Pd-list December 2007

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129 participants
239 discussions

Re: [PD] gem codec basic review
by Andrew Brouse 24 Dec '07

24 Dec '07

Hi Patrick, As Marius noted, the best CODEC depends on what you are going to do with the video. The MPEG gang of CODECs (from MPEG-2 on through H-264) are very good for standard playback and have a good quality/file-size ratio. All visual CODECs use spatial coding - reduction of perceptual redundancies in the 2D plane of a given frame; but another way these CODECs achieve such good ratios is by using temporal coding to reduce frame to frame redundancies. They take a GOP (Group of Pictures, not an antediluvian near-extinct political party) and make decisions about what information is important. Some frames are fully represented and other frames are coded with reference to the ones around them. This saves a lot of space, but you do not have a full representation of each frame. During normal playback this is not a problem, but if you want to mess with the playback rate it is. If you want to do any scrubbing, varispeed or playing backwards of the video, you need a CODEC which does not use temporal compression. Photo-JPEG is in fact a very good choice in this case and if compressed at 320 X 240 you get a good balance of file-size, picture quality and processor load. JPEG 2000 should also be a good choice (supported by QuickTime and there are libraries which support it on Linux but not sure if it will play in GEM). I have used DV video with good results and this may be a good option if you need high quality playback. However, if you have unlimited bandwidth and storage, why not just go for uncompressed D-1 video? (~30M/s) ;) cheers, Andrew On Fri, 30 Nov 2007, pd-list-request(a)iem.at wrote: > hi, > > i am on linux running the very last version of gem from cvs. i am trying > to find a good codec for gem. here's my basic research: > > --------------------------------------- > the best codec for quicktime is jpeg: > transcode -i yourvideo -y mov,null -F jpeg,,jpeg_quality=70 -o gem.mov > > gem cpu usage is 38% > mplayer cpu usage is 27% > ffplay cpu usage is 16% > lqtplay cpu usage is 1% ** > > --------------------------------------- > for avi i tried ffmpeg / mjpeg: > transcode -i yourvideo -y ffmpeg,null -F mjpeg -o gem.avi > > gem cpu usage is 33% > mplayer cpu usage is 33% > ffplay cpu usage is 22% > > --------------------------------------- > the really best codec around is mpeg4: > transcode -i yourvideo -y ffmpeg,null -F mpeg4 -o gem.avi > > gem cpu usage is: crashed** > mplayer cpu usage is 16% > ffplay cpu usage is 11% > > > * lqtplay seems to make a excellent job for decoding is own codec. would > it be possible to make a pix_qt based on the source of this player??? > > ** anybody can test this codec? that would be my second choice... after > lqtplay ported to gem... > > pat

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Fwd: complex metronomes sequencing problem
by Libero Mureddu 24 Dec '07

24 Dec '07

forwarded to pd list ---------- Forwarded message ---------- From: Andy Farnell <padawan12(a)obiwannabe.co.uk> Date: Dec 24, 2007 12:28 AM Subject: Re: complex metronomes sequencing problem To: Libero Mureddu <libero.mureddu(a)gmail.com> On Mon, 24 Dec 2007 00:00:13 +0100 "Libero Mureddu" <libero.mureddu(a)gmail.com> wrote: > Hi Andy, > > thanks for your message, it clarified a lot my problem. > In fact I need a "time aware" synchronous system, could you send a > basic example of that? I can guess that I need a metro plus counter > and different [mod]s, but I dont get how to use [moses] and [change] > for that. [moses] comes in when you want to create separate bars or phrases and attach copies or similar parts to them. Say we have a subpatch or abstraction that plays a phrase [melody1] and it takes a count from 0-127, and another phrase in [melody2] that is different but the same length. To have them alternate you can say [count 256] | [moses 127] | \ [melody1] [- 128] | [melody2] [change] is useful when you did an integer division or remainder with [/][int] or [div]. Even though the float output doesn't change in value it is repeated for every bang of the timebase. For example a counter mod 16 divided into four bars or four like this [count 16] | [/ 4] | [int] will output {0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3} Adding [change] turns this into {0, 1, 2, 3] changing on every fourth beat. > > In another attempt that I did, I made a select with many arguments, > each one representing a "playing point". Unfortunately it seems > impossible to send a list of arguments as message and set dynamically > all the values for set (at least I was unable to do that). > [multiselect] that should do that is broken. This idiom is useful to make a n beat sequencer with settable [unpack f f f] | | | \ | \ | \ | [==] [==] [==] ....... With all the left inlets connected to the timebase (remember to use a big [t b b b b b ...]. A 1 is output for each match of a list you can update. Use [sel 1] to turn that to a bang if necessary. > > Do you have an example of the sample timing based idea that you > mentioned? In fact, the compositions I'm working on are not longer > than 4-5 minutes. > > Thanks > Libero > There's a few things to browse here, including an early example of a signal domain composition with loops and synths; http://www.obiwannabe.co.uk/html/music/musictuts/Composition-000/Compositio… http://www.obiwannabe.co.uk/html/music/musictuts/Composition-001/Compositio… http://www.obiwannabe.co.uk/html/music/musictuts/Composition-002/Compositio… http://www.obiwannabe.co.uk/html/compositions/compositions.html > > From: Andy Farnell <padawan12(a)obiwannabe.co.uk> > > Subject: Re: [PD] complex metronomes sequencing problem > > To: pd-list(a)iem.at > > Message-ID: <20071223205532.01f5fcb3.padawan12(a)obiwannabe.co.uk> > > Content-Type: text/plain; charset=US-ASCII > > > > > > > > If you have two or more independent metronomes that form a polyrhythmic > > relationship then stopping them will lose the relationship. Each will > > begin its timing series from the same "zero point". > > > > A synchronous system is probably better if you want to start and stop > > the composition at arbitrary points and have it resume. > > > > The general problem with a synchronous system is that the smallest timing > > resolution is the division of the master clock at all points. > > > > But there are also two quite distinct approaches to synchronous sequencers in > > Pd having different properties. > > > > One is based on bangs and built from many subsystems that each hold their own > > state. These "state aware" subsequences use a local counter and a [select] > > object. The advantage here is that if you stop the master bang message source, > > each will remain in it's last state until new bangs start to flow. The > > disadvantage is that no part of the system is "time aware", so you cannot > > jump forwards or backwards a number of beats to see what the sequence is > > like without explicitly going through all steps. > > > > The second kind is "time aware". Instead of sending bangs you send float > > messages which represent the current time. You can use combinations of > > [moses], [mod], [change] and simple arithmetic to make subsystems behave > > in different ways. You can jump forwards, backwards or pause the sequence > > in any way you like. > > > > If you want sample accurate timing you can try an interesting approach that > > Chun Lee and I have both experimented with, composition entirely in the > > signal domain. You start with a very slow [phasor~] or [vline~] and calculate > > all sequence timings using a mixture of [wrap~], [rpole~]/[rzero~] and > > [min~]/[max~] to constrain, integrate or differentiate the timebase. This has > > some really nice features, like being able to warp the timebase and get swings > > or extremely smooth tempo changes. You can also warp parts independently and > > have them converge on some point in the future with sample accuracy (like > > spinning back a sample table and having it land exactly on the beat... which > > you cannot do in any other software afaik). The disadvantage to this is that > > you're limited to songs of less than about 5 mins because of rounding errors. > > > > > > > > > > > > On Sun, 23 Dec 2007 21:08:08 +0100 > > "Libero Mureddu" <libero.mureddu(a)gmail.com> wrote: > > > > > Hello to everybody! > > > > > > I have a problem and I'd need that someone could point me at least to > > > the right approach to solve it. > > > > > > > > > Let's say I have three simple metronomes running, built with metro. > > > Their speed is 1000 1001 and 1002 ms (in my case I have 88 of them, > > > running at different speeds). > > > I'd like to have the possibility to: > > > > > > a) keep the proportion constant between them and change the global > > > tempo (i.e. 100, 100.1, 100.2 etc) > > > b) I'd like to stop and restore the metros with their right time > > > differences: if they start at the same time (from the same bang), they > > > create a particular net of rhythms, that I'd like to control, analyze > > > and change. I'd like to be able to stop them at a certain point and > > > restart from another but keeping the same rhythmic combination. > > > > > > I know that this exist and is called sequencer :-) > > > But I want to control this using pd but I don't know really how to do > > > it, and also this is the simplest example: some parts could start at a > > > certain point a change towards a different tempo in a certain time, > > > having different dynamic according to a particular pattern etc. etc. > > > So I think pd would a good platform to implement this. > > > > > > I was thinking to have a global metro running at 1 ms speed with a > > > counter that reads many different arrays: the first of 1000 values > > > (the first "1" and the other values "0"), the second of 1001 values > > > and the third 1002 values and so on. > > > > > > But this works if I decide in advance the metros speed and leave it > > > fixed, but I want to be able to modify the speed and still being able > > > to restart, stop etc. > > > Other idea was to have many qlists, but again, a note approach would > > > give the problem of sync between the different notes. > > > > > > Any help appreciated! > > > > > > Thanks, best regards and > > > > > > Merry Christmas! > > > > > > Libero > > > > > > -- > > > Libero Mureddu > > > Vanha Viertotie, 21 as 417 > > > 00350 Helsinki > > > Finland > > > http://webusers.siba.fi/~limuredd/ > > > http://www.myspace.com/liberomureddu > > > > > > _______________________________________________ > > > PD-list(a)iem.at mailing list > > > UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list > > > > > > -- > > Use the source > > > > > > > > ------------------------------ > > > > _______________________________________________ > > PD-list mailing list > > PD-list(a)iem.at > > to manage your subscription (including un-subscription) see > > http://lists.puredata.info/listinfo/pd-list > > > > > > End of PD-list Digest, Vol 33, Issue 163 > > **************************************** > > > > > > -- > Libero Mureddu > Vanha Viertotie, 21 as 417 > 00350 Helsinki > Finland > http://webusers.siba.fi/~limuredd/ > http://www.myspace.com/liberomureddu -- Use the source -- Libero Mureddu Vanha Viertotie, 21 as 417 00350 Helsinki Finland http://webusers.siba.fi/~limuredd/ http://www.myspace.com/liberomureddu

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Pdpedia: Vandalism
by Chris 24 Dec '07

24 Dec '07

Hello list, There are several cases of vandalism at wiki.puredata.info, who takes care about that? They are all at discussion pages. Maybe there should be some kind of Captcha to prevent Bots from Spamming? Articles: http://wiki.puredata.info/en/Talk:message http://wiki.puredata.info/en/comment http://wiki.puredata.info/en/Talk:about Nearly every IP-edit in pdpedia. I would delete them, but I have no admin-account. --~~~~ Chris

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PD on a DSP?
by Spencer Russell 24 Dec '07

24 Dec '07

Has anyone had experience running PD using a dedicated DSP? I'm going to be starting an embedded PD-based project and my plan has been to use PDa on an ARM, but I'm wondering if I might be able to get more speed by offloading some of the maths to a DSP. If I used a floating-point DSP could I port mainline PD? I guess that PDa has to emulate the floating point for the message passing, which I suppose wouldn't be well-suited to a DSP anyways. Anyways, I'm just rambling... -spencer

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UC-33 and Pd
by Javier Garcia 24 Dec '07

24 Dec '07

Hi, I have an UC-33 evolution midi controller. When i turn it on, Alsa Sequencer shows it. In the same way when i go to pd, and choose Media>Alsa midi, Alsa Sequencer shows this: "Pure Data Midi-in 1" Then i go to Media>Test audio and midi, and i press the assignable buttons, or move the knobs, and nothing seems happen. Any idea? br. GARFF _________________________________________________________________ La vida de los famosos al desnudo en MSN Entretenimiento http://entretenimiento.es.msn.com/

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[PD-announce] Tcl/Tk 8.5.0 released
by Mathieu Bouchard 24 Dec '07

24 Dec '07

http://www.tcl.tk/software/tcltk/8.5.tml _ _ __ ___ _____ ________ _____________ _____________________ ... | Mathieu Bouchard - tél:+1.514.383.3801, Montréal QC Canada _______________________________________________ PD-announce mailing list PD-announce(a)iem.at http://lists.puredata.info/listinfo/pd-announce

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Re: [PD] Pduino&Ping ultrasonic sensor&arduino
by Marko Timlin 23 Dec '07

23 Dec '07

Hi Martin, thanks so much for the helpful information. I'll continue experimenting until I find the best way for my needs. The EZ1 sensors you recommended seem very interesting indeed. At the moment I'd like to use solar cells for light tracking and at the same time the Ping sensors for motion tracking. If that would be possible with the EZ1s as well, I'd be a happy man. The solar cells are connected to the analog inputs of the arduino and they work fine with Pduino. But if someone is out there who is capable of creating a module for Pduino and the Ping sensor I'd be again a happy man. Marko Marko Timlin wrote: > Moi, > does anybody know, if it is possible to control the Ping(ultrasonic range finder)sensor using only Pduino (first uploading Pd-firmware to the arduino, and then using the "arduino" pure data patch?). It doesn't work for me at the moment. > > The Ping needs you to send a trigger and wait for an echo, and the delay needs to be precisely timed. Unfortunately pd can't communicate with the arduino or anything else outside the machine it's running on with enough timing precision to do that. (Sound travels about 1 foot per millisecond and the timing jitter with comport can be up to about 10ms, so your measurements will almost always be off by several feet.) > If I write my own ping-sensor-patch for arduino and then use the PD_inputs_to_PD patch it works fine. > Because the serial communication timing is not involved. > But I'd like to use several different sensors and it would therefore be much easier to just control all of them with Pduino and not writing new code for arduino all the time. Well, guess this was the original idea of Pduino anyways :-) > > The code for many sensors is almost the same as the code for one sensor, so it shouldn't be too hard. If you must use Pduino, you could try one of the EZ1 sensors, it has an analog output that you can connect to an arduino analog in: http://www.hvwtech.com/products_view.asp?ProductID=560 I've used it with Pduino with no problems. I guess the other approach is to add modules to pduino that specifically handle specific hardware, but there is a _lot_ of hardware out there...the main ones that need doing are stepper motors (two or four pins have to change at the same time at precise times), servo motors (pulse width needs to be between 1 and 2 ms), and sonar sensors, as well as any hardware with a serial interface like servo controllers (serial data bits need to be accurately timed to about 2% of the data rate). Most everything else isn't as sensitive to timing. Martin

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complex metronomes sequencing problem
by Libero Mureddu 23 Dec '07

23 Dec '07

Hello to everybody! I have a problem and I'd need that someone could point me at least to the right approach to solve it. Let's say I have three simple metronomes running, built with metro. Their speed is 1000 1001 and 1002 ms (in my case I have 88 of them, running at different speeds). I'd like to have the possibility to: a) keep the proportion constant between them and change the global tempo (i.e. 100, 100.1, 100.2 etc) b) I'd like to stop and restore the metros with their right time differences: if they start at the same time (from the same bang), they create a particular net of rhythms, that I'd like to control, analyze and change. I'd like to be able to stop them at a certain point and restart from another but keeping the same rhythmic combination. I know that this exist and is called sequencer :-) But I want to control this using pd but I don't know really how to do it, and also this is the simplest example: some parts could start at a certain point a change towards a different tempo in a certain time, having different dynamic according to a particular pattern etc. etc. So I think pd would a good platform to implement this. I was thinking to have a global metro running at 1 ms speed with a counter that reads many different arrays: the first of 1000 values (the first "1" and the other values "0"), the second of 1001 values and the third 1002 values and so on. But this works if I decide in advance the metros speed and leave it fixed, but I want to be able to modify the speed and still being able to restart, stop etc. Other idea was to have many qlists, but again, a note approach would give the problem of sync between the different notes. Any help appreciated! Thanks, best regards and Merry Christmas! Libero -- Libero Mureddu Vanha Viertotie, 21 as 417 00350 Helsinki Finland http://webusers.siba.fi/~limuredd/ http://www.myspace.com/liberomureddu

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Long long numbers
by Dafydd Hughes 23 Dec '07

23 Dec '07

Hi everybody Working on a project that needs really long numbers. I'm sure there's a way of doing it that's obvious to those with better math brains and more experience, but I basically need to keep Pd from slipping into scientific notation. Can anybody offer hints on how to split up really long numbers so I can keep them accurate? Thanks in advance. cheers dafydd -- www.sideshowmedia.ca skype: chickeninthegrass

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Re: [PD] help with nqpoly4
by Ed Kelly 23 Dec '07

23 Dec '07

Hi there > You need to add the directory containing the abstraction you wrap in > "nqpoly4" ($2) to the Pd search path, otherwise "nqpoly4" cannot find > it. OK, so now... error: Bad arguments for object 'throw~' to object 'objectmaker' The only argument I pass it is the name of the throw~/catch~ bus. > Someone please implement segmented patch cords. ;) So we can make grid cities instead of spider maps? Best, Ed __________________________________________________________ Sent from Yahoo! Mail - a smarter inbox http://uk.mail.yahoo.com

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Pd-list December 2007