STRUCT V4L2_VP8_LOOP_FILTER(9)

✨ struct v4l2_vp8_loop_filter — NAME ✨

okay so bestie, welcome to the Kernel API Manual, section 9 💅 — today's main character is struct v4l2_vp8_loop_filter, and it's literally the VP8 loop filter parameters. that's it, that's the vibe. 🎀

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🦋 SYNOPSIS 🦋

no cap, here's the whole glow-up exactly as it ships:

struct v4l2_vp8_loop_filter {
    __s8 ref_frm_delta[4];
    __s8 mb_mode_delta[4];
    __u8 sharpness_level;
    __u8 level;
    __u16 padding;
    __u32 flags;
 };

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💖 Members 💖

okay so let's meet the cast, one by one 🫶

• ref_frm_delta — signed delta values for the reference frame. signed!! important. 🔥
• mb_mode_delta — signed delta values for the MB prediction mode. also signed, we love consistency ✨
• sharpness_level — this one matches the sharpness_level syntax element, fr fr.
• level — matches the loop_filter_level syntax element. iconic naming choice, no notes 👑
• padding — it's the padding field. and bestie, listen: it should be zeroed by applications. like, actually. do that. 🙈
• flags — go look at V4L2_VP8_LF_{} for these, iykyk 🦋

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🌸 Description 🌸

so this structure is holding all the loop filter related parameters, periodt. 💅

if you want the full lore, go read the 'mb_lf_adjustments' part of the frame header syntax, plus section '9.4. Loop Filter Type and Levels' of the VP8 specification — that's where the details live, and honestly it ate. 📖✨

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🌈 SEE ALSO 🌈

the friend group is huge, buckle up bestie 😭💀 — and also peep the 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_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_vp9_segmentation(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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and that's the whole page, bestie! 💜 this one came from the kernel source at ./include/uapi/linux, stamped October 2026 — so go forth, zero your padding, and slay 🎀✨🦋