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The SC block in VPE/VIP contains a SRAM within it. This internal memory requires to be loaded with appropriate scaler coefficients from a contiguous block of memory through VPDMA. The horizontal and vertical scaler each require 2 sets of scaler coefficients for luma and chroma scaling. The horizontal polyphase scaler requires coefficients for a 32 phase and 8 tap filter. Similarly, the vertical scaler requires coefficients for a 5 tap filter. The choice of the scaler coefficients depends on the scaling ratio. Add coefficient tables for different scaling ratios in sc_coeffs.h. In the case of horizontal downscaling, we need to consider the change in ratio caused by decimation performed by the horizontal scaler. In order to load the scaler coefficients via VPDMA, a configuration descriptor is used in block mode. The payload for the descriptor is the scaler coefficients copied to memory. Coefficients for each phase have to be placed in memory in a particular order understood by the scaler hardware. The choice of the scaler coefficients, and the loading of the coefficients from our tables to a contiguous buffer is managed by the functions sc_set_hs_coefficients and sc_set_vs_coefficients. The sc_data handle is now added with some parameters to describe the state of the coefficients loaded in the SC block. 'loaded_coeff_h' and 'loaded_coeff_v' hold the address of the last dma buffer which was used by VPDMA to copy coefficients. This information can be used by a vpe mem-to-mem context to decide whether it should load coefficients or not. 'hs_index' and 'vs_index' provide some optimization by preventing loading of coefficients if the scaling ratio didn't change between 2 contexts. 'load_coeff_h' and 'load_coeff_v' tell the vpe/vip driver whether we need to load the coefficients through VPDMA or not. Signed-off-by: Archit Taneja <archit@ti.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com> |
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| .. | ||
| common | ||
| dvb-core | ||
| dvb-frontends | ||
| firewire | ||
| i2c | ||
| mmc | ||
| parport | ||
| pci | ||
| platform | ||
| radio | ||
| rc | ||
| tuners | ||
| usb | ||
| v4l2-core | ||
| Kconfig | ||
| Makefile | ||
| media-device.c | ||
| media-devnode.c | ||
| media-entity.c | ||