Notes About Screening

Host: notes.addict.best

File: notes-about-screening.md

Scope: Screen capture quality, images→video, re-encode size math, browser publishing patterns, growth/viral mechanics, shot-list review notes.

Updated: 2026-08-03


Table of contents

1. Mac screen recording (aliases & codecs)

2. H.264 vs H.265 for screen content

3. CRF / quality settings (and videotoolbox reality)

4. Why re-encodes got tiny but still looked good

5. Images → video (OpenCV review + better practice)

6. Browser automation / no-API publishing (use carefully)

7. Content & viral mechanics (retention math)

8. High-retention video structure

9. Actions on media platforms (ops checklist)

10. Platform playbooks from zero

11. Shot-list / AI production order review

12. Quick reference tables


1. Mac screen recording (aliases & codecs)

Baseline: rec-screen (current default)

SettingValueNotes
Encoderh264_videotoolbox (hardware)Low CPU on Mac
Bitrate18 Mbps CBR (-b:v 18000k)Very good look; large files
ResolutionNative display (no scale)Often 2560×1664 (or 2560×1600) on MacBook Air
Frame rate30 fpsStable for UI demos
Outputscreen_*.mp4Keep as archive / edit source

Quality take: At 18 Mbps CBR, native res, quality is close to visually lossless for screen content. CBR still wastes bits on static frames → fat files.

AliasResolutionCodecQuality modeOutput names
rec-screenNative (e.g. 2560×1664)H.264 @ 18 Mbps CBRVery good, largescreen_*.mp4
rec-screen-10801920×1080HEVC hevc_videotoolbox-q:v 40screen_1080_*.mp4
rec-screen-2k2560×1440HEVC hevc_videotoolbox-q:v 35 (tighter)screen_2k_*.mp4

When to use which


2. H.264 vs H.265 for screen content

FactorH.264H.265 / HEVC
Screen (text, UI, sharp edges)GoodBetter — text stays crisp at lower bitrates
File size at same lookLarger~40–50% smaller typical
Mac hardware encodeh264_videotoolboxhevc_videotoolbox (also HW, low CPU)
Local macOS playbackUniversalNative
Older Windows / some browsersUniversalMay need HEVC extension / fail in browser

Rule of thumb


3. CRF / quality settings (and videotoolbox reality)

Software x264 / x265 (CRF)

Use caseCRFMeaning
General video “safe”21Fine, often overkill for UI
Screen content safety margin23–25Still clean
Screen “visually lossless, small”~28 with HEVCText stays crisp; smallest sensible files
Too aggressive28–32 H.264Risk of blocks on fine UI

CRF idea: quality-targeted — hard scenes get more bits; flat UI gets few. Better than fat fixed bitrate for screen demos.

Hardware videotoolbox (important)

hevc_videotoolbox / h264_videotoolbox do not support true CRF.

Use quality mode -q:v (lower number = better quality).

Approximate mappingvideotoolbox -q:vRough software CRF feel
1080p screen demos40~CRF mid-20s territory for UI
2K screen demos35Tighter / higher quality
“CRF 21-ish” intent~35–40 bandNot a 1:1 math formula

Practical defaults already set


4. Why re-encodes got tiny but still looked good

Rough impact order (screen / app demos):

1. Resolution drop (biggest lever)

Example: 2880×1800 → 1920×1200 ≈ 0.44× pixels. Half-ish the pixels → far fewer bits for the same perceived sharpness on laptop/phone. For UI demos, 1920 is often enough; 2880 is frequently overkill for screening.

2. Original bitrate was wasteful

Sources ~6.7–7 Mbps at high res vs outputs ~0.5–0.7 Mbps at 1920 with CRF ~20. Originals were “fat” relative to flat UI complexity.

3. CRF / quality mode, not fixed high bitrate

Avoids paying full bitrate for static frames.

4. Content type loves compression

Flat colors, UI panels, text, slow pans, little grain/noise → encoders crush size without looking soft. Grainy outdoor cinema would not shrink the same way.

5. Modern re-encode efficiency

Current libx264 + medium (or HEVC HW) often beats older near-lossless screen dumps.

6. No audio

100% of bits go to video (audio only a few MB, but simplifies the story).

What *not* to do (protects quality)

Mental model

Size ≈ pixels × motion/detail × encoder efficiency × “safety margin” bitrate

You win size by cutting pixels + safety margin (CRF/q-mode) + content that needs little bitrate (UI screens).

FAQ

QuestionAnswer
Why not always H.265?Compatibility; huge savings already available with scale + CRF H.264; HEVC is the next step if still large.
Magic?No — half pixels + smart bitrate + screen content. Not “because H.264 is magic.”

5. Images → video (OpenCV review + better practice)

What the common OpenCV tutorial does (summary)

1. Install opencv-python + pillow

2. Count .jpg/.jpeg/.png

3. Compute mean width/height, resize all frames with LANCZOS

4. cv2.VideoWriter with DIVX fourcc, 1 fps, write each frame → .avi

Review — what is solid

Review — problems / upgrades for real screening work

Issue in tutorial patternBetter practice
Overwrites originals when saving resized JPEG in placeWrite to a temp folder; never destroy masters
Mean size can yield odd dimensions (not divisible by 2)Force even width/height (w//2*2, h//2*2) for H.264/HEVC
Codec DIVX + .aviPrefer H.264/HEVC MP4 via FFmpeg for web/editors
FPS = 1For slideshow/Ken Burns: 30 fps with duration per image (e.g. 2.5–4s), not 1 fps
os.listdir order is unsortedSort filenames (or natural sort)
No audioFine for silent loops; mux music with FFmpeg + apad/-shortest if needed
Colab Drive pathsLocal: pass a folder path; avoid hard-coded Drive roots

Preferred pipeline (production-aligned)

images (sorted)
  → optional scale to even WxH (or fixed 1080×1920 / 1920×1080)
  → FFmpeg image sequence or concat demuxer
  → -framerate 30 on image inputs (VFR trap)
  → H.264 social default or HEVC archive
  → -ar 48000 if audio
  → QA: duration, non-black frames, mute-readability if text-on-screen

OpenCV is fine for prototypes / research; for screening + social delivery, FFmpeg (and editor.addict.best enhance templates) is the durable path.


6. Browser automation / no-API publishing (use carefully)

Policy: Browser/cookie automation only for your own accounts, conservative pacing, no ban-loop retries. Prefer existing Hybrid/Omni patterns over random GitHub clones.

Useful patterns (reference only)

ProjectRoleLink
Katzca/AutoSocialLocal dashboard TikTok/IG/YouTube; Playwright sessions; queues; schedule; yt-dlp + FFmpeg uniquifyhttps://github.com/Katzca/AutoSocial
xtea/auto-instagramIG Feed/Carousel/Reels via Playwright + cookies + Patchright; cron queueshttps://github.com/xtea/auto-instagram
cedonulfi/automiePlaywright + Gemini + Streamlitsearch GitHub
profullstack/social-posterMulti-platform CLI + sessionssearch GitHub

How-to sketches

Stealth helpers

Simplified CLI (API side note)

Not a substitute for cookie vault + watchdog hygiene on browser-first stacks.


7. Content & viral mechanics (retention math)

Grounding facts (2026-style)

- TikTok: aim hook intent ~1.0–1.3s

- Reels: ~1.5–2.1s

Five content archetypes that spread

1. Contrarian — “Why [popular thing] is actually hurting you”

2. Transformation / reveal — before/after, process, “X → Y”

3. Relatable pain — “Does anyone else…”, “POV:…”

4. Information gaps — “The real reason…”, “What nobody tells you…”

5. Authority by association — react to big names / viral niche moments

Golden hour & distribution

What kills growth

Hub-and-spoke (default system)

One hub piece → many spoke adaptations (Reels cut, Threads text, X post, carousel). Don’t invent six full originals from zero.


8. High-retention video structure

TimeGoalDo
0–3sPattern interruptMotion in first 0.5s; no “hey guys welcome”; triple hook: motion + on-screen text + high-stakes line
3–10sOpen narrative loopInfo gap / conditional frame (“day 1 disaster… day 20…”) without spoiling payoff
Middle ~50–80%Pacing engineVisual change every ~2–3s; micro-SFX on pops; punch-ins 10–15% on key beats
EndingCold cut / loopNo “thanks for watching”; deliver last value → cut; optional seamless loop into open

Editing techniques that help

TechniqueWhyHow
Punch-in / zoom cutsFake multi-camCut on sentence; zoom 10–15% alternating
J-cutsSmooth brain transitionNext audio leads 0.2–0.5s before picture
Word groups captionsEyes stay on frame1–3 words, highlight keywords
Speed ramp / silence killRemove dead air1.1–1.2× talk; cut micro-pauses

9. Actions on media platforms (ops checklist)

Use with ethics / account age caps elsewhere (Hybrid rules). This list is what to do, not “spam harder.”

1. Choose 2–3 primary platforms.

2. Weekly batch: core idea → native adaptations.

3. Publish → golden hour engage → next-day retention review.

4. Double down on formats above your baseline.

5. Cross-pollinate winners by adapting, not cloning.

6. Track saves/shares + early velocity.

High-leverage “treasure” edges


10. Platform playbooks from zero

PlatformFrom-zero noteCadence / tips
TikTokBest zero-to-hero odds (merit FYP)2–3 specific hashtags; less-polished often wins
InstagramBest single visual platform to master first4–7 Reels/week + Stories; carousels later; trending audio first 24h helps
YouTubePair Shorts + occasional long-formShorts often 15–30s for completion; growth back-loaded
XFastest / least forgivingGuard first 30–60 min; reply to replies; links in reply, not body (non-Premium)
ThreadsEasier room to be heard2–3 posts/day; constructive tone; avoid GPT-isms (delve, leverage, game-changer)
LinkedInProfessional spoke of hubDon’t dump the same entertainment cut
PinterestSearch engine for evergreen how-tosOptimize for search, not TikTok-style chase

First 30 days

1. Lock niche, pillars, handle, keyword bio; pick TikTok or Reels as lead; outline 10 hubs.

2. Batch film; one hub → many spokes; post lead daily-ish; Threads/X 1–2×/day.

3. Reply every comment ~first hour; track retention, saves+shares, follows-per-view.

4. Double down on winners; drop platforms with zero return — 2–3 done well > 6 thin.

30-day blitz (optional intensity)

WeekFocus
1Competitor audit, systems, high output start
2Find 3 winning formats; double down
3Collabs / pods / live once
4Repurpose top 10; optional contest

11. Shot-list / AI production order review

Review of a ~48s / 14-shot Promedic-style order:

ShotsMethodVerdict
1–9, 11–13AI photoreal videoOK
10Live screen recording of appCorrect — authentic UI, legally/clinically cleaner
14Motion-graphics outro (AE/Canva)Correct — AI logo lockups hallucinate

Discipline that matters most

Consistency workflow highlights

9:16 safe zones

Tool notes

Expert non-negotiables

1. Render textless master + captioned version separately (cheap at export; saves EN/AR rework).

2. Never let AI invent medical numbers on-screen — generate abstract UI; burn real numbers as post graphics. Liability + accuracy.


12. Quick reference tables

Screen capture decision

GoalChoice
Maximum fidelity archiveNative H.264 18 Mbps or native/2K HEVC
Share / screeningrec-screen-1080 HEVC -q:v 40
Smaller still sharpScale to 1920 + CRF/q-mode; screen content compresses hard
Max compatibility exportH.264 MP4 deliverable

Size vs quality levers (screen)

LeverEffect
Resolution ↓Biggest size win
CRF / -q:v vs fat CBRStops paying for static frames
HEVC vs H.264~40–50% smaller at same look
Content typeUI/text = easy; grain/cinema = hard

Viral ops (one screen)

Hook ≤2s (mistake-frame preferred)
→ ≥60% past 3s
→ visual change ~2–3s
→ publish
→ 60-min golden hour (reply/share/groups)
→ next day: retention + saves/shares
→ recycle winners 60–90 days

SiteRole
notes.addict.bestThis notes hub
editor.addict.bestScreen/edit agent templates (incl. Promedic pack)
content.addict.bestContent / AI-manager lectures

*End of notes-about-screening.md*