BetaPlayer with Intel 2700G support - Page 11

11-23-04, 06:52 AM

Originally Posted by PocketTV Team

But I doubt you can use their hardware IDCT which is probably not a problem because with the CPU it should be possible to get a pretty fast software IDCT.

probably sotfware idct would be fast too, but i assume transfering the full 8x8 matrix takes much more time as to transfer only the non zero idct values.

11-23-04, 06:53 AM

Originally Posted by picard_beta

Big hint: this is where you are wrong and where I was pretty suprised about my math skills :D

Well then you need to actually transform (i.e. modify) the IDCT coefficients, you cannot merely re-order them.

11-23-04, 06:58 AM

Originally Posted by PocketTV Team

Well then you need to actually transform (i.e. modify) the IDCT coefficients, you cannot merely re-order them.

exactly. you'll soon find out that it's much easier as it first seems.

11-23-04, 07:01 AM

Originally Posted by picard_beta

exactly. you'll soon find out that it's much easier as it first seems.

I would guess (from the top of my head) it's like changing the sign of the coefficients in every other column (or every other line), something like that... yes, that would be pretty simple indeed :)

11-23-04, 07:02 AM

Should I be impressed by my math skills, too ?

11-23-04, 07:03 AM

Originally Posted by PocketTV Team

Should I be impressed by my math skills, too ?

i had some joy finding it out :)

11-23-04, 07:04 AM

Originally Posted by picard_beta

i had some joy finding it out :)

Well that's quite obvious if you know the nature of the cosine functions used in the transform.

How long did it take you to figure that one out ?

I agree, it's a elegant way to solve the rotation issue with the Intel chip...

11-23-04, 07:10 AM

Originally Posted by PocketTV Team

Well that's quite obvious if you know the nature of the cosine functions used in the transform.

it took me longer to figure it out and the joy was not about the math skills (it was just a funny statement), but realizing that i can mirror with hw idct.

11-23-04, 07:11 AM

By the way, on another subject, I just learned that the "shadow" flag (to automatically save the ATI surfaces on power OFF/ON) does not work on the e800 due to a driver bug, but it should work on the hx4700. We have not confirmed that it works, though...

11-23-04, 07:17 AM

Originally Posted by picard_beta

it took me longer to figure it out and the joy was not about the math skills (it was just a funny statement), but realizing that i can mirror with hw idct.

Yes, I agree it's a good thing that we can do that so simply.

Every other column (or line) corresponds to a "odd" or "even" cosine function, starting with "even". the "even" one are symetrical in the mirroring, and the "odd" ones get sign-inverted, so it would seem logical that by changing the sign of the coefficient of all the "odd" routines, the result will be mirrored, and you can do it in either direction or in both, in which case you should end-up with the 180 degree rotation of the block, if i am not mistaking.

11-23-04, 07:25 AM

yes. i had the same thinking about the cosine function which lead to the solution.

thanks for the info about the shadow flag.

a_skeptic · 11-23-04, 08:21 AM

Wondering why someone from the moderator is not making this thread sticky!!

I think it deserves that!

11-23-04, 08:26 AM

Originally Posted by a_skeptic

Wondering why someone from the moderator is not making this thread sticky!!

I would advise to wait at least until the license issue is cleared.

tadw · 11-23-04, 08:45 AM

Since we have at least two very smart minds here on board, I want to ask you this: being able to use the Intel 2700G chip and reducing stress on the main CPU, by how much does this affectively reduce battery consumption?

Lower main CPU speed -> less battery consumption
More work for Intel 2700G chip -> more battery consumption

How do the two correlate with each other? Do they cancel each other out? Is there any information on the required battery consumption of the Intel 2700G?

Tad

Ranma13 · 11-23-04, 08:53 AM

Heh, this thread turned into a chatroom.

Regarding the GPL issue, are there any possible or promising solutions? Or is it, for now, a dead end?