Re: D3DPRESENTFLAG_VIDEO
From: Phil Taylor (phil_at_private-citizen.com)
Date: 02/04/05
- Next message: Phil Taylor: "Re: Generateskinnedmesh question"
- Previous message: Phil Taylor: "Re: Multiple Streams differ from retail vs debug directx"
- In reply to: joreg: "Re: D3DPRESENTFLAG_VIDEO"
- Messages sorted by: [ date ] [ thread ]
Date: Fri, 4 Feb 2005 11:10:05 -0800
video data is temporal in nature, and depends on information from previous
frames. mpeg has pand i-frames, if I remember the terminology correctly.
basically key frames and intermediate frames. the intermediate frames depend
on previous frames up to the last iframe.
3d has nothing like that.
so perhaps, if the driver knew it was going to handle video, it might keep
more state. or it might perform some other action to make the current
environment more friendly for mixed video and 3d. its really hw dependant.
given the DDK is now under wraps, there is no way to verify what it does
under the covers in specific. but typically the driver source in the DDK is
very vanilla with all the interesting bits removed. in practice drivers
could do quite a bit of work for you.
but really, you dont know, you cant affect it, and it doesnt matter except
for the setting of this flag since it may get you better performance. again,
if you need it, set it. if you dont, dont. what else is there to worry
about?
"joreg" <no@spam.com> wrote in message
news:OCjnc8lCFHA.868@TK2MSFTNGP10.phx.gbl...
> Phil Taylor wrote:
>> driver and hw dependent.
> ok. thats what i already understood from the line in the docs saying that
> its a hint to the driver. still i don't have a glue what a driver would
> choose to do in case it gets that hint. and if i would therefore like my
> application to hint the driver this flag or not.
>
> > it doesnt give you any opportunities to do anything special in the
> > app, so why are you worrying about it?
> perdon? i am worrying because i want to understand what the code that i am
> writing does. when my code relies on someone elses code i try to
> understand that code too. in this particular case i saw no other
> opportunity to find out about the meaning of this flag than asking here.
> if you don't know an answer, maybe someone else still does.
>
> thanks anyway for your comments.
> joreg.
>
>
>>
>> all this does is allow the driver/hw to understand that the current
>> rendering may contain video. if that means the driver/hw needs to do
>> something special, it has a hint and doesnt need to guess. what it does,
>> certainly varies from each generation and likely within a generation
>> depending on level of chip ( x300,x600,x800 for ati, 6300,6600,6800 for
>> nvidia ).
>>
>> it doesnt give you any opportunities to do anything special in the app,
>> so why are you worrying about it?
>>
>> "joreg" <no@spam.com> wrote in message
>> news:unElb%23YCFHA.960@TK2MSFTNGP09.phx.gbl...
>>
>>>yeah. thanks i saw that.
>>>but do you have any idea what a driver does with that hint?
>>>
>>>Phil Taylor wrote:
>>>
>>>>in the docs, under D3DPRESENTFLAG, I see
>>>>
>>>> D3DPRESENTFLAG_VIDEO 0x00000010 This is a hint to the driver that
>>>> the back buffers will contain video data.
>>>>
>>>>
>>>>do you not see that?
>>>>
>>>>"joreg" <no@spam.com> wrote in message
>>>>news:%23ii8AHXCFHA.3936@TK2MSFTNGP09.phx.gbl...
>>>>
>>>>
>>>>>halo.
>>>>>
>>>>>in the Flag item of the D3DPRESENT_PARAMETERS i can set a flag named:
>>>>>D3DPRESENTFLAG_VIDEO
>>>>>
>>>>>but i cannot find any further documentation on this. any ideas?
>>>>>
>>>>>thnaks.
>>>>>joreg.
>>>>
>>>>
>>
- Next message: Phil Taylor: "Re: Generateskinnedmesh question"
- Previous message: Phil Taylor: "Re: Multiple Streams differ from retail vs debug directx"
- In reply to: joreg: "Re: D3DPRESENTFLAG_VIDEO"
- Messages sorted by: [ date ] [ thread ]
Relevant Pages
|
