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Re: Suggestion for minimizing audio glitches

From: Chris Rogers <crogers@google.com>
Date: Mon, 16 Apr 2012 13:10:07 -0700
Message-ID: <CA+EzO0mdYK99+HzVGRzp3Q=LG3m4q6x=N4DyxmRN1TKzns=NkQ@mail.gmail.com>
To: lemeslep@free.fr
Cc: public-audio@w3.org
On Sun, Apr 15, 2012 at 12:22 PM, <lemeslep@free.fr> wrote:

> Hi everyone,
>
> On the current Web Audio draft, it is mentionned in 15.2 that "Audio
> glitches are caused by an interruption of the normal continuous audio
> stream, resulting in loud clicks and pops. It is considered to be a
> catastrophic failure of a multi-media system and must be avoided."
> And I can't agree more with this!
> I'm currently facing those ugly audio glitches in my project. I'm using
> Mozilla's Audio Data API at the moment, and I think I know how browsers
> could help me to mitigate this problem.
>
> The clicks and pops are happening because if the audio buffer is underrun
> by the javascript app, the audio card is not feeded anymore, and so the
> card output goes straight from the value of the last sample played to 0.
> What would be needed is, perhaps as an option in the Javascript audio node
> (?), to have the browser automatically feed the audio card by sustaining
> the last sample the javascript application sent, when the audio buffer is
> underrun.
>
> That would really go a long way towards minimizing this critical issue.
>

Hi Philippe, I don't think this will help with the glitches.  Using this
approach, an under-run will still be quite audible.  And it's not a good
idea to send a constant (non-zero) value out to the audio hardware since
this represents a "DC offset" and can cause even worse problems.

Chris


>
> Regards,
> Philippe.
>
>
>
Received on Monday, 16 April 2012 20:10:37 GMT

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