feat: add 'hasCodec' helper (#6)

cspell.json

@@ -38,6 +38,7 @@
     "libauth",
     "mindmeld",
     "mkdir",
+    "mline",
     "multistream",
     "munge",
     "ndarray",

src/index.ts

@@ -3,3 +3,4 @@ export * from './lines';
 export * from './model';
 export * from './munge';
 export * from './regex-helpers';
+export * from './utils';

src/utils.spec.ts

@@ -0,0 +1,17 @@
+import { MediaLine, RtpMapLine } from './lines';
+import { AvMediaDescription } from './model';
+import { hasCodec } from './utils';
+
+describe('hasCodec', () => {
+  it('should return true only if the codec is present', () => {
+    expect.hasAssertions();
+    const mLine = new AvMediaDescription(
+      new MediaLine('video', 9, 'UDP/TLS/RTP/SAVPF', ['96', '97', '98', '99', '100', '101', '127'])
+    );
+    mLine.addLine(new RtpMapLine(96, 'h264', 9000));
+
+    expect(hasCodec('h264', mLine)).toBe(true);
+    expect(hasCodec('H264', mLine)).toBe(true);
+    expect(hasCodec('vp8', mLine)).toBe(false);
+  });
+});

src/utils.ts

@@ -0,0 +1,14 @@
+import { AvMediaDescription, CodecInfo } from './model';
+
+/**
+ * Check if the given codec is present in the given mline.
+ *
+ * @param codecName - The string name of the codec to check for (case insensitive).
+ * @param mLine - The mline to search for the given codec.
+ * @returns True if the codec is present, false otherwise.
+ */
+export function hasCodec(codecName: string, mLine: AvMediaDescription): boolean {
+  return [...mLine.codecs.values()].some(
+    (ci: CodecInfo) => ci.name?.toLowerCase() === codecName.toLowerCase()
+  );
+}