[Fwd: Invitation to discuss about USF in MKV]

Sorry, i forgot. In case somebody is still reading here, the meeting is=20
about to start in about 1 hour ....

Christian

-------- Original-Nachricht --------
Betreff: 	Invitation to discuss about USF in MKV
Datum: 	Fri, 20 May 2005 14:53:43 +0200
Von: 	Christian HJ Wiesner <[email protected]>
Antwort an: 	[email protected]
An: 	General talk about Matroska and other products=20
<[email protected]>, unmei <[email protected]>,=20
[email protected], [email protected], Liisachan=20
<[email protected]>, Discussion about the current and future=20
development of Matroska <[email protected]>




Hi,

we decided to try to hold a brainstorming meeting to define how to store=20
USF in MKV in the best possible way, the IRC meeting is taking place=20
tomorrow on irc.corecodec.com #matroska-dev at saturday 21st May, 5 PM .

Requested Participants :

Mosu
Alexnoe
Unmei
Kaiousama
Haali

but everybody else is gladly invited to join and contribute. If any of=20
the people listed above cant join then, please come up with an=20
alternative date/time. To get an idea about what we will have to=20
discuss, read here :



=09

	ChrisHJW_ 	lo MosuAtWork

	ChrisHJW_ 	long time no see

=09
=09

	ChrisHJW_ 	unmei , MosuAtWork :=20
http://corecodec.com/modules.php?op=3Dmodload&name=3DPNphpBB2&file=3Dview=
topic&t=3D1259&start=3D15=20
<http://corecodec.com/modules.php?op=3Dmodload&name=3DPNphpBB2&file=3Dvie=
wtopic&t=3D1259&start=3D15>=20
<----- kaiousama knows how to make girls happy :D

	ChrisHJW_ 	Italians :)


=09

	ChrisHJW_ 	lol

	ChrisHJW_ 	MosuAtWork : tell me when you are ready and have the time=20
for a brainstorming with kaiousama and unmei about how to mux USF into=20
MKV in best way, i will gladly try to organize an IRC meeting then

	ChrisHJW_ 	alexnoe said its not as easy as muxing SSA if we want to do=20
it right

	ChrisHJW_ 	as USF will allow colour palette changes in a single stream

	ChrisHJW_ 	i understand that if we take the SSA route, we needed a=20
codec state element, as colour palette is defined in the track header ??

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	this weekend should be=20
fine, but not sunday evening, i'll be watching the sith ;)

	alexnoe <irc://127.0.0.1/alexnoe,isnick> 	:)

	ChrisHJW_ 	MosuAtWork : great :)

	robUx4 <irc://127.0.0.1/robux4,isnick> 	is going to watch it tonight

	ChrisHJW_ 	I'll send an email to -general , cc. to kaiousama and unmei,=20
to meet saturday afternnon ?

	ChrisHJW_ 	robUx4 : you wonna join ?

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	well CodecState has=20
been added for such changes mid-stream. we just have to revive it

	robUx4 <irc://127.0.0.1/robux4,isnick> 	nop

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	and start using it

	robUx4 <irc://127.0.0.1/robux4,isnick> 	I'm leaving to LA on tuesday so=20
I'm quite busy here

	alexnoe <irc://127.0.0.1/alexnoe,isnick> 	codec state is b0rked

<irc://127.0.0.1/alexnoe,isnick>
=09

	ChrisHJW_ 	MosuAtWork : i agree, a spec conformant way to do this would=20
be to use codec state

	ChrisHJW_ 	robUx4 : k

	robUx4 <irc://127.0.0.1/robux4,isnick> 	codec state is meant for the=20
container to know about things needed for seeking

	robUx4 <irc://127.0.0.1/robux4,isnick> 	but from what I understood it=20
may not be needed for USF

	ChrisHJW_ 	robUx4 : right, for colour palette only the container=20
wouldnt need to know and we could define this in the USF stream, but=20
what about allowing resolution changes also ?

	robUx4 <irc://127.0.0.1/robux4,isnick> 	matroska does not support=20
resolution change

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	it's not resolution chan=
ge

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	it's out-of-band=20
configuration change

	ChrisHJW_ 	robUx4 : in any case, if we leave colour palette in the USF=20
stream, should we also add it to the track header then ( the 'initial'=20
palette ), or leave it away completely ?

	robUx4 <irc://127.0.0.1/robux4,isnick> 	kaiousama and unmei can tell=20
better

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	robUx4: at the moment=20
the description of codecstate seems to be just fine

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	for this purpose

	ChrisHJW_ 	MosuAtWork : can we handle codec state on DirectShow ?

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	no clue

	robUx4 <irc://127.0.0.1/robux4,isnick> 	ok

	ChrisHJW_ 	maybe Haali could tell

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	Haali will have to=20
comment on that

	ChrisHJW_ 	alexnoe : why is codec state b0rked ?


=09

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	Haali will have to=20
comment on that

	ChrisHJW_ 	alexnoe : why is codec state b0rked ?

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	but the container=20
should be more or less indedependant of the OS APIs ;)

	robUx4 <irc://127.0.0.1/robux4,isnick> 	so we need to handle the codec=20
state in the cue as originally planned

	alexnoe <irc://127.0.0.1/alexnoe,isnick> 	ChrisHJW_ because it makes=20
remuxing b0rked

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	robUx4: it HAS to!=20
otherwise the decoder won't have the current information after seeking

	robUx4 <irc://127.0.0.1/robux4,isnick> 	alexnoe, nop

	MosuAtWork <irc://127.0.0.1/mosuatwork,isnick> 	alexnoe: why should it?

	robUx4 <irc://127.0.0.1/robux4,isnick> 	yup, that's my idea

	ChrisHJW_ 	alexnoe : USF cant be used in any other container than MKV=20
yet, so why should we care ?

	alexnoe <irc://127.0.0.1/alexnoe,isnick> 	it would allow to join=20
incompatible streams into one segment, making it necessary to create new=20
codecstates...

	robUx4 <irc://127.0.0.1/robux4,isnick> 	alexnoe, it's not much=20
different than block addition

	alexnoe <irc://127.0.0.1/alexnoe,isnick> 	:(

	robUx4 <irc://127.0.0.1/robux4,isnick> 	only the meaning is different

	robUx4 <irc://127.0.0.1/robux4,isnick> 	and the occurence

	ChrisHJW_ 	Hmmm .... somehow i wonder if using codec state would mean=20
we have reinitialize the stream on DShow ?

	ChrisHJW_ 	codec state is read and used by the parser, right ?

	ChrisHJW_ 	only alternative i see is to create another API sitting on=20
top of DShow, with USF decoder and MKV parser communicating directly

	ChrisHJW_ 	like what Toff did with Gabest's splitter, to read out track=20
header

	robUx4 <irc://127.0.0.1/robux4,isnick> 	you pass the codec state each=20
time with the codec data

	robUx4 <irc://127.0.0.1/robux4,isnick> 	or only when needed, as an=20
optional field in a structure (maybe EBML like)


http://usf.corecodec.org