Streaming Protocols

Overview

Ant Media Server supports multiple streaming protocols for both ingesting (publishing) and delivering (playing) live streams. Understanding when to use each protocol is crucial for optimizing your streaming infrastructure.

Ingest Protocols

Ingest protocols are used to publish streams to Ant Media Server.

WebRTC (Web Real-Time Communication)

Best for: Ultra-low latency streaming from browsers and mobile apps

Latency: ~0.5 seconds
Use cases: Live auctions, video conferencing, interactive streaming
Codecs: H.264, H.265 (HEVC), VP8, VP9
Transport: UDP with SRTP encryption

WebRTC is enabled by default. Set webRTCEnabled=true in your application settings.

AppSettings.java:1001

@Value ( "${webRTCEnabled:${"+SETTINGS_WEBRTC_ENABLED+":true}}" )
private boolean webRTCEnabled=true;

WebRTC Configuration

Key settings for WebRTC ingest:

webRTCEnabled=true
webRTCFrameRate=30
webRTCPortRangeMin=50000
webRTCPortRangeMax=60000
stunServerURI=stun:stun1.l.google.com:19302

RTMP (Real-Time Messaging Protocol)

Best for: Broadcasting software and hardware encoders

Latency: 3-5 seconds
Use cases: OBS Studio, hardware encoders, legacy systems
Codecs: H.264 video, AAC audio
Port: 1935 (default)

RTMP remains the most widely compatible protocol for professional broadcasting software. Ant Media Server processes RTMP streams through the RTMPAdaptor:

RTMPAdaptor.java

public class RTMPAdaptor extends Adaptor {
    // Handles RTMP stream ingestion and conversion
}

RTMP Configuration

rtmpIngestBufferTimeMs=0
rtmpMaxAnalyzeDurationMS=500

RTMP is being deprecated by major platforms. Consider migrating to SRT or WebRTC for new implementations.

SRT (Secure Reliable Transport)

Best for: Low-latency contribution over unpredictable networks

Latency: 1-3 seconds (configurable)
Use cases: Remote production, contribution feeds, replacing RTMP
Features: Built-in encryption, error correction, firewall traversal
Port: Configurable (default varies)

SRT provides superior resilience over unreliable networks through its ARQ (Automatic Repeat Request) mechanism.

SRTAdaptor.java

public class SRTAdaptor {
    // Handles SRT stream ingestion with error correction
}

RTSP (Real-Time Streaming Protocol)

Best for: IP cameras and surveillance systems

Latency: 1-3 seconds
Use cases: IP cameras, security systems, CCTV
Codecs: H.264, H.265, AAC
Transport: RTP/RTCP over TCP or UDP

Ant Media Server can pull RTSP streams from IP cameras and re-stream them:

rtspPullTransportType=tcp
rtspTimeoutDurationMs=5000

Delivery Protocols

Delivery protocols are used by viewers to watch streams.

WebRTC Playback

Best for: Ultra-low latency playback in browsers

Latency: ~0.5 seconds
Use cases: Interactive applications requiring real-time feedback
Platform support: Modern browsers, mobile apps

webRTCViewerLimit=-1
playWebRTCStreamOnceForEachSession=false

HLS (HTTP Live Streaming)

Best for: Maximum compatibility and scalability

Latency: 6-30 seconds (standard), 2-6 seconds (LL-HLS)
Use cases: Large audiences, VOD, mobile devices
Codecs: H.264, H.265, AAC, AC3
Format: MPEG-TS or fMP4 segments

HLS is the most widely supported adaptive streaming format:

AppSettings.java:854

@Value("${hlsMuxingEnabled:${"+SETTINGS_HLS_MUXING_ENABLED+":true}}")
private boolean hlsMuxingEnabled = true;

HLS Configuration

hlsMuxingEnabled=true
hlsListSize=15
hlsTime=2
hlsPlayListType=event
hlsSegmentType=mpegts
hlsflags=delete_segments+program_date_time

Use hlsSegmentType=fmp4 for HEVC/H.265 streams, as MPEG-TS segments may not play correctly with HEVC.

Low-Latency HLS (LL-HLS)

For reduced latency with HLS:

hlsEnableLowLatency=true
dashEnableLowLatency=true
hlsEnabledViaDash=true

DASH (Dynamic Adaptive Streaming over HTTP)

Best for: Standards-based adaptive streaming

Latency: 6-30 seconds (standard), 3-6 seconds (LL-DASH)
Use cases: OTT platforms, cross-platform delivery
Format: ISO BMFF (fMP4)

dashSegDuration=6
dashFragmentDuration=0.5
dashTargetLatency=3.5
dashWindowSize=5

CMAF (Common Media Application Format)

Ant Media Server supports CMAF through its DASH implementation, allowing single-file packaging for both HLS and DASH:

hlsSegmentType=fmp4
dashEnableLowLatency=true
hlsEnabledViaDash=true

Protocol Comparison

Protocol	Latency	Scalability	Compatibility	Use Case
WebRTC	~0.5s	Medium	Modern browsers	Real-time interaction
RTMP	3-5s	High	Encoders	Broadcasting software
SRT	1-3s	High	Professional tools	Contribution feeds
RTSP	1-3s	Low	IP cameras	Surveillance
HLS	6-30s	Very High	Universal	Large audiences
LL-HLS	2-6s	High	Modern clients	Low-latency at scale
DASH	6-30s	Very High	Standards-based	OTT platforms

Choosing the Right Protocol

For Ingestion

Real-time interaction needed: WebRTC
Professional broadcasting: RTMP or SRT
Unreliable networks: SRT
IP cameras: RTSP pull
Browser-based publishing: WebRTC

For Delivery

Ultra-low latency required: WebRTC
Maximum compatibility: HLS
Large-scale delivery: HLS or DASH with CDN
Low latency at scale: LL-HLS or LL-DASH
Standards compliance: DASH

Multi-Protocol Workflow

Ant Media Server excels at protocol translation. A typical workflow: The server automatically transcodes and packages streams for all enabled delivery formats:

Muxer.java:918

public synchronized boolean addStream(AVCodecParameters codecParameters, AVRational timebase, int streamIndex) 
{
    // Handles stream from any ingest protocol to all muxers
}

Get Started

Core Concepts

Deployment

Configuration

Streaming

Features

Security

Storage

SDKs

Operations

Overview

Ingest Protocols

WebRTC (Web Real-Time Communication)

WebRTC Configuration

RTMP (Real-Time Messaging Protocol)

RTMP Configuration

SRT (Secure Reliable Transport)

RTSP (Real-Time Streaming Protocol)

Delivery Protocols

WebRTC Playback

HLS (HTTP Live Streaming)

HLS Configuration

Low-Latency HLS (LL-HLS)

DASH (Dynamic Adaptive Streaming over HTTP)

CMAF (Common Media Application Format)

Protocol Comparison

Choosing the Right Protocol

For Ingestion

For Delivery

Multi-Protocol Workflow

Next Steps

Adaptive Bitrate

Ultra-Low Latency

​Overview

​Ingest Protocols

​WebRTC (Web Real-Time Communication)

​WebRTC Configuration

​RTMP (Real-Time Messaging Protocol)

​RTMP Configuration

​SRT (Secure Reliable Transport)

​RTSP (Real-Time Streaming Protocol)

​Delivery Protocols

​WebRTC Playback

​HLS (HTTP Live Streaming)

​HLS Configuration

​Low-Latency HLS (LL-HLS)

​DASH (Dynamic Adaptive Streaming over HTTP)

​CMAF (Common Media Application Format)

​Protocol Comparison

​Choosing the Right Protocol

​For Ingestion

​For Delivery

​Multi-Protocol Workflow

​Next Steps

Adaptive Bitrate

Ultra-Low Latency

Overview

Ingest Protocols

WebRTC (Web Real-Time Communication)

WebRTC Configuration

RTMP (Real-Time Messaging Protocol)

RTMP Configuration

SRT (Secure Reliable Transport)

RTSP (Real-Time Streaming Protocol)

Delivery Protocols

WebRTC Playback

HLS (HTTP Live Streaming)

HLS Configuration

Low-Latency HLS (LL-HLS)

DASH (Dynamic Adaptive Streaming over HTTP)

CMAF (Common Media Application Format)

Protocol Comparison

Choosing the Right Protocol

For Ingestion

For Delivery

Multi-Protocol Workflow

Next Steps