Issue 357599 in chromium: Reduce video flicker due to 50/60Hz power network effects.

[chro...@googlecode.com]

Status: Assigned
Owner: mca...@chromium.org
CC: to...@chromium.org
Labels: Type-Bug Pri-2 Cr-Internals-Media-Capture OS-Linux OS-Mac
OS-Windows OS-Chrome Cr-Blink-WebRTC

New issue 357599 by mca...@chromium.org: Reduce video flicker due to
50/60Hz power network effects.
http://code.google.com/p/chromium/issues/detail?id=357599

Version: Developer build 260090
OS: Mac and Linux.

What steps will reproduce the problem?
1. Open Chrome http://goo.gl/qdwf6 near a light source of appropriate
magnitude, a fluorescent tube is great.
2. Observe some horizontal bands "walking" upwards/downwards the image, or
Moire patterns, or the screen flashes with a certain periodicity.
3. Either switch off the light source and see the undesired effects
disappear, or connect antibanding/flicker removal (f.i. in Mac with WebCam
settings or in Linux with GUVCViewer).

This bug is a placeholder for platform-specific actions.

A sample flicker video: http://player.vimeo.com/video/88202356

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[chro...@googlecode.com]

Updates:
Cc: pe...@chromium.org mflo...@chromium.org

Comment #1 on issue 357599 by mca...@chromium.org: Reduce video flicker due

to 50/60Hz power network effects.
http://code.google.com/p/chromium/issues/detail?id=357599

(No comment was entered for this change.)

[chro...@googlecode.com]

Updates:
Cc: jan...@chromium.org

Comment #3 on issue 357599 by mca...@chromium.org: Reduce video flicker due

to 50/60Hz power network effects.
http://code.google.com/p/chromium/issues/detail?id=357599

(No comment was entered for this change.)

[chro...@googlecode.com]

Comment #4 on issue 357599 by jan...@chromium.org: Reduce video flicker

due to 50/60Hz power network effects.
http://code.google.com/p/chromium/issues/detail?id=357599

ETA Windows?

[chro...@googlecode.com]

Updates:
Labels: merge-merged-git-svn

Comment #5 on issue 357599 by bugdro...@chromium.org: Reduce video flicker

due to 50/60Hz power network effects.

http://code.google.com/p/chromium/issues/detail?id=357599#c5

The following revision refers to this bug:

https://chromium.googlesource.com/chromium/src.git/+/7c5c4d1eb2ef86d5fc612fa5b85cdb032b0b2622

commit 7c5c4d1eb2ef86d5fc612fa5b85cdb032b0b2622
Author: mca...@chromium.org
<mca...@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98>
Date: Wed Apr 23 15:35:54 2014 +0000

Win DirectShow: connect antibanding/anti-flicker where supported.

Some Win UVC devices implement the
PROPSETID_VIDCAP_VIDEOPROCAMP API [1]. For them, set
the anti-banding/anti-flicker/power frequency rejection to
the appropriate frequency (50/60Hz).

This settings sinks all the way into the WebCam DSP so
it's hard to know for sure what is being done, similarly
to http://crrev.com/216263007, although is likely
to avoid certain exposure rates non-multiples of the
power frequency.

IAMVideoProcAmp interface provides access to the
same IKsPropertySet.

[1]
http://msdn.microsoft.com/en-us/library/windows/hardware/ff568122(v=vs.85).aspx

BUG=357599

Review URL: https://codereview.chromium.org/220193006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@265646
0039d316-1c4b-4281-b951-d872f2087c98

[chro...@googlecode.com]

Comment #6 on issue 357599 by bugdro...@chromium.org: Reduce video flicker

due to 50/60Hz power network effects.

http://code.google.com/p/chromium/issues/detail?id=357599#c6

------------------------------------------------------------------
r265646 | mca...@chromium.org | 2014-04-23T15:35:54.328610Z

Changed paths:
M
http://src.chromium.org/viewvc/chrome/trunk/src/media/video/capture/win/video_capture_device_win.cc?r1=265646&r2=265645&pathrev=265646
M
http://src.chromium.org/viewvc/chrome/trunk/src/media/video/capture/win/video_capture_device_win.h?r1=265646&r2=265645&pathrev=265646

Win DirectShow: connect antibanding/anti-flicker where supported.

Some Win UVC devices implement the
PROPSETID_VIDCAP_VIDEOPROCAMP API [1]. For them, set
the anti-banding/anti-flicker/power frequency rejection to
the appropriate frequency (50/60Hz).

This settings sinks all the way into the WebCam DSP so
it's hard to know for sure what is being done, similarly
to http://crrev.com/216263007, although is likely
to avoid certain exposure rates non-multiples of the
power frequency.

IAMVideoProcAmp interface provides access to the
same IKsPropertySet.

[1]
http://msdn.microsoft.com/en-us/library/windows/hardware/ff568122(v=vs.85).aspx

BUG=357599

Review URL: https://codereview.chromium.org/220193006

-----------------------------------------------------------------

[chro...@googlecode.com]

Comment #7 on issue 357599 by jan...@chromium.org: Reduce video flicker

due to 50/60Hz power network effects.
http://code.google.com/p/chromium/issues/detail?id=357599

Looks good on Windows.

We did however discover that there are some lights that still causes some
flicker e.g. the anti flicker algorithm does not select a shutter speed
(exposure) that's evenly divisible by the AC frequency, it could just be
that the camera does not have the "resolution" or "steps" in shutter speed
to cover this.

However Chrome does enable the antiflicker option for the camera hence it's
working, the observations above are a camera/driver limitation.

[chro...@googlecode.com]

Comment #12 on issue 357599 by src...@woolworths.com.au: Reduce video

flicker due to 50/60Hz power network effects.

https://code.google.com/p/chromium/issues/detail?id=357599

Hi, we are also having this issue on Chromebooks and CFM units in certain
offices in Australia. We have raised this with our google contacts who
directed us to this Issue.

[chro...@googlecode.com]

Comment #13 on issue 357599 by mca...@chromium.org: Reduce video flicker

due to 50/60Hz power network effects.
https://code.google.com/p/chromium/issues/detail?id=357599

srcrew@, what are the effects you are seeing? Can you describe the camera
model used and the lightning in detail? Can you confirm the system timezone
for your machine(s) is (are) configured correctly and that, according to
[1], you should have 50Hz power line.

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/media/video/capture/video_capture_device.cc&sq=package:chromium&type=cs&q=GetPowerLineFrequencyForLocation&l=65

[chro...@googlecode.com]

Comment #14 on issue 357599 by src...@woolworths.com.au: Reduce video

flicker due to 50/60Hz power network effects.
https://code.google.com/p/chromium/issues/detail?id=357599

Hi, We are seeing a flickering of the image in the affected office (Lines
up and down, consistent with frequency issues). We have confirmed it is to
do with the fluro lighting (Turning the lights off, issue goes away). Power
in Australia is generally set to 50Hz, and this issue in only happening in
older offices, generally have older fluro light fittings. The newer offices
with energy efficient lighting, we do not have the issue. (Very expensive
to retrofit 1000's of light fittings)

We are in Timezone GMT+9:30, we also have units in GMT+10:00 and GMT+8:00
with the issues as well. Yes configured correctly for the timezone too.

In terms of models, we are using the Logitech c920 that comes with the
Chromebox for Meeting units. THe same model camera and the Logitech c615
also have the same issue on a standard chromebox. Also have the issue on mu
Pixel, Acer c720P and Samsung 550.

We are in the process too of rolling out 100 Chromebox for Meeting units,
and this is being noticed as an issue. If you need, we can get a video of
the issue.

[chro...@googlecode.com]

Comment #15 on issue 357599 by mca...@chromium.org: Reduce video flicker

due to 50/60Hz power network effects.
https://code.google.com/p/chromium/issues/detail?id=357599

srcrew@, can you try guvcview [1] (in Linux systems) or AmCap [2] (in
Windows platforms) and the C920 or any other USB cameras you might see
having issues? Using either program, just connect the WebCam and play with
the Deflickering settings (50Hz / 60Hz / Auto) and visually check if you
can remove the power coupling.


[1] http://guvcview.sourceforge.net/
[2] http://noeld.com/programs.asp?cat=video

[chro...@googlecode.com]

Comment #17 on issue 357599 by src...@woolworths.com.au: Reduce video

flicker due to 50/60Hz power network effects.

https://code.google.com/p/chromium/issues/detail?id=357599

Have tested on a Windows XP PC with a logitech c920, using AmCap.

Setting to PAL - 50Hz, webcam performs fine with no flickering
Setting to NTSC - 60Hz, webcam flickers.

On the laptop, there was no power coupling to remove.

DO you need anymore info?

[chro...@googlecode.com]

Comment #18 on issue 357599 by mca...@chromium.org: Reduce video flicker

due to 50/60Hz power network effects.
https://code.google.com/p/chromium/issues/detail?id=357599

srcrew@, thanks, another test is needed:

- Plug the C920 camera, launch AmCap and set it to remove 60 Hz frequency.
- You should see the flicker of the coupled noise.
- Close AmCap, run Chrome,
- Browse f.i. apprtc.appspot.com, allow capture from the C920 camera, wait
until you can see your own video feed -- do you see the coupled noise still?
- Reopen AmCap, open the C920, then open the configuration dialog, and
check if the setting for frequency removal is still at 60Hz -- this means
that Chrome couldn't set it to 50Hz and/or didn't recognise the time zone
for some reason. If that's the case, then we'd need to take a look at Debug
logs.

[chro...@googlecode.com]

Comment #19 on issue 357599 by src...@woolworths.com.au: Reduce video

flicker due to 50/60Hz power network effects.
https://code.google.com/p/chromium/issues/detail?id=357599

Hi, have done some more testing.

On my chromebook, being a pixel, with the external logitech c920 plugged
in, we no longer see the flickering. It seems somewhere around v37 of
chrome OS, it was resolved for chromebooks

However, we still see the issue on the Chromebox for Meetings unit, running
v37 of chrome OS. Further investigation show, we only see the issue when
the kiosk app for hangouts is running. If we break out of the kiosk app,
log in and start a hangout manually, there is no flickering. So just to
confirm, the issue now only lies in the CFM unit when the kiosk app is
running.

I did confirm on a windows XP machine running v35 of browser, the issue
existed. So either v36 or v37 resolved.

[chro...@googlecode.com]

Updates:
Cc: w...@chromium.org fisc...@chromium.org bul...@chromium.org
ser...@chromium.org

Comment #20 on issue 357599 by mca...@chromium.org: Reduce video flicker

due to 50/60Hz power network effects.
https://code.google.com/p/chromium/issues/detail?id=357599

Issue 304174 has been merged into this issue.