Encoders

Encoders send audio from your station to streaming servers for distribution to listeners.

Overview

An encoder compresses audio and transmits it to a streaming server (Icecast, SHOUTcast, or similar). The streaming server then distributes the audio to listeners.

Station → Encoder → Streaming Server → Listeners

Key Concepts

What is an encoder? An encoder converts raw audio into a compressed stream format (MP3, AAC, Opus) and transmits it to a remote server using a streaming protocol.

Why use multiple encoders?

• Provide different quality levels (128 kbps for mobile, 320 kbps for high fidelity)
• Stream to multiple platforms simultaneously
• Maintain backup streams for redundancy

Encoder vs streaming server: The encoder sends audio. The streaming server receives it and distributes it to listeners. Your streaming provider supplies the server; xtra audio provides the encoder.

Setup

Prerequisites

• Streaming server credentials from your provider
• Server address and port
• Mount point (for Icecast servers)

Add an Encoder

1. Navigate to Encoders in the station sidebar
2. Click Add Encoder
3. Enter the connection details (see table below)
4. Click Save

Connection Settings

Field	Description	Required
Name	Internal identifier	Yes
Host	Server address	Yes
Port	Server port	Yes
Mount Point	Stream path (Icecast)	Yes
Username	Source username	Yes
Password	Source password	Yes
Genre	Station genre tag	No
Enabled	Toggle encoder on or off	—

The connection parameters define how the encoder reaches the streaming server:

• Host: IP address or hostname of the Icecast or SHOUTcast server
• Port: TCP port the server listens on
• Mount Point: stream path on the server (Icecast)
• Username: source account username
• Password: source account password

Encoders can be deactivated without deleting them by toggling the Enabled setting. Disabled encoders show a "Disabled" badge.

An SSL/TLS indicator (shield icon) appears when the encoder uses a secure connection.

Audio Settings

Audio passes through loudness processing before it reaches the encoder. Configure target loudness in EBU R128 to ensure consistent levels across the stream.

Codec Comparison

Feature	MP3	AAC	Opus
Compatibility	Universal	Good	Modern players only
Efficiency	Baseline	30% better than MP3	50% better than MP3
Quality at 128 kbps	Good	Excellent	Excellent
Quality at 64 kbps	Poor	Good	Good
Bitrate range	64–320 kbps	32–256 kbps	32–256 kbps
Latency	Low	Low	Very low
License	Royalty-free	May require license	Royalty-free

Codec Selection

Codec	Best For	Bitrate Range
MP3	Maximum compatibility	64–320 kbps
AAC	Mobile listeners, efficiency	32–256 kbps
Opus	Best quality at low bitrates	32–256 kbps

Metadata

Configure how track information appears to listeners.

Metadata Format

The metadata format is a template that combines text and placeholders. The format determines the string sent to the streaming server for each track.

{{artist}} - {{title}}

This template produces Miles Davis - So What for a track by Miles Davis. Static text outside placeholders appears unchanged. An empty placeholder resolves to an empty string.

Template Variables

Variable	Output
{{artist}}	Track artist
{{title}}	Track title
{{album}}	Album name
{{station}}	Station name

Case Transformation

Option	Result
None	Original casing
Upper	ALL UPPERCASE
Lower	all lowercase
Title	Title Case

Status and Monitoring

Status	Meaning
connected	Streaming active
connecting	Establishing connection
offline	Not streaming
timeout	Connection timed out
busy	Server reports mount point in use
ssl_error	SSL/TLS handshake failed
cast_denied	Authentication rejected by server
internal	Internal error

The station.encoder.statuschange webhook trigger fires whenever an encoder transitions between these states. Use it to alert on disconnects or failed connections. See Webhooks.

Troubleshooting

Connection Refused

• Verify host and port
• Check if server is running
• Confirm firewall allows outbound traffic

Authentication Failed

• Verify username and password
• Check mount point spelling (Icecast)
• Ensure source account exists

Frequent Disconnections

• Check network stability
• Reduce bitrate
• Contact server provider

Icecast vs SHOUTcast

Feature	Icecast	SHOUTcast
License	Open source (GPL)	Proprietary
Codecs	MP3, AAC, Opus, Vorbis, FLAC	MP3, AAC
Mount points	Multiple streams per server	One stream per port
Metadata	Full support	Basic support
Cost	Free (self-hosted)	Free tier + paid plans
Fallback streams	Built-in	Limited

Bandwidth Calculator

Listeners	Bitrate	Hourly	Monthly (24/7)
10	128 kbps	576 MB	414 GB
50	128 kbps	2.88 GB	2.07 TB
100	128 kbps	5.76 GB	4.15 TB
10	64 kbps	288 MB	207 GB
50	64 kbps	1.44 GB	1.04 TB

Formula: listeners × bitrate (kbps) × 3600 / 8 / 1024 = MB per hour

FAQ

What is the best codec for internet radio?

MP3 at 128 kbps offers the best balance of quality and compatibility. For bandwidth-constrained scenarios, AAC at 64 kbps provides similar quality at half the bitrate.

How much bandwidth does streaming use?

Bandwidth depends on bitrate and listener count. A 128 kbps stream uses approximately 57.6 MB per listener per hour. Multiply by concurrent listeners for total usage.

Can I stream to multiple servers?

Yes. Create multiple encoders, each with different server credentials. All encoders stream simultaneously from the same audio source.

What causes stream buffering?

Buffering occurs when listeners cannot download audio fast enough. Common causes include high bitrate on slow connections, server capacity limits, or network congestion.

Should I use stereo or mono?

Use stereo for music stations (128+ kbps). Use mono for talk/speech to save bandwidth.

Related

• Station Configuration - Complete station setup
• EBU R128 - Loudness normalization settings
• Sound Processing - Audio processing before encoding