[GEM-dev] problem to play movies at normal speed with GEM objects

Matteo Sisti Sette matteosistisette at gmail.com
Mon Aug 10 13:23:14 CEST 2009


Hi,

Maybe this won't help at all (I only use gem on windows), but just in 
case it does:

Does it work as expected if you disable the "auto" mode and pass the 
frame number to the right outlet?

If the answer is yes, than a workaround would be:

[gemhead]
|
[t b]
|
[any implementation of a counter]
|
(to the right outlet of pix_movie)

I am not good at ASCII art, but if you want a frame rate different than 
1:1 (meaning one movie frame per gem frame), you can implement the 
"counter" with necessary calculations and roundings to get the needed 
frame number.

Obviously, if the answer to the initial question is "NO" and/or if the 
framerate unstability you describe is not only in the playing of the 
pix_movie but also in the framerate of the gemwin, then all this won't 
be of any help.

I always use this technique (well it's too simple to call it a 
"technique") and never the "auto" mode even if I have never experienced 
problems with auto: the fact is that this also lets you easily control 
the playing speed.
But I have to say that I have only used codecs that compress each frame 
separately (namely DV-PAL in my case); with any codec that uses previous 
frames to decode a given frame, this method may give, I guess, problems 
of performance.

Bye
m.

Jack escribió:
> The behavior of [pix_film] is not the same on Macosx and on Ubuntu.
> What is described in the help file seems to work only for Linux OS.
> I am a newbie on Ubuntu, that's why i am a little surprised to have a
> different behavior between the two OS. And, if i'm right, the movie
> doesn't play each frame on MacOSX and it play in loop when you click on
> [auto 1(.
> However, you are right on Linux ;) I have tested and see that the frame
> started at 25 and go down to 7 !
> So my question is : how to have a approximate 'constant' frame rate ?
> (to send a bang to [gemhead] with a [metro] changes not at all the
> problem).
> Thanx.
> ++
> 
> Jack
> 
> 
> Le lundi 10 août 2009 à 09:47 +0200, Max a écrit :
>> In the helpfile to pix_film is written:
>> -----
>> use the "auto" message, to automatically proceed to the next frame  
>> each rendering cycle.
>> -----
>> that means that the movie is never played back according to a header  
>> information about the real fps, but according to the frame rate the  
>> gemwin is running at.
>>
>> so i the behavior you are describing is expected. no movie will run  
>> just like in VLC other than purely by coincidence.
>> please correct me if i'm wrong.
>>
>> max
>>
>> Am 10.08.2009 um 00:48 schrieb Jack:
>>
>>> Hello,
>>>
>>> I encounter a problem to play movies at normal speed with [pix_film]  
>>> and
>>> [pix_movie]. I tried with a .mov (photo JPEG) and a .avi movies.  
>>> During
>>> the movie play, sometimes the movies go fast, sometimes they go  
>>> slowly.
>>> I use the message [auto 1( to start the movies or the second inlet  
>>> with
>>> a counter but still have the problem !?
>>> So i think i have something wrong with Pd (or Ubuntu) and not GEM.
>>> For information, all is ok to play these movies with VLC.
>>> Can you help me to configure something wrong on my computer ? :)  
>>> Thanx a
>>> lot !
>>>
>>> Here my configuration :
>>> Pd version 0.41.4-extended
>>> GEM: ver: 0.92.CVS
>>> GEM: compiled: Jun 15 2009
>>> Ubuntu 9.04
>>> GPU : Nvidia 9700M GTS
>>>
>>> ++
>>>
>>> Jack
>>>
>>>
>>>
>>> _______________________________________________
>>> GEM-dev mailing list
>>> GEM-dev at iem.at
>>> http://lists.puredata.info/listinfo/gem-dev
> 
> 
> _______________________________________________
> GEM-dev mailing list
> GEM-dev at iem.at
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-- 
Matteo Sisti Sette
matteosistisette at gmail.com
http://www.matteosistisette.com




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