SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
The LDC can process a portion of the image, rather than the entire image. This saves time by letting an image process through multiple software/LDC interactions to correct only a portion of the image.
An intermediate interrupt can occur after processing each macro block. This lets the LDC operation be pipelined with other tasks.
To process only a portion of the image, the following parameters are required:
Figure 6-136 is an example of multiple-pass processing with middle-of-the-image skipped.
The LDC does not copy skipped blocks from the input frame to the output frame (necessary task unless output frame = input frame); software must set up and initiate this memory copy.
A note on in-place operation to conserve external memory: Depending on the offset table and configuration parameters, it may not be feasible to point the output image at the input image and have corrected pixels overwriting the source image. Software must determine whether it is feasible to overwrite, and allocate a separate frame buffer when it is not feasible. The LDC does not care if the input and output image pointers coincide, nor does it check any dependency violations.
The starting address of the input frame, corresponding to input coordinate (0, 0), is specified in the LDC_RD_BASE[31:0] RBASE bit field and offset in the LDC_RD_OFST[15:0] ROFST bit field ((Y and Cb/Cr base required for YCbCr4:2:0: LDC_420C_RD_BASE[31:0] RBASE)). The LDC does not clips input block to input frame size if any of the input block falls outside the input frame.