Check in some starter thinking around a media API in bitjs.

.github/workflows/node.js.yml

@@ -16,7 +16,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [17.x, 18.x]
+        node-version: [17.x, 18.x, 19.x]
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
 
     steps:

media/README.md

@@ -0,0 +1 @@
+Dealing with digital media files (audio, video, images). Mostly a thought-experiment for now.

media/media.js

@@ -0,0 +1,35 @@
+console.warn(`This is not even an alpha-level API. Do not use.`);
+
+// A Container Format is a file that embeds multiple data streams into a single file.
+// Examples:
+//   - the ZIP family (ZIP, JAR, CBZ, EPUB, ODF, OOXML)
+//   - the ISO-BMFF family (MP4, HEVC, AVIF, MOV/QT, etc)
+//   - the Matroska family (MKV, WebM)
+//   - the RIFF family (WAV, AVI, WebP)
+//   - the OGG family (OGV, OPUS)
+
+// The ZIP container needs special processing to determine what files are present inside it :(
+// The ISO-BMFF container needs special processing because of its "compatible brands" array :(
+// The Matroska container needs special processing because the sub-type can appear anywhere :(
+// The OGG container needs special processing to determine what kind of streams are present :(
+
+/**
+ * @readonly
+ * @enum {number}
+ */
+export const ContainerType = {
+  UNKNOWN: 0,
+  ZIP: 1,
+  ISOBMFF: 100,
+  MATROSKA: 101,
+  RIFF: 102,
+  OGG: 103,
+};
+
+/**
+ * @param {ArrayBuffer} ab
+ * @returns {ContainerType}
+ */
+export function getContainerType(ab) {
+  return ContainerType.UNKNOWN;
+}