STRUCT RPPX1_LSC_PARAMS(9)

🌸 struct rppx1_lsc_params(9) — like, the manual page, bestie 🌸

okay so welcome to the Kernel API Manual, page for struct rppx1_lsc_params(9) 💅 this is the Lens Shading Correction configuration struct and she is lowkey iconic. grab a snack, we're reading a struct definition together 🍓

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✨ NAME ✨

struct rppx1_lsc_params — Lens Shading Correction configuration 🎀

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✨ SYNOPSIS ✨

struct rppx1_lsc_params {
    struct v4l2_isp_params_block_header header;
    __u16 r_data[RPPX1_LSC_SAMPLES_MAX][RPPX1_LSC_SAMPLES_MAX];
    __u16 gr_data[RPPX1_LSC_SAMPLES_MAX][RPPX1_LSC_SAMPLES_MAX];
    __u16 gb_data[RPPX1_LSC_SAMPLES_MAX][RPPX1_LSC_SAMPLES_MAX];
    __u16 b_data[RPPX1_LSC_SAMPLES_MAX][RPPX1_LSC_SAMPLES_MAX];
    __u16 x_grad[RPPX1_LSC_NUM_SECTORS];
    __u16 y_grad[RPPX1_LSC_NUM_SECTORS];
    __u16 x_sect_size[RPPX1_LSC_NUM_SECTORS];
    __u16 y_sect_size[RPPX1_LSC_NUM_SECTORS];
 };

no cap, that's the whole thing. now let's meet her members one by one 🫶

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🌈 Members 🌈

• header — the block header, and her type is RPPX1_PARAMS_BLOCK_TYPE_LSC (that's literally her whole identity bestie)
• r_data — correction factors for the red channel, in Q2.10 format ❤️
• gr_data — correction factors for the green (red) channel, in Q2.10 format 💚
• gb_data — correction factors for the green (blue) channel, in Q2.10 format 💚
• b_data — correction factors for the blue channel, in Q2.10 format 💙
• x_grad — interpolation gradients for each horizontal sector (12 bits) ✨
• y_grad — interpolation gradients for each vertical sector (12 bits) ✨
• x_sect_size — horizontal sectors sizes
• y_sect_size — vertical sectors sizes

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🦋 Description 🦋

so the RPP-X1 Lens shading correction module? she's available on the PRE1 and PRE2 pre-fusion pipes 👑 and userspace gets to pick which pipe to operate by setting the header.type field to RPPX1_PARAMS_BLOCK_TYPE_LSC_PRE1 or RPPX1_PARAMS_BLOCK_TYPE_LSC_PRE2. choose your fighter, iykyk 💅

the module applies per-color channel correction factors r_data, gr_data, gb_data and b_data as a 16x16 grid mapped on the image. and the size of each grid segment is expressed by the x_sect_size and y_sect_size arrays 📐

🚨 okay important part, don't skip this: each segment shall be at least 8 pixels in size, and the sum of all horizontal segments x_sect_size shall match the input frame size width. fr fr, that's a hard requirement 😭

the correction factors values are expressed as unsigned Q2.10 integers ranging from 1 to 3.999 ⭐

and pre-calculated interpolation factors shall be provided in the x_grad and y_grad fields, expressed as 12 bits integer values ✨

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🧚 SEE ALSO 🧚

• Kernel file ./include/uapi/linux/media/dreamchip/rppx1-config.h (go read the source, bestie, it's giving main character energy)
• struct rppx1_window(9)
• enum rppx1_meas_chan(9)
• enum rppx1_params_block_type(9)
• enum rppx1_wbmeas_mode(9)
• struct rppx1_wbmeas_params(9)
• struct rppx1_awbg_params(9)
• enum rppx1_exm_mode(9)
• struct rppx1_exm_params(9)
• enum rppx1_hist_mode(9)
• struct rppx1_hist_params(9)
• struct rppx1_bls_fixed(9)
• enum rppx1_bls_mode(9)
• enum rppx1_bls_win_en(9)
• struct rppx1_bls_params(9)
• struct rppx1_ccor_params(9)
• enum rppx1_ga_seg_mode(9)
• struct rppx1_ga_params(9)
• struct rppx1_lin_params(9)
• RPPX1_PARAMS_MAX_SIZE(9)
• enum rppx1_stats_block_type(9)
• struct rppx1_wbmeas_stats(9)
• struct rppx1_exm_stats(9)
• struct rppx1_hist_stats(9)
• RPPX1_STATS_MAX_SIZE(9)

like, that's a whole friend group and every single one of them slays 💜

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alright that's the page!! sign-off time 🎀 this one comes from ./include/uapi/linux/media/dre... and it's dated October 2026, so bookmark it, screenshot it, send it to the group chat — periodt 💅✨🦋