Maybe many of the readers have the same problem I have: disk space. As
far as I understand the mpeg standard it should be possible to generate
mpeg output directly from pov, without having to store every one and
single frame of an animaton on disk before compressing.

Here is the idea:

- Tell povray the sequence scheme of I/P/B frames.

- Write single frames into files (e.g. ppm)

- Every time an I-frame is generated, compress the last I-to-I sequence,
append it to the mpeg file, generate a valid mpeg header and delete the
uncompressed images.


Of course, one could do this without modifying Povray:

- Generate a Povray INI file depending on the I/P/B scheme.

- Shell out from the Povray animation loop after every I-frame has
finished rendering and call a program that does the same as descibed
above.


That way you would only have to store a few uncompressed images (e.g. 10
if you use IBBPBBPBBI). I am not volunteering for writing such a program
or asking anyone to do so. I would just like to get some comments, if
you think this would work and/or be a good idea to do.

/PETER/

-- 
Peter Santo (PUMP development)
HP: http://www.exaweb.de
> Ever heard of .cshrc?
That's a city in Bosnia.  Right?

Post a reply to this message

Peter Santo wrote:
> 
> Maybe many of the readers have the same problem I have: disk space. As
> far as I understand the mpeg standard it should be possible to generate
> mpeg output directly from pov, without having to store every one and
> single frame of an animaton on disk before compressing.
> 
> Here is the idea:
> 
> - Tell povray the sequence scheme of I/P/B frames.
> 
> - Write single frames into files (e.g. ppm)
> 
> - Every time an I-frame is generated, compress the last I-to-I sequence,
> append it to the mpeg file, generate a valid mpeg header and delete the
> uncompressed images.
> 
> Of course, one could do this without modifying Povray:
> 
> - Generate a Povray INI file depending on the I/P/B scheme.
> 
> - Shell out from the Povray animation loop after every I-frame has
> finished rendering and call a program that does the same as descibed
> above.
> 
> That way you would only have to store a few uncompressed images (e.g. 10
> if you use IBBPBBPBBI). I am not volunteering for writing such a program
> or asking anyone to do so. I would just like to get some comments, if
> you think this would work and/or be a good idea to do.
> 
> /PETER/
> 
> --
> Peter Santo (PUMP development)
> HP: http://www.exaweb.de
> > Ever heard of .cshrc?
> That's a city in Bosnia.  Right?

I can see the advantage. On the other hand: you trash your raw material on the
fly, so what if you find you need that in the end after all? I'm also suffering
from a chronical shortage of diskspace, but I don't think I would go this far.
As it is, i even keep the raw pov-output in a zip even after an animation is
finished. Of course I keep those zips on a cd, not on my harddisk.
My point is: mpeg-compression destroys part of the image-quality so if you need
part of the frames for another purpose, or want to change them, you'll have to
rerender them (or even the whole animation).

Regards,

Remco

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Remco de Korte <rem### [at] xs4allnl> wrote:
: My point is: mpeg-compression destroys part of the image-quality so if you need
: part of the frames for another purpose, or want to change them, you'll have to
: rerender them (or even the whole animation).

  Or if you chose the wrong quality and want to make the mpg with a better
quality.

  Since I stopped using pirate software, I have never run out of disk space.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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>As far as I understand the mpeg standard it should be 
>possible to generate mpeg output directly from pov

>- Generate a Povray INI file depending on the I/P/B scheme

POV already has ini files for DTA in the render folder. I've
never played with them before ,so I'm probably wrong, but it
looks like they do what your looking for(DTA doesn't do mpeg
though).

Is this right or am I confused?

-- 
Phil
...coffee?...yes please! extra sugar,extra cream...Thank you.

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Nieminen Juha wrote:
> 
>   Since I stopped using pirate software, I have never run out of disk space.
> 

I don't see the connection. My disk space is crammed with POV-stuff. 8)

Remco

Post a reply to this message

Remco de Korte <rem### [at] xs4allnl> wrote:
: I don't see the connection. My disk space is crammed with POV-stuff. 8)

  You have been raytracing for too long when your 6.5 Gigabytes hard disk
is always full of pov-stuff...

  I'm not THAT hardcore povrayer! :)

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

Post a reply to this message

Nieminen Juha wrote:
> 
> Remco de Korte <rem### [at] xs4allnl> wrote:
> : I don't see the connection. My disk space is crammed with POV-stuff. 8)
> 
>   You have been raytracing for too long when your 6.5 Gigabytes hard disk
> is always full of pov-stuff...
> 
>   I'm not THAT hardcore povrayer! :)

I am !!!

 One of the drawbacks of being the linkmaster is that I visit so many
Pov related sites and see so many Pov related goodies that I just cannot
resist downloading them. Then there is all of the great stuff posted here
that I like to play with. Add to all of that the fact that I am an avid
user of the program and have a prolific amount of POV-Ray output is has
put a tremendous burden on my hard drive resources. I'm an not complaining
mind you but that's the facts as I know them.

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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Peter Santo wrote:
> 
> Maybe many of the readers have the same problem I have: disk space. As
> far as I understand the mpeg standard it should be possible to generate
> mpeg output directly from pov, without having to store every one and
> single frame of an animaton on disk before compressing.

  I brought this up a few months ago when I found out that the Mac
version of POV-Ray had built in animation support. It seems that
the way the the apple quick time support is so deeply associated
with the Macintosh platform it was an easy task to write into the
Mac POV-Ray interface.
  When I made the suggestion that something similar be added to the
Windows version of the program it fell mostly upon deaf ears and
no one spoke up in favor of the idea except Thorsten who mentioned
how easy it was with the Mac version.

  The only problem I can see if you tried to integrate this into
POV-Ray across the board you might have a cross platform compatibility
issue to resolve. Which animation format do you adopt ?  MpegI and
MpegII, AVI, MOV, and all of the other animation formats that are
currently available. Which video codecs do you support ? What happens
like others mention if you choose the wrong frame rate and all of
your render time goes for nothing ?

It seems there are a lot of what if's to work out before it could
become a reality though I personaly am in favor of some form of
built in animation support.

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

Ken wrote:

>   I brought this up a few months ago when I found out that the Mac
> version of POV-Ray had built in animation support. It seems that
> the way the the apple quick time support is so deeply associated
> with the Macintosh platform it was an easy task to write into the
> Mac POV-Ray interface.

To see the thread I started on this subject see:

      Subject: Mpeg support
         Date: Fri, 23 Jul 1999 19:13:35 -0700
         From: Ken <tyl### [at] pacbellnet>
 Organization: Tyler Engineering Services
   Newsgroups: povray.unofficial.patches

-- 
Ken Tyler -  1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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Not exactly like the output to Jpg thing for sure, saving space does have
it's advantages when making animations but I wonder if the feasibilty is
relevant enough considering multi-gigabyte hard disks these days.
Although it was only a year ago I was finding myself struggling with little
room to manuever with a total of 8 GB and 150 MB free (my fault, I was
doubling and triplicating files on other partitions and second HD in case of
potential data loss of course, no backup hardware).
I don't see the idea as being a bad one, just not real important unless the
animation were to be very large, say 1000 frames at 640x480 res. making
somewhere around 1400 MB I think.
Something to consider would be the added rendering time due to the ever
growing Mpg file being appended to with each access causing a delay (always
increasing delay at that possibly).

Bob

Peter Santo <spa### [at] exawebde> wrote in message
news:38141F91.C71A9963@exaweb.de...
> Maybe many of the readers have the same problem I have: disk space. As
> far as I understand the mpeg standard it should be possible to generate
> mpeg output directly from pov, without having to store every one and
> single frame of an animaton on disk before compressing.
>
> Here is the idea:
>
> - Tell povray the sequence scheme of I/P/B frames.
>
> - Write single frames into files (e.g. ppm)
>
> - Every time an I-frame is generated, compress the last I-to-I sequence,
> append it to the mpeg file, generate a valid mpeg header and delete the
> uncompressed images.
>
>
> Of course, one could do this without modifying Povray:
>
> - Generate a Povray INI file depending on the I/P/B scheme.
>
> - Shell out from the Povray animation loop after every I-frame has
> finished rendering and call a program that does the same as descibed
> above.
>
>
> That way you would only have to store a few uncompressed images (e.g. 10
> if you use IBBPBBPBBI). I am not volunteering for writing such a program
> or asking anyone to do so. I would just like to get some comments, if
> you think this would work and/or be a good idea to do.
>
> /PETER/
>
> --
> Peter Santo (PUMP development)
> HP: http://www.exaweb.de
> > Ever heard of .cshrc?
> That's a city in Bosnia.  Right?

Post a reply to this message