feat(casting): add Chromecast device profile builder

utils/casting/buildProfile.test.ts

@@ -0,0 +1,55 @@
+import { describe, expect, test } from "bun:test";
+import { buildChromecastProfile } from "./buildProfile";
+import { CONSERVATIVE_CAPABILITIES } from "./capabilities";
+
+describe("buildChromecastProfile", () => {
+  test("conservative caps produce an H.264-only video codec list", () => {
+    const profile = buildChromecastProfile(CONSERVATIVE_CAPABILITIES);
+    const videoCodecProfile = profile.CodecProfiles?.find(
+      (c) => c.Type === "Video",
+    );
+    expect(videoCodecProfile?.Codec).toBe("h264");
+  });
+
+  test("HEVC-capable caps include hevc in the video codec list", () => {
+    const profile = buildChromecastProfile({
+      ...CONSERVATIVE_CAPABILITIES,
+      hevc: true,
+    });
+    const videoCodecProfile = profile.CodecProfiles?.find(
+      (c) => c.Type === "Video",
+    );
+    expect(videoCodecProfile?.Codec).toContain("hevc");
+  });
+
+  test("maxVideoBitrate drives MaxStreamingBitrate", () => {
+    const profile = buildChromecastProfile({
+      ...CONSERVATIVE_CAPABILITIES,
+      maxVideoBitrate: 5_000_000,
+    });
+    expect(profile.MaxStreamingBitrate).toBe(5_000_000);
+  });
+
+  test("maxAudioChannels constrains transcoding profiles", () => {
+    const profile = buildChromecastProfile(CONSERVATIVE_CAPABILITIES);
+    const videoTranscode = profile.TranscodingProfiles?.find(
+      (p) => p.Type === "Video",
+    );
+    expect(videoTranscode?.MaxAudioChannels).toBe("2");
+  });
+
+  test("non-10bit HEVC caps add a video bit-depth condition", () => {
+    const profile = buildChromecastProfile({
+      ...CONSERVATIVE_CAPABILITIES,
+      hevc: true,
+      hevc10bit: false,
+    });
+    const videoCodecProfile = profile.CodecProfiles?.find(
+      (c) => c.Type === "Video",
+    );
+    const bitDepthCondition = videoCodecProfile?.Conditions?.find(
+      (cond) => cond.Property === "VideoBitDepth",
+    );
+    expect(bitDepthCondition).toBeDefined();
+  });
+});