STRUCT V4L2_ISP_BLOCK_HEADER(9)

💅 struct v4l2_isp_block_header(9) — like, the V4L2 extensible block header, bestie

okay so this is from the Linux Kernel API Manual (the 9 section, kernel stuff, iykyk) and it's genuinely not scary, i promise 🫶

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✨ NAME ✨

struct v4l2_isp_block_header — the V4L2 extensible block header. that's it, that's the vibe. it's the little header that every ISP block wears like a cute accessory 🎀

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🌸 SYNOPSIS 🌸

struct v4l2_isp_block_header {
    __u16 type;
    __u16 flags;
    __u32 size;
 };

look at her. three fields. absolute main character energy 👑

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🦋 Members 🦋

• type — the parameters-or-statistics block type. and like, it's driver-specific, so don't come for me asking what the values are, the driver decides 💁‍♀️
• flags — a bitmask of block flags. also driver-specific, bestie. bitmasks are literally just feral little numbers wearing a trenchcoat ✨
• size — the size, in bytes, of the block — and yes, that includes this very header. she counts herself. self-aware icon 💅

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💖 Description 💖

so this structure is the common part — the shared DNA, the group-chat-of-record — of all the ISP configuration or statistic blocks. every single block shall embed an instance of this structure type as its first member, followed by the block-specific configuration or statistic data. no cap, it goes first, always, that's the rule 🫶

the type field is an ISP driver-specific value that identifies the block type. simple. iconic. the size field specifies the size of the block, including this header. (yes, again. she really wants you to know she's included. respect.)

the flags field is a bitmask of per-block flags:

• if a block is used for configuration parameters, this field can be a combination of V4L2_ISP_PARAMS_FL_* and driver-specific flags 🍓
• if a block is used for statistics, this field is used to report optional driver-specific flags, if any

ngl the split between "params" and "stats" using the same field is very much a "same hat" moment and i am obsessed 😭 keep both behaviours straight in your head or the driver will simply not respect you.

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🔥 SEE ALSO 🔥

• Kernel file ./include/uapi/linux/media/v4l2-isp.h enum
• v4l2_isp_version(9)
• v4l2_isp_params_block_header(9)
• struct v4l2_isp_buffer(9)
• v4l2_isp_params_buffer(9)

go read those, they're all in the same friend group 🌈

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⭐ and that's the page!! sign-off time: this beauty lives at ./include/uapi/linux/media, dated October 2026, and she answers to struct v4l2_...block_header(9). mwah. periodt 💜🧚