07:42:29 RRSAgent has joined #mediafrag 07:42:29 logging to http://www.w3.org/2010/06/16-mediafrag-irc 07:42:31 RRSAgent, make logs public 07:42:31 Zakim has joined #mediafrag 07:42:33 Zakim, this will be IA_MFWG 07:42:33 ok, trackbot; I see IA_MFWG()3:00AM scheduled to start 42 minutes ago 07:42:34 Meeting: Media Fragments Working Group Teleconference 07:42:34 Date: 16 June 2010 07:43:05 davy has joined #mediafrag 07:44:37 FD has joined #mediafrag 07:45:46 erik has joined #mediafrag 07:46:27 Chair: Erik, Raphaël 07:47:05 Present: Jack, Yves, Raphaël, Erik, Davy, Wim, Frank 07:47:43 Wim has joined #mediafrag 07:48:28 hackerjack has joined #mediafrag 07:49:51 agenda: http://www.w3.org/2008/WebVideo/Fragments/wiki/SixthF2FAgenda 07:50:03 regrets: Michael 07:50:18 SCribe: jack 07:50:28 ScribeNick: hackerjack 07:52:19 raphael has joined #mediafrag 07:53:43 agenda: http://www.w3.org/2008/WebVideo/Fragments/wiki/SixthF2FAgenda 07:54:19 IA_MFWG()3:00AM has now started 07:54:26 +Meeting_Room 07:54:28 agenda: http://www.w3.org/2008/WebVideo/Fragments/wiki/SixthF2FAgenda 07:54:36 trackbot start teleconf 07:54:37 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 07:58:19 Raphael: About Silvia's mail of yesterday: BNF is incomplete when only the "include-setup" is returned. 08:00:22 All: agree. Yves to fix it now. 08:00:40 Topic: 1. Protocol Handling (cont.) 08:03:49 Erik: Let's revisit the redirect idea for track and id we discussed yesterday. 08:04:31 ... for id it seems to be a good idea, but for track we could go both ways (redirect or direct implementation) 08:07:24 Room: discussing again the pro/cons of the track + id handling 08:07:36 ... track is now handled as ID, and not as time 08:08:15 ... the redirect to query is a fallback solution just because the proble is that we will have too many characters in HTTP headers 08:09:52 Raphael: should we document two solutions for handling track ... one using the redirect and another one similar to time? 08:10:11 Jack: well, in this case, we are re-introducing the problem for caching cascading projections 08:10:35 Erik: the only cascading problem will be track + time 08:19:15 Jack: rationale, if we go the redirect way, the spec is finished today, and we can take it out 08:19:36 ... if we go with Davy's solution, then more work is needed, we do not know how cache will behave 08:20:43 Jack: most of the use cases will be time selection, some will be track selection, combination will be even rarer 08:22:53 Jack: how robust is our current text for caching tracks? We need more implementation experience 08:28:12 All: discussion about cacheability (by classic caches) of multipart 08:28:37 +silvia 08:29:38 Erik: maybe we shoulnd't worry too much about old-style caches: there will be a strong push towards mf-aware (once mf is popular) 08:29:54 Discussing: http://www.w3.org/2010/06/15-mediafrag-minutes.html#item06 08:33:02 FD has joined #mediafrag 08:42:09 Jack: explaining the issues of yesterday and this morning to Silvia, and sketching tradeoffs (elegance versus quick publishing) 08:42:51 Silvia: we shouldn't worry overmuch about cache implementation in our LC spec. We need implementations before we can be 08:42:57 ... sure our text is corect. 08:43:03 s/corect/sorrect 08:47:34 Silvia: issue with redirect, specifically with redirect leading to new resource. 08:47:47 Jack: but client knows about the linking to the old one. 08:47:52 Silvia: that is a hack. 08:49:42 Silvia: I think that if you have a #track URL in the browser and get redirected to the ?track URL, it may not remember the context, because you have loaded a new resource 08:49:58 … so, getting back to the original resource and its tracks may be impossible 08:50:48 … also, I am not too worried about these things yet, because I would wait and see what browser vendors implement 08:51:10 … it is good for us to identify these issues, but I'm not sure we can solve them fully 08:51:24 .. without implementations we won't have the answer to everything now 08:51:56 … for #track, I would offer both options to browser vendors, then see how they go ;) 08:54:14 OK Silvia 08:54:34 we plan to enforce also the use of a Link header ... so context towards the original resource is here! 09:00:36 Silvia: http://www.web-polygraph.org/docs/userman/ranges.html <- looks like it supports multiple byte ranges 09:00:43 Silvia: but that might be a server and not a proxy... 09:06:12 5.2 has the following paragraph: 09:06:15 It is possible to add an additional HTTP response header called "Link" that refers the new resource back to the original resource and enables the UA to retrieve further information about the original resource, such as its full length. In this case, the user agent is also enable to choose to display the dimensions of the primary resource or the one created by the query. 09:06:32 Raphael: proposal. First, we document the redirect option, specifically as an option (to be used at the server's discretion) in stead of the "real" implementation 09:07:22 ok 09:07:28 Raphael: second, 09:08:42 ... we make sure that the spec correctly specifies fragmenting of tracks 09:10:27 ... third, similar for ID 09:15:22 I think a web browser has actually 3 options: 09:15:33 … 1. use byte ranges 09:15:44 … 2. use redirect 09:15:55 … 3. do locally 09:17:27 silvia, you dropped from the audio 09:20:27 FD has joined #mediafrag 09:23:35 All: discussion about whether lots of small fragments will work for the clients anyway. 09:24:39 Silvia: talked to browser vendors, they will probably get whole resourcce, because their decoders may not handle it 09:25:16 zakim, mute me 09:25:16 silvia should now be muted 09:40:17 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 09:40:45 scribenick: raphael 09:40:59 -silvia 09:41:20 Summary: for the 3 dimensions, time, track and id, they will be a double mechanism described in the protocol 09:41:33 ... either a direct way as it is described in the spec 09:42:27 ... or as a redirect (30x reply) pointing to the same request that replace the # by the ? 09:43:05 ... the second server reply MAY or MUST? contain a Link header pointing to the original resource the new one is derived from 09:47:17 PROPOSED: Documenting in the spec the redirect mechanism in a new section 5.1.3 (that will point to 5.2) as an option (to be used at the server's discretion) and we make sure that the reader understands the two possible options 5.1.2 and 5.1.3 at server discretion 09:51:06 Jack: proposed headline for new section 5.1.3 = Server triggered redirect 09:58:25 Davy: but there is another issue with a redirect. The server has no way to communicate to the client whether the returned new resource 09:58:48 ... has the mf completely applied or not. In the latter case the client would still have work to do. 10:00:21 issue with the redirect is fragment handling on the redirected resource 10:08:11 http://tools.ietf.org/html/draft-nottingham-http-link-header-10 10:08:47 wouldn't the redirect be to e.g. video.ogv?track=video#t=10,20 - then sent to the server again by the client - then have all the appropriate headers? 10:10:40 it's an actual HTTP redirect, right? 10:11:27 Yes, it is a real redirect 10:12:07 ... the issue is: imagine that the UA has just requested a track (#track=audio4) 10:12:26 ... the server cannot extract the track, but send a 307 pointing to the full resource 10:12:57 ... how the UA knows whether the redirects points to the track it has originally requested or to the full resource? 10:13:23 ... Ninsuna proxy currently works like this, send a redirecto to the full resource when it cannot extract the fragments 10:13:45 but ours has a link header? 10:13:50 ... idea would be to add a link header in the 307 reply to convey this information 10:14:15 I'm talking of the first reply, the 307, not the second one with the actual data which has a Link header 10:15:42 Yves: for the second reply, I suggest we use the property named 'alternate' 10:15:51 ... so syntax would be: 10:16:42 Link: alternate 10:17:53 Jack: perhaps we should use another term, it seems to me a hack 10:18:07 ... no, I fully agree now, Yves convinced me 10:18:33 Yves: for the first reply, the 307, we need a new term 10:21:45 ... e.g. fragment 10:21:51 ... so syntax would be: 10:22:26 Link: fragment 10:22:43 Location: http://www.example.com/video.ogv 10:23:01 Location: http://www.example.com/video.ogv?track=audio4 10:23:05 Vary: * 10:23:14 ... in order to not cache the 307 reply 10:25:37 Raphael: the description of how it works should now be completed, back to the proposal 10:25:39 PROPOSED: Documenting in the spec the redirect mechanism in a new section 5.1.3 (that will point to 5.2) as an option (to be used at the server's discretion) and we make sure that the reader understands the two possible options 5.1.2 and 5.1.3 at server discretion 10:25:44 let's vote 10:26:00 +1 10:26:08 +1 10:26:12 +1 10:27:18 +1 10:27:21 +1 10:29:21 =1 10:29:35 s/=/+/ 10:29:36 s/-1/+1 10:29:58 rrsagent draft minutes 10:30:07 +1 10:30:11 RESOLUTION: Documenting in the spec the redirect mechanism in a new section 5.1.3 (that will point to 5.2) as an option (to be used at the server's discretion) and we make sure that the reader understands the two possible options 5.1.2 and 5.1.3 at server discretion 10:30:24 RRSAgent, draft minutes 10:30:24 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html hackerjack 10:31:42 ACTION: Davy to edit a new section 5.1.3 named "Server triggered redirect" that documents fully this solution 10:31:42 Created ACTION-176 - Edit a new section 5.1.3 named "Server triggered redirect" that documents fully this solution [on Davy Van Deursen - due 2010-06-23]. 10:33:20 Erik: admin stuff. If we stop the normal agenda at 1400 that gives Davy time to do the edits, us all to wrap up, and end at 5. 10:35:26 Raphael: let's drop test cases, not important for LC 10:36:31 Raphael: proposal: we allow for a testcase f2f in september, if needed. 10:37:29 Raphael: proposal: after lunch we do the "wednesday morning agenda". 10:37:49 [lunch break] 10:39:58 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 11:02:04 -Meeting_Room 11:02:05 IA_MFWG()3:00AM has ended 11:02:05 Attendees were Meeting_Room, silvia 11:21:18 scribenick: raphael 11:21:31 Topic: 2. ISSUE-4: Discovery of Track and Named fragments 11:29:39 Zakim has left #mediafrag 11:32:26 ISSUE-4? 11:32:26 ISSUE-4 -- Should we pre-define some track names? -- open 11:32:26 http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/4 11:34:14 Raphael: http://www.w3.org/WAI/PF/HTML/wiki/Media_MultitrackAPI 11:34:27 ... how do we know which tracks are available for selection 11:34:42 ... could be extended to, how do we know which id/names are available for selection 11:35:13 Yves: why do we care? 11:35:30 ... our task is to enable the construction of the selection and the protocol handling 11:35:42 ... how the discovery is performed does not matter too us 11:37:08 Jack: all what we are saying is that track names are UTF-8 strings 11:37:10 I agree with Yves - I think with point to things like ROE and the JavaScript API, we have done all we can to propose a solution to discovery of track names 11:45:37 Jack: we all agree, let's replace the ed note in the section 4.3.3 by a paragraph stating that they are no pre-defined track names 11:46:13 ... but we mention the existing discovery mechanism such as ROE, Media Annotations, HTML5 MediaMultiTrack API 11:46:46 Davy: I'm editing the spec right now 11:46:47 Raphael: ok, all agreed, Davy will fix the text 11:46:54 Raphael: can we close this issue? 11:47:26 yes, please 11:48:23 comment ISSUE-4 track names discovery is handled by others and we list example techniques 11:48:27 close ISSUE-4 11:48:27 ISSUE-4 Should we pre-define some track names? closed 11:48:57 Topic: 3. ISSUE-5 11:49:01 ISSUE-5? 11:49:01 ISSUE-5 -- Handling spatial cropping requires information at client-side -- open 11:49:01 http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/5 11:49:38 Raphael: is this clear that in the case of the spatial dimension, nothing is sent to the server? 11:49:42 Davy: yes 11:50:09 ... in 5.1.2 11:50:11 ... spatial media fragments are typically not expressible in terms of byte ranges. Spatial fragment extraction would thus require transcoding operations resulting in new resources rather than fragments of the original media resource. As described in section 3 URI fragment and URI query, spatial fragment extraction is in this case better represented by URI queries. 11:50:39 comment ISSUE-5 not relevant anymore 11:50:46 close ISSUE-5 11:50:46 ISSUE-5 Handling spatial cropping requires information at client-side closed 11:51:20 Topic: 4. ISSUE-6 11:51:27 ISSUE-6? 11:51:27 ISSUE-6 -- Temporal clips that require transcoding -- open 11:51:27 http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/6 11:56:40 Erik: The section 3.1 is crystal clear 11:56:43 ... Resources that are "fit" can therefore be addressed with a URI fragment. Resources that are "conditionally fit" can be addressed with a URI fragment with an additional retrieval action that retrieves the modified syntax elements but leaves the codec data untouched. Resources that are "unfit" require transcoding. Such transcoded media fragments cannot be addressed with URI fragments, but only with URI queries. 11:56:50 ... that closes the ISSUE 11:56:56 jakub has joined #mediafrag 11:57:24 ... editor note needs to be removed? 11:57:36 ... link towards the UC doc needs to be modified 11:58:36 ... no link to fix 12:01:28 Davy: ed note removed 12:01:32 close ISSUE-6 12:01:32 ISSUE-6 Temporal clips that require transcoding closed 12:02:07 Jack: references are ugly, need to fix this 12:03:40 Jack: Issue is: unmatch element in the references, but xhtml document. 12:03:42 Topic: 5. ISSUE-7 12:03:49 ISSUE-7? 12:03:49 ISSUE-7 -- User Agent Media Fragment Resolution and Processing -- open 12:03:49 http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/7 12:04:35 Yves: this is the protocol description 12:04:39 ... this is now done! 12:04:49 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 12:05:06 comment ISSUE-7 This is the protocol description now nicely described 12:05:16 close ISSUE-7 12:05:16 ISSUE-7 User Agent Media Fragment Resolution and Processing closed 12:05:37 Topic: 6. ISSUE-12 12:05:42 ISSUE-12? 12:05:42 ISSUE-12 -- What's the relationship between Images (CSS) Sprites and the spatial dimension of the Media Fragments URI scheme? -- open 12:05:42 http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/12 12:07:09 Raphael: use of the spatial dimension for highlighting region (current implementation) or cropping (sprite) 12:07:19 Jack: this is 2 different use cases 12:07:36 Yves: no, the first intent is to define a region ... and not to define what to do with it 12:08:03 Jack: yes, but in the temporal case, we provide more information 12:08:20 ... perhaps in Section 7, we should write, "unlike the temporal dimension ..." 12:09:34 Jack: I sugges to edit Section 7.1 to clarify this ... 12:10:09 I agree 12:10:16 ... what I'm doing is changing the paragraph "For a spatial URI fragment, it is recommended to emphasize the spatial region during playback. For instance, the spatial region could be indicated by means of a bounding box or the background (i.e., all the pixels that are not contained within the region) could be blurred or darkened. " 12:10:36 ... to state we have two use cases: 1/ highlight 2/ sprite 12:17:17 Jack: done 12:17:42 comment ISSUE-12: the third paragraph of Section 7.1 has been updated 12:17:46 close ISSUE-12 12:17:46 ISSUE-12 What's the relationship between Images (CSS) Sprites and the spatial dimension of the Media Fragments URI scheme? closed 12:22:04 Topic: 7. Section 4.1 12:22:31 Raphael: is the pseudo algorithm written by Philip useful? 12:30:26 Yves and Jack: the pseudo code is useless 12:30:45 Erik: +1 12:31:00 Jack: we are not writing workaround for existing sloppy implementations 12:34:04 Raphael: I see 3 options: a/ statu quo; b/ move 4.1.1 and 4.1.2 down in an Annex or in Section 7? ; c/ remove these 2 sub-sections 12:34:25 b, c 12:34:40 b, c 12:34:43 b, c (in order) 12:34:52 b 12:34:59 b 12:36:30 Jack: new Appendix D: notes on parsing media fragment URIs 12:36:44 Jack: I'm editing 12:37:07 ACTION: raphael to email philip about this decision 12:37:07 Sorry, couldn't find user - raphael 12:37:16 ACTION: troncy to email philip about this decision 12:37:16 Created ACTION-177 - Email philip about this decision [on Raphaël Troncy - due 2010-06-23]. 12:38:39 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 12:43:28 close ACTION-177 12:43:28 ACTION-177 Email philip about this decision closed 12:52:19 Raphael: mail sent 12:52:50 Jack: I'm moving the editorial note of Silvia in ex 4.1.2 into Section 7 and drafting a new paragraph 12:53:01 Topic: 8. Internaitonalization 12:53:32 Raphael: Yves sent an email yesterday to the i18n group 12:53:34 ... see http://lists.w3.org/Archives/Public/public-media-fragment/2010Jun/0022.html 12:53:45 ... I suggest to open an Issue for tracking this 12:54:08 ISSUE: Media Fragment track names and IRIs 12:54:08 Created ISSUE-17 - Media Fragment track names and IRIs ; please complete additional details at http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/17/edit . 12:56:16 Silvia suggested on the list to redefine the production rules in terms of rfc 3987 rather than 3986 12:56:23 Yves: I think it would be more difficult 12:56:27 ... we don't know the encoding, etc. 12:56:41 ... let's i18n fix this which touches several groups 12:59:18 Topic: 9. ISSUE-14 12:59:20 ISSUE-14? 12:59:20 ISSUE-14 -- How to deal with embedded time stamps -- open 12:59:20 http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/14 13:04:56 Jack: for container-based timestamps (which may have gaps), we think there is no issue 13:05:03 ... gaps will be preserved so to speak 13:06:03 ... for the other case, smpte timestamps with labels ... it is almost as id 13:06:07 ... there are many issues 13:06:29 ... not being 0 based is one issue, but you can also have strange gaps 13:06:38 ... unclear what a media player will do with it 13:16:07 Jack: I'm adding a new sentence in the section 7.3 13:16:48 ... "Embedded Timecodes: " 13:16:56 ... in order to close this issue 13:23:02 s/Embedded/SMPTE 13:23:18 RRSAgent, draft minutes 13:23:18 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html hackerjack 13:26:09 Room: problem regarding the units requested versus the units used in the response 13:26:17 ... should it be enforced to be the same? 13:26:27 ... should we say something at all about this? 13:27:14 Yves: we say nothing since we infer that people will use smpte time code know what they are doing 13:27:58 ISSUE-14? 13:27:58 ISSUE-14 -- How to deal with embedded time stamps -- open 13:27:58 http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/14 13:28:16 close ISSUE-14 13:28:16 ISSUE-14 How to deal with embedded time stamps closed 13:29:46 ISSUE-16? 13:29:46 ISSUE-16 -- Combining axis is probably not going to be done by LC, but we should write somewhere that this is doable -- open 13:29:46 http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/16 13:30:54 Davy: the biggest issue was with the spatial dimension 13:30:58 issue-13? 13:30:58 ISSUE-13 -- Write a IETF draft for proposing how to register the fragment scheme for all media types -- open 13:30:58 http://www.w3.org/2008/WebVideo/Fragments/tracker/issues/13 13:31:21 ... we can close it since we are doign combination now, e.g. track + time 13:31:29 close ISSUE-16 13:31:29 ISSUE-16 Combining axis is probably not going to be done by LC, but we should write somewhere that this is doable closed 13:32:04 Yves: I have discussion with larry masinter and IETF about this 13:32:18 ... we don't need this for Last Call 13:32:22 ... ongoing issue 13:32:38 ... we need to figure out what would be the process, in our own spec, in a RFC, etc. 13:32:59 Topic: 10. Last Call Resolution 13:33:04 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 13:33:04 +1 13:33:08 +1 13:33:21 PROPOSED: the document is good enough to be a Last Call 13:33:24 +1 13:33:24 +1 13:33:27 +1 13:33:28 +1 13:33:28 +1 13:33:29 +1 13:33:35 Silvia has agrees also 13:33:41 no objections 13:33:46 s/agrees/agreed/ 13:33:51 s/agrees/agreed 13:34:23 see http://www.w3.org/2005/08/online_xslt/xslt?xmlfile=http://www.w3.org/2005/08/01-transitions.html&xslfile=http://www.w3.org/2005/08/transitions.xsl&docstatus=lc-wd-tr 13:35:00 Silvia, please review the doc (the one by end of this week) 13:35:11 RESOLUTION: Publish the document as a Last Call Working Draft next week 13:35:25 Raphael: yves will complete his actions by Sunday 13:35:50 ... davy will have finished 176 today 13:35:54 ... we need internal review 13:35:58 Erik: I suggest Silvia 13:37:08 ACTION: Silvia to review the complete document, remove unnecessary editorial notes before publication 13:37:09 Created ACTION-178 - Review the complete document, remove unnecessary editorial notes before publication [on Silvia Pfeiffer - due 2010-06-23]. 13:37:39 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 13:45:03 Raphael: we need to decide on which groups we want and wish to have reviews from 13:53:08 ... MUST working groups: HTML WG, Media Annotations WG, SYMM, Semantic Web CG, Hypertext CG, TAG, IETF 13:53:35 ... WISH to have additional reviews from: CSS, SVG, TimedText, I18N, Audio XG 13:54:39 Yves: deadline for comments? 13:55:37 ... end of August! 13:57:56 Topic: 11. AOB 13:58:11 Raphael: Media Annotations LCWD 13:58:17 ... how do we make a group reply? 13:58:30 ... or do we make individual replies? 13:59:11 Jack: I want to read this with my media fragments hat on 13:59:23 ... discuss by email about a group reply? 14:01:31 jack: people comment on their own name 14:01:55 ... write replies to our group when this is common issues for the MF WG 14:03:14 p 14:03:19 s/p// 14:04:08 Raphael: LCWD of Media annotations: Ontology = http://www.w3.org/TR/2010/WD-mediaont-10-20100608/ 14:04:18 ... APi: http://www.w3.org/TR/2010/WD-mediaont-api-1.0-20100608/ 14:05:34 ... we provide a group reply with all the collected issues that interest the group 14:05:49 ... we dedicate one of the upcoming telecon about this 14:08:45 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 14:14:26 on behalf of the chairs ... a BIG thanks to all contributors of this F2F ... LC here we come :) 14:23:49 Davy: section 5.1.3 now completed! 14:23:55 Room: reviewing ... 14:23:56 Thx Davy! 14:24:10 close ACTION-176 14:24:10 ACTION-176 Edit a new section 5.1.3 named "Server triggered redirect" that documents fully this solution closed 14:24:20 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 14:24:58 Frank: perhaps add in the reference section a ref to the Link Header 14:33:30 Added ref to the Web Linking draft 14:33:31 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael 14:35:24 thanks davy 14:35:28 Meeting successful 14:35:31 [adjourned] 14:35:40 I have made the request to generate http://www.w3.org/2010/06/16-mediafrag-minutes.html raphael