IRC log of mediafrag on 2009-12-02

Timestamps are in UTC.

09:40:25 [RRSAgent]
RRSAgent has joined #mediafrag
09:40:25 [RRSAgent]
logging to
09:40:27 [trackbot]
RRSAgent, make logs public
09:40:27 [Zakim]
Zakim has joined #mediafrag
09:40:29 [trackbot]
Zakim, this will be IA_MFWG
09:40:29 [Zakim]
ok, trackbot; I see IA_MFWG()5:00AM scheduled to start in 20 minutes
09:40:30 [trackbot]
Meeting: Media Fragments Working Group Teleconference
09:40:30 [trackbot]
Date: 02 December 2009
09:41:06 [raphael]
Chair: Raphael
09:41:12 [raphael]
Regrets: Erik, Davy, Jack
09:41:39 [raphael]
09:41:46 [RRSAgent]
I have made the request to generate raphael
10:03:10 [raphael]
zakim, code?
10:03:10 [Zakim]
the conference code is 3724 (tel:+1.617.761.6200 tel:+ tel:+44.117.370.6152), raphael
10:03:23 [Zakim]
IA_MFWG()5:00AM has now started
10:03:30 [Zakim]
+ +49.300.aaaa
10:03:37 [raphael]
zakim, aaaa is me
10:03:37 [Zakim]
+raphael; got it
10:04:21 [Zakim]
+ +1.617.324.aabb
10:04:27 [raphael]
Present: Raphael, Silvia, Yves, Philip (irc), Michael
10:06:52 [Zakim]
10:08:05 [Zakim]
+ +3539149aacc
10:08:10 [mhausenblas]
Zakim, aacc is me
10:08:10 [Zakim]
+mhausenblas; got it
10:08:42 [silvia]
zakim, mute me
10:08:42 [Zakim]
Silvia should now be muted
10:09:12 [Yves]
Scribe: Yves
10:09:59 [raphael]
Minutes from last week:
10:10:02 [raphael]
+1 for accepting
10:10:19 [Yves]
no objection => accepted
10:10:24 [silvia]
10:11:46 [Yves]
Topic: Specification
10:12:19 [raphael]
10:12:19 [trackbot]
ACTION-112 -- Raphaƫl Troncy to propose a digest of Conrad and current's proposal regarding the use of existing and custom headers for the communication UA server -- due 2009-09-25 -- OPEN
10:12:19 [trackbot]
10:12:20 [Yves]
We have the one round trip version, and the two round trips versions
10:12:29 [raphael]
close ACTION-112
10:12:29 [trackbot]
ACTION-112 Propose a digest of Conrad and current's proposal regarding the use of existing and custom headers for the communication UA server closed
10:12:51 [Yves]
Yves: what make you think that the one-round trip version can't be cached?
10:13:20 [Yves]
Raphael: implementation issue only, current implementation can't without knowing the unit
10:14:03 [Yves]
Yves: right, but implementation can't exist before the spec is ready :)
10:14:28 [silvia]
zakim, unmute me
10:14:28 [Zakim]
Silvia should no longer be muted
10:14:40 [Yves]
Raphael: we can then document expectation on cient servers and proxies (wrt support/implementation)
10:15:11 [Yves]
Yves: that would do it
10:15:20 [raphael]
10:15:53 [raphael]
Silvia: there is a optimal solution and then divergent cases ... this is how section 3 is written
10:16:30 [raphael]
Yves: changing the UA is not easy
10:16:47 [Yves]
Silvia: changing servers and clients is easy, proxies are not easy to update
10:17:21 [Yves]
Yves: By proxy you mean caches, proxies will work perfectly well
10:18:02 [silvia]
I mean caching proxies indeed
10:18:29 [silvia]
zakim, mute me
10:18:29 [Zakim]
Silvia should now be muted
10:18:46 [foolip]
request to speak (write)
10:19:36 [Zakim]
10:19:43 [raphael]
Raphael: indeed my asumption is that we have a UA conformant to the media fragment spec (parse), a server like Davy's one that support MF URI and that's it
10:19:44 [Yves]
Yves: just to mention that I am not against the two round trip approach :)
10:19:57 [raphael]
... i.e. no caches have been modified
10:20:40 [Zakim]
10:20:53 [silvia]
zakim, ??P4 is silvia
10:20:53 [Zakim]
+silvia; got it
10:21:01 [silvia]
zakim, mute me
10:21:01 [Zakim]
silvia should now be muted
10:21:08 [raphael]
Raphael: do you agree that the 2 round-trips approach allow to cache fragments without changing cache implementation ?
10:21:30 [Yves]
10:21:42 [Yves]
GET /2008/WebVideo/Fragments/media/fragf2f.mp4 HTTP/1.1
10:21:42 [Yves]
10:21:42 [Yves]
Accept: video/*
10:21:42 [Yves]
Fragment: time:npt=12-21
10:21:42 [raphael]
Yves: time ranges are cacheable but need implementation. 2 rounds trip is a hack to allow current proxies to cache
10:21:47 [Zakim]
10:21:55 [Yves]
10:21:55 [Yves]
Content-Length: 3571437
10:21:55 [Yves]
Content-Fragment: time:npt=12-21
10:21:55 [Yves]
Vary: Fragment
10:22:51 [Yves]
we should add Content-Location: /2008/WebVideo/Fragments/media/fragf2f.mp4?t=12-21
10:23:00 [raphael]
Yves: in Conrad's proposal, case 1.2.b, we need to add a Content-Location header in the response
10:23:48 [Zakim]
10:24:05 [silvia]
zakim, ??P4 is silvia
10:24:05 [Zakim]
+silvia; got it
10:24:08 [silvia]
zakim, mute me
10:24:08 [Zakim]
silvia should now be muted
10:24:29 [foolip]
is there a speaker queue?
10:24:41 [raphael]
yes, Philip
10:25:07 [raphael]
Yves: my concern is that in the case of Conrad's proposal, if you have 2 request, the second one will flush the cache of the first one
10:25:08 [foolip]
I would like to note that the NPT syntax in the HTTP headers examples are inconsistent. Would it not be best to define a normalized form? The UA would have to pick a formatting anyway unless it just copies it verbatim (in which case it doesn't actually know which offset it is requesting or if it's valid syntax).
10:26:11 [raphael]
Philip, can you point us to this inconsistency ?
10:26:13 [raphael]
I don't see it
10:26:38 [foolip]
"time:npt 11.85-21.16/36" vs "time:npt=12-21"
10:26:55 [Yves]
ah it's the range reply syntax
10:27:08 [Yves]
which is starting time -end time / total time
10:27:15 [silvia]
zakim, unmute me
10:27:15 [Zakim]
silvia should no longer be muted
10:27:24 [Yves]
you have the same asymetry in byte ranges
10:27:56 [foolip]
in either case, NPT should be normalized, so that it isn't sometimes 0:00:12, sometimes 12 and sometimes 12s
10:28:04 [raphael]
Philip: we follow the same pattern that the bytes range request ... with a dissimetry between request and response
10:28:15 [silvia]
zakim, mute me
10:28:15 [Zakim]
silvia should now be muted
10:28:22 [raphael]
it is not 0:00:12
10:28:30 [raphael]
where did you see this Philip ?
10:28:40 [foolip]
raphael: some more zeroes?
10:28:50 [silvia]
foolip: the syntax is given in
10:28:56 [raphael]
I thought I have normallized the npt syntax
10:29:06 [silvia]
foolip: if something does not conform to that syntax, it is a typo
10:29:13 [raphael]
Section 5 contains indeed typos
10:29:24 [foolip]
so which format is normalized?
10:29:27 [silvia]
I think section 5 still needs a general work-over
10:29:35 [foolip]
the ABNF allows any kind of variation
10:30:13 [foolip]
not any, but many variations of the same time
10:30:46 [silvia]
ah, yes, we decided to give the user the freedom to specify relatively freely, but the syntax on the wire is fixed
10:31:05 [foolip]
that's good, where is it defined?
10:31:28 [silvia]
not yet in the spec - needs to go into section 5
10:31:37 [foolip]
ok, so we are already in agreement that this is neeed
10:31:40 [foolip]
10:31:41 [foolip]
10:31:54 [silvia]
yup, indeed
10:32:12 [foolip]
I suggest normalizing to seconds without s, but that's just me
10:32:16 [foolip]
anything is fine
10:33:15 [RRSAgent]
I have made the request to generate raphael
10:33:26 [foolip]
as long as there can only be one possible string output for each input (makes writing conformance test suites lot easier too)
10:33:38 [silvia]
yes, indeed
10:33:46 [raphael]
OK, philip, I try to solve your problem ...
10:34:01 [foolip]
10:34:01 [raphael]
what do you would like to be changed in the spec?
10:34:14 [raphael]
I'm not sure I understand it :-(
10:34:40 [raphael]
1) The Media Fragment URI syntax ? 2) The HTTP request header syntax ? 3) The HTTP response header ?
10:34:49 [foolip]
it should say that when sending header X, the format MUST be Y, with Y unambiguously defined
10:34:52 [raphael]
... for example in the case of npt
10:35:03 [foolip]
2 and 3
10:35:20 [foolip]
1) is the parsing end, which we'll get to later I think
10:35:33 [silvia]
zakim, unmute me
10:35:33 [Zakim]
silvia should no longer be muted
10:35:42 [foolip]
this should be a conformance requirement of both UAs and servers
10:35:50 [raphael]
OK Philip, now I understand, indeed, we haven't specified yet the syntax for 2) and 3)
10:36:03 [raphael]
The only things we have:
10:36:16 [foolip]
OK, then it's just a matter of time, I shall not worry any more :)
10:36:59 [raphael]
10:37:06 [raphael]
... or worry later
10:37:12 [Yves]
Silvia, we need some ABNF there as well
10:37:52 [silvia]
zakim, mute me
10:37:52 [Zakim]
silvia should now be muted
10:37:58 [Yves]
Yves: to summarize, lax URI syntax, strict header
10:39:09 [silvia]
part of the syntax was started in
10:39:22 [Yves]
10:39:28 [silvia]
but needs to go into ABNF
10:39:46 [raphael]
Silvia, yes, it is even better summarized in
10:40:04 [Yves]
10:40:14 [Yves]
other-ranges-specifier = other-range-unit "=" other-range-set
10:40:14 [Yves]
other-range-set = 1*CHAR
10:40:36 [Yves]
other-range-unit = token
10:40:56 [Yves]
ACTION: Yves to come up with ABNF for header syntax
10:40:56 [trackbot]
Created ACTION-123 - Come up with ABNF for header syntax [on Yves Lafon - due 2009-12-09].
10:41:42 [foolip]
ABNF syntax without any use of " / " to that.
10:43:13 [raphael]
Topic: Specific (cont.) - 2 roundtrips
10:43:30 [Yves]
Yves: on the two round trip I have some reservation with the first 200 OK reply
10:43:33 [raphael]
Yves: In the case of 2.1, first roundtrip response should be a 307 instead of 200
10:43:43 [Yves]
may be better to have a 307 and redirect to itself with the right headers
10:43:47 [Yves]
will followup by email
10:44:49 [Yves]
Raphael: we need to update section 5
10:45:00 [silvia]
zakim, unmute me
10:45:00 [Zakim]
silvia should no longer be muted
10:45:15 [Yves]
Silvia: happy to work on it
10:45:27 [raphael]
Topic: Rework of the section 5
10:45:30 [raphael]
10:46:16 [Yves]
Sivia: what you summarized is in sync with what I had in mind, writing this will clarify things
10:46:33 [Yves]
10:46:57 [Yves]
...not clear that we need the Fragment: header, but don't remember what Conrad wanted it for
10:47:07 [Yves]
...but good that the email thread restarted
10:47:20 [silvia]
zakim, mute me
10:47:20 [Zakim]
silvia should now be muted
10:47:40 [Yves]
Raphael: I proposed a restructuration plan for section 5
10:48:36 [mhausenblas]
10:48:40 [silvia]
zakim, unmute me
10:48:40 [Zakim]
silvia should no longer be muted
10:49:00 [Yves]
Raphael: Silvia, do you want to work on specific sections? or all of them?
10:49:14 [Yves]
Silvia: better if it is consistent
10:49:48 [Yves]
ACTION: Silvia to rework section 5 according to Raphael's restructuration plan due 2009-12-15
10:49:48 [trackbot]
Created ACTION-124 - Rework section 5 according to Raphael's restructuration plan due 2009-12-15 [on Silvia Pfeiffer - due 2009-12-09].
10:50:45 [silvia]
zakim, unmute me
10:50:45 [Zakim]
silvia was not muted, silvia
10:50:51 [silvia]
zakim, mute me
10:50:51 [Zakim]
silvia should now be muted
10:51:01 [foolip]
where in section 5 will the processing requirements (parsing) go? part of MF resolution?
10:51:50 [Yves]
depends on the author :)
10:51:51 [silvia]
I think it should be section 5.5 ABNF for HTTPrequest & response headers
10:52:07 [Yves]
ACTION: Michael to revisit his ednote in section 5
10:52:07 [trackbot]
Created ACTION-125 - Revisit his ednote in section 5 [on Michael Hausenblas - due 2009-12-09].
10:52:23 [foolip]
I agree that most parts can be given as ABNF, but not all of it
10:52:34 [foolip]
I can elaborate if it's not clear why.
10:52:49 [silvia]
why not?
10:53:07 [raphael]
Yes please Philip, I suggest we wait for Silvia's input and then complain what is not sufficiently specified
10:53:53 [Yves]
Raphael: on the test cases, lots of action. postpone?
10:53:55 [foolip]
sorry, difficult to guess who's talking over IRC
10:54:00 [Yves]
=> postponed
10:54:04 [raphael]
10:54:04 [trackbot]
ACTION-119 -- Yves Lafon to request admins to set up a cvs notifications mailing list and notifications -- due 2009-10-14 -- OPEN
10:54:04 [trackbot]
10:54:50 [Yves]
Yves: oops, will work on this
10:54:56 [silvia]
foolip, can you clarify your opinion on ABNF via email?
10:55:06 [foolip]
silvia: to you or the list?
10:55:12 [silvia]
the list
10:55:14 [foolip]
will do
10:55:25 [Yves]
10:55:28 [Zakim]
10:55:30 [Zakim]
10:55:32 [Zakim]
10:55:35 [RRSAgent]
I have made the request to generate Yves
10:55:40 [Zakim]
10:55:41 [Zakim]
IA_MFWG()5:00AM has ended
10:55:43 [Zakim]
Attendees were +49.300.aaaa, raphael, +1.617.324.aabb, Yves, Silvia, +3539149aacc, mhausenblas
10:55:44 [Yves]
tracker, end telcon
10:55:55 [raphael]
Raphael: I will make sure we follow-up the current thread of dicussion so we can converge rapidly between Conrad's and current's proposal
10:56:02 [Yves]
trackbot, end telcon
10:56:02 [trackbot]
Zakim, list attendees
10:56:02 [Zakim]
sorry, trackbot, I don't know what conference this is
10:56:03 [trackbot]
RRSAgent, please draft minutes
10:56:03 [RRSAgent]
I have made the request to generate trackbot
10:56:04 [trackbot]
RRSAgent, bye
10:56:04 [RRSAgent]
I see 3 open action items saved in :
10:56:04 [RRSAgent]
ACTION: Yves to come up with ABNF for header syntax [1]
10:56:04 [RRSAgent]
recorded in
10:56:04 [RRSAgent]
ACTION: Silvia to rework section 5 according to Raphael's restructuration plan due 2009-12-15 [2]
10:56:04 [RRSAgent]
recorded in
10:56:04 [RRSAgent]
ACTION: Michael to revisit his ednote in section 5 [3]
10:56:04 [RRSAgent]
recorded in