[PD] line~ for syncing to video
Hans-Christoph Steiner
hans at eds.org
Fri Nov 14 15:42:55 CET 2008
On Nov 14, 2008, at 7:41 AM, cyrille henry wrote:
> Hans-Christoph Steiner a écrit :
>> That seems like a lot more work, converting from message to DSP
>> and back to messages.
> work for patching or work for the CPU?
> i think both are negligible.
>
>> Do you think that the timing of [metro] is not accurate enough?
> since pd does the timing for both clock, it should work.
>
> but having a master clock at 25Hz, and over-sample it at 44100Hz is
> somthing that hurt my sens of logic.
In this case, it was 30fps and 48000Hz, so it is an even multiple. I
guess it seems odd to me to be using ~ objects for the frame clock,
but I suppose it could be not so weird. But if this is all in Pd,
then the timing should be coming from the same place either way, right?
.hc
>
> cyrille
>
>> I basically created a [line] that is driven by the frame numbers,
>> then feed that to [line~] when needed. Seemed to work pretty
>> well. See attached patch.
>> .hc
>> On Nov 12, 2008, at 5:55 AM, cyrille henry wrote:
>>> hello,
>>>
>>> you can use frame number as a trigger, that's not incompatible
>>> with a sync from audio to video.
>>>
>>> see attachement patch.
>>>
>>> cyrille
>>>
>>>
>>> Hans-Christoph Steiner a écrit :
>>>> What I am working on are tools for composing audio to someone
>>>> else's video. I've worked on a couple projects like this, I am
>>>> in the midst of one know. Basically, think sound design for a
>>>> movie and things like it. They generate the movie, and so far,
>>>> I have found the easiest way to communicate with the people
>>>> making the video is to use frame numbers.
>>>> Therefore, to compose my sound, I need to frame numbers as a
>>>> reference. Therefore, I need to generate line data from video
>>>> frame numbers, unless someone has a better idea. If the video
>>>> guys tell me, "this animation starts on frame 1234 and ends on
>>>> 1623", then it seems to me that I want to be using frame numbers
>>>> as my triggers.
>>>> .hc
>>>> On Oct 31, 2008, at 11:08 AM, chris clepper wrote:
>>>>> Cyrille points out the correct method of syncing video to an
>>>>> audio clock. All hardware devices and professional software
>>>>> use the audio to clock the video.
>>>>>
>>>>> On Fri, Oct 31, 2008 at 4:48 AM, cyrille henry
>>>>> <cyrille.henry at la-kitchen.fr <mailto:cyrille.henry at la-
>>>>> kitchen.fr>> wrote:
>>>>>
>>>>> hello,
>>>>>
>>>>> i'm wondering why did you sync audio on video : i think it is
>>>>> easier to sync the video on the audio.
>>>>> just make all the line~ as you wish for the audio, then
>>>>> snapshot~
>>>>> periodically and convert audio position to frame number...
>>>>>
>>>>> cyrille
>>>>>
>>>>>
>>>>> Hans-Christoph Steiner a écrit :
>>>>> > I am trying to make a version of [line~] that gives me a
>>>>> line based
>>>>> > on the frame numbers I give it. Basically, I give it a
>>>>> frame
>>>>> counter
>>>>> > in the first inlet, then start frame and stop frame as
>>>>> arguments.
>>>>> > The hard part is that I want it to behave like [line] in
>>>>> that the
>>>>> > last value stays in effect until something else overrides
>>>>> it.
>>>>> >
>>>>> > How do I do that with DSP data? If I use [switch~], then
>>>>> the
>>>>> > [outlet~] will just retain its last value.
>>>>> >
>>>>> > .hc
>>>>> >
>>>>> >
>>>>> >
>>>>>
>>>>> ------------------------------------------------------------------
>>>>> ------
>>>>> > ----
>>>>> >
>>>>> > 'You people have such restrictive dress for women,' she
>>>>> said,
>>>>> > hobbling away in three inch heels and panty hose to
>>>>> finish out
>>>>> > another pink-collar temp pool day. - "Hijab Scene #2",
>>>>> by Mohja
>>>>> Kahf
>>>>> >
>>>>> >
>>>>> >
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>>>>>
>>>> -------------------------------------------------------------------
>>>> ---------
>>>> If you are not part of the solution, you are part of the problem.
>>> #N canvas 64 128 625 478 10;
>>> #X obj 79 193 line~;
>>> #X floatatom 79 25 5 0 0 0 - - -;
>>> #X text 130 25 frame number;
>>> #X obj 79 45 / 25;
>>> #X text 135 45 time in s;
>>> #X obj 79 73 * 1000;
>>> #X text 143 73 time in ms;
>>> #X obj 79 97 t f f;
>>> #X obj 79 146 pack f f;
>>> #X obj 111 119 + 100000;
>>> #X msg 79 169 \$1 \, \$2 100000;
>>> #X text 186 169 go to 100 0 ms latter \, in 100 000ms;
>>> #X text 126 194 master time for everything (in ms since beggining of
>>> files);
>>> #X obj 215 236 *~ 44.1;
>>> #X text 280 237 position in the audio file;
>>> #X obj 79 314 snapshot~;
>>> #X obj 100 288 metro 1;
>>> #X obj 100 265 loadbang;
>>> #X text 170 289 1ms precision for video is ok;
>>> #X obj 79 340 / 40;
>>> #X text 125 343 time of each frame;
>>> #X obj 79 363 i;
>>> #X obj 79 384 change;
>>> #X text 146 386 frame number;
>>> #X floatatom 92 409 5 0 0 0 - - -;
>>> #X connect 0 0 13 0;
>>> #X connect 0 0 15 0;
>>> #X connect 1 0 3 0;
>>> #X connect 3 0 5 0;
>>> #X connect 5 0 7 0;
>>> #X connect 7 0 8 0;
>>> #X connect 7 1 9 0;
>>> #X connect 8 0 10 0;
>>> #X connect 9 0 8 1;
>>> #X connect 10 0 0 0;
>>> #X connect 15 0 19 0;
>>> #X connect 16 0 15 0;
>>> #X connect 17 0 16 0;
>>> #X connect 19 0 21 0;
>>> #X connect 21 0 22 0;
>>> #X connect 22 0 24 0;
>> ---------------------------------------------------------------------
>> ------- Mistrust authority - promote decentralization. - the
>> hacker ethic
>> ---------------------------------------------------------------------
>> ---
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