Siddharth
90 lines
2.3 KiB
TypeScript
90 lines
2.3 KiB
TypeScript
import {
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BufferTarget,
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EncodedAudioPacketSource,
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EncodedPacket,
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EncodedVideoPacketSource,
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Mp4OutputFormat,
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Output,
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} from "mediabunny";
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import type { ExportConfig } from "./types";
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export class VideoMuxer {
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private output: Output | null = null;
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private videoSource: EncodedVideoPacketSource | null = null;
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private audioSource: EncodedAudioPacketSource | null = null;
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private hasAudio: boolean;
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private target: BufferTarget | null = null;
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private config: ExportConfig;
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constructor(config: ExportConfig, hasAudio = false) {
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this.config = config;
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this.hasAudio = hasAudio;
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}
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async initialize(): Promise<void> {
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// Create the buffer target
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this.target = new BufferTarget();
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this.output = new Output({
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format: new Mp4OutputFormat({
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fastStart: "in-memory",
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}),
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target: this.target,
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});
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// Create video source - codec will be deduced from metadata
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this.videoSource = new EncodedVideoPacketSource("avc");
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this.output.addVideoTrack(this.videoSource, {
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frameRate: this.config.frameRate,
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});
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// Create audio source if needed
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if (this.hasAudio) {
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this.audioSource = new EncodedAudioPacketSource("opus");
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this.output.addAudioTrack(this.audioSource);
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}
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// Start the output to begin accepting media data
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await this.output.start();
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}
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async addVideoChunk(chunk: EncodedVideoChunk, meta?: EncodedVideoChunkMetadata): Promise<void> {
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if (!this.videoSource) {
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throw new Error("Muxer not initialized");
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}
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// Convert WebCodecs chunk to Mediabunny packet
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const packet = EncodedPacket.fromEncodedChunk(chunk);
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// Add metadata with the first chunk
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await this.videoSource.add(packet, meta);
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}
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async addAudioChunk(chunk: EncodedAudioChunk, meta?: EncodedAudioChunkMetadata): Promise<void> {
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if (!this.audioSource) {
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throw new Error("Audio not configured for this muxer");
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}
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// Convert WebCodecs chunk to Mediabunny packet
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const packet = EncodedPacket.fromEncodedChunk(chunk);
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// Add metadata with the first chunk
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await this.audioSource.add(packet, meta);
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}
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async finalize(): Promise<Blob> {
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if (!this.output || !this.target) {
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throw new Error("Muxer not initialized");
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}
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await this.output.finalize();
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const buffer = this.target.buffer;
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if (!buffer) {
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throw new Error("Failed to finalize output");
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}
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return new Blob([buffer], { type: "video/mp4" });
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}
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}
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