STRUCT V4L2_VP9_SEGMENTATION(9)

🎀 NAME 🎀

okay so welcome to the struct v4l2_vp9_segmentation(9) page, straight out of the Kernel API Manual — we're doing the VP9 segmentation parameters today, and honestly? kind of iconic.

short version, for the bestie who just got here: this struct is where all the segmentation info lives. it's giving "the group chat roster for your video frame" fr fr.

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✨ SYNOPSIS ✨

here's the whole vibe laid out 💅 (copy it exact, don't touch the formatting, it's perfect as-is):

struct v4l2_vp9_segmentation {
    __s16 feature_data[8][4];
    __u8 feature_enabled[8];
    __u8 tree_probs[7];
    __u8 pred_probs[3];
    __u8 flags;
    __u8 reserved[5];
 };

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🫶 MEMBERS 🫶

okay bestie, let's meet the whole cast. every single one of them, no skips 🌸

• feature_data — this is the data attached to each feature. big yikes energy if you forget this: a data entry is only valid if the feature is enabled. the array shall be indexed with the segment number as the first dimension (0..7) and one of V4L2_VP9_SEG_{} as the second dimension. so like, segment first, feature second. don't flip it, i'm begging 🙈
• feature_enabled — a bitmask defining which features are enabled in each segment ✨ the value for each segment is a combination of V4L2_VP9_SEGMENT_FEATURE_ENABLED(id) values where id is one of V4L2_VP9_SEG_LVL_{}. it's a whole little bitmask situation, she's organized 💅
• tree_probs — specifies the probability values to be used when decoding a Segment-ID 🔥 see the 5.15. Segmentation map section of the VP9 specification for more details. the spec is right there, go read it, i believe in you 🫶
• pred_probs — specifies the probability values to be used when decoding a Predicted-Segment-ID 💖 see the 6.4.14. Get segment id syntax section of :ref:vp9 for more details. yes, predicted. it's a different thing. she's mysterious like that.
• flags — combination of V4L2_VP9_SEGMENTATION_FLAG_{} flags ⭐ mix and match, live your truth
• reserved — padding field. should be zeroed by applications. like, actually zero it. no cap. this is the "clean your room before guests come over" of struct fields 🧹

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💜 DESCRIPTION 💜

okay so what does the whole thing do? it encodes the quantization parameters 💅 and for the full lore, see section 7.2.10 Segmentation params syntax of the VP9 specification — she's got the details, i'm just the messenger ✨

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🔥 SEE ALSO 🔥

bestie. sit down. this list is LONG and every single one of them is here, in order, untouched. it's giving "tag yourself i'm struct v4l2_vp9_quantization(9)" 😭

kernel file: ./include/uapi/linux/v4l2-controls.h

• enum v4l2_mpeg_video_av1_profile(9)
• enum v4l2_mpeg_video_av1_level(9)
• enum v4l2_stateless_h264_decode_mode(9)
• enum v4l2_stateless_h264_start_code(9)
• struct v4l2_ctrl_h264_sps(9)
• struct v4l2_ctrl_h264_pps(9)
• struct v4l2_ctrl_h264_scaling_matrix(9)
• struct v4l2_ctrl_h264_pred_weights(9)
• struct v4l2_h264_reference(9)
• struct v4l2_ctrl_h264_slice_params(9)
• struct v4l2_h264_dpb_entry(9)
• struct v4l2_ctrl_h264_decode_params(9)
• struct v4l2_ctrl_fwht_params(9)
• struct v4l2_vp8_segment(9)
• struct v4l2_vp8_loop_filter(9)
• struct v4l2_vp8_quantization(9)
• struct v4l2_vp8_entropy(9)
• struct v4l2_vp8_entropy_coder_state(9)
• struct v4l2_ctrl_vp8_frame(9)
• struct v4l2_ctrl_mpeg2_sequence(9)
• struct v4l2_ctrl_mpeg2_picture(9)
• struct v4l2_ctrl_mpeg2_quantisation(9)
• struct v4l2_ctrl_hevc_sps(9)
• struct v4l2_ctrl_hevc_pps(9)
• struct v4l2_hevc_dpb_entry(9)
• struct v4l2_hevc_pred_weight_table(9)
• struct v4l2_ctrl_hevc_slice_params(9)
• struct v4l2_ctrl_hevc_decode_params(9)
• struct v4l2_ctrl_hevc_scaling_matrix(9)
• struct v4l2_vp9_loop_filter(9)
• struct v4l2_vp9_quantization(9)
• struct v4l2_ctrl_vp9_frame(9)
• struct v4l2_vp9_mv_probs(9)
• struct v4l2_ctrl_vp9_compressed_hdr(9)
• struct v4l2_ctrl_av1_sequence(9)
• struct v4l2_ctrl_av1_tile_group_entry(9)
• enum v4l2_av1_warp_model(9)
• enum v4l2_av1_reference_frame(9)
• struct v4l2_av1_global_motion(9)
• enum v4l2_av1_frame_restoration_type(9)
• struct v4l2_av1_loop_restoration(9)
• struct v4l2_av1_cdef(9)
• enum v4l2_av1_segment_feature(9)
• struct v4l2_av1_segmentation(9)
• struct v4l2_av1_loop_filter(9)
• struct v4l2_av1_quantization(9)
• struct v4l2_av1_tile_info(9)
• enum v4l2_av1_frame_type(9)
• enum v4l2_av1_interpolation_filter(9)
• enum v4l2_av1_tx_mode(9)
• struct v4l2_ctrl_av1_frame(9)
• struct v4l2_ctrl_av1_film_grain(9)

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okay that's the whole page, you ate it up, no crumbs 💅 go forth and segment responsibly 🦋

byeee 🫶

this has been the struct v4l2_vp9_segmentation(9) page, sourced from ./include/uapi/linux, dated October 2026 — she's a classic, she's timeless, she's literally the whole manual page 💖