Modern & secure adaptive streaming on the Web by Katarzyna Dusza

Modern web streaming requires segmentation, adaptive bitrate streaming and DRM to ensure smooth playback

Two main streaming protocols are used:

• MPEG-DASH (Dynamic Adaptive Streaming over HTTP)
• HLS (HTTP Live Streaming by Apple)

Media Source Extensions (MSE) enable:

• Control over data buffering
• Playing fragmented content
• Switching between different bitrates

Key components for adaptive streaming:

• Content split into small segments (typically 2 seconds)
• Multiple bitrate versions of same content
• DASH manifest file (.mpd) describing content structure
• Client-side bitrate switching based on bandwidth

Three main DRM systems:

• Google Widevine
• Apple FairPlay
• Microsoft PlayReady

Encrypted Media Extensions (EME) provides:

• DRM functionality in the browser
• Communication between web app and Content Decryption Module (CDM)
• License acquisition and content decryption

MP4 file structure consists of:

• File type atom (ftyp)
• Movie metadata atom (moov)
• Media data atom (mdat)
• Protection info atom (sinf) for encrypted content

Smooth playback requires:

• Proper content segmentation with consistent segment lengths
• Multiple bitrate versions for adaptive streaming
• DRM integration for protected content
• Buffer management through MSE

Tools for content preparation:

• FFmpeg for transcoding/encoding
• Bento4 for MP4 manipulation and encryption
• DASH manifest generators