recreate divx compression error

i tried that once. even asked that same question in doom9 and got some scary
looks.
you can try to do a 2pass encoding and before the second pass fiddle with
the numbers in the first pass generated txt file. thats kinda funky but not
that predictable.
ye, that effect is great and i love it when it happens.
when i think about it it can be done in jitter with cv.jit pixel flow
tracker and some op.

On Jan 21, 2008 5:13 PM, freeka wrote:

>
> Hi there,
> i'm trying to recreate that compression error that we can see on divx
> especially with VLC with you are seeking or when you re doing a preview a
> movie you are downloading before the download is done..
> (the image freeze or partialy freeze and it looks like the animation is
> still running on the back changing the actuall image .. kind of morphing
> stuff..)
>
> if somebody have an idea of where to start...
>
> thanks a lot
>
> freeka
>

hey thanks for your reply!
cv.jit pixel flow tracker ?? what do you mean??

you re talking about the cv.jit.tracker????

The issue here is that jitter gives you the decoded pixels, whereas
the 'image processing' happens during the decoding stage within the
divx codec itself, which is somewhat out of jitters realm, so you
would have to do 'glitch alike', and reverse engineer the look with
expensive pixel operations.

Ive often fantasized about a set of jitter objects that let you:

1) read raw data off disk and pass a matrix through somehow
2) munge its binary data with jit.op whatevers before:
3) passing this raw encoded binary matrix to various different
jit.decode.jpeg, jit.decode.png etc software decoders, or perhaps
automatic objects that wrap around installed qt components

thus you might have just a new jit.encode and jit.decode, which would
perhaps take in a binary stream, and output a 4 char matrix of size
determined by the binary stream, and with jit.encode you would have a
4 char matrix whatever dim producing a jit.encoded binary stream output.

You could then do things super easily like finding harmonics in video
encoders by feeding back the output of the jpeg decoder to the jpeg
encoder with a jit.xfade for feedback... live!

fuck yes. Would be amazing.

On Jan 21, 2008, at 10:40 AM, yair reshef wrote:

> i tried that once. even asked that same question in doom9 and got
> some scary looks.
> you can try to do a 2pass encoding and before the second pass fiddle
> with the numbers in the first pass generated txt file. thats kinda
> funky but not that predictable.
> ye, that effect is great and i love it when it happens.
> when i think about it it can be done in jitter with cv.jit pixel
> flow tracker and some op.
>
> On Jan 21, 2008 5:13 PM, freeka < freeka.freeka@gmail.com> wrote:
>
> Hi there,
> i'm trying to recreate that compression error that we can see on
> divx especially with VLC with you are seeking or when you re doing a
> preview a movie you are downloading before the download is done..
> (the image freeze or partialy freeze and it looks like the animation
> is still running on the back changing the actuall image .. kind of
> morphing stuff..)
>
> if somebody have an idea of where to start...
>
> thanks a lot
>
> freeka
>

word!
but until we get that we can lick our bones :D

hum i had a look on the jitter recipe book
40.scenewarp... which is actually a good start i think do you think
i dunno about the jit.gl stuff.. but do you think its possible to put a second video on the back to substitute the white screen that appear when we start the deformation? Puting the same video but without the deformation will be great!

The Debris recipe does a passable job of collecting bits of pixel trash
in real-time, if that is what you are looking for. Trying to mimic an
aesthetic or effect is a great learning exercise, and you often come up
with great ideas in the process, even if it doesn't end up looking just
right. Let us know what you come up with

Andrew B.

Here's my clumsy tryout of 'divx' effect recreation, I think it's the
same idea Yair mentioned - cv.jit.hsflow+jit.repos.
It's quite heavy&dirty since this is one of those train patches('make
it clean' vs 'end up in Dordrecht').

best,
nesa

i recently experienced *amazing* compression errors by simply
exporting a video via [jit.qt.record] using the "sorenson" codec.

it actually outperforms divx in terms of glitch aesthetic.

./eth

>Hi there,
i'm trying to recreate that compression error that we can see on divx
especially with VLC

freeka skrev:
> Hi there,
> i'm trying to recreate that compression error that we can see on divx especially with VLC with you are seeking or when you re doing a preview a movie you are downloading before the download is done..
> (the image freeze or partialy freeze and it looks like the animation is still running on the back changing the actuall image .. kind of morphing stuff..)
>
haha, I have been sooooo wondering about that thing since getting into
Jitter. As an aside, I wonder if people are documenting those kinds of
errors online, or even deliberately creating them?

The weirdest error I ever saw was in a movie where the main character
walked around with a fragment of old video plastered across his face,
wrapped to conform to his face - FREAKY!