Re: Question about blitting from RGB surface to YUV surface

yes, to a software guy orthagonality in the API means a lot, and thus
forward and reverse transformations of data to/from formats is thought of as
"just obvious".

but, to a hardware guy, every feature costs gates, takes up area, uses
power, and generates heat.

so if a spec doesnt ask for a feature, the hw guy wont think to add it,
typically.

I suspect if you look at the DDI spec in the DDK, you will find support for
this feature is either called out as optional or not called out at all.
which means the hw and hw driver guys never see the feature as important or
never see it at all.

That and YUV is typically seen as a video format and not a 3D format. Since
the chips are 3D, and in my experience the 2D and 3D teams dont get along,
ipso post facto, video support is sometimes questionable. For instance,
D3D10 and D3D11 do not natively support DShow and playing DShow formats as a
texture. You should be aware of this fact and have your company ( or you )
send design feedback in. There is usually an address for both the DX SDK
(D3D ) and the Windows SDK ( DShow ) so get your asks in, dont assume
others are doing that. And you can ask the driver teams for a feature.
Perhaps the hw does it, its just not exposed yet. The more feedback a
feature gets, the more likely it gets implemented..


"sundx" <sodar@xxxxxxx> wrote in message
news:F2876020-5416-486C-A5BF-4247775997C7@xxxxxxxxxxxxxxxx
Taylor,

Thanks for the reply.

After several day's study, I realize that DDCAPS_BLTFOURCC commonly means
the capability of blitting from FOURCC surface to RGB. If a YUV->RGB
conversion needed, I should do the work programmly. But I still don't
understand why graphic drivers supply YUV->RGB conversion by hardware but
no
reverse one.

sundx



"Phil Taylor" <PhilTaylor@xxxxxxxxxxxxxxxxxxxxxxxxx> ????
news:352B55A0-2023-46C7-8280-89933403B14A@xxxxxxxxxxxxxxxx
FOURCC means you have to do extra work with a FOURCC surface.

what does the debug runtime output tell you?
--
Phil Taylor
somewhat D3D knowledgeable :-)


"sodar" wrote:

Hi,

I'm working on an application with DirectDraw7. I need create an overlay
surface and blit image to it from the primary surface. It works fine on
some
PC with ATI graphic card, I notice that a RGB-format overlay surface was
created. But on some other graphics cards, only YUV format overlay be
supported. When I do a RGB->YUV blitting, it returns an
DDERR_UNSUPPORTED
error. (I think the primary surface should *always* be RGB-format,
please
correct me if not so.)

But the card do have DDCAPS_BLTFOURCC capability. From MSDN,
"DDCAPS_BLTFOURCC: Display hardware is capable of color space
conversions
during the blit operations." I think the card should be capable to do
color
space conversion by hardware. Am I missing something? If I have to do
the
conversion by software, it's so so slow!


Thanks

sundx









.

Relevant Pages

  • Re: Auto Date Conversion Not Requested
    ... You now have to *remove* the conversion formula, ... Please keep all correspondence within the Group, ... concerts the results into date format. ... > the auto conversion feature to a date occurs. ...
    (microsoft.public.excel.worksheet.functions)
  • Proposal: String::Format::General
    ... It provides format string parsing and output assembly, you provide the code that implements the individual conversion characters. ... Format syntax is kind of a cross between sprintf and strftime, but how close it is to each of these depends on the semantics implemented by the user. ... Note that the following is pre-alpha documentation; the interface to the output conversion code has changed since yesterday, ... conversion character, and contain a number of optional fields which may ...
    (comp.lang.perl.modules)
  • Proposal: String::Format::General
    ... This should be considered pre-Alpha, since it has changed since yesterday, and I am seriously considering passing the format parameters to the output conversion code as a hash reference instead of a large number of arguments. ... Some limited heading capability is provided. ... This module provides a formatter class which allows its user to ...
    (comp.lang.perl.modules)
  • Proposal: String::Format::General
    ... It's almost a meta-formatter with the user providing individual conversion code behind a sprintf/strftime-like interface. ... A format is basically a string into which data are to be inserted. ... conversion character, and contain a number of optional fields which may ...
    (comp.lang.perl.modules)
  • Re: Proposal: String::Format::General
    ... It's almost a meta-formatter with the user providing individual conversion code behind a sprintf/strftime-like interface. ... A format is basically a string into which data are to be inserted. ... conversion character, and contain a number of optional fields which may ...
    (comp.lang.perl.modules)
Loading