SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The CSC unit converts the video-encoded pixel values from YUV4:4:4 format into RGB24 or RGB30 format. The output format depends on the video pipeline configuration selected:
In case of YUV4:2:0 or YUV4:2:2 formats, a chrominance resampling to YUV4:4:4 is required before converting the YUV into RGB values (see Section 11.2.4.10.3.1, Chrominance Resampling). YUV4:2:2 or YUV4:2:0 to YUV4:4:4 chrominance resampling is a preprocessing to the color space conversion.
Figure 11-50 through Figure 11-53 show the 3 × 3 11-bit coefficients used to convert from YUV4:4:4 into RGB24. The coefficients are set according to the standard used to encode the pixel data in YUV color space. Table 11-71 summarizes the coefficients with their respective bit fields.
Coefficients | Bit Field Registers |
---|---|
RY | DISPC_VIDp_CONV_COEF0[10:0] RY |
RCr | DISPC_VIDp_CONV_COEF0[26:16] RCR |
RCb | DISPC_VIDp_CONV_COEF1[10:0] RCB |
GY | DISPC_VIDp_CONV_COEF1[26:16] GY |
GCr | DISPC_VIDp_CONV_COEF2[10:0] GCR |
GCb | DISPC_VIDp_CONV_COEF2[26:16] GCB |
BY | DISPC_VIDp_CONV_COEF3[10:0] BY |
BCr | DISPC_VIDp_CONV_COEF3[26:16] BCR |
BCb | DISPC_VIDp_CONV_COEF4[10:0] BCB |
If the active range for the luminance samples (Y) is [235:16] and [240:16] for the chrominance samples (Cb and Cr), the range selection is done by setting the DISPC_VIDp_ATTRIBUTES[11] FULLRANGE bit to 0x0. The values of R, G, and B output components are clipped to the range [255:0].
The scaling and CSC clipping is set by the same bit, DISPC_VIDp_ATTRIBUTES[11] FULLRANGE.
If the active range for the luminance samples (Y) and chrominance samples (Cb and Cr) is [255:0], the range selection is done by setting the DISPC_VIDp_ATTRIBUTES[11] FULLRANGE bit to 0x1. The values of R, G, and B output components are clipped to the range [255:0].
If the active range for the luminance samples (Y) is [940:64] and [960:64] for the chrominance samples (Cb and Cr), the range selection is done by setting the DISPC_VIDp_ATTRIBUTES[11] FULLRANGE bit to 0x0. The values of R, G, and B output components are clipped to the range [1023:0].
The scaling and CSC clipping is set by the same bit, DISPC_VIDp_ATTRIBUTES[11] FULLRANGE.
If the active range for the luminance samples (Y) and chrominance samples (Cb and Cr) is [1023:0], the range selection is done by setting the DISPC_VIDp_ATTRIBUTES[11] FULLRANGE bit to 0x1. The values of R, G, and B output components are clipped to the range [1023:0].