SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The data coming from the VPs into the RSZ module can be cropped: this applies to RAW and YUV4:2:2 data. It is mandatory to crop the data as early as possible in the RSZ processing pipeline to reduce power consumption. It is mandatory to crop the data before storing it in the input data buffer. Figure 9-97 is the block diagram of the RSZ input data cropper.
Figure 9-97 ISS ISP RSZ Input Data Cropper Block DiagramThe input data are in YUV4:2:2 interleaved format or RAW format.
For YUV4:2:2 format, the data come as Cb0, Y0, Cr0, Y1, Cb2, Y2, Cr2, Y3, etc. Y denotes the Luma component value and Cb/Cr denotes the Chroma component values. There are as many Y components as Cb/Cr components per line.
Figure 9-98 shows input data cropping. Only the cropped data is stored in the input data buffer. The names used in the figure correspond to the register names. If no cropping is desired, the RSZ_SRC_HPS and RSZ_SRC_VPS registers, which set the horizontal and vertical positions, respectively, must be set to 0; the start size from the RSZ_SRC_HSZ register must be set to the input image width minus 1, and the RSZ_SRC_VSZ register must be set to the input image height minus 1. These are common settings for both resize engines inside the RSZ module. After setting, more flexibility is present through the RZx_i_VPS and RZx_i_HPS registers for vertical and horizontal positioning, respectively, of the input/output (where x = A or B, i = I or O).
After the RSZ second level cropping (defined by RZA_I_VPS and RZB_I_VPS register settings), the height of the image frame must be two lines or larger. A one-line image is not allowed.
Depending on the input data format, different constraints apply to the registers that set the cropping parameters:
These features and constraints are common for both resizer engines inside the RSZ module. Figure 9-98 shows the input data cropping.
Figure 9-98 ISS ISP RSZ Input Data Cropping