IRC log of mediafrag on 2009-04-16

Timestamps are in UTC.

07:56:20 [RRSAgent]

RRSAgent has joined #mediafrag

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logging to http://www.w3.org/2009/04/16-mediafrag-irc

07:56:22 [trackbot]

RRSAgent, make logs public

07:56:22 [Zakim]

Zakim has joined #mediafrag

07:56:24 [trackbot]

Zakim, this will be IA_MFWG

07:56:24 [Zakim]

ok, trackbot; I see IA_MFWG()3:00AM scheduled to start 56 minutes ago

07:56:25 [trackbot]

Meeting: Media Fragments Working Group Teleconference

07:56:25 [trackbot]

Date: 16 April 2009

07:56:31 [jackjansen]

zakim, code?

07:56:31 [Zakim]

the conference code is 3724 (tel:+1.617.761.6200 tel:+33.4.89.06.34.99 tel:+44.117.370.6152), jackjansen

07:57:58 [Zakim]

IA_MFWG()3:00AM has now started

07:58:06 [Zakim]

+ +34.93.401.aaaa

07:59:47 [Zakim]

- +34.93.401.aaaa

07:59:49 [Zakim]

IA_MFWG()3:00AM has ended

07:59:49 [Zakim]

Attendees were +34.93.401.aaaa

08:00:21 [jackjansen]

to fill you in: we can physically call, but we may run into trouble with uni burocracy here.

08:00:28 [jackjansen]

Will try something else.

08:01:20 [raphael]

Silvia, you can use the phone number and code above

08:01:26 [raphael]

... but you will be alone on the phone

08:01:31 [raphael]

we will phone through skype

08:01:42 [raphael]

but get the mic and speaker from a laptop

08:02:04 [raphael]

interim solution till lunch, when we hope to talk to MIT guys that can call us

08:02:38 [jackjansen]

yves: is the thing that needs to be done at MIT a one-time action? i.e. if they do the magic later today, will we be able

08:02:45 [jackjansen]

... to use the speakerphone tomorrow morning?

08:02:59 [Yves]

jack; I will ask what is possible

08:09:46 [jackjansen]

zakim, code?

08:09:46 [Zakim]

the conference code is 3724 (tel:+1.617.761.6200 tel:+33.4.89.06.34.99 tel:+44.117.370.6152), jackjansen

08:10:17 [Zakim]

IA_MFWG()3:00AM has now started

08:10:23 [Zakim]

+??P0

08:10:33 [mhausenblas]

we R in!

08:10:37 [jackjansen]

zakim, ??P0 is all of us in the meeting room.

08:10:37 [Zakim]

I don't understand '??P0 is all of us in the meeting room', jackjansen

08:10:39 [raphael]

zakim, ??P0 is Barcelona_Room

08:10:39 [Zakim]

+Barcelona_Room; got it

08:10:44 [jackjansen]

zakim, get a life!

08:10:44 [Zakim]

I don't understand 'get a life!', jackjansen

08:10:55 [jackjansen]

zakim, you failed the turing test.

08:10:55 [Zakim]

I don't understand 'you failed the turing test', jackjansen

08:11:10 [Zakim]

+ +61.2.801.2.aaaa

08:11:11 [mhausenblas]

Zakim, how is Ralph doing?

08:11:11 [Zakim]

I don't understand your question, mhausenblas.

08:12:59 [raphael]

Agenda: http://www.w3.org/2008/WebVideo/Fragments/wiki/ThirdF2FAgenda

08:13:06 [raphael]

RRSAgent, draft minutes

08:13:06 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

08:13:42 [raphael]

Chair: Erik, Present

08:14:13 [raphael]

s/Present/Raphael

08:15:12 [raphael]

Present: conrad, michael, jack, erik, davy, frank (canon observer), raphael, dave singer, silvia (phone), yves (phone)

08:15:20 [raphael]

Scribe: raphael

08:15:27 [raphael]

Scribenick: raphael

08:15:32 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

08:16:39 [raphael]

Topic: 1. Administrative

08:16:58 [raphael]

Agenda is at: http://www.w3.org/2008/WebVideo/Fragments/wiki/ThirdF2FAgenda

08:17:15 [raphael]

Chairs would like to ammend the agenda, and start with a proposal to publish our FPWD

08:17:43 [raphael]

... needs the group approval

08:20:57 [raphael]

Silvia: I think I have corrected all the markup errors

08:21:10 [silvia]

+1

08:21:36 [raphael]

PROPOSAL: publish the document at http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-reqs/ as a first public working draft

08:21:39 [raphael]

Any objections ?

08:21:55 [silvia]

no objections - publication approved

08:22:01 [mhausenblas]

no objections

08:22:02 [conrad]

no objections

08:22:04 [erik]

no objections

08:22:04 [raphael]

no objections

08:22:07 [davy]

no objections

08:22:13 [dsinger]

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08:22:18 [jackjansen]

no objections

08:22:34 [raphael]

Please, dave, so you have any objections to publish http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-reqs/ as a FPWD?

08:22:41 [FD]

FD has joined #mediafrag

08:23:05 [dsinger]

no, we can publish and continue to revise, that's fine

08:23:11 [dsinger]

I mean, no objections

08:23:25 [Yves]

same :)

08:23:38 [raphael]

RESOLUTION: The Media Fragments agree to publish its FPWD

08:23:47 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

08:24:12 [raphael]

Topic: 2. Yves/Silvia/Conrad: Specification discussion

08:24:13 [raphael]

* discuss the story of the single-step vs dual-step partial GET (aka 2-ways, 4-ways handshake);

08:24:13 [raphael]

o discuss the Silvia's proposal: new headers Accept-TimeURI, Accept-SpaceURI, Accept-TrackURI and Accept-NameURI;

08:24:13 [raphael]

o discuss Yves's proposal: a GET of the media header (so a few bytes, depending on how much is enough), and the server answers with that + one or more Link: headers linking to different mappings (time to bytes is an example) or at least a resolver URI, linking to the sub-resource, to parent etc...

08:24:14 [raphael]

o discuss the pro/cons of each solution

08:24:16 [raphael]

* check with the evolving link header draft;

08:24:19 [raphael]

* Yves: present the clarifications of HTTPBis.

08:24:20 [dsinger]

I have detailed comments, I'll try to get them to the group over these two days

08:25:57 [raphael]

zakim, who is here ?

08:25:57 [Zakim]

On the phone I see Barcelona_Room, +61.2.801.2.aaaa

08:25:58 [Zakim]

On IRC I see FD, dsinger, Zakim, RRSAgent, conrad, raphael, mhausenblas, davy, jackjansen, erik, silvia, Yves, trackbot

08:26:06 [raphael]

Yves, can you call to hear us ?

08:26:08 [raphael]

we are on the phone

08:26:21 [raphael]

zakim, aaaa is Silvia

08:26:21 [Zakim]

+Silvia; got it

08:26:59 [Zakim]

+Yves

08:27:21 [silvia]

blog: http://blog.gingertech.net/2008/11/10/media-fragment-uri-addressing/

08:27:50 [silvia]

read the last comment - FYI

08:29:30 [raphael]

Yves: we need to clarify, in the dual step partial GET, how the resolution between time ranges and bytes work

08:29:45 [raphael]

Silvia: the WD now explains how it works

08:30:51 [raphael]

Yves is reading http://www.w3.org/2008/WebVideo/Fragments/WD-media-fragments-reqs/#dual-step

08:31:34 [raphael]

Yves: there is something wrong in the first reply, you have a Content-Range but a 200 OK response

08:33:29 [raphael]

... if there is a Content-Range header, it should be a 206 response

08:35:36 [raphael]

Michael, I think a 100 response means the server sends something, and then something else but no interaction from the UA in the middle

08:35:45 [raphael]

... while in our case the UA remakes its request

08:36:16 [mhausenblas]

Michael: I agree with silvia re caching header but not caching the entire message for scalability reasons

08:37:06 [raphael]

Yves: first concern should be on user experience rather than caches/proxies efficiency .... they would anyway tune the right way the softwares

08:37:21 [mhausenblas]

not sure, raphael re 100 response is totally out of question

08:37:49 [mhausenblas]

Yves? what's your opinion on this?

08:38:51 [raphael]

Silvia: for spatial fragments, there is no way we can cache things anyway

08:39:08 [raphael]

Yves: I'm not sure we should forbid transcoding

08:39:27 [raphael]

... I would ask for more people

08:39:29 [jackjansen]

q+ to note that caching temporal fragments is *much* more interesting that spatial fragments

08:41:19 [raphael]

Silvia: your problem seems to be that there is 2 requests

08:41:25 [raphael]

... TBL had the same feeling in Cannes

08:41:35 [jackjansen]

q-

08:42:18 [raphael]

... but the first request has no real data, so no delay

08:42:42 [conrad]

correction: but the first request retreives real data, so it is not unnecessary

08:43:15 [raphael]

Yves: I would approach some TAG members informally

08:43:59 [conrad]

so having two HTTP request/response cycles does not introduce noticeable overhead in retrieving large amounts of data

08:44:22 [conrad]

Yves: headers+keyframes are not fake data

08:44:37 [Yves]

they are, as they are not part of the resource representation

08:45:08 [conrad]

Yves, i respectfully disagree, they are a necessary part of the segment representation

08:45:26 [raphael]

ACTION: Yves to ask the TAG whether transcoding should be forbidden or not when we send a fragment of a resource

08:45:26 [trackbot]

Created ACTION-62 - Ask the TAG whether transcoding should be forbidden or not when we send a fragment of a resource [on Yves Lafon - due 2009-04-23].

08:45:28 [Yves]

of the segment, yes, but not the whole resource, which is addressed by the first get :)

08:45:55 [Yves]

plus there may be a mismatch of content between the first and second request

08:46:05 [raphael]

Jack: the current WD does not say which anwsers has headers data and which ones has just headers

08:46:47 [raphael]

Conrad: let me explain how things will work

08:47:31 [raphael]

... I tend to see that the dual step is just a fallback of the single step

08:47:58 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

08:49:14 [davy]

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08:49:30 [raphael]

Conrad's schema:

08:50:29 [Zakim]

-Barcelona_Room

08:50:46 [raphael]

Conrad: user request URL = http://www.example.com/video.ogg?t=10,20

08:50:53 [Zakim]

-Silvia

08:51:18 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

08:51:34 [erik]

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08:51:50 [jackjansen]

jackjansen has joined #mediafrag

08:51:56 [jackjansen]

We lost our network.

08:52:00 [jackjansen]

And our phone.

08:52:05 [jackjansen]

Time for coffee.

08:53:52 [Zakim]

-Yves

08:53:54 [Zakim]

IA_MFWG()3:00AM has ended

08:53:55 [Zakim]

Attendees were Barcelona_Room, +61.2.801.2.aaaa, Silvia, Yves

08:58:14 [raphael]

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08:59:34 [raphael]

Yves: in temporal URI for annodex, we only used ? for remote retrievals - # was done locally only in the client

08:59:51 [raphael]

trackbot, start teleco

08:59:51 [trackbot]

Sorry, raphael, I don't understand 'trackbot, start teleco'. Please refer to http://www.w3.org/2005/06/tracker/irc for help

08:59:54 [raphael]

trackbot, start telecon

08:59:56 [trackbot]

RRSAgent, make logs public

08:59:58 [trackbot]

Zakim, this will be IA_MFWG

08:59:58 [Zakim]

ok, trackbot; I see IA_MFWG()3:00AM scheduled to start 119 minutes ago

08:59:59 [trackbot]

Meeting: Media Fragments Working Group Teleconference

08:59:59 [trackbot]

Date: 16 April 2009

09:00:20 [raphael]

Yves with ? you have no problem, you just return the whole fragment with header as a response to the GET, no need to to anything extra

09:00:36 [raphael]

Yves: as ...?t=1,2 is different form ?t=2,3 and won't be cached as the same resource by caches anyway

09:00:48 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

09:01:45 [raphael]

Conrad: back to the explanation, I explain how temporalURI works

09:02:42 [foolip]

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09:03:38 [philipj]

hi all

09:04:34 [philipj]

I browsed through http://www.w3.org/2008/WebVideo/Fragments/wiki/ThirdF2FAgenda but couldn't figure out which parts were on teleconf

09:05:41 [philipj]

would be nice if the next F2F were in Stockholm, since I live not too far from there :)

09:05:43 [raphael]

this is the agenda for the 2 days, we are now on the first topic: Specification discussion

09:07:55 [mhausenblas]

Zakim, what's the code?

09:07:55 [Zakim]

the conference code is 3724 (tel:+1.617.761.6200 tel:+33.4.89.06.34.99 tel:+44.117.370.6152), mhausenblas

09:08:06 [Zakim]

IA_MFWG()3:00AM has now started

09:08:13 [Zakim]

+[IPcaller]

09:09:06 [raphael]

zakim, +[IPcaller] is Barcelona_Room

09:09:06 [Zakim]

sorry, raphael, I do not recognize a party named '+[IPcaller]'

09:09:22 [raphael]

zakim, +IPcaller is Barcelona_Room

09:09:22 [Zakim]

sorry, raphael, I do not recognize a party named '+IPcaller'

09:09:30 [raphael]

zakim, IPcaller is Barcelona_Room

09:09:30 [Zakim]

+Barcelona_Room; got it

09:09:55 [davy]

davy has joined #mediafrag

09:10:24 [Zakim]

-Barcelona_Room

09:10:24 [Zakim]

+Barcelona_Room

09:10:24 [Zakim]

+Yves

09:11:01 [mhausenblas]

Zakim, who is here?

09:11:01 [Zakim]

On the phone I see Barcelona_Room, Yves

09:11:02 [Zakim]

On IRC I see davy, philipj, raphael, jackjansen, erik, FD, dsinger, Zakim, RRSAgent, mhausenblas, silvia, Yves, trackbot

09:11:05 [raphael]

Conrad agree with Yves's point

09:11:11 [raphael]

Re: ? vs #

09:11:30 [raphael]

Conrad will continue his explanation of TemporalURI

09:12:27 [raphael]

Conrad: URL = http://www.example.com/video.ogv?t=10,20

09:12:36 [raphael]

... Client do a GET URL

09:12:52 [raphael]

... with a new header: Accept-Range-Refer: bytes

09:13:19 [raphael]

... Server: it udnerstands the range referal

09:13:28 [raphael]

... will answer a 200 OK

09:14:02 [raphael]

... with new headers: Range-Refer: this, 0-1000

09:14:04 [Yves]

http://www.example.com/video.ogv?t=10,20 is a plain URI, unrelated to http://www.example.com/video.ogv. Why not serving the content directly?

09:16:48 [raphael]

good question :-)

09:17:38 [raphael]

Conrad: ... Range-Refer: URL2, a-b

09:17:50 [raphael]

... Vary: Range-Refer and the body

09:18:07 [raphael]

Client: will make another GET URL-2 request with the range a-b

09:20:27 [raphael]

Jack: in the case the server does not understand the ?t=10,20 ... it will answer a 404

09:20:49 [Yves]

will answer with a 404... that depends on the server configuration

09:20:59 [raphael]

... while in the case the server does not understand the #t=10,20 the way we want, it will send the whole resource, better for the UA

09:21:15 [Yves]

in some cases the ? will be ignored and you will save in a cache 100+ times the full content (attached to different URIs)

09:22:16 [raphael]

Yves: this is a URI the server does not know about ... how can it be different from a 404 ?

09:22:54 [Yves]

raphael, try to access http://www.w3.org/ and http://www.w3.org/?foo=bar

09:23:06 [Yves]

that example work with lots of other servers ;)

09:23:39 [raphael]

well done :-)

09:24:15 [Yves]

so accessing http://media.exampe.com/bigvideo.mp4 http://media.exampe.com/bigvideo.mp4?t=1,2

09:24:22 [Yves]

will cache twice the big content

09:24:31 [philipj]

unrecognized query strings will almost certainly be ignored by most servers, not return 404

09:24:42 [Yves]

all because of a quite common server configuration issue

09:25:04 [Yves]

(as the right thing would be to return a 404)

09:25:10 [jackjansen]

ok. So people shouldn't issue ? temporal uris to non-capable servers.

09:25:29 [Yves]

jack, yes, basically you need to know in advance

09:26:04 [philipj]

sounds rather unreliable

09:26:12 [Yves]

yep

09:26:33 [philipj]

btw, is it worth saying things on IRC or do I need to join by phone? I happen to not have a phone nearby.

09:27:07 [Yves]

I still think that if you have http://media.example.com/media?t=1,10 should return the fragment with the header as a complete resource

09:27:25 [mhausenblas]

might also want to take http://www.w3.org/2001/tag/doc/whenToUseGet.html#safe into consideration ...

09:27:35 [FD]

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09:27:42 [philipj]

Yves, haha, ok then

09:29:53 [raphael]

yep, this is what Conrad said too !

09:30:34 [raphael]

Yves: fragment + header meaning a complete resource

09:30:55 [raphael]

Conrad: we will just ONE round trip, and a 200 OK in the case of a capable server understanding temporalURI

09:31:12 [raphael]

... what is the fallback plan?

09:31:36 [philipj]

how can one detect if the server does not understand temporalURI?

09:32:16 [philipj]

sorry, I will be afk for lunch

09:33:28 [mhausenblas]

wondering why the server shouldn't just send a 501 http://tools.ietf.org/html/rfc2616#section-10.5.2

09:33:56 [raphael]

Conrad answer: in temporal URI, the client uses another header: Accept-TimeURI

09:33:56 [Yves]

mhausenblas, in which case?

09:34:23 [mhausenblas]

what philipj was asking and we are discussing here, now (server does not understand temporalURI?)

09:34:45 [raphael]

... further: the header in the ogg file returned will contain a In-point=10, so the client knows he didn't get the full resource, but this is media format dependant

09:35:02 [raphael]

... it will work for ogg, perhaps for mp4, but certainly not for avi for example

09:35:45 [mhausenblas]

or, how are odds that HTTPbis will introduce a new code for that case ...

09:36:08 [mhausenblas]

Yves, yes I guess you are right, so just for the record, 501 is NO option, right?

09:36:40 [Yves]

(I was wondering if you meant "if the server doesn't know how to handle it, it should reply with a 501', which is againt the 'ignore what you don't understand' paradigm)

09:36:48 [Yves]

so yes 501 is not an option

09:37:22 [raphael]

Raphael: let's kick out the ? for now, and work on the #

09:37:39 [mhausenblas]

s/wich is againt/which is against

09:37:55 [raphael]

Jack: our premises are that the client are easy to modify, while your asumption is that you think we should adop servers

09:38:04 [mhausenblas]

+1 to raphael's proposal to focus on the #

09:38:13 [raphael]

s/wich is againt/which is against

09:38:54 [Yves]

if the # implies client sending a range request, then the server would do the work

09:39:14 [mhausenblas]

raphael: is drawing a table

09:39:18 [Yves]

and the client will do the work as a fallback

09:39:32 [mhausenblas]

the intention is to capture/structure the current state

09:39:49 [mhausenblas]

Scribenick: mhausenblas

09:40:32 [mhausenblas]

raphael: two cases at the table

09:41:01 [mhausenblas]

... either the UA makes a request using a unit like sec which is transformed into range request

09:41:19 [mhausenblas]

... and the server knows how to handle the mapping

09:41:32 [mhausenblas]

David agrees so far

09:41:49 [mhausenblas]

raphael: the second case is where we need a resolver

09:42:24 [mhausenblas]

David again on the board

09:43:14 [mhausenblas]

s/David/Conrad

09:43:41 [mhausenblas]

s/David agrees so far/Conrad agrees so far

09:43:52 [mhausenblas]

rrsagent, draft minutes

09:43:52 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html mhausenblas

09:45:32 [mhausenblas]

Conrad: client - GET URL, Aceept-TimeURI, Media-Fragment: t=10,20

09:46:12 [mhausenblas]

... Server: 206 partial content (with body, H' + K + D2)

09:47:21 [jackjansen]

For the people not in the room: the original media is H + D1 + D2 + D3

09:47:22 [mhausenblas]

and Server: Content-Range: in sec and bytes (?)

09:47:41 [jackjansen]

... D1 is seconds 0-10, D2 10-20, D3 20-30.

09:48:08 [jackjansen]

... H' is modified header, K is synthetic keyframes etc. to be able to interpret D2 correct.

09:49:27 [mhausenblas]

Conrad: let's assume the URI is .../video.ogg#t=smpte-25:00'10.23.25,

09:49:45 [mhausenblas]

... hence we need to specify the unit in the Range

09:51:25 [mhausenblas]

raphael: if we specify the unit in the Range, we can agree on that?

09:51:48 [davy_]

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09:52:32 [mhausenblas]

jackjansen: I ran into the same issue when implementing it

09:53:31 [Zakim]

-Barcelona_Room

09:53:50 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

09:55:25 [jackjansen]

jackjansen has joined #mediafrag

09:56:43 [Zakim]

+??P0

09:56:45 [Zakim]

-??P0

09:56:45 [Zakim]

+??P0

09:57:00 [jackjansen]

zakim, who is here?

09:57:00 [Zakim]

On the phone I see Yves, ??P0

09:57:01 [Zakim]

On IRC I see jackjansen, davy, FD, philipj, raphael, Zakim, RRSAgent, silvia, Yves, trackbot

09:57:13 [mhausenblas]

mhausenblas has joined #mediafrag

09:57:16 [mhausenblas]

Yves, we are back

09:57:56 [erik]

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09:57:57 [mhausenblas]

raphael: sums up last 5min

09:58:34 [Yves]

a new header won't trigger partial responses

09:58:34 [mhausenblas]

raphael: Conrad suggests to introduce a new header and let the server do the magic

09:59:27 [Yves]

the right way would be in this case to do conneg and point to a CL and a Vary, but in that case we mandate multiple URIs, and defeat caches again ;)

09:59:41 [mhausenblas]

Conrad: this was my first issue with Range:

09:59:45 [mhausenblas]

... now second

10:00:00 [mhausenblas]

(scribe notes that we have not yet fully resolved this issue)

10:00:28 [mhausenblas]

Yves, in *which* case - new header?

10:00:47 [Yves]

if a new Media-Fragment: header is introduced in place of Range

10:00:59 [mhausenblas]

ok, thanks for the clarification

10:01:56 [mhausenblas]

Conrad drawing UA - Proxy - Original Server

10:02:06 [raphael]

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10:02:39 [Zakim]

+Silvia

10:03:37 [mhausenblas]

Michael: note what 206 (http://tools.ietf.org/html/rfc2616#section-10.2.7) says about caching ...

10:05:03 [Yves]

michael, see also http://tools.ietf.org/html/draft-ietf-httpbis-p5-range-06

10:05:32 [mhausenblas]

ta, Yves, was hoping that you come up with a recent state ;)

10:06:00 [mhausenblas]

is there a big difference?

10:06:06 [Yves]

no small clarifications only

10:06:31 [Yves]

in rfc2616, the text was open to new units, but without any way of doing it, in httpbis it has been clarified

10:09:46 [raphael]

Yves: summary, we understand the concern of Conrad: single step partial GET, with a 206 response works, but it is not cachable

10:09:53 [raphael]

... which we know, written in 7.3 !

10:10:08 [mhausenblas]

Michael: are we seeking a trade-of between cachability and round-trip?

10:10:09 [silvia]

in current web proxies not cachable

10:10:13 [mhausenblas]

jackjansen: yes

10:10:16 [mhausenblas]

Conrad: no

10:12:50 [mhausenblas]

jackjansen: let' ignore the No-Cache for now, different issue

10:12:51 [Yves]

things we can add is a header in the reply indicating where D2 is and its relationship to bytes in the original file

10:14:00 [silvia]

I agree with the addition of such a header

10:15:56 [mhausenblas]

jackjansen: we should optimise for the case where a URI is embedded in an Web page

10:18:30 [mhausenblas]

silvia: for example in youtube case, each time you click on a time-offset it's a different URI

10:18:59 [mhausenblas]

jackjansen: do I understand correctly: every time I click on it I get a new URI?

10:19:02 [mhausenblas]

silvia: yes

10:19:58 [mhausenblas]

raphael: let's move on

10:20:19 [mhausenblas]

... we seem to agree on the one-step process but the cachable part

10:21:17 [silvia]

in the YouTube case there is a special server and a proprietary client - we cannot really tell what is going on; but when you click on an offset, a new connection is opened and new buffering is started

10:22:46 [mhausenblas]

jackjansen: a super-clever proxy would cache the entire bits and handle the parts accordingly

10:23:12 [Yves]

and a not so clever proxy could return the same content when the same second range is requested

10:23:22 [raphael]

yes Yves

10:23:41 [Yves]

'second' or 'other unit then bytes'

10:23:47 [raphael]

Conrad would like to move on the 4-ways handshake

10:24:13 [Yves]

but ading a mapping header in the reply (if possible would be a good thing, and only 'informative', so nothing mandatory to implement on the receiving end

10:24:34 [jackjansen]

gui walks in

10:24:41 [silvia]

I agree with Yves

10:24:43 [Yves]

and that would help a lot Silvia and Conrad's use case

10:24:48 [mhausenblas]

Guilleaume has arrived

10:25:01 [Yves]

s/ading/adding/

10:25:26 [raphael]

+1 for Yves

10:25:37 [mhausenblas]

+1 as well from me

10:27:09 [raphael]

Conrad: I don't think doing 200 response or 206 response should be our goal

10:27:35 [raphael]

... my solution will add new headers on the client side but would be pretty similar

10:28:12 [mhausenblas]

Conrad now explains now his solution with # and no Range

10:28:15 [raphael]

I will take a picture of Conrad complet's proposam

10:28:24 [raphael]

s/proposam/proposal

10:28:35 [mhausenblas]

rrsagent, draft minutes

10:28:35 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html mhausenblas

10:30:29 [mhausenblas]

Conrad: GET URL, Accept-Range-Refer: bytes, Media-Fragment:t=10,20

10:31:39 [mhausenblas]

Server: 200 OK, body Hi+K+D2

10:32:39 [mhausenblas]

... and additionally a header in the response ... Content-Media-Fragment:t=10,20

10:32:59 [mhausenblas]

(it's raining)

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10:37:03 [mhausenblas]

Conrad: Range-Refer: this, 0-1000

10:37:19 [mhausenblas]

note that 'this' is meant verbatim

10:38:20 [mhausenblas]

Conrad: continuing Range-Refer: URL2, Varu: Range-Refer, body

10:38:45 [mhausenblas]

jackjansen: let's not use 'this' but just blank (?)

10:39:11 [raphael]

ping

10:40:23 [mhausenblas]

(we seem to agree to disagree)

10:41:03 [mhausenblas]

raphael: see no big difference between Conrad's proposal and what is in the current draft

10:41:21 [mhausenblas]

right

10:41:33 [mhausenblas]

Yves is leaving

10:41:40 [Zakim]

-Yves

10:43:36 [raphael]

PIctures are in http://www.w3.org/2008/WebVideo/Fragments/meetings/2009-04-16-f2f_barcelona/

10:43:38 [mhausenblas]

jackjansen: we should structure the document in the fall-back flow

10:44:22 [mhausenblas]

... much easier to grock, then

10:44:27 [mhausenblas]

Michael: +1

10:45:48 [mhausenblas]

Silvia: can we modify the current draft and enhance it with Conrad's proposal?

10:45:58 [mhausenblas]

raphael: still need to understand better

10:46:45 [philipj]

is the proposal to allow either or both of these methods?

10:47:32 [philipj]

conrad's single and dual step GET

10:48:47 [silvia]

IIUC the one-step GET is preferrable, but it doesn't work with existing Web proxy caching infrastructure other than by keeping multiple copies; the two-step GET is for making media fragment URIs work with existing caching Web proxies

10:49:19 [mhausenblas]

raphael: re philipj's question, its a fallback-stack

10:49:45 [philipj]

I see

10:54:49 [mhausenblas]

raphael: in most of the cases, URL and URL2 are identical

10:55:08 [mhausenblas]

(scribe notes also that there are two or more servers involved)

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10:56:33 [Zakim]

-Barcelona_Room

10:56:35 [silvia]

where does a and b come from? are they 0 - 1000 ?

10:56:39 [Zakim]

-Silvia

10:56:41 [Zakim]

IA_MFWG()3:00AM has ended

10:56:42 [Zakim]

Attendees were Barcelona_Room, Yves, Silvia

10:57:32 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

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10:59:48 [mhausenblas]

raphael: before lunch two questions

11:00:34 [mhausenblas]

... (1) for me the UA does not know that it has to do another request

11:01:16 [mhausenblas]

and these will be discussed/ansewered after lunch

11:02:20 [mhausenblas]

jackjansen: is the more general approach of Conrad worth it re the introduced complexity which is apparently much higher

11:02:29 [mhausenblas]

+1

11:03:22 [mhausenblas]

ACTION: Conrad to update the Wiki with his more general approach with precisely the same exmples

11:03:22 [trackbot]

Created ACTION-63 - Update the Wiki with his more general approach with precisely the same exmples [on Conrad Parker - due 2009-04-23].

11:03:25 [silvia]

I still do not understand the different

11:03:33 [silvia]

yes, please :)

11:04:09 [jackjansen]

time for lunch. Silvia: will you still be here later?

11:04:23 [mhausenblas]

sorry, silvia you will have to wait a bit - Conrad suggests to read his blog ;)

11:04:37 [mhausenblas]

we will be back in roughly an hour

11:04:54 [silvia]

ok, I may not be back

11:05:18 [silvia]

I'm rather tired tonight and the phone is really exhausting

11:05:22 [silvia]

but I will linger here

11:05:39 [silvia]

I read the blog, which I found just as confusing :)

12:25:29 [Zakim]

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12:29:35 [Yves]

trackbot, start telcon

12:29:37 [trackbot]

RRSAgent, make logs public

12:29:37 [Zakim]

Zakim has joined #mediafrag

12:29:39 [trackbot]

Zakim, this will be IA_MFWG

12:29:39 [Zakim]

ok, trackbot; I see IA_MFWG()3:00AM scheduled to start 329 minutes ago

12:29:40 [trackbot]

Meeting: Media Fragments Working Group Teleconference

12:29:40 [trackbot]

Date: 16 April 2009

12:59:38 [erik]

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13:00:10 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

13:01:57 [philipj]

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13:03:08 [davy]

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13:03:56 [raphael]

yeahhhhhhhhhhhhhhhh

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13:05:54 [FD]

FD has joined #mediafrag

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davy has joined #mediafrag

13:12:13 [mhausenblas]

Zakim, what's the code?

13:12:13 [Zakim]

the conference code is 3724 (tel:+1.617.761.6200 tel:+33.4.89.06.34.99 tel:+44.117.370.6152), mhausenblas

13:12:23 [Zakim]

IA_MFWG()3:00AM has now started

13:12:30 [Zakim]

+[IPcaller]

13:12:40 [raphael]

zakim, IPcaller is Barcelona_Room

13:12:40 [Zakim]

+Barcelona_Room; got it

13:13:43 [Zakim]

+Yves

13:18:04 [FD]

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13:18:20 [mhausenblas]

raphael: Yves please update us on HTTP Link: header

13:19:21 [conrad]

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13:20:36 [jackjansen]

raphael, are you reffering to http://tools.ietf.org/html/draft-ietf-httpbis-p5-range-06 ?

13:21:07 [raphael]

yes

13:22:19 [conrad]

"If a range unit is not understood in a request, a server MUST ignore

13:22:19 [conrad]

the whole Range header"

13:24:13 [conrad]

url for link header draft?

13:24:57 [mhausenblas]

Michael: see http://lists.w3.org/Archives/Public/ietf-http-wg/2009AprJun/0189.html for updates on HTTP Link:

13:25:05 [Yves]

http://tools.ietf.org/html/draft-nottingham-http-link-header-04

13:26:51 [mhausenblas]

jackjansen: if only partially available? say file is 100bytes, and I request 50 - 150, it will be cut of at 100?

13:26:54 [mhausenblas]

Yves: yes

13:27:23 [mhausenblas]

jackjansen: all our replies should hence also incl. the time range, not only the bytes

13:28:17 [mhausenblas]

raphael: we will also have to be more precisely in the edge cases handling and their explanation

13:28:38 [Yves]

if you always get 200 you won't get fragments :)

13:29:02 [Yves]

http://tools.ietf.org/html/draft-ietf-httpbis-p5-range-06#section-3.2

13:29:06 [Yves]

is actually unit-agnostic

13:29:27 [raphael]

yep, I phrased that wrongly

13:29:32 [Yves]

"none of the

13:29:32 [Yves]

ranges-specifier values in this field overlap the current extent of

13:29:33 [Yves]

the selected resource"

13:30:40 [raphael]

In Conrad's proposal, in the case of the dual-step partial GET, the second request is still a normal Range request, so will get the normal 206 (or 416) response code

13:31:19 [raphael]

... only the first request will be answered by a 200 OK response, since it contains just the header + key frames data in the body

13:31:49 [mhausenblas]

jackjansen: so, if the query would be empty in any of the dimension, the result would be a 416

13:32:27 [raphael]

http://www.w3.org/2008/WebVideo/Fragments/meetings/2009-04-16-f2f_barcelona/

13:33:07 [conrad]

http://blog.kfish.org/2009/04/proposal-for-generalizing-byte-range.html

13:33:15 [Yves]

ohh

13:33:18 [Yves]

that's bad

13:33:24 [Yves]

two axis to identify a resource :)

13:33:41 [Yves]

URI request + media-fragment header

13:34:29 [Yves]

why do you need to send H1+K in the first request as you do a request to URL2 where you can send the whole thing?

13:35:33 [raphael]

because the answer of the second GET will be cached ?

13:35:41 [Yves]

what is the relationship between URL and URL2?

13:35:49 [raphael]

URL = URL 2

13:35:56 [raphael]

... in most of the cases

13:35:56 [mhausenblas]

90% yes ;)

13:35:59 [Yves]

?????

13:37:49 [raphael]

Jack: is your URL/URL2 re-inventing the http-redirect?

13:38:04 [Yves]

I don't get why we need this complexity. at worst we need to locate a resolver and get the API to call it

13:38:51 [raphael]

I *think* the main purpose is to have the cacheability feature on the code data

13:39:05 [raphael]

... but I think we have it with the current dual-step partial GET

13:40:40 [raphael]

Conrad: we need to do a bytes redirection for the second request

13:40:57 [raphael]

Raphael: in the spec, we have currently: X-Range-Redirect (new header)

13:41:56 [raphael]

... Yves, how will you tell the user agent needs to issue another request to get the core of the video data ? do we need this new header ?

13:43:36 [mhausenblas]

Michael: I would be very careful introducing complexity if the benefit is not totally clear and 'fool-proof'; lowers implementation barriers if we keep it simple

13:44:45 [raphael]

Jack: well, it is good in theory to call for a resolver (do the mapping between bytes and seconds) ... but in practice, this resolver will need to construct K (the key frames)

13:44:56 [raphael]

... thus access the media, thus be on the server

13:46:55 [raphael]

Raphael: Yves, what is not clear in the current draft (among others :-), is the content of the body response of the first request in the dual step GET

13:47:27 [raphael]

... should we have just the video data header (H') constructed on the server ?

13:47:35 [Yves]

I think that the clarification using letters is quite good and shoul make it to the 2nd publication :)

13:47:38 [raphael]

... should we add also K (the key frames)

13:48:14 [raphael]

do you have the picture with the H, K?

13:51:30 [raphael]

Yves, http://www.w3.org/2008/WebVideo/Fragments/meetings/2009-04-16-f2f_barcelona/ogv_video_decomposition.jpg for the H, H', K, etc.

13:54:41 [raphael]

Yves: in the current draft, we haven't specify what is in the BODY of each response, right ?

13:54:52 [Yves]

no, but we should

13:55:18 [raphael]

Conrad mentions that in his solution: 1st response body contains the H' and K (new information/bytes constructed on the server)

13:55:36 [raphael]

... while the 2nd response body contains only bytes coming from the original file

13:55:42 [Yves]

in the single GET solution the returned content should be H' K D2

13:55:48 [raphael]

... and UA does the concatenation to get a complete playable resource

13:55:55 [raphael]

YES

13:56:10 [raphael]

in the case of the dual-step ?

13:56:10 [Yves]

and we shold craft that header to define where D2 is and its relation to the whole resource, as bytes

13:56:25 [raphael]

how ?

13:57:23 [Yves]

like Range-Mapping: bytes 1234-2345/58588; original=11234-12345/39849384

13:58:10 [Yves]

(or annodex might have a better format for that already :) )

13:58:34 [raphael]

well, this is what Conrad proposes with its Range-Refer ... re his blog post :-)

13:58:40 [Yves]

no

13:58:48 [Yves]

he proposes a way to redirect without redirecting

13:59:01 [Yves]

I propose a mapping header for caches

13:59:22 [raphael]

he proposes to send the headers in the body of the first request, and the real video data in the body of the second request

13:59:45 [Yves]

on different URIs

13:59:51 [raphael]

I will bring your position in the room

14:00:05 [raphael]

... no no no, assume now that URI = URI2

14:00:25 [Yves]

then it will confuse caches :)

14:00:44 [Yves]

basically if URL=URL2 the cache will flush what it cached at each request

14:01:17 [raphael]

well, the first response is not meant to be cached (just headers), the second one is a clear extract in terms of bytes of the resource and will be cached

14:01:35 [raphael]

the request is not the same

14:01:36 [Yves]

yeah, but a subsequent request on the same thing will invalidate what has just been cached

14:01:50 [raphael]

no, if this is not the same request ?

14:01:58 [raphael]

the second request is a normal Range request

14:01:59 [Zakim]

-Yves

14:03:41 [mhausenblas]

Zakim, who is on the phone?

14:03:41 [Zakim]

On the phone I see Barcelona_Room

14:04:12 [guillaume]

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14:07:45 [mhausenblas]

jackjansen: let's use an example video (from last F2F) and do practical experiments

14:08:18 [mhausenblas]

... and figure out how different formats (MPEG4, OGG) actually behave

14:10:51 [mhausenblas]

Michael: I second jackjansen proposal

14:11:26 [mhausenblas]

raphael: yes, let's do it and document in the Wiki

14:12:33 [Zakim]

-Barcelona_Room

14:12:33 [Zakim]

+Barcelona_Room

14:12:35 [Zakim]

+Yves

14:12:40 [mhausenblas]

Scribenick: guillaume

14:12:56 [guillaume]

Topic: discoverability

14:13:11 [mhausenblas]

Zakim, who is here?

14:13:11 [Zakim]

On the phone I see Barcelona_Room, Yves

14:13:12 [Zakim]

On IRC I see guillaume, conrad, FD, davy, dsinger, philipj, raphael, erik, Zakim, mhausenblas, jackjansen, RRSAgent, silvia, Yves, trackbot

14:14:01 [guillaume]

Previously : Describe Conrad solution using the example (http implementation wiki page) to be enhanced with Conrad proposal

14:15:27 [guillaume]

Conrad : what happen when we come across an URL like video.ogv#t=smpte-25=00'10.23.25,...

14:15:56 [guillaume]

What would the code look like in the User Agent (the "smart" user agent)

14:17:59 [guillaume]

It could be that the user agent split at the #, then after the request, start parsing what' s after the # (not good enough). It would have to check if it matches the syntax first. Reply comes back.

14:19:18 [guillaume]

It' s the owner of the MIMIE type that understands what' s happening beyond the # (because so far, # "belongs / could be used" in any HTML document)

14:20:17 [guillaume]

The server knows the MIME type, hence, the way to interpret the #etc...

14:24:08 [guillaume]

ACTION mhausenblas Michael to write into the WD section 6.4, what the client should do with #everything after the hash : "Client Side Media Fragment Resolution"

14:24:08 [trackbot]

Sorry, couldn't find user - mhausenblas

14:24:24 [dsinger]

servers don't get the # part, it's supposed to be stripped by the UA, isn't it?

14:24:39 [raphael]

ACTION: Michael to write into the WD section 6.4, what the client should do with #everything after the hash : "Client Side Media Fragment Resolution"

14:24:39 [trackbot]

Created ACTION-64 - Write into the WD section 6.4, what the client should do with #everything after the hash : "Client Side Media Fragment Resolution" [on Michael Hausenblas - due 2009-04-23].

14:25:20 [guillaume]

Coffee break time!

14:25:23 [jackjansen]

zakim, who is here?

14:25:23 [Zakim]

On the phone I see Barcelona_Room, Yves

14:25:24 [Zakim]

On IRC I see guillaume, conrad, FD, davy, dsinger, philipj, raphael, erik, Zakim, mhausenblas, jackjansen, RRSAgent, silvia, Yves, trackbot

14:25:24 [mhausenblas]

coffeeeeeeeeeee

14:25:33 [Zakim]

-Barcelona_Room

14:25:52 [Zakim]

-Yves

14:25:53 [Zakim]

IA_MFWG()3:00AM has ended

14:25:53 [Zakim]

Attendees were Barcelona_Room, Yves

14:29:55 [silvia]

oh

14:30:02 [silvia]

I will probably be asleep when you get back

14:30:17 [silvia]

looks like there is progress :)

14:44:08 [mhausenblas]

raphael: we will do now the joint meeting with the Annotation WG

14:44:21 [guillaume]

Resuming

14:44:31 [mhausenblas]

Zakim?

14:44:53 [guillaume]

Use cases + requirements could make 1 separate document

14:45:03 [Zakim]

IA_MFWG()3:00AM has now started

14:45:06 [Zakim]

+Yves

14:45:06 [guillaume]

the specification of the syntax would be the core document

14:45:14 [Zakim]

+Mediafrag

14:45:50 [guillaume]

Yeah, the teleconf is working

14:45:52 [jackjansen]

zakim, who is here?

14:45:53 [Zakim]

On the phone I see Yves, Mediafrag

14:45:57 [Zakim]

On IRC I see guillaume, conrad, FD, davy, dsinger, philipj, raphael, erik, Zakim, mhausenblas, jackjansen, RRSAgent, silvia, Yves, trackbot

14:46:05 [mhausenblas]

Michael: we should only go with the Syntax REC-Track

14:46:19 [guillaume]

We are going to have the joint meeting with the Media Annotation WG

14:46:34 [mhausenblas]

... the Test Cases (TC) and the Implementation Report (IR) should be a Note only

14:46:47 [guillaume]

Topic: Numbers of documents

14:47:04 [guillaume]

1. Use cases & Reqs

14:47:10 [guillaume]

2. Synthax

14:47:29 [mhausenblas]

raphael: current UC and Req will be split into UCR and Syntax doc

14:48:11 [guillaume]

Action raphael Current UC and Req will be split into UCR and Syntax doc

14:48:11 [trackbot]

Sorry, couldn't find user - raphael

14:48:29 [raphael]

trackbot, status

14:48:42 [guillaume]

Action Raphaël Current UC and Req will be split into UCR and Syntax doc

14:48:42 [trackbot]

Created ACTION-65 - Current UC and Req will be split into UCR and Syntax doc [on Raphaël Troncy - due 2009-04-23].

14:49:25 [guillaume]

3. Potentialy a 3rd document with Test cases

14:49:30 [mhausenblas]

rrsagent, draft minutes

14:49:30 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html mhausenblas

14:50:09 [guillaume]

University people would like to make publications out of the work we produce here at the MFWG.

14:50:37 [guillaume]

We would then add all our names to the joint co-authored paper(s)

14:50:38 [mhausenblas]

+1

14:50:50 [guillaume]

+1

14:51:39 [erik]

+1

14:51:46 [Zakim]

-Yves

14:52:07 [Zakim]

IA_MFWG()3:00AM has ended

14:52:07 [Zakim]

Attendees were Yves, Mediafrag

14:53:36 [silvia]

+1 (papers are always good )

14:53:41 [mhausenblas]

;)

14:56:44 [jackjansen]

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15:21:43 [raphael]

ACTION: Jack to look at the organisation of the 4th F2F meeting in Amsterdam on September 17-18 (just after IBC)

15:21:43 [trackbot]

Created ACTION-66 - Look at the organisation of the 4th F2F meeting in Amsterdam on September 17-18 (just after IBC) [on Jack Jansen - due 2009-04-23].

15:36:49 [raphael]

ACTION: Erik to sync with Jean Pierre to get the edit units spec reference

15:36:49 [trackbot]

Created ACTION-67 - Sync with Jean Pierre to get the edit units spec reference [on Erik Mannens - due 2009-04-23].

15:48:34 [nessy]

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15:48:54 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

16:18:09 [raphael]

ACTION: Raphael to ask the Media Annotations WG to review our document

16:18:09 [trackbot]

Sorry, couldn't find user - Raphael

16:18:16 [raphael]

trackbot, status?

16:18:41 [raphael]

ACTION: Raphaël to ask the Media Annotations WG to review our document

16:18:41 [trackbot]

Created ACTION-68 - Ask the Media Annotations WG to review our document [on Raphaël Troncy - due 2009-04-23].

16:19:02 [RRSAgent]

I have made the request to generate http://www.w3.org/2009/04/16-mediafrag-minutes.html raphael

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