STRUCT RPPX1_BLS_PARAMS(9)

💅 struct rppx1_bls_params(9) — like, the whole manual, bestie

okay so this is the man page for struct rppx1_bls_params, straight out of the Kernel API Manual, and it's literally all about the RPP-X1 Black Level Subtraction Module. grab a 🍓 and let's go.

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✨ NAME ✨

struct rppx1_bls_params — the RPP-X1 Black Level Subtraction Module. that's it, that's the vibe. 🖤

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🌸 SYNOPSIS 🌸

struct rppx1_bls_params {
    struct v4l2_isp_params_block_header header;
    struct rppx1_window window1;
    struct rppx1_window window2;
    struct rppx1_bls_fixed fixed;
    __u8 mode;
    __u8 en_windows;
    __u8 samples;
    __u8 reserved[5];
 };

that's the whole struct, no cap. every field, character for character. 💅

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🎀 Members 🎀

• header — the block header, and its type is RPPX1_PARAMS_BLOCK_TYPE_BLS_PRE1 or type == RPPX1_PARAMS_BLOCK_TYPE_BLS_PRE2 👑
• window1 — BLS measurement window 1 (14 bits), queen of the measurement windows fr
• window2 — BLS measurement window 2 (14 bits), the optional sidekick
• fixed — the fixed subtraction values (peep enum rppx1_bls_fixed)
• mode — the BLS subtraction mode (peep enum rppx1_bls_mode)
• en_windows — the BLS measurement mode (peep rppx1_bls_win_en)
• samples — log2 of the number of measured pixels per Bayer position, like, math but make it cute
• reserved — padding. it's just there. it's giving background character energy 💀

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🦋 Description 🦋

the RPP-X1 Black Level Subtraction module lives on the PRE1 and PRE2 pre-fusion pipes, bestie. userspace gets to pick which pipe it's operating on by setting the header.type field to RPPX1_PARAMS_BLOCK_TYPE_BLS_PRE1 or RPPX1_PARAMS_BLOCK_TYPE_BLS_PRE2. pick one, periodt. ✨

the BLS module operates on fixed or measured data, and which one it does depends on how you set the mode field. vibe check time:

• when RPPX1_BLS_MODE_FIXED is used, userspace shall provide the per-channel black levels in fixed
• when RPPX1_BLS_MODE_MEAS is used, userspace shall configure the measurement windows window1 and optionally window2 to select the optically black pixels region in the input frame 👀

and the samples field controls how many measure samples get used for averaging the measured black levels. that's the whole tea. 🫖

ngl, "shall" is doing a lot of heavy lifting here — those fields are required, not suggestions, so don't skip them 🙈

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🌈 SEE ALSO 🌈

so many friends, honestly iconic. all of these are in the kernel file ./include/uapi/linux/media/dreamchip/rppx1-config.h:

• 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_ccor_params(9)
• struct rppx1_lsc_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)

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that's the whole page, bestie — go read some structs, you're gonna slay 💖

sign-off time 🫶: this one's from ./include/uapi/linux/media/dre... (yes it's abbreviated, don't come for me), dated October 2026, and it's the manual page for struct rppx1_bls_params(9). mwah. 💋