captions-overlay
قانون‌گذاری هوشمند برای کپشن‌های overlay در ویدیوهای HyperFrames
این skill برای طراحی کپشن در ویدیوهای talking-head، explainer و launch، هر عبارت را به سه مدل drop، rail یا embed تقسیم می‌کند. متن معمولی روی rail می‌ماند، عبارت‌های زائد حذف می‌شوند و فقط اوج‌های روایی به‌صورت embed برجسته می‌شوند.
همچنین یادآوری می‌کند که کپشن یک overlay روی فیلم است، نه نوار رزروشده در پایین تصویر. بنابراین composition روی مرکز واقعی فریم قرار می‌گیرد، محتوا تا لبه‌ها ادامه پیدا می‌کند و فقط متن‌های کوچک و حیاتی از محل برخورد کپشن دور نگه داشته می‌شوند.
چه چیزی می‌گیرید
- تشخیص عبارت‌های قابل حذف با مدل drop
- طراحی rail برای نمایش خوانای متن گفتاری به‌صورت verbatim
- تعیین embedهای کمیاب برای لحظه‌های اوج و رعایت فاصله بین آن‌ها
- جلوگیری از ایجاد نوار خالی یا جابه‌جایی composition برای کپشن
- راهنمای بررسی خوانایی کپشن روی محتوای واقعی فریم
برای چه کاری خوب است
- ویدیوهای talking-head و explainer که بیشتر متن باید به‌صورت زیرنویس خوانا نمایش داده شود
- ویدیوهای launch یا تبلیغاتی که به چند لحظه اوج بصری برای برجسته‌سازی نیاز دارند
- compositionهایی که باید با کپشن فعال، همچنان روی مرکز واقعی فریم متمرکز بمانند
برای چه کاری نیست
- پروژه‌هایی که به پیاده‌سازی کامل موتور captioning یا تبدیل گفتار به متن نیاز دارند
- ویدیوهای pure-cinematic که عمداً همه متن را به شکل embed نمایش می‌دهند، مگر با درخواست صریح
- چیدمان‌هایی که نیازمند یک نوار ثابت و خالی برای کپشن هستند
دربارهٔ این اسکیل
Captions Overlay Doctrine
Overlay doctrine — supplements the upstream
/hyperframesskill'sreferences/captions.md. Applies ON TOP of it; do not expect it folded into the upstream skill.
Two ideas combine here. First, the caption model — every spoken phrase is drop,rail, or embed, and embed is the scarce earned peak, not the default. Second, the
overlay law — a caption line is composited ON TOP of the film as an overlay; it is
NOT a reserved zone, so you never shift content up or leave a dead band to "make room"
for it. The two reinforce each other: because captions ride as an overlay (the verbatim
rail in front, the occasional embed behind the subject), the composition keeps its full
frame and centers on the true vertical center.
The caption model — drop / rail / embed
Every spoken phrase is one of three things:
| What | How it's shown | |
|---|---|---|
| drop | filler — um/uh, stutters, self-corrections | not shown |
| rail | the default — ordinary spoken content (verbatim) | clean lower-third subtitle, in front, readable. A punch word can get an inline emphasis highlight (accent colour / active-word pop) — it stays on the rail. |
| embed | a promoted peak — the headline beat | one big word composited behind the subject (matte occlusion), designed entrance + exit |
The rail carries most of the text; embed is the scarce, earned peak — ≤1 per beat,
never two adjacent/co-visible, spaced ≥ a beat apart. A short clip → usually one embed;
a long explainer → ~one per section. Embedding every word is the common mistake.
This is the default shape (rail = the verbatim lower-third; embed = the climax
composited behind the subject). A pure-cinematic treatment drops the rail and makes
everything embed-style — use it only for pure-cinematic asks, never for explainer /
voiceover where the words must read.
Rail-first, embed-scarce (the load-bearing rules)
- Rail-first for talking-head / explainer. Don't embed the whole transcript — most text is the rail; embed only peaks. Embedding everything is the default mistake.
- Embed is scarce + spaced. ≤1 embed per sentence/beat, never two adjacent or co-visible, ≥ a beat apart, at most one
apex. climax = per-beat peak, not "the single payoff of the entire clip."
The overlay law — captions are NOT a reserved band
In a composed video with captions enabled, the caption line is a **small, minimal
word-by-word line** composited as an overlay layer ON TOP of the whole film (a single
text line, bottom-centered, roughly the bottom ~5-8% of canvas height). It is an
overlay, not a reserved zone:
- Center the composition on the TRUE vertical center — y = H / 2 (landscape 540, portrait 960). Do not shift content up to "make room" for captions; a composition centered at 0.42 × H with a dead lower band is the bug, not the fix.
- Content may extend to the canvas bottom. Full-bleed subjects, rails, and backgrounds all welcome.
- One soft courtesy rule: avoid parking _critical small readable text_ (a URL line, a legal line, a sub-caption) exactly in the bottom ~80px center span where the caption line sits — the overlay would fight it. Large imagery / cards / ambient content under the captions is fine; the caption skin is designed to read over content.
- There is no machine keep-out gate (the old
captions.mjs keepoutcheck is retired). Snapshot review judges caption-over-content legibility visually.
When captions are disabled: identical positioning freedom — the overlay simply
doesn't exist.
Why these two rules are one doctrine
The model says the rail rides in front and an embed is a rare word composited
behind the subject — both are layers added to footage that ships untouched. The
overlay law says the caption line is a layer composited on top of the whole film,
not a band carved out of the layout. So whether captions go over footage or over a
composed film, they are an overlay you add, not a zone you reserve:
- Keep the full frame; center on true center; let content run to the edges.
- Make the rail (or the small overlay caption line) carry the verbatim words.
- Promote a word to an embed only at a genuine peak — scarce, spaced, never two at once.
- Reserve nothing; judge legibility of captions-over-content visually, not by a keep-out gate.