Hardsubbed subs in avi as a stream

[esby]

I was wondering if it could be possible to make hardsubbed subs
in a separate stream in an avi.

Of course this will not be a conventionnal avi, but this will
provide some advantages of the softsubs like:
-toggling untoggling the subs view.
-multisubs language
Without the inconvenient:
-subs are hardcoded, so nobody can easily steal them & edit them.

But at a price:
I've tested quicly encoding a video with an ssa script.
I used divx sbc, one pass with an ecf inserting kf at each subs start & subs end.
the results are here:
4min28 of subs = 2mb of avi.
on a later test i ve got 24min of subs for 9,3mb.
Of course, the results will vary according to the number of line
of the subs. But i think it's a good approximation.

Anyone here that feels the guts to try to implement it?
Or who have useful suggestions ;) or critics?

The first clip i produced can be found here:
http:\\www.chez.com\esbyphp\test.avi
(c/p it in a blank ie or browser to get it)

esby

[NoWoL]

You may want to look at OGM (http://www.doom9.org/ogg.htm)

[esby]

Well i was knowing ogm before doing this post.
And actually the structure of ogm is quite different of what i want to do,
since the subs are just put in a text stream.

I won't talk of the probably but limited synchro allowed by this system,
but just of the possibity of script theft with ogm subs.
Since subs are just plain text in the avi and you can rip them, edit etc.
You can consider these problems as minor, but this is
one of the reason that makes most of the fansub groups using hardsubs.

esby

PS1: Of course, with what i'm suggesting you can still do ocr on the subs,
like for a dvd but this is not an easy process, requires work and takes time to do it.
PS2: By the way my talking was not limited to avi, but any format that could contain several streams.
PS3: I'm thinking it's possible to reduce the size of the image subs,
by using more appropriate compression algorithm than in my test (using divx).

[Belgabor]

Originally posted by esby
PS1: Of course, with what i'm suggesting you can still do ocr on the subs,
like for a dvd but this is not an easy process, requires work and takes time to do it.

The few times I tried it it was a very easy process, didnt require much work and didn't take too much time (ok, I admit it took more time than demuxing a textual sub stream would ;))

Originally posted by esby
PS3: I'm thinking it's possible to reduce the size of the image subs,
by using more appropriate compression algorithm than in my test (using divx).
divx (and all lossy codecs) are completely unfit to compress such data. To overlay the subs you would have to do some kind of colorkeying (define one color as transparent), which is simply impossible with lossy codecs.
I can only see this work if you use either a lossless codec (e.g. huffyuv or the coming huffyv12) or write/use a special codec able to cope with an alpha channel (where only that would have to be compressed losslessly).

You're idea is a pretty good compromise for fansub groups, so don't take what I said as a big 'NO', just some points to be considered.

Cheers

[ChristianHJW]

Encrypted subs and picture subs are a very big subject on the upcoming new subtitles standard USF (http://usf.corecodec.org), developed by the Core Mediaplayer Team around BlackSun and targeted to be used in matroska container.

Current specs will only include XML, but USF will have a PNG and even a BMP profile for easy hardware support, with very powerful timing features ... ask mf on the irc.freenode.net #xvid channel and Pamel on #matroska , or [Toff] ( main developer ) on irc.corecodec.com #coreplayer and #usf , or read more on Corecodec Forum (http://www.corecodec.com/modules.php?op=modload&name=phpBB2&file=index) .

EDIT :

LOL :p .. Blacksun told me the USF Homepage is up, but i guess i should have checked it before linking to it :D ... go here instead : http://corecodec.org/projects/usf, but pls. be aware there is not much to be found yet ...

[esby]

go here instead : http://corecodec.org/projects/usf, but pls. be aware there is not much to be found yet ...
Indeed :D


But to be serious, I've got some thinking on the subject.
Encrypted subs are not really a solution unless you go
for an all encrypted & secured environment...
I dont think we need a Paladium system... like Msoft is suggesting...
Because, once you are able to play the subs alone, rippîng them is only a matter of time.

The same goes for what i was suggesting:
-Subs are separate from video, they can be extracted and added
to another video source (eek... that could be a big problem with
fansub ethic, since anybody could do a bootleg with a 'fansub script').
Of course this is an ethical question, once you owns the support, i think the fairuse rights allow this.
-For the same reason, it could be possible to reencode the subs
with a specifical tool, allowing editing, crap, etc.

So i'm more & more thinking that this idea was maybe not bad, but surely not very good actually.

esby
'All hails to Rand Al Thor, King of the World' (WOT 10 out for those who dont understood :D )

[ChristianHJW]

Latest USF specs are to be found here : http://christophe.paris.free.fr/usf/USF_V100-20021204.txt

EDIT : link fixed

[esby]

The links seems evil or not working properly here

esby

anyway thanks for the info