 176 74 67 196617 +~ 2646000;
#P newex 77 41 112 196617 count~ 0 2646000 1 1;
#P newex 36 135 93 196617 poke~ Circ_Buffer;
#B color 5;
#P connect 4 1 7 0;
#P fasten 5 0 4 0 240 160 273 160;
#P connect 5 0 6 0;
#P fasten 2 0 5 0 181 97 240 97;
#P connect 2 0 3 1;
#P connect 1 0 0 1;
#P fasten 1 0 2 0 82 70 181 70;
#P connect 8 0 0 0;
#P lcolor 16;
#P fasten 8 0 3 0 41 101 140 101;
#P lcolor 16;
#P window clipboard copycount 10;

The buffer is TWICE as long as you actually need – it writes twice into the buffer at a time so that wherever you stop you can always read the last N ms contiguously (it doesn’t move stuff – it just has two copies).

To get the bit you want subtract from the write position output the length of time you require and it will start at that point in the buffer. I’d leave a few ms spare at the end of the buffer to account for timing inaccuracies between max and msp. The length of the buffer is set in samples (in the count and +~ object – they need to be the same number) and in the code as sent is 60 secs at 44.1kHz sampling rate.

There is an upper limit to how long you can record accurately for in this way, as determined by the 32 bit floating point format (at some point counting will fail because you run out of bits) – there are 24 bits of accuracy in a 32 bit float – so thats 2^ 24 = 16777216 samples if my maths is correct, which would be about 380 seconds or about 6 minutes at 44.k Hz, but only about 1 minute twenty at 192kHz, so be careful. In addition to this because you need a double buffer for the technique I’m proposing that time is halved – there’s no workaround for this using standard max objects – that’s just the way it is.

If you want to then save the recording it you may need to copy / or crop the buffer somehow just to get the bit you want – there are plenty of posts here on the forum regarding those topics (it wasn’t relevant to what I was trying to do).

Alex

Re: Continiously recording into buffer

maaaxit — Fri, 22 Jan 2010 14:21:44 +0000

Yes, as I have wrote in a comment in the patch, there is this kind of limitation in my approach. You can have two couples of tapin-tapout (one for the recording and one for playing in order to get continuous sound),but if you need quickly availability of the buffer, my patch doesn’t work.

But this can be a good question for the forum:
there is a way for writing a buffer directly from tapin?

Probably not useful for you, but here the patch for 4.5

max v2;
#N vpatcher 10 59 529 676;
#P button 364 267 15 0;
#P button 344 268 15 0;
#P window setfont “Sans Serif” 9.;
#P window linecount 5;
#P comment 190 472 282 196617 the problem of this approach is that the buffer is not quickly available , you have to wait the recording of it: if the buffer is 120 seconds , it takes 120 seconds to record it , and this can be an hard limitation. I don’t know if there is a way for writing a buffer directly from tapin;
#P toggle 115 414 15 0;
#P window linecount 1;
#P message 151 442 14 196617 0;
#P newex 115 442 29 196617 sig~;
#P newex 115 474 68 196617 groove~ xxx;
#P newex 236 439 92 196617 buffer~ xxx 5000;
#P newex 401 405 44 196617 sel 500;
#N counter 500;
#X flags 0 0;
#P newobj 401 381 66 196617 counter 500;
#P newex 401 357 52 196617 metro 10;
#P newex 344 439 67 196617 record~ xxx;
#P toggle 344 324 15 0;
#P message 364 286 14 196617 0;
#P message 344 286 14 196617 1;
#P button 228 174 34 0;
#P message 277 229 48 196617 freeze 0;
#P message 228 229 48 196617 freeze 1;
#P newex 228 331 71 196617 tapout~ 5000;
#P newex 228 286 65 196617 tapin~ 5000;
#P newex 84 331 71 196617 tapout~ 5000;
#P newex 84 286 65 196617 tapin~ 5000;
#P user ezdac~ 50 524 94 557 0;
#P message 70 103 30 196617 open;
#N sfplay~ 1 120960 0 ;
#P newobj 50 138 44 196617 sfplay~;
#P toggle 50 102 15 0;
#P comment 96 356 100 196617 delayed sound;
#P window linecount 3;
#P comment 273 175 100 196617 here you can record the last 5 seconds of sound;
#P connect 4 0 3 0;
#P connect 2 0 3 0;
#P connect 3 0 5 0;
#P connect 3 0 6 0;
#P connect 6 0 7 0;
#P connect 21 0 5 1;
#P connect 7 0 5 1;
#P connect 24 0 22 0;
#P connect 23 0 21 0;
#P connect 22 0 21 0;
#P connect 24 0 23 0;
#P connect 12 0 10 0;
#P fasten 11 0 8 0 282 275 233 275;
#P connect 10 0 8 0;
#P connect 3 0 8 0;
#P connect 8 0 9 0;
#P fasten 19 0 11 0 406 429 396 429 396 214 282 214;
#P fasten 10 0 26 0 233 260 349 260;
#P connect 26 0 13 0;
#P connect 14 0 15 0;
#P connect 13 0 15 0;
#P connect 15 0 16 0;
#P fasten 9 0 16 0 233 406 349 406;
#P fasten 19 0 27 0 406 431 388 431 388 255 369 255;
#P connect 27 0 14 0;
#P fasten 15 0 17 0 349 346 406 346;
#P connect 17 0 18 0;
#P connect 18 0 19 0;
#P pop;

Re: Continiously recording into buffer

hmarstra — Tue, 26 Jan 2010 10:09:24 +0000

Sorry for the weekend absens. Many many thanks for posting patches. Maaxit, as you point out its the timedelay issue with the tapin/ out approach. I will keep this option as a backup solution if I cant make the other one work.

AlexHarker: Great. I will dive into it. So the input is the audiosignal. What about the two outputs. Where do they go? (they both say write position (ms) )

Re: Continiously recording into buffer

AlexHarker — Tue, 26 Jan 2010 10:56:53 +0000

The outputs are what you calculate the read offset from. One is in samples – the other in milliseconds – probably the milliseconds one is more useful… See above for how to work out the offset to read from. If you want to turn recording on and off you’ll need to modify the patch a bit (see the count~ helpfile~). In my case my needs were for the buffer to be constantly updating.

Re: Continiously recording into buffer

hmarstra — Wed, 27 Jan 2010 10:26:04 +0000

Thanks. Finally got it right
I used waveform and its crop (based on selection) message to resize the buffer

#P window setfont “Sans Serif” 9.;
#P window linecount 1;
#P message 32 556 33 196617 clear;
#P newex 570 417 49 196617 + 60000;
#P user pictslider 260 489 19 76 0 0 0 0 wfknob.pct 1 wfmodes.pct 1 2146 0 0 196608 1. 1.;
#P comment 721 438 47 196617 select all;
#P message 718 452 51 196617 0 -1 0 -1;
#N vpatcher 40 55 278 404;
#P window setfont “Sans Serif” 9.;
#P newex 96 202 27 196617 int;
#N coll ;
#T flags 1 0;
#T 0 mode select;
#T 1 mode loop;
#T 2 mode move;
#T 3 mode draw;
#P newobj 131 255 53 196617 coll;
#P button 75 117 15 0;
#N comlet waveform~ mode messages;
#P inlet 74 164 15 0;
#P newex 113 88 27 196617 < < 1;
#P newex 96 140 40 196617 change;
#P newex 96 164 45 196617 select 0;
#P newex 96 117 27 196617 |;
#P outlet 131 284 15 0;
#P newex 45 62 78 196617 modifiers 100;
#P connect 5 0 7 0;
#P connect 7 0 2 0;
#P connect 0 3 2 0;
#P connect 2 0 4 0;
#P connect 4 0 3 0;
#P connect 6 0 9 0;
#P connect 3 0 9 0;
#P connect 0 4 5 0;
#P connect 5 0 2 1;
#P connect 3 1 8 0;
#P connect 9 0 8 0;
#P connect 8 0 1 0;
#P pop;
#P newobj 279 431 50 196617 p wfkeys;
#P message 567 586 35 196617 set $1;
#P message 471 586 35 196617 set $1;
#P message 375 586 35 196617 set $1;
#P message 279 586 35 196617 set $1;
#P newex 319 590 45 196617 loadbang;
#P comment 376 648 247 196617 crop buffer~ to current selection (destructive edit);
#P message 346 647 28 196617 crop;
#P comment 630 455 68 196617 select end ms;
#P comment 508 455 75 196617 select start ms;
#P comment 386 455 83 196617 display length ms;
#P flonum 639 469 49 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 519 469 49 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 399 469 49 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P flonum 279 469 49 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P newex 91 590 140 196617 buffer~ Circ_Buffer 120000;
#P message 346 629 90 196617 set Circ_Buffer 1;
#P user waveform~ 279 489 490 93 3 9;
#W mode move;
#W mouseoutput continuous;
#W clipdraw 1;
#W unit ms;
#W grid 500.;
#W ticks 8;
#W labels 1;
#W vlabels 1;
#W vticks 1;
#W vzoom 0.12;
#W voffset 0.04;
#W bpm 120. 4.;
#W frgb 16 0 0;
#W brgb 94 166 169;
#W rgb2 63 112 185;
#W rgb3 0 0 0;
#W rgb4 0 0 0;
#W rgb5 169 165 207;
#W rgb6 108 108 108;
#W rgb7 78 74 220;
#P comment 266 455 83 196617 display start ms;
#P comment 439 630 178 196617 link waveform~ to [ buffer , channel];
#P user ezdac~ 294 191 338 224 0;
#P message 198 84 14 196617 0;
#P message 184 64 14 196617 1;
#P message 149 39 28 196617 open;
#N sfplay~ 2 40320 0 ;
#P newobj 149 119 206 196617 sfplay~ 2;
#B color 5;
#P newex 242 265 64 196617 snapshot~ 5;
#P newex 275 301 66 196617 sampstoms~;
#P newex 142 266 93 196617 poke~ Circ_Buffer;
#B color 5;
#P newex 183 205 67 196617 +~ 2646000;
#P newex 84 172 112 196617 count~ 0 2646000 1 1;
#P newex 43 266 93 196617 poke~ Circ_Buffer;
#B color 5;
#P connect 4 1 13 2;
#P connect 4 1 34 0;
#P connect 6 0 0 0;
#P connect 6 0 3 0;
#P connect 6 0 10 0;
#P connect 35 0 15 0;
#P connect 34 0 13 3;
#P connect 1 0 0 1;
#P fasten 1 0 2 0 89 201 188 201;
#P connect 1 0 5 0;
#P fasten 25 0 14 0 324 614 351 614;
#P connect 15 1 14 0;
#P fasten 6 2 8 0 350 154 365 154 365 45 189 45;
#P connect 13 3 29 0;
#P connect 13 2 28 0;
#P connect 33 1 30 0;
#P connect 26 0 16 0;
#P fasten 23 0 13 0 351 674 284 674;
#P connect 16 0 13 0;
#P connect 14 0 13 0;
#P connect 30 0 13 0;
#P connect 13 0 26 0;
#P connect 13 1 27 0;
#P connect 27 0 17 0;
#P connect 17 0 13 1;
#P connect 28 0 18 0;
#P connect 18 0 13 2;
#P connect 29 0 19 0;
#P connect 19 0 13 3;
#P fasten 31 0 13 4 723 469 764 469;
#P connect 6 1 10 1;
#P fasten 5 0 4 0 247 291 280 291;
#P connect 2 0 3 1;
#P connect 7 0 6 0;
#P connect 9 0 6 0;
#P connect 8 0 6 0;
#P window clipboard copycount 36;

just have to remember to send size 120000 to buffer~ when you want to make a new recording after cropping (to 60000)