Remotion Composer

remotion-composer

Intent

Sixth stage of the AnimeLegends generative pipeline. Receives artifact paths (generated images, videos, voice audio) from gen-director, loads the appropriate Remotion v4 composition template based on channel (PowerScaling / Philosophy / LoreDrop / TrainingArc / LegendsLabs), composites all shots into a single timeline with timing from ScriptManifest and StoryboardManifest, applies the AnimeLegends brand LUT (color grading), adds gold particle intro animation (2s), appends 3s brand bumper outro with subscribe CTA, renders final MP4 at 1080×1920 vertical format (Day 1-30) or 2160×3840 4K (Day 31+), 30fps (Day 1-30) or 60fps (Day 31+), and outputs the rendered video path for publish-orchestrator to distribute.

Inputs

What this skill expects to receive:

interface RemotionComposerInput {
  generate_manifest: GenerateManifest;      // from gen-director (required)
  script_manifest: ScriptManifest;          // from script-forge (for dialogue timing)
  storyboard_manifest: StoryboardManifest;  // from storyboard-forge (for shot metadata)
  render_quality?: "preview" | "production"; // default: production
  output_resolution?: "1080p" | "4K";       // default: 1080p (Day 1-30), 4K (Day 31+)
}

Source of input: GenerateManifest from gen-director, with references to ScriptManifest and StoryboardManifest for timing and metadata.

Outputs

What this skill produces:

interface RemotionComposerOutput {
  render_id: string;                        // UUID v4
  generate_id: string;                      // parent generate UUID
  topic: string;                            // clean topic text
  channel: string;                          // PowerScaling | Philosophy | LoreDrop | TrainingArc | LegendsLabs
  video_path: string;                       // final rendered MP4 file path
  render_stats: {
    resolution: string;                     // "1080x1920" | "2160x3840"
    fps: number;                            // 30 | 60
    duration_sec: number;                   // total video duration (original + intro + outro)
    file_size_mb: number;                   // final MP4 file size
    render_time_sec: number;                // wall-clock render time
    template_used: string;                  // Remotion template name
  };
  timestamp: string;                        // ISO 8601
}

Where the output goes: passed to publish-orchestrator as input (if publishing), logged to grimoire-keeper, saved to renders/ directory.

Core logic / rules

1. Template selection — Map script_manifest.channel to Remotion composition template:

   • PowerScaling → templates/PowerScaling.tsx (red/gold accent, dynamic energy, comparison overlays)
   • Philosophy → templates/Philosophy.tsx (blue/purple gradient, contemplative pacing, symbol overlays)
   • LoreDrop → templates/LoreDrop.tsx (green/teal accent, archive aesthetic, timeline graphics)
   • TrainingArc → templates/TrainingArc.tsx (orange/warm gradient, journey framing, progress bars)
   • LegendsLabs → templates/LegendsLabs.tsx (silver/tech accent, grid overlays, technical diagrams)

2. Resolution and FPS determination — Check render date to determine output specs:

   • Day 1-30 (before 2026-09-16): 1080×1920 vertical, 30fps
   • Day 31+ (after 2026-09-16): 2160×3840 vertical 4K, 60fps
   • Respect output_resolution override if provided (for testing).

3. Asset loading — For each shot in generate_manifest.artifacts:

   • Load image_path (PNG/JPG) as still frame or I-frame for video
   • Load video_path (MP4) if shot has motion
   • Load audio_path (WAV/MP3) voice audio
   • Verify file exists and is readable; if missing, skip shot and log warning to Grimoire.

4. Timeline composition — Arrange shots on Remotion timeline:

   • Intro sequence (0-2s): gold particle burst animation + AnimeLegends logo fade-in
   • Shot sequence (2s to 2s+duration_sec): each shot placed at shot.start_sec + 2s (offset by intro)
     • Layer video (or static image) on video track
     • Layer voice audio on audio track
     • Apply shot-specific transitions (crossfade between shots, 0.3s overlap)
   • Outro sequence (2s+duration_sec to 5s+duration_sec): 3s brand bumper with subscribe CTA
     • Gold particle outro animation
     • "Follow for more [channel] content" text overlay
     • AnimeLegends logo hold

5. Brand LUT application — Apply color grading via LUT (look-up table):

   • AnimeLegends LUT: contrast +15%, saturation +10%, shadows lifted +8%, gold particle hue preserved (±5° tolerance)
   • LUT applied globally to all shots (except intro/outro which have pre-graded assets)

6. Audio mixing — Mix voice audio tracks:

   • Normalize voice audio to -3dB peak (prevent clipping)
   • Apply per-mascot reverb/EQ (already in gen-director voice files, but re-verify)
   • Add background music bed (optional, low-level ambient drone at -18dB if available in assets/music/)
   • Master output to -1dB peak

7. Remotion render — Invoke Remotion CLI to render composition:

   npx remotion render [template] [output_path] \
     --props='{"artifacts": [...], "channel": "PowerScaling", ...}' \
     --codec=h264 \
     --crf=18 \
     --preset=slow \
     --audio-codec=aac \
     --audio-bitrate=192k
   

   • CRF 18 for high quality (lower = higher quality, 18-23 range recommended)
   • Preset "slow" for better compression (acceptable for production)
   • Audio codec AAC at 192kbps (standard for social media)

8. Output verification — After render completes:

   • Verify video_path file exists and size >0 bytes
   • Verify duration matches expected: intro(2s) + duration_sec + outro(3s)
   • Compute file size in MB
   • If render failed (file missing or zero size), abort and log error to Grimoire.

9. Manifest generation — Populate RemotionComposerOutput with all fields, generate UUID for render_id, set timestamp to ISO 8601 UTC.

10. Grimoire logging — Log invocation to grimoire-keeper with stage="remotion-composer", input_id=generate_id, output_id=render_id, decision="accept" (if successful) or "error" (if render failed), rationale (one-line: template + resolution + render time), duration_ms.

Worked examples

Example 1: 30s PowerScaling video, 1080p render

Input:

{
  "generate_manifest": {
    "generate_id": "dddd4444-eeee-5555-ffff-666677778888",
    "topic": "Why speed doesn't beat power",
    "duration_sec": 30,
    "artifacts": [
      { "shot_num": 1, "video_path": "/workspace/artifacts/gen/shot_001_video.mp4", "audio_path": "/workspace/artifacts/gen/shot_001_audio.wav" },
      { "shot_num": 2, "video_path": "/workspace/artifacts/gen/shot_002_video.mp4", "audio_path": "/workspace/artifacts/gen/shot_002_audio.wav" },
      { "shot_num": 3, "video_path": "/workspace/artifacts/gen/shot_003_video.mp4", "audio_path": "/workspace/artifacts/gen/shot_003_audio.wav" }
    ]
  },
  "script_manifest": { "channel": "PowerScaling" },
  "storyboard_manifest": { /* shot metadata */ }
}

Output:

{
  "render_id": "eeee5555-ffff-6666-aaaa-777788889999",
  "generate_id": "dddd4444-eeee-5555-ffff-666677778888",
  "topic": "Why speed doesn't beat power",
  "channel": "PowerScaling",
  "video_path": "/workspace/renders/powerscaling_20260816_103000.mp4",
  "render_stats": {
    "resolution": "1080x1920",
    "fps": 30,
    "duration_sec": 35,
    "file_size_mb": 18.7,
    "render_time_sec": 120,
    "template_used": "PowerScaling"
  },
  "timestamp": "2026-08-16T10:30:00Z"
}

Why this output: PowerScaling template selected. 1080p@30fps (Day 1-30 default). 3 shots composited: intro (2s) + 30s content + outro (3s) = 35s total. Render time 120s (4× real-time, typical for Remotion h264 slow preset). File size 18.7 MB (~0.53 MB/s bitrate).

Example 2: 45s Philosophy video, 4K render (Day 31+)

Input:

{
  "generate_manifest": {
    "generate_id": "ffff6666-aaaa-7777-bbbb-888899990000",
    "topic": "Why Domain is philosophically perfect",
    "duration_sec": 45,
    "artifacts": [ /* 5 shots */ ]
  },
  "script_manifest": { "channel": "Philosophy" },
  "output_resolution": "4K"
}

Output:

{
  "render_id": "aaaa7777-bbbb-8888-cccc-999900001111",
  "generate_id": "ffff6666-aaaa-7777-bbbb-888899990000",
  "topic": "Why Domain is philosophically perfect",
  "channel": "Philosophy",
  "video_path": "/workspace/renders/philosophy_20260916_140000_4k.mp4",
  "render_stats": {
    "resolution": "2160x3840",
    "fps": 60,
    "duration_sec": 50,
    "file_size_mb": 67.3,
    "render_time_sec": 310,
    "template_used": "Philosophy"
  },
  "timestamp": "2026-09-16T14:00:00Z"
}

Why this output: Philosophy template selected. 4K@60fps (Day 31+ or explicit override). 5 shots composited: intro (2s) + 45s content + outro (3s) = 50s total. Render time 310s (6× real-time for 4K 60fps). File size 67.3 MB (1.35 MB/s bitrate, higher for 4K).

Example 3: Render failed (missing artifact)

Input:

{
  "generate_manifest": {
    "generate_id": "gggg8888-cccc-9999-dddd-000011112222",
    "topic": "Test topic",
    "duration_sec": 30,
    "artifacts": [
      { "shot_num": 1, "video_path": "/workspace/artifacts/gen/shot_001_video.mp4", "audio_path": "/workspace/artifacts/gen/shot_001_audio.wav" },
      { "shot_num": 2, "video_path": "/workspace/artifacts/gen/shot_002_MISSING.mp4", "audio_path": "/workspace/artifacts/gen/shot_002_audio.wav" },
      { "shot_num": 3, "video_path": "/workspace/artifacts/gen/shot_003_video.mp4", "audio_path": "/workspace/artifacts/gen/shot_003_audio.wav" }
    ]
  },
  "script_manifest": { "channel": "PowerScaling" }
}

Output:

{
  "error": "Render failed: missing artifact /workspace/artifacts/gen/shot_002_MISSING.mp4 for shot 2",
  "stage": "remotion-composer",
  "decision": "error",
  "rationale": "missing_artifact_shot_2",
  "remediation": "Re-run gen-director to regenerate missing shot 2 artifacts."
}

Why this output: Shot 2 video file missing. Asset loading step failed. Render aborted. Error logged to Grimoire with specific missing file path.

Failure modes

• Missing artifact files — If any video_path or audio_path in generate_manifest.artifacts does not exist on disk, skip that shot and log warning to Grimoire with rationale="missing_artifact_shot_N". If >50% of shots are missing, abort render and return error: "Render failed: too many missing artifacts (X/Y shots)".

• Remotion render timeout — If npx remotion render command times out (>600s for 1080p, >1200s for 4K), abort render and log error: "Render timeout exceeded". User may need to reduce quality preset (slow → medium) or resolution.

• Remotion CLI not installed — If npx remotion command not found, abort with error: "Remotion v4 CLI not installed. Run: npm install -g remotion". Log to Grimoire with decision="error", rationale="remotion_not_installed".

• FFmpeg not installed — If FFmpeg not available (required by Remotion for video encoding), abort with error: "FFmpeg not installed. Install via system package manager.". Log to Grimoire with decision="error", rationale="ffmpeg_not_installed".

• Insufficient disk space — If render output directory has <1GB free space, abort with error: "Insufficient disk space for render. Require 1GB free, found X MB.". Log to Grimoire.

• Invalid template — If script_manifest.channel does not match one of the five templates (PowerScaling / Philosophy / LoreDrop / TrainingArc / LegendsLabs), fall back to "PowerScaling" template (default) and log warning.

• Audio sync issue — If voice audio duration does not match expected shot duration (±1s tolerance), stretch or compress audio to fit (via FFmpeg atempo filter), log warning to Grimoire with rationale="audio_resampled_shot_N".

Grimoire logging contract

Every invocation of this skill logs via grimoire-keeper. Fields logged:

• stage: "remotion-composer"
• input_id: generate_id from input
• output_id: render_id from generated output (or null if aborted)
• decision: "accept" (success) | "error" (render failed)
• rationale: one-line explanation (e.g., "PowerScaling_1080p30_120s", "missing_artifact_shot_2", "remotion_not_installed")
• cost_usd: 0.00 (no external API costs; compute is local or via internal render farm)
• duration_ms: elapsed time from input receipt to render completion (or abort)
• file_size_mb: final MP4 file size (or 0 if aborted)
• resolution: "1080x1920" | "2160x3840"
• fps: 30 | 60
• render_time_sec: wall-clock render time (or 0 if aborted)

Legal firewall

This skill does not generate new content or invoke external APIs. It only composites assets generated upstream by gen-director, which already enforced legal filtering. Intro/outro brand assets (logo, particle animations) are AnimeLegends original IP. No copyrighted material is introduced at composition stage.

Quality gates

• Output RemotionComposerOutput has all required fields (render_id, generate_id, topic, channel, video_path, render_stats, timestamp)
• render_id is valid UUID v4
• video_path file exists on disk and size >0 bytes
• render_stats.duration_sec equals intro(2s) + generate_manifest.duration_sec + outro(3s) (±1s tolerance)
• render_stats.resolution matches expected format: "1080x1920" or "2160x3840"
• render_stats.fps is 30 or 60
• render_stats.file_size_mb >0
• render_stats.template_used is one of: PowerScaling, Philosophy, LoreDrop, TrainingArc, LegendsLabs
• Grimoire log entry created with all required fields
• Final MP4 plays back successfully in standard video player (manual verification recommended)
• Audio tracks are in sync with video (±0.1s tolerance)
• Brand LUT applied (verify color grading matches AnimeLegends aesthetic)
• Intro and outro sequences present (intro 0-2s, outro last 3s)

Changelog

0.1.0 — 2026-08-16

• Initial release
• Five Remotion v4 templates (PowerScaling, Philosophy, LoreDrop, TrainingArc, LegendsLabs)
• Resolution progression: 1080p@30fps (Day 1-30) → 4K@60fps (Day 31+)
• Brand LUT color grading (+15% contrast, +10% saturation, +8% shadow lift)
• Gold particle intro (2s) and brand bumper outro (3s)
• Audio mixing with per-mascot reverb/EQ
• H.264 codec, CRF 18, slow preset for high quality
• Asset loading with missing file handling
• Grimoire logging integration with render stats