feat: a codecs subpath, and let the host name the thing

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@profullstack/player",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "description": "One web player for every source a Profullstack site serves: MP4, HLS, MPEG-2 transport streams and audio, with one control bar, on desktop, mobile, PWA and television.",
   "keywords": [
     "video",
@@ -32,6 +32,10 @@
       "types": "./dist/index.d.ts",
       "default": "./dist/index.js"
     },
+    "./codecs": {
+      "types": "./dist/codecs.d.ts",
+      "default": "./dist/codecs.js"
+    },
     "./react": {
       "types": "./dist/react/index.d.ts",
       "default": "./dist/react/index.js"

src/codecs.ts

@@ -0,0 +1,16 @@
+/**
+ * The codec table on its own, with no player attached.
+ *
+ * genrewatch and tipoffwatch each carry a copy of this file. It is the most
+ * expensive 150 lines in either repo -- every rule in it was written in
+ * response to a channel that failed in production, and two of them were got
+ * wrong twice -- and three copies of it is exactly the thing this package
+ * exists to stop.
+ *
+ * A subpath rather than the root export, because those two bundle their client
+ * by hand and are careful about its weight: importing from the root would pull
+ * the player and its dynamic engine imports into a bundle that wants a lookup
+ * table and nothing else.
+ */
+
+export { codecName, mseCandidates, unplayableReason, type MediaInfoLike } from './engines/codecs';

src/engines/codecs.ts

@@ -119,11 +119,16 @@ export function mseCandidates(kind: 'video' | 'audio', codec: string | undefined
  *   is testable without a browser.
  * @param advice appended when there is a problem — the host site's suggestion
  *   for what to do instead, which this package cannot know.
+ * @param subject what the thing is called on the host site. genrewatch and
+ *   tipoffwatch say "channel" because that is what their reader clicked; a
+ *   recording is a "stream" at best. Naming it wrongly is a small thing that
+ *   makes shared copy read as though it came from somewhere else.
  */
 export function unplayableReason(
   info: MediaInfoLike | null | undefined,
   isTypeSupported: (type: string) => boolean,
-  advice = ''
+  advice = '',
+  subject = 'stream'
 ): string | null {
   if (!info || typeof isTypeSupported !== 'function') return null;
 
@@ -158,5 +163,5 @@ export function unplayableReason(
   // Both halves unplayable is one sentence, not two: the reader is going
   // elsewhere either way, and listing two problems reads as two things to fix.
   const what = bad.length === 1 ? bad[0] : `${String(bad[0])} and ${String(bad[1])}`;
-  return `This stream is ${String(what)}, which this browser cannot decode.${advice ? ` ${advice}` : ''}`;
+  return `This ${subject} is ${String(what)}, which this browser cannot decode.${advice ? ` ${advice}` : ''}`;
 }

test/codecs.test.ts

@@ -84,6 +84,13 @@ describe('unplayableReason', () => {
     );
   });
 
+  it('lets the host name the thing its reader clicked', () => {
+    // genrewatch and tipoffwatch say "channel"; a recording is a "stream".
+    expect(unplayableReason({ videoCodec: 'hvc1.1' }, supports([]), '', 'channel')).toBe(
+      'This channel is H.265, which this browser cannot decode.'
+    );
+  });
+
   it('appends the host site’s advice when given some', () => {
     const reason = unplayableReason({ videoCodec: 'hvc1.1' }, supports([]), 'Try VLC.');
     expect(reason).toBe('This stream is H.265, which this browser cannot decode. Try VLC.');

tsup.config.ts

@@ -14,7 +14,7 @@ import { defineConfig } from 'tsup';
  * anyone who already has one.
  */
 export default defineConfig({
-  entry: ['src/index.ts', 'src/react/index.tsx'],
+  entry: ['src/index.ts', 'src/react/index.tsx', 'src/codecs.ts'],
   format: ['esm'],
   target: 'es2022',
   splitting: true,