How do I segment an MP4 file for HLS using MP4Box.js?

Use the segmentation API: call setSegmentOptions on tracks with nbSamples for chunk size, then initializeSegmentation and start to generate fragments. The onSegment callback provides ArrayBuffers ready for MSE playback, as detailed in the README's segmentation section.

MP4Box.js vs ffmpeg.js for video processing?

MP4Box.js excels at MP4 container manipulation like parsing and segmentation, while ffmpeg.js is better for encoding, transcoding, and multi-format support. Choose MP4Box.js for browser-native MP4 tasks and ffmpeg.js for broader media processing with WebAssembly overhead.

Does MP4Box.js support WebAssembly for better performance?

No, MP4Box.js is a pure JavaScript library, so it relies on JavaScript execution without WebAssembly acceleration. This can impact performance for large files compared to WebAssembly-based alternatives but ensures broader browser compatibility.

How to extract audio samples from an MP4 with MP4Box.js?

Use the extraction API: setExtractionOptions on an audio track with nbSamples, then start to receive samples via onSamples callback. Each sample includes data as an ArrayBuffer for custom processing, as shown in the extraction examples.

Can MP4Box.js handle already fragmented MP4 files?

Yes, the info object from onReady includes an isFragmented boolean to detect fragmented files, and the API supports parsing and further segmentation of such files, making it suitable for adaptive streaming workflows.

What browsers are compatible with MP4Box.js for MSE usage?

MP4Box.js works in modern browsers supporting Media Source Extensions and ArrayBuffer APIs, such as Chrome, Firefox, and Edge. Check the demos for examples, but ensure MSE is enabled and test for specific version support.

MP4Box.js — MP4 Parser for Browser & Node.js

What is MP4Box.js?

MP4Box.js is a JavaScript library that provides advanced MP4 file processing capabilities, including parsing, segmentation, and sample extraction. It solves the problem of manipulating MP4 container formats directly in JavaScript environments, enabling developers to build media applications without relying on server-side tools or native binaries.

Target Audience

Frontend and Node.js developers building video processing applications, adaptive streaming players, media analysis tools, or applications requiring MP4 metadata inspection and manipulation.

Value Proposition

Developers choose MP4Box.js because it's the most comprehensive JavaScript implementation of MP4 processing, offering browser-native performance, progressive parsing, and full compatibility with the industry-standard GPAC MP4Box tool while being modular and bundle-size conscious.

JavaScript version of GPAC's MP4Box tool

Use Cases

Best For

Building adaptive streaming players with Media Source Extensions (MSE)
Creating MP4 file inspection and metadata analysis tools
Extracting audio or video samples for custom processing pipelines
Segmenting MP4 files for HTTP Live Streaming (HLS) or DASH
Developing browser-based video editing applications
Analyzing MP4 file structures for debugging or educational purposes

Not Ideal For

Real-time video encoding or live transcoding applications
Graphical video editing tools with drag-and-drop interfaces
Projects requiring support for multiple container formats like AVI, MKV, or WebM
Simple video playback without MP4 manipulation or segmentation needs

Pros & Cons

Pros

Progressive Parsing Support

Enables metadata analysis as the file loads, allowing early access to information without waiting for the entire download, as shown in the API's appendBuffer and onReady callbacks.

MSE-Compatible Segmentation

Provides built-in tools to split MP4 files for adaptive streaming with Media Source Extensions, detailed in the segmentation API with setSegmentOptions and onSegment callbacks.

Cross-Platform Consistency

Works identically in both browser and Node.js environments with a unified API, ensuring developers can use the same codebase across platforms, as stated in the key features.

Modular Build Options

Offers all and simple flavors to control bundle size by including only necessary features, allowing customization via tsup builds to optimize performance, as explained in the Build section.

Cons

Complex Setup and Configuration

Requires building with tsup and selecting features from multiple files, which can be daunting for quick integration and adds overhead compared to drop-in libraries.

Low-Level API Design

Mirrors the original C tool's API, leading to a non-intuitive JavaScript experience with callback-heavy methods like onReady and manual buffer management, as seen in the API examples.

MP4-Only Focus

Limited to MP4 container formats, lacking support for other common media formats like AVI or WebM, which restricts its use in broader media processing pipelines.

Frequently Asked Questions

What is MP4Box.js?

Target Audience

Frontend and Node.js developers building video processing applications, adaptive streaming players, media analysis tools, or applications requiring MP4 metadata inspection and manipulation.

Value Proposition

Use Cases

Best For

Building adaptive streaming players with Media Source Extensions (MSE)
Creating MP4 file inspection and metadata analysis tools
Extracting audio or video samples for custom processing pipelines
Segmenting MP4 files for HTTP Live Streaming (HLS) or DASH
Developing browser-based video editing applications
Analyzing MP4 file structures for debugging or educational purposes

Not Ideal For

Real-time video encoding or live transcoding applications
Graphical video editing tools with drag-and-drop interfaces
Projects requiring support for multiple container formats like AVI, MKV, or WebM
Simple video playback without MP4 manipulation or segmentation needs

Pros & Cons

Pros

Progressive Parsing Support

Enables metadata analysis as the file loads, allowing early access to information without waiting for the entire download, as shown in the API's appendBuffer and onReady callbacks.

MSE-Compatible Segmentation

Provides built-in tools to split MP4 files for adaptive streaming with Media Source Extensions, detailed in the segmentation API with setSegmentOptions and onSegment callbacks.

Cross-Platform Consistency

Works identically in both browser and Node.js environments with a unified API, ensuring developers can use the same codebase across platforms, as stated in the key features.

Modular Build Options

Offers all and simple flavors to control bundle size by including only necessary features, allowing customization via tsup builds to optimize performance, as explained in the Build section.

Cons

Complex Setup and Configuration

Requires building with tsup and selecting features from multiple files, which can be daunting for quick integration and adds overhead compared to drop-in libraries.

Low-Level API Design

Mirrors the original C tool's API, leading to a non-intuitive JavaScript experience with callback-heavy methods like onReady and manual buffer management, as seen in the API examples.

MP4-Only Focus

Limited to MP4 container formats, lacking support for other common media formats like AVI or WebM, which restricts its use in broader media processing pipelines.

Frequently Asked Questions

MP4Box.js

What is MP4Box.js?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

MP4Box.js

What is MP4Box.js?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?