SVG Working Group Teleconference -- 19 Jan 2012

<trackbot> Date: 19 January 2012

<scribe> scribenick: ChrisL

svg in border- and background-image

ed: raised in css images spec a long time ago

<ed> http://lists.w3.org/Archives/Public/www-style/2011Dec/0427.html

ed: asking what to do when border-image references an svg image.slices into 9,not clear how it should work - split beforeor after computing aspect ration
... elika says if we want it to work a particular way we should define it, not css

heycam: does css spec give us some hooks?

ed: not sure

<ed> http://dev.w3.org/csswg/css3-images/

heycam: section 3 in there

ed: also section 5.1

<ed> http://dev.w3.org/csswg/css3-images/#sizing

heycam: assume the way its defined is that you put the box for the outer svg element for the size before slicing up and nothing special to be done for aspect ration

ed: so you then stretch the bitmap

heycam: why

ed: where you renderthe border in a different aspect ratio

ChrisL: prefer to see this as clipping regions rather than re-scaling a raster result

heycam; like if you had an svg element in an htmldoc and set the width and height properties

<krit> krit in th channel yes

krit: is that on the border width of the element that uses svg as the border image?

heycam: maybe something can be done with intrinsiic aspect ratio?

krit: we have default values for width and height

heycam: the 300 150?

<krit> :)

heycam: whitespace on top and bottom makes it less useful. put PAR none
... if you use a raster image, the middle parts get scaled?

ChrisL: you can scale them or replicate them

<krit> http://www.css3.info/preview/border-image/

Tav: need an example

ChrisL: a lot of stretch, which is why its better to do as a clip and render atthe exact size needed

<ed> http://www.w3.org/TR/css3-background/

heycam: sounds like we know what we want to put in the spec

ed: is there a test suite

ChrisL: a bit

ed: and none for this particular case? can take action to make some

<scribe> ACTION: erik to make css3 background and border tests [recorded in http://www.w3.org/2012/01/19-svg-minutes.html#action01]

<trackbot> Created ACTION-3228 - Make css3 background and border tests [on Erik Dahlström - due 2012-01-26].

heycam: suggested text that eleika pointed to in her second mail ....

<heycam> http://lists.w3.org/Archives/Public/www-style/2012Jan/0809.html

krit: from the second email we would not be able to use repeat, looks the same as stretch

heycam; seems like its done after the

ChrisL: need to work out an integer number of repeats, scale slightly so theywork out to an integer multiple

krit: yes

heycam: if you have an explicit w&h on svg,can use that to do the repititions
... but if only an intrinsic aspect ratio

Tav: nothing to divide by

heycam: you dont have the intrinsic width

ChrisL: aim is to stretch the replicated part as little as possible

heycam: fit each of the 8 sections separately ... sounds sensible

ChrisL: we can define this and also give authoring guidelines to use it well

heycam; so weshould propose some wording back

ed: wanted to hear what group thought of responses so far. want what is best for authors
... so lets go for the separate sections
... getting a feel for what is most natural

heycam: good to work the same as for raster - consistency

ChrisL: while still gettingthe benefit of vector

heycam: yes
... someone should look into the repeating while preserving aspect ratio before repeating

<scribe> ACTION: chris to look into the repeating while preserving aspect ratio before repeating [recorded in http://www.w3.org/2012/01/19-svg-minutes.html#action02]

<trackbot> Created ACTION-3229 - Look into the repeating while preserving aspect ratio before repeating [on Chris Lilley - due 2012-01-26].

svg2 requirements

<heycam> http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#the_.27snapshotTime.27_attribute_on_the_.3Csvg.3E_element

heycam: we are on the tiny 1.2ones - i will edit as we go

snapshot time

heycam: i like that
... as a way to render animated documents for a static view
... easier to specify a particular time

ChrisL: it is good, but only for implementations that do animation and need a paster image

krit: if you have multipleanimations?

ChrisL: yes, its on the whole document

krit: and events
... events that are generated?

ChrisL: yes, you run the whole animation intil the clock is the snapshot time, then you render that state

heycam: in batik i did a set current time
... so you get all the syncbase stuff. not sure if hyperlinking dispatches the start and end events
... better to do like that rather thsn have two ways to seek through the document

ChrisL: suggest we accept the requirement and tighten up the spec on how you seek

ed: spec does not say the snapshotTime image must be rendered for anything in the svg spec itself, it's suggested it may be used for still images, but doesn't require it to be used by the UA

heycam: printingis a case, for html when would it

ChrisL: (the use case was a set of animated icons, whose animation was disabled, but re-enabled on user interaction like mouseover) :)

heycam: the snapshot time could be the base values before you run the animation

ChrisL: need to stop it being displayed at the start of the animation though

heycam: happy to bring this over - would still be metadata

ChrisL: would be good to add a fragment like the view ones, to say render at the snapshot time

ed: strange that its optional on 1.2T - we could tighten it up

resolution: svg2 will add snapshot time for animated documents and may specify how to get at the rendered image

the 'timelineBegin' attribute

http://www.w3.org/Graphics/SVG/WG/wiki/index.php?title=SVG2_Requirements_Input

http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#the_.27timelineBegin.27_attribute_on_the_.3Csvg.3E_element

heycam; wanted to get brian's input on the nextr few animation ones

<ed> here's an example of timelineBegin: http://dahlström.net/svg/smil/lennon-google-smil.svg

<heycam> http://www.w3.org/TR/SVGTiny12/struct.html#SVGElementTimelineBegin

heycam: ties into alignment with css animations, which do not wait for document load
... want to mail brian and ask before we decide on these

ChrisL: makes sense

ed: useful functionality, waiting for document load is poor for large files

<scribe> ACTION: cameron to mail brian about thesvgt 1.2 animation items [recorded in http://www.w3.org/2012/01/19-svg-minutes.html#action03]

<trackbot> Created ACTION-3230 - Mail brian about thesvgt 1.2 animation items [on Cameron McCormack - due 2012-01-26].

<heycam> http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#the_.27requiredFonts.27_and_.27requiredFormats.27_conditional_processing_attributes

the 'requiredFonts' and 'requiredFormats' conditional processing attributes

ChrisL: formats was to allow for audio and video where there is variable support

heycam: html5 does it differently without a switch
... is it useful for content outside of video

ed: for raster image formats and other special image formats; also for audio

heycam; should use same mechanism as video

ed: not so useful for image formats

heycam; handling fallback for raster images is not well specified, but how often do people use other formats

ChrisL: bitonal tiff is common for cad

krit: so on video and audio, html5 does not use requiredFormats

heycam; right you use the track and the first supported one is used

scribe: you cant have other svg displayed conditional on the format support tough

heycam: media types do not specify the codec
... what about codec registries

ChrisL; yes the intent is to add a parameter to the media type,to specify the codec

heycam; registry is for avi and wav containers

scribe: not clear its up to date

heycam: neutral on requiredFormats in general

krit; we don't need requiredFormats because html5 video and audio don't use it

ed: with downloadable fonts, requiredFonts is less useful

ChrisL: does add value if the font is 404, and it allows tro depend on a set of fonts being available. css does not have that although it has been requested

heycam; agree it is not otherwise available

ed: opera implements them both, not seen that much use. ok either way

ChrisL: with dl fonts its actually more useful to be able to do conditional based on a set of fonts

heycam; reqFonts is simpler than reqFornmats (no codec worries) so more in favor

scribe: still unsure about the switch-heavy approach in general

krit: neutral on requiredFonts

<ed> you can use the required* attributes without switch too

<ed> even if it's more useful with probably :)

heycam: accept requirement for requiredFonts

resolution: SVG2 wil adopt the requiredFonts attribute
... SVG2 will not adopt the requiredFormats attribute

the Progressive Rendering algorithm

http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#the_Progressive_Rendering_algorithm

ChrisL: this is good clarification

heycam; agree we should be more precise than with 1.1. Need to tie in with HTML5 document processing.

scribe: start with the text here and modify it wrt html5

resolution: SVG2 will add more precise text on progressive rendering, drawing on svgt 1.2 and html5

the <prefetch> element

<heycam> http://www.w3.org/Graphics/SVG/WG/wiki/SVG2_Requirements_Input#the_.3Cprefetch.3E_element

http://www.w3.org/TR/SVGTiny12/struct.html#PrefetchElement

ChrisL: its for explicit prefetch rather than relying on @w or @h zero

heycam; in scripting this can be done with new image - but this works for non scripted

scribe: has a bunch of attrs that are relevant for media, like how many seconds to prefetch and how much bandwidth to use(!)
... not sure about the media-specific things

ChrisL: why

heycam; conflict with html5, and not sure thay are super useful

krit; spec says ua can ignore the prefetch hint

heycam: can have an image with visibility: hidden which causes prefetch - but would not want the audio to start

ed: opera did not implement this for media, just for images

ChrisL: remember we resolved to have a audio voume property so itcould be prefetched and muted

heycam: since we can prefetch anyway, not sure how useful the optional prefetch hint is
... first para says svg 1.1does not define when referenced resources start downloading. we should define thst, to make vis: hidden prefetching reliable
... then we would not need prefetch element

krit: agree

ed: not that useful

ChrisL; ok

resolution: svg2 will not have the prefetch element but will clarify when resources start doanloading

<ed> i would like us to state whether resources start downloading as soon as you set the href, even if it's not appended to the document

<ed> similar to Image in html, e.g var img = new Image(); img.src = "foo"

- DRAFT -

SVG Working Group Teleconference

19 Jan 2012

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