v4l2_detect_cvt(9)

✨ v4l2_detect_cvt(9) ✨

okay so this is a page from the Kernel API Manual, and the star of the show is v4l2_detect_cvt — bestie, its whole job is to detect if the given timings follow the CVT standard 🎀

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🌸 NAME 🌸

v4l2_detect_cvt — detect if the given timings follow the CVT standard

no cap, that's literally it. it checks the vibe of your timings against CVT 💅

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✨ SYNOPSIS ✨

bool v4l2_detect_cvt (unsigned int frame_height , unsigned int hfreq ,
       unsigned int vsync , unsigned int active_width , u32 polarities , bool
       interlaced , const struct v4l2_dv_timings_cap *cap , struct
       v4l2_dv_timings *fmt );

she takes eight arguments, and yes, you have to give her all of them 🫶

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🦋 ARGUMENTS 🦋

• frame_height — the total height of the frame (including blanking) in lines. total. blanking included. don't forget the blanking, bestie 😭
• hfreq — the horizontal frequency in Hz.
• vsync — the height of the vertical sync in lines.
• active_width — active width of image (does not include blanking). heads up: this info is needed only in case of version 2 of reduced blanking. In other cases, this parameter does not have any effect on timings. so like... sometimes she's just standing there, not doing anything 🧚
• polarities — the horizontal and vertical polarities (same as struct v4l2_bt_timings polarities).
• interlaced — if this flag is true, it indicates interlaced format.
• cap — the v4l2_dv_timings_cap capabilities.
• fmt — the resulting timings. this is where the answer lands, so keep it safe 👑

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💖 DESCRIPTION 💖

so what she does is: this function will attempt to detect if the given values correspond to a valid CVT format. If so, then it will return true, and fmt will be filled in with the found CVT timings. 🎀

like, she's doing a vibe check on your numbers, and if they pass? true, and fmt gets the whole look. iconic behavior honestly ⭐

the function only attempts the detect — valid CVT format in, true out. anything else and the answer is no. no guessing, no inventing timings, periodt 💅

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🌈 SEE ALSO 🌈

we stay linking, fr fr:

Kernel file ./include/media/v4l2-dv-timings.h, plus these lovely little functions:

• v4l2_calc_timeperframe(9)
• v4l2_check_dv_timings_fnc(9)
• v4l2_valid_dv_timings(9)
• v4l2_enum_dv_timings_cap(9)
• v4l2_find_dv_timings_cap(9)
• v4l2_find_dv_timings_cea861_vic(9)
• v4l2_match_dv_timings(9)
• v4l2_print_dv_timings(9)
• v4l2_detect_gtf(9)
• v4l2_calc_aspect_ratio(9)
• v4l2_dv_timings_aspect_ratio(9)
• can_reduce_fps(9)
• struct v4l2_hdmi_colorimetry(9)

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okay that's the whole page!! this one came out of ./include/media and it's dated October 2026 — so yeah, mark your calendar and stan the CVT standard 💜🦋💖