SAA7111 YUV

Hi,

I have stored YUV422 16 bit data from Philips SAA7111A. The Y data and UV data in 2 files. Now how to combine Y and UV into RGB format for display on PC?

Please reply to snipped-for-privacy@pub3.fz.fj.cn

Thanks in advance.

Wang, Feng

Reply to
Wang Feng
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a simple C program can do that...one RGB format is called BMP... google YUV to RGB conversion and see...

Kelvin

Reply to
kelvin8157

Hi,

I can help you with this issue by providing you transformation formulaes.

However, please note that the formula heavily depends on the settings of the SAA7111A. AND NOBODY USUALLY TELLS YOU ABOUT THIS !!!

So :

1) what are the values of your registers 0B, 0C and 0D. Namely BRIG , CONT and SATN ???

You have to understand that no mathematics will work unless you know how you've set-up the chip.

Talk to you later,

Regards,

Claps

Reply to
claps

Philips publishes the algorithm they use in their own media processors (PNX 1300 series). See:

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Chapter 14 talks about the image coprocessor and includes the algorithms.

Reply to
Gabor Szakacs

Sorry I posted a link to the glossy sales literature. The data sheet is at:

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This has the algoriths in chapter 14

Reply to
Gabor Szakacs

On a sunny day (10 May 2004 15:14:15 -0700) it happened snipped-for-privacy@alacron.com (Gabor Szakacs) wrote in :

panteltje:~/download/html# wget

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--01:13:57--

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=> `pnx1300-CQS.pdf' Connecting to
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connected! HTTP request sent, awaiting response... 401 Authorization Required Connecting to
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connected! HTTP request sent, awaiting response... 401 Authorization Required Authorization failed. JP

Reply to
Jan Panteltje

O.K. that site requires registration

Here's a clip from the datasheet:

14.5.4 YUV to RGB Conversion

In the ICP, YUV to RGB conversion is done by sequentially processing triplets of Y, U, and V pixel data to convert the pixels to an internal YUV 4:4:4 format and applying the YUV to RGB conversion algorithm on the YUV

4:4:4 pixels. The results of this conversion normally go to the PCI bus but can also go back to SDRAM. YUV to RGB conversion has two steps. First the Y, U and a V pixel data are used to generate an RGB pixel at the output location. When the Y,U, and V pixels are ready, YUV to RGB conversion is performed using the following algorithms: R = Y + 1.375(V)= Y + (1 + 3/8)(V) G = Y - 0.34375(U) - 0.703125(V) = Y - (11/32)(U) - (45/64)(V) B = Y + 1.734375(U) = Y + (1 + 47/64)(U)

In CCIR601, the U and V values are offset by +128 by inverting the most significant bit of the 8-bit byte. This is the way the U and V values are stored in SDRAM. The above algorithms assume that the U and V values are converted back to normal signed two's complement values by inverting the MSB before being used.

...

The values used are not exactly those specified in the CCIR601 specification, but they seem to work quite well and the constants make for small multipliers.

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Reply to
Gabor Szakacs

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