[PD] how to avoid (most/many/some) readsf~ dropouts
Matt Barber
brbrofsvl at gmail.com
Tue Jul 15 05:41:20 CEST 2008
Hey Greg,
I threw together a couple of abstractions to show how I usually do it,
but I'm not sure it will help with playback of multiple 8-channel
files. I've never tried this before, but I wonder what would happen
if you split your 8-channel files and played them simultaneously as
4-channel soundfiles... or, if it's always running on your computer,
you might try storing half of your soundfiles on one disk and the
other half on another -- it's hard to know whether the disk is going
bonkers or readsf~ breaks. Depending on the size of your files you
might bite the bullet and load them into tables...
At any rate, you should have three files -- one is a generic
abstraction that shows the general method. The other abstraction
(playback_8ch_fade) is based on your first patch, and is generalized
to play any 8-channel soundfile -- hopefully the comments in them are
useful. I kept your 6<n<56 ms "humanization" in the file, as well as
the throws to ch1-ch8 (I'd probably use outlet~ more often than not,
but this is fine if you know how you need to set up the rest of the
patch).
It uses the same general method as the generic patch, but adds some
other goodies I would feel obligated to provide if I were giving the
abstraction to someone to use... but maybe it's way overkill for
personal use, or inside a patch where nobody's gonna see it. It has
some basic type-checking and conversion, but no error printing, which
I would normally do if I had the time or were building a library. It
also has a small example of some dynamic patching, which might better
be left out, and could maybe even be avoided in this example (nothing
comes to mind instantly)... I like having the option to change things
on the fly, though, so I use this kind of thing in my own patches all
the time. Let me know if it's even readable. The third file (marked
"revised") is an example of how to use the bigger abstraction. I
haven't fully debugged it all, and lots of optimizations could be made
all over the place but I think it should work as an example patch.
Of course others are welcome to comment if it sucks, or use any of it
if they find it compelling. =o) Let me know if this helps out, but
I've a feeling your problem is deeper than any method for using
[readsf~].
Matt
On Mon, Jul 14, 2008 at 12:51 PM, Dr. Greg Wilder
<gregwilder at orpheusmediaresearch.com> wrote:
> Matt Barber wrote:
>>>
>>> Date: Sat, 12 Jul 2008 13:56:54 +0200
>>> From: Damian Stewart <damian at frey.co.nz>
>>> Subject: [PD] how to avoid (most/many/some) readsf~ dropouts
>>> To: PD-List <pd-list at iem.at>
>>> Message-ID: <48789C06.4030401 at frey.co.nz>
>>> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>>>
>>> hey,
>>>
>>> one thing i've noticed with readsf~ using it in my own live-performance
>>> sets is that doing this
>>>
>>> [symbol blahblahblah.aif]
>>> |
>>> [open $1, bang(
>>> |
>>> [readsf~]
>>>
>>> sometimes causes dropouts. but if you go
>>>
>>> [symbol blahblahblah.aif]
>>> |
>>> [t b a]
>>> | \____
>>> | \
>>> [del 50] [open $1(
>>> | __________/
>>> |/
>>> [readsf~]
>>>
>>> then you remove (all/many/some) of the dropouts. i haven't extensively
>>> tested this, but anecdotal evidence seems to suggest that it works.
>>>
>>
>>
>> I think this is because the former method may not let the buffer fill
>> before you start playing. I usually don't like the second method,
>> either, because of the 50 ms delay (which isn't much, but I'm finicky
>> about that kind of thing). Depending on the setup, I usually prefer
>> something like the following:
>>
>> [loadbang]
>> |
>> | [r open]
>> | /
>> [open file.ext (
>> [0 ( [1 ( |
>> | \__ |
>> [t b f ]_____\ |
>> | [readsf~ ]
>> [s open] |
>> [s open]
>>
>>
>> I hope things line up okay there... at any rate, you load the buffer
>> at the beginning, or if your piece/performance has a master clock, a
>> couple of seconds before you need it. Then for rehearsal, if you need
>> to stop the file you can use a trigger to reload it immediately.
>> Also, if you need to play the file again, you can send the "open"
>> message when the file is done playing. This makes the whole process a
>> little more "front-loaded," so that the soundfile is always "open" no
>> matter what. My intuition is that it's more robust than other schemes
>> I've tried. I haven't tested it very hard, though, as I've only ever
>> needed up to 9-10 simultaneous 96k files... maybe it would be neat to
>> find some old, slow hardware to see how far different methods can be
>> pushed. =o)
>>
>> More advanced for stopping would be something that fades out the sound
>> with a [line~] over 20 ms or so, and then sends the stop message to
>> [readsf~] after a comparable delay -- that way you won't get an
>> annoying transient upon stop -- same deal with a fade in if you are
>> starting in the middle of the soundfile, but without the delay. I
>> usually wrap the whole thing in an abstraction -- I keep three or four
>> different ones lying around with different properties for different
>> situations, and I'm happy to share with anyone who might find them
>> useful.
>>
>>
>> Thanks,
>>
>>
>> Matt
>
>
> Matt and Damian,
>
> In working on a recent piece for marimba and 8-channel computer
> (24bit/88.2kHz), I consistently experienced intermittent clicks and audio
> dropouts -- even on high-end hardware running GNU/Linux. Increasing the
> readsf buffer and the time between file load (open) and playback (readsf)
> helped some, but not enough. Since the premiere last month, I've been
> rebuilding the abstractions for better efficiency, but am still not happy
> with the results -- and before the soloist can safely tour the piece, I need
> to work out a more robust solution.
>
> I've attached the latest version of my "basic" playback (w/fade) patch for
> suggestions/comments... Unfortunately, your ascii patch didn't line up,
> would you mind posting an example patch that shows your method?
>
> Best,
> G
>
> --
> http://www.orpheusmediaresearch.com/
> http://www.gregwilder.com/
> +1 215-764-6057 (office)
> +1 215-205-2893 (cell)
>
> #N canvas 65 224 902 519 10;
> #X msg 86 198 1;
> #X msg 129 198 0;
> #X obj 175 128 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1
> -1;
> #X obj 129 178 r stop;
> #X obj 86 105 + 6;
> #X floatatom 86 125 5 0 0 0 - - -;
> #X obj 175 373 *~;
> #X obj 383 147 loadbang;
> #X obj 441 147 r reset_vol;
> #X text 401 127 master volume;
> #X obj 86 84 random 50;
> #X obj 243 373 *~;
> #X obj 174 395 throw~ ch1;
> #X obj 242 395 throw~ ch2;
> #X obj 312 373 *~;
> #X obj 380 373 *~;
> #X obj 311 395 throw~ ch3;
> #X obj 379 395 throw~ ch4;
> #X obj 574 145 delay 500;
> #X msg 383 168 100;
> #X msg 441 168 100;
> #X obj 667 241 \$1;
> #X obj 395 351 vline~;
> #X obj 328 351 vline~;
> #X obj 258 351 vline~;
> #X obj 191 351 vline~;
> #X obj 86 143 delay;
> #X obj 448 373 *~;
> #X obj 516 373 *~;
> #X obj 584 373 *~;
> #X obj 574 224 dbtorms;
> #X floatatom 574 185 5 0 0 0 - - -;
> #X obj 574 203 * 1;
> #X obj 652 373 *~;
> #X obj 667 351 vline~;
> #X obj 600 351 vline~;
> #X obj 531 351 vline~;
> #X obj 464 351 vline~;
> #X text 599 204 (vol%);
> #X obj 447 395 throw~ ch5;
> #X obj 515 395 throw~ ch6;
> #X obj 583 395 throw~ ch7;
> #X obj 651 395 throw~ ch8;
> #X msg 175 151 open 8ch_acheron_blasts.wav;
> #X msg 574 165 0;
> #X msg 667 262 \$1 3500;
> #X obj 667 283 unpack f f;
> #X obj 724 304 + 1025;
> #X text 719 262 fade time in ms;
> #X floatatom 724 325 5 0 0 0 - - -;
> #X obj 441 189 delay;
> #X obj 441 209 bng 15 250 50 0 empty empty empty 0 -6 0 10 -262144
> -1 -1;
> #X obj 175 67 r acheron_play;
> #X obj 574 124 r acheron_fade;
> #X obj 175 215 readsf~ 8 1e+06;
> #X connect 0 0 54 0;
> #X connect 1 0 54 0;
> #X connect 2 0 43 0;
> #X connect 2 0 26 0;
> #X connect 3 0 1 0;
> #X connect 4 0 5 0;
> #X connect 5 0 26 0;
> #X connect 6 0 12 0;
> #X connect 7 0 19 0;
> #X connect 8 0 20 0;
> #X connect 10 0 4 0;
> #X connect 11 0 13 0;
> #X connect 14 0 16 0;
> #X connect 15 0 17 0;
> #X connect 18 0 44 0;
> #X connect 19 0 31 0;
> #X connect 20 0 31 0;
> #X connect 21 0 45 0;
> #X connect 22 0 15 1;
> #X connect 23 0 14 1;
> #X connect 24 0 11 1;
> #X connect 25 0 6 1;
> #X connect 26 0 0 0;
> #X connect 27 0 39 0;
> #X connect 28 0 40 0;
> #X connect 29 0 41 0;
> #X connect 30 0 21 0;
> #X connect 31 0 32 0;
> #X connect 32 0 30 0;
> #X connect 33 0 42 0;
> #X connect 34 0 33 1;
> #X connect 35 0 29 1;
> #X connect 36 0 28 1;
> #X connect 37 0 27 1;
> #X connect 43 0 54 0;
> #X connect 44 0 31 0;
> #X connect 45 0 22 0;
> #X connect 45 0 23 0;
> #X connect 45 0 24 0;
> #X connect 45 0 25 0;
> #X connect 45 0 37 0;
> #X connect 45 0 36 0;
> #X connect 45 0 35 0;
> #X connect 45 0 34 0;
> #X connect 45 0 46 0;
> #X connect 46 1 47 0;
> #X connect 47 0 49 0;
> #X connect 49 0 50 1;
> #X connect 50 0 20 0;
> #X connect 50 0 51 0;
> #X connect 51 0 1 0;
> #X connect 52 0 10 0;
> #X connect 52 0 2 0;
> #X connect 53 0 18 0;
> #X connect 53 0 50 0;
> #X connect 54 0 6 0;
> #X connect 54 1 11 0;
> #X connect 54 2 14 0;
> #X connect 54 3 15 0;
> #X connect 54 4 27 0;
> #X connect 54 5 28 0;
> #X connect 54 6 29 0;
> #X connect 54 7 33 0;
>
>
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