Nothern Utah WebSDR Logo - A skep with a Yagi The Northern Utah WebSDR

Fixing audio problems when using the Chrome and Safari browsers



Problems with Safari?

If you are using the Safari Browser, you may have noticed a recent problem in which you get no audio - even after pressing the "Audio Start" button.

Because I don't use Safari, it didn't affect me - and I couldn't test it, either.  Fortunately, Stan sent me the following note:

I enjoy your SDR but a couple of weeks ago I had no audio on my Mac Safari ... apparently after an update. After a couple of weeks trying to figure out why, I found on Safari v12 the following settings that restored the audio:

Safari -> Preferences  -> Websites -> AutoPlay = Allow All Auto-Play

Don't know if you've had this question, but it worked for me.

Thanks for the heads up!
Important note:  There are new problems with the Chrome browser as of early September, 2018!

It would appear that a very recent update to the Chrome web browser (e.g. 69.0.3497.81) has caused yet another problem:  Very loud white noise when the WebSDR starts up, often accompanied with a blank waterfall.

A quick "fix" for this problem may be to toggle the mute button just below the S-meter (e.g. mute, then un-mute).  It has been reported that this usually works - at least for a while.


Other than toggling the mute button below the S-meter, there's no known work-around
- yet - so it's recommended that you use a different browser if this is a recurring problem for you:  Firefox works well and is recommended!




If you hear NO audio in Chrome:

If there is a button on the WebSDR interface that says "Chrome Audio Start", press it!

The Problem:

When you land on this or another WebSDR - and you are using the "Chrome" browser, but hear no audio - you may have to enable it.

Why did they do this?

The reason for this is to require that the users click on something to enable multi-media (audio, video) to avoid annoying sites from blasting you with unwanted audio - and, possibly, protect against something nefarious.  It is incumbent on those running web sites with built-in audio to add code to detect that the user is running Chrome and provide the button to be pressed, but if this code is not present, the user may have to jump through the hoops (below) to figure out how to re-enable audio.

Because WebSDR use web-based audio, it, too, may be affected by this.

Comment:  There are reports that after the initial release of Chrome version 66 that required one to "click" or otherwise enable audio, this requirement may have been rolled back a bit - but it will probably come back again in the future.


Using Chrome on a mobile device

As you may have noticed, when you are using a mobile device such as a phone or a tablet, you are given the option to use the "mobile" version of the WebSDR interface.  When you do this, a "lightweight" version of the web page appears with fewer options - but streamlined to work better on these types of devices.

Support for Chrome was recently added - which also requires one to press the "Audio Start" button - and although it seems to work, it may be buggy.

One issue with the Chrome+Mobile option is that when the screen goes dark, the audio may also stop:  We are looking at ways to work around that.

If you choose to use Chrome with the "normal" Web page, there are reports that the audio will stutter and drop out due to the browser/processor providing enough time to properly service the audio routines.  If this happens, there are two options:

- Disable the waterfall by clicking the "blind" button above and to the left of the waterfall.  You may need to click on the "one band" and then back to the "blind" button for it to take effect.

-
Use a different browser.  It would seem that the Firefox browser works reliably on (pretty much) all mobile devices - and it seems to work properly if you run either the Mobile or "Full" versions of the WebSDR - although the battery consumption of the mobile version may be slightly lower, particularly if you turn off the waterfall using the "stop waterfall" button.


Before you do anything else, check:


Did you mute the audio yourself?  Before you go any farther, you may have muted the audio in one (or more) of several places:

Do you get audio on other programs/web sites using Chrome?  If so, not all of the suggestions below may apply.
If you've ruled out operator error, read on.

The next thing to try:  Click the "Button"

Increasingly, some web browsers are requiring the user to "activate" the multimedia (audio/video) if a site has it - and Chrome is no exception.  To do this, the code on the web site itself needs to be modified to provide this button - but not all web sites have this.

We have added this button on the Northern Utah WebSDR - so you need only click on the button that says "Chrome audio start".  You may need to do this every time you visit the WebSDR, though - and again, this button may not be present on every WebSDR.  Other WebSDRs may or may not have a similar button.


Work-around #1 - the most reliable:

Use a different browser such as FireFox, Seamonkey or PaleMoon to name but a few.


It is possible that these other browsers will eventually follow suit in disabling audio by default, but we'll deal with that if/when it happens.

The suggestions below may work to enable sound in Chrome with the WebSDR, but reports indicate that it may not be consistent - or continue to work after software updates.
Figure 1:
Check to see if the browser tab shows a tiny "muted speaker" icon.  If it does, right click on the muted speaker to open up a dialog box:  If you see "Unmute site", click on it.  If it says "Mute site", it is not already muted.
Important:  Chrome "remembers" if you muted the site last time you visited it which means that even if you reboot or restart Chrome, it will still be muted!
Location of audio muting in tab while using Chrome


Work-around #2:

Disable the security "feature" in Chrome so that audio works on all web sites that have it, just like it did before - this option seems to be the most reliable if the site doesn't have a "start" button of some sort: Work-around #3:

Enable the sound on the browser for that specific web page.

While this option may be present on Windows-based computers, it may not be available on other operating systems.

It also seems that these settings may not "stick" and quit working and/or the option disappears entirely after it is used.  If this is the case, use work-around #2, above.




"How did you fix the "audio start" problem with Chrome on the Northern Utah WebSDR?"

Ideally, we'd like to have the audio in Chrome auto-start without the user having to press a button - but an initial "read" of the issue would seem to indicate that if the above steps don't work, you will have to press a button every time.  If this is the case - and you find it a pain to do - I would suggest the use of the FireFox or Pale Moon web browsers.

Do you run a WebSDR system and wish to know how to modify the code to allow Chrome to work?  Go to the Chrome WebSDR fix page for details.
Figure 2:
A screen shot of what needs to be changed to always enable "auto play" to get WebSDR audio in Chrome.
Select the "User gesture is required..." option (highlighted) and then click the "Relaunch Now" button at the bottom of the screen (not shown) to restart the browser.
Click on the image for a full-sized version.
Changes in Chrome to permit audio to work with a WebSDR

As noted above, there's no known permanent fix (yet) for the "white noise" problem that may occur when you first start the WebSDR in Chrome:  It's believed to be some sort of pointer/array corruption issue in the browser-run code that decompresses the waterfall and audio streams from the WebSDR.




Additional information:

Go to the Northern Utah WebSDR