InformAction Forums

I am posting this question again since the more recent threads I found are dated from 2009 and since this is Feb 2015 I am assuming some things have changed.

Whenever I play a Flash video (any video from any website) the video stutters but the audio is fine. Videos run fine in other browsers, and in Firefox the problem is definitely with the NoScript plugin since it is the only active plugin. I found older posts on this topic and did the following based upon those posts:

1. Turned off 'Enable hardware acceleration' in Flash settings. (no change)
2. Cleared all caches (no change)
3. In Flash allowed YouTube to cache 1MB data (using YouTube to test) (no change)
4. Changed volume using the volume slider in Flash (no change)
5. Turned off ClearClick protection for both trusted and untrusted sites (minimal change - stutter is less, but accelerates if the mouse is moved)
6. Unchecked "Show the NOSCRIPT element which follows a blocked SCRIPT" under Advanced -> Trusted (no change)

I am running Firefox 36.0, NoScript 2.6.9.15, Adobe Flash 16.0.0.305, on a Mac running Mac OS 10.6.8

> the problem is definitely with the NoScript plugin since it is the only active plugin

You cannot assume that.
Disable NoScript entirely, restart FF, & see if the stuttering persists.

(Then try & figure that out .)

I turned off all plugins and extensions then restarted in safe mode. Video playback was fine.
Restarted with all plugins and extensions still off. Video playback was fine.
Activated NoScript, restarted. Video stuttered.

The only difference between video stuttering and not stuttering was turning on NoScript.

> I turned off all plugins and extensions

I thought NoScript was your only extension (or at least enabled)?

And what Plugins do you have?
If you disabled them all, did you also disable Flash?
And so were the videos then playing via HTML5?
(HTML5 did seems to work better for me those few days that Youtube turned it on.)

> The only difference between video stuttering and not stuttering was turning on NoScript.

Hmm?

In order to troubleshoot and find the root cause of the problem I eliminated everything I could. When I turned off all of the plugins and extension I had to manually allow Flash (it is set to 'Ask to Activate' instead of 'Always Activate'). Even when I activated NoScript I left Flash in the 'Ask to Activate' mode so I could confirm the video is a Flash video and I would have to manually start Flash. I have not tested HTML5 video and don't plan on testing it until and unless I get Flash video fixed.

The configuration I am currently running is with NoScript active (it is set to 'Always Activate') and Flash set to 'Ask to Activate' with all other plugins and extensions set to 'Never Activate'. Except the changes I noted in my original post and adding some websites to the whitelist I have not made any changes from the default NoScript settings.

Flash videos run fine when NoScript is not active, but the video stutters when NoScript is active. The question is why and how to fix the issue.

What is your hardware specs (in particular, CPU and RAM)?

It is an older MacBook with 2.4 GHz Intel Core 2 Duo with 4 GB 667 MHz DDR2 SDRAM.

I just tested Firefox with QuickJava 2.0.6 instead of NoScript and I am not getting the stuttering. Same as when I use FF with NoScript off and with other browsers (Chrome and Safari).

I would think that's enough to run Flash decently...
(I asked because I saw similar on an obsolete computer from over 10 years ago, didn't have any reason to suspect NoScript, ended up "fixing" it by getting a new computer )

Are you running any antivirus software that might be slowing things down?

Does this happen in completely default NoScript configuration?

Please try disabling various features of NoScript, re-enabling if no difference:
1) XSS: NoScript Options > Advanced > XSS, un-check both boxes
2) ABE: NoScript Options > Advanced > ABE, un-check "Enable ABE"
3) Inclusion type checking: about:config > set noscript.inclusionTypeChecking to false
4) Surrogates: about:config > set noscript.surrogate.enabled to false
5) [Some other sort of XSS protection, not sure exactly what] about:config > set noscript.xss.checkInclusions to false

Before I started with the list I put the setting back to what I started with, but with ClearClick disabled. I noticed that the video was generally stable unless I moved the mouse over a link, then with a minor delay the video would stutter.

I re-enabled ClearClick and disabled each of the following and re-enabled when nothing changed. After each change I restarted FF.

1) XSS: NoScript Options > Advanced > XSS, un-check both boxes
2) ABE: NoScript Options > Advanced > ABE, un-check "Enable ABE"
3) Inclusion type checking: about:config > set noscript.inclusionTypeChecking to false
4) Surrogates: about:config > set noscript.surrogate.enabled to false
5) [Some other sort of XSS protection, not sure exactly what] about:config > set noscript.xss.checkInclusions to false

I then disable ClearClick and tested each one again. No changes were noted.
Next, leaving ClearClick disabled I started disabling features starting with #5 and working up the list to #1. I did not re-enable any of the disabled features, but left them disabled to see if a combination of disabled features stopped the stuttering. In the end none of these changes worked. I have since re-enabled XSS, but left the rest disabled.

With ClearClick disabled I don't get the video freezing, but do get stutter when I pass over links. I don't know what features are kicked off by passing over a link. Maybe someone has an idea why passing over a link causes a stutter after a slight delay.

Hmm, see what setting about:config > noscript.clearClick.rapidFireCheck to false does?

> see what setting about:config > noscript.clearClick.rapidFireCheck to false does

No difference, even with all of the other settings tested before still disabled I still get the stutter when mousing over links. I also changed noscript.clearClick.pompt and noscript.clearClick.plugins to false and changed noscript.clearClick.threshold from 18 to 50, but still no improvement.

NoScript is the only extension enabled and Flash is the only plugin enabled.

Fascinating.