Re: New Editor's Draft of MediaStream Image Capture

On 05/14/2014 03:52 AM, Mandyam, Giridhar wrote:
> Hi All,
>
> Have uploaded a new version to Github (http://gmandyam.github.io/image-capture/), and am enclosing a PDF version in this email for archival purposes.  Please note the following changes:
>
> a) 'zoom' setting and 'autofocus' setting added to PhotoOptions - see http://gmandyam.github.io/image-capture/#photooptions.  Note that other native focus modes are not currently considered in the specification, but I am open to suggestions.
> b) Error in example corrected as per guidance in https://www.w3.org/Bugs/Public/show_bug.cgi?id=25226.
> c) Provided an option for promise-based implementation of API - see http://gmandyam.github.io/image-capture/#promise-extensions-to-imagecapture.  Note that the method for changing camera settings is not a promise, as it is assumed that settings may change at any time (e.g. end user manually changing settings on the physical capture device) .  I am open to suggestions, however.
>
> Comments/questions/corrections are all welcome.
>
> -Giri Mandyam, Qualcomm Innovation Center
>
Just brief scanning... no promises that I won't comment more on stuff 
later...

section 2:

" Raise a|FrameGrabEvent|event containing the|ImageData|to 
the|onframe|event handler" - I don't think this is how it should be 
described.

I'd think "fire a "frame" event on the ImageCapture object with a 
FrameGrabEvent containing the ImageData" would be more correct - but 
people who understand how to specify events can correct me.

section 7:

ImageCaptureError - we've decided not to use integer codes for errors if 
we can avoid them. Can you get rid of them here too?

7.2 In general, I find the pattern of "code X means that you called 
interface Y and it failed" to be singularly useless; the code will 
either already know what interface you were calling, or it will not be 
programmed to care about the difference. Can we just replace them all 
with "something went wrong"?

section 10:

 1. The/ISO/setting of a camera describes the sensistivity of the camera
    to light. It is a numeric value, where the lower the value the
    greater the sensitivity. This setting in most implementations
    relates to shutter speed, and is sometimes known as the ASA setting.

I have never understood how one could set the ISO setting on a digital 
camera (when we used film, it referred to the chemical light sensitivity 
of the film), but I don't think it's related to the shutter speed 
(except that in automatic mode, shutter speed will be faster when the 
ISO setting goes up, because you need less light for a complete 
exposure; you may instead choose to increse the f/stop).

Can this be worded differently?

section 13:

I don't think WebIDL allows overloading of functions based on the return 
value. (overloading based on the arguments is allowed).

Can the "promises" versions have different names, or the whole interface 
have a different name?