Re: Reconciling ConvolverNode's output channel dependencies with the mixing rules in the spec

On Fri, May 17, 2013 at 10:33 PM, Chris Rogers <crogers@google.com> wrote:

>
> For the web in general, the vast majority of playback systems are stereo.
>  But, as I said, it's pretty easy to get multi-channel convolution today.
>  You can try it if you like, since we now support multi-channel output
> devices  in Chrome.
>

My point is that the current API does not make it easy to get multi-channel
convolution. Stereo is directly supported, but 5.1 or 7.1 require custom
code.

The web may be mostly stereo today, but we may as well think about
tomorrow.
Your employer has surely thought about bringing the web to the living room,
with web gaming with full theatrical surround.
To code out support for that is, IMHO, shortsighted.



> You make it sound so complicated, but it's really just a few lines of
> JavaScript.  The "summing junctions" don't even require nodes, since the
> summing happens automatically by simply making multiple connections to an
> input:
>
> https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#UpMix-section
>
> It's just a few lines of code, but if the presentation of the API still
> bothers you, then it's trivial to wrap this up in a JavaScript object that
> hides all of these details and gives exactly the API you want.
>

Yes, it is not that difficult to write. But then neither is most of what is
in the WebAudio API. The whole point of the API is to make things easy and
make it so people don't have to write things like this.



> I've designed the base-level of the API to work well, with little fuss or
> muss "out of the box" for the vast majority of applications.  And for the
> advanced applications, it's pretty easy to work it out.
>

I just disagree with this. In my world, the vast majority of applications
are surround. The current API does not work "out of the box" with little
fuss or muss for surround.
ConvolverNode does not support surround, PannerNode does not support
surround, surround formats are inadequately specified simply by channel
count.


Sorry if this all sounds negative and critical. I appreciate your work on
the API.

But I do want to see it live up to some of the initial aspirations, which
included things supporting pro audio and DAWs.
To me, pro audio means, among other things, supporting the formats used in
theatrical sound, triple-A games, and HDMI.
And it means being consistent with the scientific literature in the related
fields such as signal processing and acoustics.

Sincerely,
    Frederick