This guide concerns the buffer and latency of Streaming Radio. While latency is inevitable, proper buffer management can optimize your broadcasts while minimizing interruptions.

Introduction

• The buffer, or memory buffer, is a small memory area that must be filled before the Player starts playing the music from your audio stream. It corresponds to a few seconds of audio. It is designed for a more comfortable listening experience, to prevent small interruptions in the stream from being audible, which leads to choppy and unpleasant sound.
• The receiving and broadcasting servers also have buffers; real-time transmission is never instantaneous due to several technical factors:
  • A latency of 3 to 4 seconds between the generation of the sound and its reception is normal.
  • Players always buffer at least 1 to 2 seconds before starting playback.
  • Icecast uses a 64KB buffer by default, which is equivalent to approximately 4 seconds of streaming at 128kb mp3.
  • Encoding clients also have buffers to prevent interruptions.
  • Reducing the size of the buffers can reduce latency, but this practice is risky.
  • Since Internet connections do not guarantee a constant bandwidth, smaller buffers can lead to interruptions.

Analyze buffer stability

The diagnostic available in your Manager displays the amount of memory occupied by the buffer each second. If the stream is working correctly, the values should be stable:

An unstable buffer indicates either poor connection quality or line saturation. Consult this other guide if you are looking for troubleshooting steps.

This test is also useful for helping to detect temporary saturations of an Internet line. If the buffer is sometimes stable and sometimes unstable, it may be a sign that some users sharing the Internet line are occasionally saturating the line, causing disruptions to your stream.

To verify this hypothesis, run a long-duration buffer test during peak usage times and observe any potential disruptions.