862382 - Linksys WVC54GCA webcam view no longer works in FF 20

Status: RESOLVED DUPLICATE of bug 861595

(Core :: Graphics: ImageLib, defect)

Description

[mrc]

Attachment: Screencap of page with no video

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:20.0) Gecko/20100101 Firefox/20.0
Build ID: 20130409194949

Steps to reproduce:

I can access the webcam settings and homepage, but the View option no longer display the cam feed ever since upgrading FF from 19.x to 20.0.1.


Actual results:

The View page comes up, minus the actual image/video.  The spinning green "loading" circle continues indefinitely.  See screenshot.  The only mention of this I could find elsewhere is in the forums: https://support.mozilla.org/en-US/questions/951765  I can provide access to one of my cameras to help troubleshoot/fix.


Expected results:

The view page should come up with the image/video.

Comment 1

[Stefan W.]

I experienced the same issue, the exact same webcam is used.

After setting the browser to offline mode via File->Work offline it displays the image of the exact second where you enabled offline mode. After going back to online mode and reloading the page via F5 the video shows correctly - which leads me to the guess that there has to be something wrong with the live display and not the stream itself. Also the video stream gets transferred to the client without any problem.

The camera has been working fine in all firefox versions prior to 20.0.

Comment 2

[Lou Mergens]

I have the same Cam with the same Problem. I use the same way with offline and online switch to resolve it....i hope Mozilla can fix the Problem soon

Comment 4

[Matthew Gregan [:kinetik]]

It looks like these devices support some form of MPEG-4 and MJPEG.  Can you confirm which format you're using? There have been changes to handling of both recently.  Do you still see the problem in a current Nightly build?

But given the Firefox 19 to 20 window, this is probably a regression from bug 799315, suggesting MPEG-4 and that previous versions were probably falling back (either to MJPEG or using Flash for playback?).  Toggling the pref media.windows-media-foundation.enabled to false will confirm if bug 799315 is implicated.

It'd be very useful to have a saved copy of the page and the video stream to debug this further.

Comment 5

[Chris Pearce [:cpearce (Not reading bugmail)]]

media.windows-media-foundation.enabled should be false in FF20, it was preffed on in 21, but bug 799315 does seem like the most likely culprit.

Could you try preffing media.windows-media-foundation.enabled on and see if that helps? A link to a camera feed (if possible) would be very helpful. You can email it directly to me if you don't want to add it to a comment here.

Comment 6

[mrc]

I tried changing that to True and that did not help things. I also emailed you a camera link.

Comment 7

[Chris Pearce [:cpearce (Not reading bugmail)]]

Thanks, I was kindly emailed links to two webcams (thanks very much!) and have narrowed the regression range down in Nightly builds. That last good build is 2012-12-05, so that means this regressed in this range:

http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=1942b4d64dc8&tochange=3c81e1c0d252

This also reproduces on Linux, and I see the following error in the console on Linux in a locally built build that reproduces the bug:

JPEG decoding error:
Unsupported marker type 0x7f

This isn't a bug in HTML5 <video>, it's an image decoding bug. I will try narrowing the range further by doing local builds.

Comment 8

[Joe Drew (not getting mail)]

Seth and I have been kicking around the idea that things like this are caused by bug 791258, but I don't know if that one was a regression.

Comment 9

[Seth Fowler [:seth] [:s2h]]

Hmm, could bug 792438 be involved? Pinging Patrick.

Comment 10

[Chris Pearce [:cpearce (Not reading bugmail)]]

I've done a revision bisection:

Last good revision:
17278474949a	Ethan Hugg — Bug 814329 Protect fim_process_event from NULL input r=jesup

First bad revision:
6c63bb77ddef	Patrick McManus — bug 792438 - part 0. imagelib proxies should share load group root r=joedrew

So this is definintely a regression from bug 792438.

Comment 11

[Patrick McManus [:mcmanus]]

hey chris, a fix for 792438 was checked into nightly recently. It basically reverts any changes imglib should be able to see. Does this still happen on the most recent nightly?

Comment 12

[Chris Pearce [:cpearce (Not reading bugmail)]]

On latest Nightly I saw a flash of the image, and then nothing. So it looks like we're getting the first frame, but then nothing after that.

Comment 13

[Lou Mergens]

Sorry for the Delay, now i switched my Webcam  online again! Thanks for all the Help  and i hope you can find a Solution for  my Webcam-Problem

http://loumergens.dyndns.org/img/main.cgi?next_file=main.htm

MFG Ludger Mergens

Comment 14

[Matt W.]

Greetings. I am joining in this discussion, we use a couple of these webcams for viewing birdfeeders at our facility. Many thanks to Lou Mergens for supplying a publicly available cam for testing, sorry I'm not allowed to do that, but ours are identical and doing the same thing. Willing to help out and try different things as needed. We use both Windows and Linux (OpenSUSE). Thanks.

Matt W.

Comment 15

[Seth Fowler [:seth] [:s2h]]

I can't reproduce the problem here (OS X, latest Nightly). Is there anyone who can?

Comment 16

[Matt W.]

Hi Seth, Just visit Lou's URL ...

http://loumergens.dyndns.org/img/main.cgi?next_file=main.htm

You'll see the Linksys page come up and then the status bar says "Transferring data...". Normally that would last only a moment, and then the video will display inside of this page (and you could see this using Firefox 17.x) but with Firefox 20 it gets stuck there and never displays the video. Confirmed on two Windows and one Linux host. Suggest trying the URL with Firefox 17.x to see how it is supposed to work, and then try with Firefox 20.

Comment 17

[Seth Fowler [:seth] [:s2h]]

Matt, that was how I tried to reproduce the problem, indeed. On my machine it seems very intermittent. Most of the time it works perfectly for me, but after refreshing several times I've been able to reproduce the issue.

At this point, unless Patrick thinks differently, I am starting to believe that this is indeed a manifestation of bug 791258.

Comment 18

[Patrick McManus [:mcmanus]]

(In reply to Seth Fowler [:seth] from comment #17)
> Matt, that was how I tried to reproduce the problem, indeed. On my machine
> it seems very intermittent. Most of the time it works perfectly for me, but
> after refreshing several times I've been able to reproduce the issue.
> 
> At this point, unless Patrick thinks differently, I am starting to believe
> that this is indeed a manifestation of bug 791258.

I'm hoping to triage this next week.. I'm sorry about the lag.

Comment 19

[Wayne E]

I'm experiencing identical issue with multiple versions of the camera.  None work in FF20 or greater.  Works great in FF19.0.2, and works great in IE.