Tactical Media Broadcast Hub — initial release

Self-hosted multi-platform broadcast newsroom for activist collectives:
publishing pipeline with group approval and DST-proof scheduling, TweetDeck-style
column wall with hostile-content-safe rendering, live control room with Auto
Director, bridged chat governance with polls and quorum, distributed sandboxed
transcode workers, encrypted content-addressed archive, monthly analytics.

MIT licensed. See README.md and docs/.

apps/media-worker/src/compositor/scene-plan.ts

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+import type { ProductionOverlay, ProductionScene, ProductionSpec } from "../production";
+import { layoutRects, rectFromBasisPoints, type Canvas, type CompositorGraph, type MixInput, type OverlaySpec, type TileSpec } from "./command-builder";
+
+/** Desired-state v2 scene → typed compositor graph over a list of source ids (input order). */
+export interface ScenePlan {
+  sourceIds: string[];
+  /** Same order as sourceIds: whether the compositor needs that source's audio. */
+  audio: boolean[];
+  assetIds: string[];
+  graph: CompositorGraph;
+  /** Things in the snapshot this slice renders as black/skips, for the observed reason. */
+  skipped: string[];
+}
+
+export function programScene(spec: ProductionSpec): ProductionScene {
+  const scene = spec.scenes.find((s) => s.id === spec.buses.program);
+  if (!scene) throw new Error("program bus names no scene");
+  return scene;
+}
+
+/**
+ * `available(sourceId)` says whether the worker has an ingest for that source:
+ * S2a ingests HLS sources only; playlist sources (S2b feeder) render black.
+ * Overlay order: `layer` ascending, snapshot order within a layer.
+ */
+export function planScene(spec: ProductionSpec, scene: ProductionScene, canvas: Canvas, available: (sourceId: string) => boolean): ScenePlan {
+  const skipped: string[] = [];
+  const sourceIds: string[] = [];
+  const indexOf = (id: string): number => {
+    let i = sourceIds.indexOf(id);
+    if (i < 0) { sourceIds.push(id); i = sourceIds.length - 1; }
+    return i;
+  };
+  const grid = layoutRects(scene.layout, canvas);
+  const slots = [...scene.slots].sort((a, b) => a.index - b.index);
+  const tiles: TileSpec[] = [];
+  const gains = new Map<number, number>();
+  for (const slot of slots) {
+    const rect = slot.rect ? rectFromBasisPoints(slot.rect, canvas) : grid[slot.index];
+    if (!rect) continue;
+    let source: number | null = null;
+    if (slot.sourceId !== null) {
+      if (available(slot.sourceId)) source = indexOf(slot.sourceId);
+      else skipped.push(`slot ${slot.index}: source ${slot.sourceId} has no ingest in this worker build`);
+    }
+    tiles.push({ source, rect, fit: slot.fit });
+    if (source !== null && slot.audioMode !== "off") gains.set(source, Math.max(gains.get(source) ?? -Infinity, slot.gainDb));
+  }
+  const audio = sourceIds.map((_, i) => gains.has(i));
+  const mix: MixInput[] = [...gains.entries()].sort((a, b) => a[0] - b[0]).map(([source, gainDb]) => ({ source, gainDb }));
+
+  const assetIds: string[] = [];
+  const overlays: OverlaySpec[] = [];
+  const ordered = spec.overlays
+    .map((o, i) => ({ o, i }))
+    .filter(({ o }) => o.sceneId === scene.id && o.enabled)
+    .sort((a, b) => a.o.layer - b.o.layer || a.i - b.i)
+    .map(({ o }) => o);
+  for (const o of ordered) {
+    const spec = overlaySpec(o, canvas, (assetId) => {
+      let i = assetIds.indexOf(assetId);
+      if (i < 0) { assetIds.push(assetId); i = assetIds.length - 1; }
+      return i;
+    });
+    if (spec) overlays.push(spec);
+    else skipped.push(`overlay ${o.id}: ${o.kind} is not composited in S2a`);
+  }
+  return {
+    sourceIds, audio, assetIds, skipped,
+    graph: { canvas, layout: scene.layout, tiles, overlays, audio: { inputs: mix, masterGainDb: spec.audio.masterGainDb } },
+  };
+}
+
+function overlaySpec(o: ProductionOverlay, canvas: Canvas, asset: (id: string) => number): OverlaySpec | null {
+  if (o.assetId === null) return null; // clock: server-generated drawtext is a later slice
+  const x = Math.min(canvas.width, Math.round((o.position.x * canvas.width) / 10_000));
+  const y = Math.min(canvas.height, Math.round((o.position.y * canvas.height) / 10_000));
+  if (o.kind === "chyron" && o.chyron) return { kind: "chyron", asset: asset(o.assetId), y, speedPxPerSec: o.chyron.speedPxPerSec };
+  if (o.kind === "lower_third" || o.kind === "logo") return { kind: "image", asset: asset(o.assetId), x, y };
+  return null;
+}