Intent to unship: URL.createObjectURL(MediaStream)

[Andrea Marchesini]

Per spec ( https://w3c.github.io/mediacapture-main/ ), this was removed in
2013.
I introduced a deprecated message in bug 1334564, the 7th, February 2017.

I think it's time to remove this method completely. I wrote the patch in
bug 1454889.

About other browsers:
. chrome has a deprecated message as well but the method has not removed
yet: https://bugs.chromium.org/p/chromium/issues/detail?id=591719
. safari throws
. I haven't checked edge (I don't run windows locally)
. We have WPT.

[Anne van Kesteren]

On Mon, Apr 23, 2018 at 9:50 AM, Andrea Marchesini
<amarc...@mozilla.com> wrote:
> . I haven't checked edge (I don't run windows locally)

Ask for a BrowserStack account (not entirely sure who arranges these
though, I got mine via jst).

Edge still supports it:
https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/17021183/.


--
https://annevankesteren.nl/

[Mats Palmgren]

On 4/23/18 10:01 AM, Anne van Kesteren wrote:
> On Mon, Apr 23, 2018 at 9:50 AM, Andrea Marchesini
> <amarc...@mozilla.com> wrote:
>> . I haven't checked edge (I don't run windows locally)
>
> Ask for a BrowserStack account (not entirely sure who arranges these
> though, I got mine via jst).

Or you can get a gratis Win10 VM here:
https://developer.microsoft.com/en-us/microsoft-edge/tools/vms/

/Mats

[Mats Palmgren]

On 4/23/18 10:01 AM, Anne van Kesteren wrote:

> On Mon, Apr 23, 2018 at 9:50 AM, Andrea Marchesini
> <amarc...@mozilla.com> wrote:
>> . I haven't checked edge (I don't run windows locally)
>
> Ask for a BrowserStack account (not entirely sure who arranges these
> though, I got mine via jst).

[Boris Zbarsky]

On 4/23/18 3:50 AM, Andrea Marchesini wrote:
> I introduced a deprecated message in bug 1334564, the 7th, February 2017.

When we have this data, it's worth mentioning what telemetry shows for
such a deprecation message.

I just checked and out of about 5.8 billion pageloads on Beta 60, about
160,000 used this method [1]. For Beta 59 those numbers are 7.6 billion
and 700,000 respectively [2].

So about .01% of pageloads are using this feature on beta 59; about
.003% on beta 60.

That does seem low enough that removal might be reasonable, as long as
there isn't some site like Hangouts which uses it, and is not usable in
Firefox yet but we would like to be usable...

-Boris

[1]
https://telemetry.mozilla.org/new-pipeline/dist.html#!cumulative=0&end_date=2018-04-18&keys=__none__!__none__!__none__&max_channel_version=beta%252F60&measure=USE_COUNTER2_DEPRECATED_URLCreateObjectURL_MediaStream_PAGE&min_channel_version=null&processType=*&product=Firefox&sanitize=1&sort_keys=submissions&start_date=2018-03-04&table=0&trim=1&use_submission_date=0

[2]
https://telemetry.mozilla.org/new-pipeline/dist.html#!cumulative=0&end_date=2018-03-01&keys=__none__!__none__!__none__&max_channel_version=beta%252F59&measure=USE_COUNTER2_DEPRECATED_URLCreateObjectURL_MediaStream_PAGE&min_channel_version=null&processType=*&product=Firefox&sanitize=1&sort_keys=submissions&start_date=2017-11-13&table=0&trim=1&use_submission_date=0

[Martin Thomson]

This seems like it's about time. bz's numbers aren't awe-inspiring,
but low enough that I think we'll manage.

I checked, and there was a question about reviving this in the spec,
but that resolved over a year ago (just before when the deprecated
message was added in Firefox, perhaps coincidentally).

https://github.com/w3c/mediacapture-main/issues/404

On Mon, Apr 23, 2018 at 9:50 AM, Andrea Marchesini
<amarc...@mozilla.com> wrote:

> Per spec ( https://w3c.github.io/mediacapture-main/ ), this was removed in
> 2013.

> I introduced a deprecated message in bug 1334564, the 7th, February 2017.
>

> I think it's time to remove this method completely. I wrote the patch in
> bug 1454889.
>
> About other browsers:
> . chrome has a deprecated message as well but the method has not removed
> yet: https://bugs.chromium.org/p/chromium/issues/detail?id=591719
> . safari throws

> . I haven't checked edge (I don't run windows locally)

> . We have WPT.
> _______________________________________________
> dev-platform mailing list
> dev-pl...@lists.mozilla.org
> https://lists.mozilla.org/listinfo/dev-platform

[Randell Jesup]

I was behind on m.d.platform, I'm afraid.

tl;dr: This is Long, but in the end I support removal of
createObjectURL(MediaStream) in 62.

For anyone who wants to see why, read below. It does make some
important points to think about when considering removal, especially
about how to gauge usage.

>On 4/23/18 3:50 AM, Andrea Marchesini wrote:
>> I introduced a deprecated message in bug 1334564, the 7th, February 2017.
>
>When we have this data, it's worth mentioning what telemetry shows for such
>a deprecation message.
>
>I just checked and out of about 5.8 billion pageloads on Beta 60, about
>160,000 used this method [1]. For Beta 59 those numbers are 7.6 billion
>and 700,000 respectively [2].
>
>So about .01% of pageloads are using this feature on beta 59; about .003%
>on beta 60.

So: I Really Really want to see createObjectURL(MediaStream) go away - I
fought for srcObject, we got it into the spec, and I fought attempts to
ignore it by Google. And I fought attempts to reinstate it.

That said...

>That does seem low enough that removal might be reasonable, as long as
>there isn't some site like Hangouts which uses it, and is not usable in
>Firefox yet but we would like to be usable...

I think first-tier sites like Hangouts, appear.in, WebEx, talky.io, etc
will be fine and likely are using srcObject already (or will quickly
switch).

Second-tier sites I suspect will have a fair number get hit by it, but
likely they'll mostly correct it quickly. Some may well do the "use
Chrome" bit. Some do that already (Slack, I'm looking at you!!)

Small sites, demos, unusual uses, examples all over the web: they'll
mostly stay broken. Of course no matter when we change a lot of them
will break - almost by definition they're not being updated. (Some blog
posts/demos might get updated or people will comment "change to srcObject".)

So, I'm torn. I want to see it gone, and usage will never be 0.
However... With lots of (not all) web features, disabling it doesn't
kill the entire page/application. Perhaps something doesn't look right,
or some subset of the page doesn't work. With WebRTC (and friends like
WebAudio), if the connection the media elements fails, then the entire
application is likely fubar.

And until not that long ago, Chrome didn't even support srcObject, let
alone promote it in all their demos, examples, etc. They added support
for it in Chrome 52, less than 2 years ago. They did an
IntentToDeprecate in January, with plans to deprecate in 65 or 66 and remove
in 68 - 70 was suggested (because they're worried too many sites still rely
on it). 66 only just shipped a few weeks ago. Their demo sites as of
January still mostly used srcObject (they did a PR for HTML5 Rocks after
deciding to deprecate).

Deprecation in blink discussion:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/tWzutytXsqc

Safari supported srcObject by late 2017 in Safari 11 (perhaps also in
10), and as of early this year had already removed
createObjectURL(MediaStream).

We announced deprecation almost 6 months before Chrome even supported
srcObject, so when we announced deprecation isn't really the driving
factor here.

When comparing Chrome's usage for createObjectURL(MediaStream) and
srcObject, it's clear that while srObject is getting used more in the
last ~3 months (since the decision to deprecate??), and is used more
than createObjectURL, usage of createObjectURL isn't decreasing - if
anything it's slightly trending up. And ~1/4 of all uses are
createObjectURL.

https://www.chromestatus.com/metrics/feature/timeline/popularity/1606
https://www.chromestatus.com/metrics/feature/timeline/popularity/1603

This goes back to Boris's discussion of the usage in telemetry -
unfortunately, that doesn't tell us how much the alternative/replacement
for the deprecated feature is used. (For future telemetry on
feature-disabling, this would be a good idea when it's feasible.) And
of course we only have beta stats, not release (which chrome has).

BTW, this is the 'real' bug in Chrome for removing it:
https://bugs.chromium.org/p/chromium/issues/detail?id=800767&desc=2
The patch to the Deprecation file tells devs it'll be gone in 68.

At 1.5-2 months per Chrome release, that means that in about 2.5 months
it will be removed from Chrome, if they don't delay removal. They might.


So, in the end, I absolutely support removing it, since if we remove in
62, it will get to release in about Sep 9th, which is likely *after*
Chrome actually removes it (likely around late July or August). If
Chrome delays to 70 as someone in the thread suggested (and I see as
possible), that would be perhaps October-ish.

Kill it with fire. :-)

>-Boris
>
>[1]
>https://telemetry.mozilla.org/new-pipeline/dist.html#!cumulative=0&end_date=2018-04-18&keys=__none__!__none__!__none__&max_channel_version=beta%252F60&measure=USE_COUNTER2_DEPRECATED_URLCreateObjectURL_MediaStream_PAGE&min_channel_version=null&processType=*&product=Firefox&sanitize=1&sort_keys=submissions&start_date=2018-03-04&table=0&trim=1&use_submission_date=0
>
>[2]
>https://telemetry.mozilla.org/new-pipeline/dist.html#!cumulative=0&end_date=2018-03-01&keys=__none__!__none__!__none__&max_channel_version=beta%252F59&measure=USE_COUNTER2_DEPRECATED_URLCreateObjectURL_MediaStream_PAGE&min_channel_version=null&processType=*&product=Firefox&sanitize=1&sort_keys=submissions&start_date=2017-11-13&table=0&trim=1&use_submission_date=0

--
Randell Jesup, Mozilla Corp
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