# Track: Video Analysis — Stanford CS336 Lecture 3: Architectures

**Status:** Not started (umbrella published 2026-06-21)
**Type:** Research-only child track (Pass 1 of 3)
**Owner:** Tier 2 Tech Lead (execution)
**Cluster:** E (Stanford course VODs >1hr)

> **Parent:** Child #11 of the [video_analysis_campaign_20260621](../../video_analysis_campaign_20260621/) umbrella. See [umbrella spec.md](../../video_analysis_campaign_20260621/spec.md) for full design.

---

## 1. Video

| Field | Value |
|---|---|
| **Title** | Stanford CS336 — Language Modeling from Scratch, Spring 2026, Lecture 3: Architectures |
| **Author** | Stanford CS336 Spring 2026 |
| **URL** | https://youtu.be/lVynu4bo1rY |
| **Cluster** | E (Stanford course VODs >1hr) |
| **Estimated duration** | >1hr (Stanford course lecture) |
| **Slug** | `cs336_architectures` |
| **Execution order** | #11 of 12 (deep dive on transformer architectures; pairs back to CS229 with full context from prior videos) |

**Pre-execution note (2026-06-21):** This video's oEmbed API fetch returned 401. This may indicate a private/age-restricted video; `yt-dlp` may still work. **Phase 1 of this track must verify yt-dlp access before downloading the mp4.** If `yt-dlp` also fails, fall back to manual transcript sourcing (if available) or escalate.

**Position rationale:** Placed late (after Clusters A/B/C) rather than early so the Tier 3 worker has full context from CS229 + math + Platonic + biological videos when analyzing the architecture details. CS229 (#1) sets the "why" for transformer architectures; CS336 (#11) is the "how" deep dive.

---

## 2. Deliverables

| Artifact | Path | Target |
|---|---|---|
| Transcript | `artifacts/transcript.json` | All segments |
| Download log | `artifacts/download.log` | yt-dlp output |
| Frames | `artifacts/frames/*.jpg` | 50-500 |
| Extraction meta | `artifacts/extraction_meta.json` | Frame paths + hashes |
| OCR | `artifacts/ocr.md` | Full OCR per frame |
| Deep-dive report | `report.md` | **1000-10000 LOC markdown** |
| Summary | `summary.md` | 200-400 words |

---

## 3. Pipeline (5 phases)

- [ ] **Phase 1: Acquire.** Run `extract_transcript.py` + `download_video.py`. Verify `yt-dlp` access first.
- [ ] **Phase 2: Keyframes.** `extract_keyframes.py` with threshold 0.4.
- [ ] **Phase 3: OCR.** `ocr_frames.py`.
- [ ] **Phase 4: Synthesis.** Tier 3 worker: transcript + OCR + frames → `report.md` (1000-10000 LOC).
- [ ] **Phase 5: Verification.** Idempotency + audit + end-of-track report.

---

## 4. Report structure

8 sections per umbrella spec §FR6.

```
# Stanford CS336 Lecture 3: Architectures
**Source:** https://youtu.be/lVynu4bo1rY
**Author:** Stanford CS336 Spring 2026
**Cluster:** E
**Slug:** cs336_architectures

## 1. TL;DR
## 2. Key Concepts  ← expect transformer architectures, attention, FFN, MoE, etc.
## 3. Frame Analysis  ← expect dense formulas/diagrams; OCR critical
## 4. Transcript Highlights
## 5. Mathematical / Theoretical Content  ← dominant
## 6. Connections  ← heavy cross-refs to CS229 + prior cluster videos
## 7. Open Questions
## 8. References
```

---

## 5. Connections

- **Forward to:** `creikey_dl_cv` (applied capstone — uses these architectures in games).
- **Backward from:** `cs229_building_llms` (sets "why transformer architectures"), `score_dynamics_giorgini` (training dynamics), `platonic_intelligence_kumar` (representations inside the architecture).
- **Likely rich cross-references:** `cs229_building_llms` (most direct — same LLM topic, different depth), `platonic_intelligence_kumar` (representations inside architectures).

---

## 6. Verification

- [ ] All 7 deliverables present
- [ ] `report.md` 1000-10000 LOC
- [ ] Tests pass

---

## 7. See also

- [Umbrella spec.md](../../video_analysis_campaign_20260621/spec.md)
- [Umbrella README.md](../../video_analysis_campaign_20260621/README.md)
