On Fri, Sep 16, 2022 at 11:19 PM Dale Curtis <dalecur...@chromium.org> wrote:
> Contact emailsdalecur...@chromium.org > > ExplainerNone > > Specificationhttps://github.com/w3c/webcodecs/issues/508 > > Summary > premultiplyAlpha tells ImageDecoder to multiply the alpha channel into the > RGB channels of decoded images. It was added to mirror the capabilities of > ImageBitmapOptions, but in retrospect doesn't make sense. > > Feature has no observable effects in primary use cases (drawing), but may > constrain implementations in suboptimal ways. E.g., requiring YUV be > converted to RGB. See https://github.com/w3c/webcodecs/issues/508 for a > more detailed description. Per consensus of WebCodecs spec editors and lack > of usage (0.000000339% - 0.00000687% of page loads per a UseCounter in > M105), we propose deprecating and removing this feature starting with M108. > What would breakage look like? What would happen to callers who still pass that option? > > Blink componentBlink>Media>WebCodecs > <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EMedia%3EWebCodecs> > > TAG reviewNot applicable > TAG review statusNot applicable > > Risks > It's possible that there exists some client which was accessing raw pixel > data in JavaScript may observe that the alpha channel is no longer > premultiplied into RGB channels. Clients wishing for this functionality can > either do the multiply themselves or use createImageBitmap() to do this. > > Interoperability and Compatibility > > > > *Gecko*: Positive Firefox co-editor supports removal. > I don't know if we can consider this <https://github.com/w3c/webcodecs/issues/508#issuecomment-1248720618> a Mozilla position. At the same time, this seems small enough to not warrant an explicit issue. (and it's good to have consensus on the issue) > > *WebKit*: No signal > > *Web developers*: No signals > > *Other signals*: Microsoft co-editor supports removal. > > WebView application risks > > Does this intent deprecate or change behavior of existing APIs, such that > it has potentially high risk for Android WebView-based applications? > > > No. > > > > Debuggability > > n/a > > > Will this feature be supported on all six Blink platforms (Windows, Mac, > Linux, Chrome OS, Android, and Android WebView)?Yes > > Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> > ?Yes > > Flag namen/a > > Requires code in //chrome?False > > Tracking bughttps://bugs.chromium.org/p/chromium/issues/detail?id=1340190 > > Launch bughttps://bugs.chromium.org/p/chromium/issues/detail?id=1340190 > > Estimated milestones > > M108 > > > Anticipated spec changes > > Open questions about a feature may be a source of future web compat or > interop issues. Please list open issues (e.g. links to known github issues > in the project for the feature specification) whose resolution may > introduce web compat/interop risk (e.g., changing to naming or structure of > the API in a non-backward-compatible way). > https://github.com/w3c/webcodecs/pull/562 > > Link to entry on the Chrome Platform Status > https://chromestatus.com/feature/4560781148946432 > > This intent message was generated by Chrome Platform Status > <https://chromestatus.com/>. > > -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to blink-dev+unsubscr...@chromium.org. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAPUDrwc%3D7%2B2KC73kKTUdWUmvQNubFtZGphhh8DXgQXnr%2BJc_LQ%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAPUDrwc%3D7%2B2KC73kKTUdWUmvQNubFtZGphhh8DXgQXnr%2BJc_LQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAL5BFfWOBpNYeT%3DStH916MvxLNii402P_2SF4yH%3DLWkWH%3DyjWQ%40mail.gmail.com.
