From 81268299d0a6c9bcd6446873e07b74167788ef48 Mon Sep 17 00:00:00 2001
From: Matthias Van Parijs <matvp91@gmail.com>
Date: Thu, 29 Aug 2024 22:28:26 +0200
Subject: [PATCH] feat: maxResolution for master manifest

---
 packages/stitcher/package.json          |  4 +--
 packages/stitcher/src/contract.ts       |  1 +
 packages/stitcher/src/playlist.ts       |  7 ++++++
 packages/stitcher/src/session.ts        |  8 ++++++
 packages/stitcher/src/types.ts          |  1 +
 packages/stitcher/test/playlist.test.ts | 33 +++++++++++++++++++++++++
 6 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/packages/stitcher/package.json b/packages/stitcher/package.json
index 20a0b9f5..620a690f 100644
--- a/packages/stitcher/package.json
+++ b/packages/stitcher/package.json
@@ -3,8 +3,8 @@
   "type": "module",
   "scripts": {
     "build": "tsc",
-    "start": "node ./dist/index.js",
-    "dev": "tsc-watch --noClear --onSuccess \"node ./dist/index.js\"",
+    "start": "node ./dist/src/index.js",
+    "dev": "tsc-watch --noClear --onSuccess \"node ./dist/src/index.js\"",
     "test": "NODE_OPTIONS=--experimental-vm-modules jest"
   },
   "devDependencies": {
diff --git a/packages/stitcher/src/contract.ts b/packages/stitcher/src/contract.ts
index f36d66c5..6c367cb8 100644
--- a/packages/stitcher/src/contract.ts
+++ b/packages/stitcher/src/contract.ts
@@ -15,6 +15,7 @@ export const postSessionBodySchema = z.object({
     )
     .optional(),
   bumperAssetId: z.string().optional(),
+  maxResolution: z.number().optional(),
 });
 
 export const contract = c.router({
diff --git a/packages/stitcher/src/playlist.ts b/packages/stitcher/src/playlist.ts
index 29226757..f0597b87 100644
--- a/packages/stitcher/src/playlist.ts
+++ b/packages/stitcher/src/playlist.ts
@@ -16,6 +16,13 @@ export async function formatMasterPlaylist(session: Session) {
 
   const master = await fetchPlaylist<MasterPlaylist>(url);
 
+  master.variants = master.variants.filter((variant) => {
+    if (!variant.resolution) {
+      return true;
+    }
+    return variant.resolution.height <= session.maxResolution;
+  });
+
   return stringify(master);
 }
 
diff --git a/packages/stitcher/src/session.ts b/packages/stitcher/src/session.ts
index e4fb1c42..03140a2f 100644
--- a/packages/stitcher/src/session.ts
+++ b/packages/stitcher/src/session.ts
@@ -15,6 +15,7 @@ export async function createSession(data: {
   vmapUrl?: string;
   interstitials?: Interstitial[];
   bumperAssetId?: string;
+  maxResolution?: number;
 }) {
   const sessionId = randomUUID();
 
@@ -42,10 +43,17 @@ export async function createSession(data: {
     });
   }
 
+  let maxResolution = data.maxResolution;
+  if (!maxResolution) {
+    const MAX_RESOLUTION_8K = 4320;
+    maxResolution = MAX_RESOLUTION_8K;
+  }
+
   const session = {
     id: sessionId,
     assetId: data.assetId,
     interstitials,
+    maxResolution,
   } satisfies Session;
 
   const redisKey = getRedisKey(sessionId);
diff --git a/packages/stitcher/src/types.ts b/packages/stitcher/src/types.ts
index 989cdca9..f3dc7c5f 100644
--- a/packages/stitcher/src/types.ts
+++ b/packages/stitcher/src/types.ts
@@ -2,6 +2,7 @@ export type Session = {
   id: string;
   assetId: string;
   interstitials: Interstitial[];
+  maxResolution: number;
 };
 
 export type Interstitial = {
diff --git a/packages/stitcher/test/playlist.test.ts b/packages/stitcher/test/playlist.test.ts
index 9af48694..a9b2faee 100644
--- a/packages/stitcher/test/playlist.test.ts
+++ b/packages/stitcher/test/playlist.test.ts
@@ -22,6 +22,7 @@ describe("playlist", () => {
       id: "sessionId",
       assetId: "assetId",
       interstitials: [],
+      maxResolution: 1080,
     });
 
     expect(master).toMatchInlineSnapshot(`
@@ -64,6 +65,7 @@ describe("playlist", () => {
         id: "sessionId",
         assetId: "assetId",
         interstitials: [],
+        maxResolution: 1080,
       },
       "video_1080"
     );
@@ -135,6 +137,7 @@ describe("playlist", () => {
             assetId: "ad3",
           },
         ],
+        maxResolution: 1080,
       },
       "video_1080"
     );
@@ -161,4 +164,34 @@ describe("playlist", () => {
       #EXT-X-DATERANGE:ID="10",CLASS="com.apple.hls.interstitial",START-DATE="2022-02-21T17:35:10.000Z",X-ASSET-LIST="/session/sessionId/asset-list.json?timeOffset=10",X-RESUME-OFFSET=0,X-RESTRICT="SKIP,JUMP""
     `);
   });
+
+  test("should remove resolutions below maxResolution", async () => {
+    fetchMock.mock("https://s3-public.com/package/assetId/hls/master.m3u8", {
+      status: 200,
+      body: `
+        #EXTM3U
+        #EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2149280,CODECS="mp4a.40.2,avc1.64001f",RESOLUTION=100x720,NAME="720" 
+        720.m3u8
+        #EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2149280,CODECS="mp4a.40.2,avc1.64001f",RESOLUTION=100x480,NAME="480" 
+        480.m3u8
+        #EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2149280,CODECS="mp4a.40.2,avc1.64001f",RESOLUTION=100x360,NAME="360" 
+        360.m3u8
+      `,
+    });
+
+    const master = await formatMasterPlaylist({
+      id: "sessionId",
+      assetId: "assetId",
+      interstitials: [],
+      maxResolution: 480,
+    });
+
+    expect(master).toMatchInlineSnapshot(`
+      "#EXTM3U
+      #EXT-X-STREAM-INF:BANDWIDTH=2149280,CODECS="mp4a.40.2,avc1.64001f",RESOLUTION=100x480,PROGRAM-ID=1
+      480.m3u8
+      #EXT-X-STREAM-INF:BANDWIDTH=2149280,CODECS="mp4a.40.2,avc1.64001f",RESOLUTION=100x360,PROGRAM-ID=1
+      360.m3u8"
+    `);
+  });
 });