Add InputTrack.number

src/input-track.ts

@@ -32,6 +32,7 @@ export type PacketStats = {
 
 export interface InputTrackBacking {
 	getId(): number;
+	getNumber(): number;
 	getCodec(): MediaCodec | null;
 	getInternalCodecId(): string | number | Uint8Array | null;
 	getName(): string | null;
@@ -94,6 +95,15 @@ export abstract class InputTrack {
 		return this._backing.getId();
 	}
 
+	/**
+	 * The 1-based index of this track among all tracks of the same type in the input file. For example, the first
+	 * video track has number 1, the second video track has number 2, and so on. The index refers to the order in
+	 * which the tracks are returned by {@link Input.getTracks()}.
+	 */
+	get number() {
+		return this._backing.getNumber();
+	}
+
 	/**
 	 * The identifier of the codec used internally by the container. It is not homogenized by Mediabunny
 	 * and depends entirely on the container format.