[Theora-dev] YUV and Direct3D
mike at multimedia.cx
Tue Oct 11 15:53:41 PDT 2005
Paulo Zaffari wrote:
> Hi all,
> I am developing a Theora player wich I intend to use with 3D
> applications in a near future.
> I have quite a few doubts wich I belive might be cleared by those reading
> this e-mail... or so I hope.
> In order to have maximum performance I would like a hint on what D3DFMT
> to use while creating a texture. So far my guess is D3DFMT_UYVY, but
> something seems to be wrong in my texture update routine.
> I am using the following code:
Hmm: Apple, meet orange; orange, apple. "Not the same thing" is
what I am trying to say here. It looks like Direct3D allows you to
create textures using "packed" YUV formats. This means that the Y, U,
and V samples are interleaved. Most modern video codecs, Theora
included, decode to "planar" YUV formats. In memory, there is Y data,
followed by U data, followed by V data. More on planar and packed formats:
I did a quick Google search on "D3DFMT_I420" and "D3DFMT_YV12" (YUV
4:2:0 planar formats). Neither identifier appears to exist. In my
(limited) experience with 3D graphics, the special hardware generally
deals with packed pixel formats only.
Short answer: You will have to convert YUV 4:2:0 data to another
format. Either that, or use the appropriate Windows video API to display
the YUV data directly (DirectShow?). Alternatively, you can take a look
at this paper regarding a method for displaying planar YUV data using 3D
I got it to work on the Sega Dreamcast hardware. I have always wondered
how it would work on other hardware.
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