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HTTP-FLV

HTTP-FLV Player and MSE Diagnostics

Learn how HTTP-FLV can be played through browser MSE using mpegts.js, flv.js or Jessibuca.

Browser direct play
Playable
Pipeline role
Low-latency HTTP stream
Browser result
Requires an MSE player

Short answer

HTTP-FLV is often used for low-latency live preview. It is not a native browser video format, but players such as mpegts.js, flv.js or Jessibuca can handle it.

Where it sits in a video pipeline

HTTP-FLV means the server continuously outputs FLV data over one HTTP connection, while the frontend player parses it as it arrives.

It is commonly used as a web preview output converted from RTSP/RTMP.

How to use it in a browser project

Do not expect `<video src="live.flv">` to work across browsers. The frontend needs a player to extract audio/video from FLV and feed browser media APIs.

The common playable combination is H.264 video + AAC audio.

What the server has to do

The server must keep FLV data continuous, avoid proxy buffering, set CORS correctly and handle reconnects.

Common development scenarios

  • Internal monitoring preview, engineering debugging, live dashboards and cases needing lower latency than HLS without WebRTC.

Debugging order

  • First confirm the response is real FLV, not an HTML error page or JSON auth error.
  • Then check MSE availability, H.264/AAC codecs and whether CORS allows the player to read the stream.

Recommended conversion paths

  • RTSP/RTMP -> HTTP-FLV for low-latency engineering preview.
  • For large public delivery, provide HLS as well.

Minimum usable implementation

  • Frontend: load the FLV URL with mpegts.js or a similar player.
  • Backend: output valid FLV tags, disable unwanted proxy buffering and provide CORS headers.

Developer decision rule

HTTP-FLV should be judged by its role in the delivery chain, not by the protocol name alone. Browser result: Requires an MSE player. Before promising playback, confirm the source type, whether a server conversion is required, CORS and HTTPS policy, codec support and the latency target.

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