HTTP-FLV Protocol

HTTP-FLV is a protocol that transmits FLV audio/video data over HTTP long connections. Compared to HLS, HTTP-FLV offers lower latency; compared to RTMP, it uses standard HTTP ports, making it more friendly to firewalls and CDNs.

Basic Information

Property	Value
Transport Layer	HTTP (shares the engine HTTP port)
Publish	❌ Not supported
Subscribe	✅ Supported
Latency	1-3 seconds
Feature Flag	`flv`

Configuration

Feature Activation

[features]
flv = ["dep:plugin-flv"]

Configuration File

flv:
  enable: true

Option	Type	Default	Description
`enable`	bool	`true`	Whether to enable the FLV plugin

URL Format

http://host:port/flv/{streamPath}.flv

{streamPath}: Stream path, e.g., live/test
The .flv suffix is optional

Examples:

http://localhost:8080/flv/live/test.flv
http://localhost:8080/flv/live/test

The FLV plugin also supports transmitting FLV data via WebSocket, suitable for browser-based playback:

ws://host:port/flv/{streamPath}.flv

Subscribing

Subscribing with FFplay

ffplay http://localhost:8080/flv/live/test.flv

Recording with FFmpeg

# Subscribe to HTTP-FLV stream and save to file
ffmpeg -i http://localhost:8080/flv/live/test.flv -c copy output.flv

# Subscribe and remux to MP4
ffmpeg -i http://localhost:8080/flv/live/test.flv -c copy output.mp4

Browser Playback

In the browser, you can use flv.js or mpegts.js to play HTTP-FLV streams:

<script src="https://cdn.jsdelivr.net/npm/mpegts.js/dist/mpegts.js"></script>
<video id="player" controls></video>
<script>
  if (mpegts.isSupported()) {
    const player = mpegts.createPlayer({
      type: 'flv',
      url: 'http://localhost:8080/flv/live/test.flv',
      isLive: true,
    });
    player.attachMediaElement(document.getElementById('player'));
    player.load();
    player.play();
  }
</script>

WebSocket-FLV method:

const player = mpegts.createPlayer({
  type: 'flv',
  url: 'ws://localhost:8080/flv/live/test.flv',
  isLive: true,
});

FLV Recording

The FLV plugin supports recording streams as FLV files:

# Start recording
curl -X POST http://localhost:8080/flv/record/start/live/test

# Stop recording
curl -X POST http://localhost:8080/flv/record/stop/live/test

# List recordings
curl http://localhost:8080/flv/record/list

# Check recording status
curl http://localhost:8080/flv/record/status/live/test

Audio Codec Support

HTTP-FLV supports the following audio codecs:

Codec	Description
AAC	Standard support
G.711A	Supported (commonly used in security surveillance)
G.711U	Supported (commonly used in security surveillance)

Typical Workflow

# 1. Publish via RTMP
ffmpeg -re -i input.mp4 -c copy -f flv rtmp://localhost:1935/live/test

# 2. Subscribe via HTTP-FLV for playback
ffplay http://localhost:8080/flv/live/test.flv