[Csnd] pvoc and time pointer
| Date | 2011-05-13 07:55 |
| From | Alex Weiss |
| Subject | [Csnd] pvoc and time pointer |
| Hi list I frequently use the pvoc opcode for extreme time-stretching, and it performs extremely well. The only thing that drives me crazy every single time is the time pointer parameter; every other opcode that deals with time stretching implements a scaling factor parameter, whereas pvoc requires a time pointer. That makes it really awkward to implement tempo changes -- I often find myself mentally integrating the tempo functions I have in mind and trying to construct graphs out of that. Clearly, that's not intuitive at all.
Any chance an additional optional parameter could be implemented that changes the time pointer to a scaling factor? Alex
|
| Date | 2011-05-13 08:00 |
| From | Victor Lazzarini |
| Subject | Re: [Csnd] pvoc and time pointer |
Why don't you use temposcal instead?
Victor
On 13 May 2011, at 07:55, Alex Weiss wrote:
> Hi list
>
> I frequently use the pvoc opcode for extreme time-stretching, and it
> performs extremely well. The only thing that drives me crazy every
> single time is the time pointer parameter; every other opcode that
> deals with time stretching implements a scaling factor parameter,
> whereas pvoc requires a time pointer. That makes it really awkward
> to implement tempo changes -- I often find myself mentally
> integrating the tempo functions I have in mind and trying to
> construct graphs out of that. Clearly, that's not intuitive at all.
> Any chance an additional optional parameter could be implemented
> that changes the time pointer to a scaling factor?
>
> Alex
Dr Victor Lazzarini
Senior Lecturer
Dept. of Music
NUI Maynooth Ireland
tel.: +353 1 708 3545
Victor dot Lazzarini AT nuim dot ie
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|
| Date | 2011-05-13 08:07 |
| From | Alex Weiss |
| Subject | Re: [Csnd] pvoc and time pointer |
| Haven't heard of it, will give it a shot. Thanks for letting me know. I assume its quality is comparable to pvoc? Also, I was wondering why there is a cap on the FFT size for both pvanal and the pvs* opcode family; 8192 seems to be the largest possible size, whenever I try 16384 I get an error message. The same applies to really low hop sizes.
On Fri, May 13, 2011 at 12:00 AM, Victor Lazzarini <Victor.Lazzarini@nuim.ie> wrote: Why don't you use temposcal instead? |
| Date | 2011-05-13 08:19 |
| From | Victor Lazzarini |
| Subject | Re: [Csnd] pvoc and time pointer |
| Was not aware of it. I will check. On 13 May 2011, at 08:07, Alex Weiss wrote: Haven't heard of it, will give it a shot. Thanks for letting me know. I assume its quality is comparable to pvoc? Dr Victor Lazzarini Senior Lecturer Dept. of Music NUI Maynooth Ireland tel.: +353 1 708 3545 Victor dot Lazzarini AT nuim dot ie |
| Date | 2011-05-13 08:22 |
| From | Victor Lazzarini |
| Subject | Re: [Csnd] pvoc and time pointer |
| Can't reproduce it? What is the hopsize that is causing trouble? On 13 May 2011, at 08:19, Victor Lazzarini wrote:
Dr Victor Lazzarini Senior Lecturer Dept. of Music NUI Maynooth Ireland tel.: +353 1 708 3545 Victor dot Lazzarini AT nuim dot ie |
| Date | 2011-05-13 08:32 |
| From | Alex Weiss |
| Subject | Re: [Csnd] pvoc and time pointer |
| For pvanal, it seems that whenever the hop size is equal to or less than 1/128 of the fft size it doesn't work. For example, neither 8192/64 nor 4096/32 works. The error message is the same in both cases: "128 is a bad window overlap index" On Fri, May 13, 2011 at 12:22 AM, Victor Lazzarini <Victor.Lazzarini@nuim.ie> wrote:
|
| Date | 2011-05-13 08:37 |
| From | Alex Weiss |
| Subject | Re: [Csnd] pvoc and time pointer |
| Regarding large FFT sizes: analyzing with an FFT size of 16384 works, but pvoc then gives an error message: "FFT size 16384 too large for Csound." Something similar happens with pvsanal.
On Fri, May 13, 2011 at 12:32 AM, Alex Weiss <alexweiss86@gmail.com> wrote: For pvanal, it seems that whenever the hop size is equal to or less than 1/128 of the fft size it doesn't work. For example, neither 8192/64 nor 4096/32 works. The error message is the same in both cases: "128 is a bad window overlap index" |
| Date | 2011-05-13 08:54 |
| From | Victor Lazzarini |
| Subject | Re: [Csnd] pvoc and time pointer |
I can't reproduce it (with pvsanal etc), maybe it's a question of ksmps size (what is your ksmps?). Is this with pvoc and pvanal? On 13 May 2011, at 08:32, Alex Weiss wrote: For pvanal, it seems that whenever the hop size is equal to or less than 1/128 of the fft size it doesn't work. For example, neither 8192/64 nor 4096/32 works. The error message is the same in both cases: "128 is a bad window overlap index" Dr Victor Lazzarini Senior Lecturer Dept. of Music NUI Maynooth Ireland tel.: +353 1 708 3545 Victor dot Lazzarini AT nuim dot ie |
| Date | 2011-05-13 08:55 |
| From | Victor Lazzarini |
| Subject | Re: [Csnd] pvoc and time pointer |
| Again, no such problems here with pvsanal. Victor On 13 May 2011, at 08:37, Alex Weiss wrote: Regarding large FFT sizes: analyzing with an FFT size of 16384 works, but pvoc then gives an error message: "FFT size 16384 too large for Csound." Something similar happens with pvsanal. Dr Victor Lazzarini Senior Lecturer Dept. of Music NUI Maynooth Ireland tel.: +353 1 708 3545 Victor dot Lazzarini AT nuim dot ie |
| Date | 2011-05-13 09:00 |
| From | Victor Lazzarini |
| Subject | Re: [Csnd] pvoc and time pointer |
| pvsanal will switch to sliding if ksmps > hopsize, so that cannot be the problem. Victor On 13 May 2011, at 08:54, Victor Lazzarini wrote:
Dr Victor Lazzarini Senior Lecturer Dept. of Music NUI Maynooth Ireland tel.: +353 1 708 3545 Victor dot Lazzarini AT nuim dot ie |
| Date | 2011-05-13 09:01 |
| From | Alex Weiss |
| Subject | Re: [Csnd] pvoc and time pointer |
| Yes, that was with pvoc and pvanal. I just checked pvsanal, and it worked indeed. I must have confused something. But the issue is definitely there with pvoc and pvanal.
On Fri, May 13, 2011 at 12:54 AM, Victor Lazzarini <Victor.Lazzarini@nuim.ie> wrote:
|
| Date | 2011-05-13 09:04 |
| From | Victor Lazzarini |
| Subject | Re: [Csnd] pvoc and time pointer |
| I see the restriction on lpanal. Not sure it's required anymore, I will investigate it and hopefully lift it. I don't think this applies to pvsanal or any other phase-vocoder-based opcode. Victor On 13 May 2011, at 08:55, Victor Lazzarini wrote:
Dr Victor Lazzarini Senior Lecturer Dept. of Music NUI Maynooth Ireland tel.: +353 1 708 3545 Victor dot Lazzarini AT nuim dot ie |
| Date | 2011-05-13 09:09 |
| From | Victor Lazzarini |
| Subject | Re: [Csnd] pvoc and time pointer |
| I am removing this restriction on lpanal, leaving a warning at the moment (but will probably remove the warning as well). GIT has been updated. Victor On 13 May 2011, at 09:04, Victor Lazzarini wrote:
Dr Victor Lazzarini Senior Lecturer Dept. of Music NUI Maynooth Ireland tel.: +353 1 708 3545 Victor dot Lazzarini AT nuim dot ie |
| Date | 2011-05-13 09:14 |
| From | Alex Weiss |
| Subject | Re: [Csnd] pvoc and time pointer |
| Thanks. What about pvoc and pvanal? Same fix? On Fri, May 13, 2011 at 1:09 AM, Victor Lazzarini <Victor.Lazzarini@nuim.ie> wrote:
|
| Date | 2011-05-13 09:25 |
| From | Victor Lazzarini |
| Subject | Re: [Csnd] pvoc and time pointer |
| that was pvanal sorry, not lpanal! I've got LPC in my head these days. The restriction seems to be on pvanal only. pvoc should work with any hopsize. Victor On 13 May 2011, at 09:14, Alex Weiss wrote: Thanks. What about pvoc and pvanal? Same fix? Dr Victor Lazzarini Senior Lecturer Dept. of Music NUI Maynooth Ireland tel.: +353 1 708 3545 Victor dot Lazzarini AT nuim dot ie |
| Date | 2011-05-13 09:45 |
| From | peiman khosravi |
| Subject | Re: [Csnd] pvoc and time pointer |
|
I would suggest to use temposcal with no phase locking for extreme
time-stretching. It works very well and it is much more convenient
than pvoc. P On 13/05/2011 08:19, Victor Lazzarini wrote: Was not aware of it. I will check. |