SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The RGB-to-YUV CSC unit converts the encoded pixel values from RGB24 into YUV4:4:4 format. For YUV4:2:0 or YUV4:2:2 formats, a chrominance sub-sampling is required after converting the RGB into YUV values. Because of the subsampling, the following limitations must be considered:
Figure 11-67 and Figure 11-68 show the 3 × 3 11-bit coefficients used to convert from RGB24 into YUV4:4:4. The user sets the coefficients according to the standard used to encode the pixel data in YUV color space. Table 11-77 lists the coefficients with their respective bit fields.
| Coefficients | Bit Fields |
|---|---|
| YR | DISPC_WB_CONV_COEF0[10:0] YR |
| YG | DISPC_WB_CONV_COEF0[26:16] YG |
| YB | DISPC_WB_CONV_COEF1[10:0] YB |
| CrR | DISPC_WB_CONV_COEF1[26:16] CRR |
| CrG | DISPC_WB_CONV_COEF2[10:0] CRG |
| CrB | DISPC_WB_CONV_COEF2[26:16] CRB |
| CbR | DISPC_WB_CONV_COEF3[10:0] CBR |
| CbG | DISPC_WB_CONV_COEF3[26:16] CBG |
| CbB | DISPC_WB_CONV_COEF4[10:0] CBB |
If the active range for the luminance samples (Y) is [16:235] and [16:240] for the chrominance samples (Cb and Cr), the values of Y, Cb, and Cr output components are clipped to the range [0:255]. The range selection is done by setting the DISPC_WB_ATTRIBUTES[11] FULLRANGE bit to 0x0.
Figure 11-67 DISPC RGB to YCbCr (FULLRANGE = 0)If the active range for the luminance samples (Y) and or the chrominance samples (Cb and Cr)is [0:255], the values of Y, Cb, and Cr output components are clipped to the range [0:255]. The range selection is done by setting the DISPC_WB_ATTRIBUTES[11] FULLRANGE bit to 0x1.
Figure 11-68 DISPC RGB to YCbCr (FULLRANGE = 1)