Re: [media-types] image/webp rfc review

Hi Paul,

On Tue, May 4, 2021 at 1:21 PM Paul Libbrecht <paul=
40hoplahup.net@dmarc.ietf.org> wrote:

> Hello James,
>
> On 4 May 2021, at 2:33, James Zern wrote:
>
> com.google.webp sounds to be an Apple Uniform Type Identifier
> <
> https://developer.apple.com/library/archive/documentation/Miscellaneous/Reference/UTIRef/>
> .
> Is that correct?
>
> Yes. I found that when looking for something as a replacement for the
> deprecated Macintosh code as you mention [3]. I notice now that its value
> is 'org.webmproject.webp' not 'com.google.webp', however.
>
> Fantastic.
>
> - Macintosh Uniform Type Identifier: com.google.webp conforms to
> public.image and to public.data.
>
> I think mentioning the direct relationship to public.image may be best
> given you can follow it upwards past public.data. And maybe 'Apple Uniform
> Type Identifier' would be more appropriate now.
>
> Excellent and a very good point of changing Macintosh to Apple.
>

I posted a new revision with this change yesterday.

> - Windows Clipboard Flavour Name: WebP
>
> I didn't see a registered reference for a standard clipboard format, but
> GDI was updated to support the format with the ImageFormatWEBP GUID [4] .
>
> I asked the person I know has been working close to that for Math and he
> indicated that GDI does not seem to contain clipboard
>
>
> https://docs.microsoft.com/en-us/windows/win32/dataxchg/standard-clipboard-formats
> would be the list of standard clipboard types. And webP is not inside there.
>

That is what I found too. It's not clear to me how extensive this is meant
to be since these are externally controlled values and not intrinsic to the
file format. The inclusion of the Macintosh format on its own in 6838 was
odd to me. As an identifier I would think a GUID would be closer on the
Microsoft side to the Apple identifier than anything to do with the
clipboard.

> I also do not find it at this codeproject page
> <https://www.codeproject.com/reference/1091137/windows-clipboard-formats>.
>
> From searching around about GDI and clipboard, it seems that the only way
> to copy with a GDI bitmap is to transfer it as a buffer. I would suspect,
> that it does not preserve the WebP characteristics for which you would need
> to write to a stream of bytes. All examples I found only copy BMP.
>
> Thanks
>
> Paul
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