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Re: [css3-speech] voice-balance and azimuth

From: Daniel Weck <daniel.weck@gmail.com>
Date: Thu, 7 Jul 2011 10:58:29 +0100
Message-Id: <02A96E4B-151E-470D-B038-B3CBF13C28EE@gmail.com>
To: "www-style@w3.org style" <www-style@w3.org>, fantasai <fantasai.lists@inkedblade.net>

On 6 Jul 2011, at 22:43, fantasai wrote:
> For example, if I output the same amount of sound from all speakers in
> the system, on a stereo system this is the same as a center-located
> voice, but in a surround-sound system, a center-located voice would
> instead be sound coming out of only the front-center speaker.


Ultimately, the mapping between CSS spatial audio positioning and  
concrete audio channels depends on what speaker system is plugged-in,  
and on how precisely the user-agent can dispatch the audio streams  
(driver). What matters is the author intent, right?

Let's assume that the authored content says "voice-balance: center".  
The content is played with a Level 3 user agent. A stereo audio system  
is plugged-in, which means that both speakers output the speech  
synthesis at the same volume level. Now, a surround audio system is  
plugged-in (e.g. "5.1"), and the user-agent is able to interface with  
it properly (e.g. not just left/right distribution, but full 5 channel  
control...yeah, the bass channel can be ignored for now!). Even though  
the user-agent only understands the Level 3 notation, it is perfectly  
able to map 'center' to the appropriate audio channel(s). Let's now  
say that the content remains the same, but the user-agent supports the  
Level 4 syntax. The 'center' keyword retains the same semantics (in  
terms of perceived audio output, not of actual channels to dispatch  
to), so depending on what audio system is plugged-in, the user-agent  
will be able to distribute the audio streams to the adequate channels.

Am I making sense?
Dan
Received on Thursday, 7 July 2011 09:58:59 GMT

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