Does SPCast support MP3 and AAC+?

Yes. SPCast provides native support for the two most widely used audio codecs in web radio broadcasting: MP3 (MPEG-1/2 Audio Layer III) and AAC+ (HE-AAC v1 and v2). You can broadcast your primary master stream at full studio fidelity up to 320 kbps while simultaneously delivering automated transcoders for mobile listeners.

Supported Codecs and Bitrates

With SPCast, you can configure multiple parallel output streams across varying quality tiers and bandwidth profiles:

• MP3 Primary Stream: 128 kbps, 192 kbps, 256 kbps, or 320 kbps for universal compatibility across all audio players and playback devices.
• MP3 Transcoders: 96 kbps or 128 kbps for listeners on standard connections or desktop web players seeking bandwidth conservation.
• AAC+ Transcoders (HE-AAC): 32 kbps, 48 kbps, or 64 kbps for cellular listeners, automotive audio systems, and smart speakers with minimal data consumption.

Comparing MP3 and AAC+ Codecs

Both codecs utilize distinct compression algorithms suited for specific broadcast scenarios:

MP3 (Universal Device Compatibility)

MP3 represents the most established and widely supported audio format on the Internet. Virtually every playback hardware device (from standalone Wi-Fi tuners and AV receivers to contemporary smartphones) plays MP3 streams without third-party codec installations. For balanced stereo imaging and clear highs, a bitrate between 192 and 320 kbps is recommended.

AAC+ / HE-AAC (Maximum Efficiency at Low Bitrates)

HE-AAC (High Efficiency Advanced Audio Coding) incorporates advanced tools like Spectral Band Replication (SBR) and Parametric Stereo (PS). Consequently, an AAC+ stream operating at just 48 to 64 kbps achieves acoustic quality comparable to a 128 to 192 kbps MP3 stream. This preserves mobile data quotas for your audience while substantially decreasing server bandwidth consumption.

Real-Time Server-Side Transcoding

A major technical advantage of SPCast is its native, resource-efficient transcoding pipeline:

1. Single Studio Uplink: Your broadcast studio or presenter sends only one high-definition source feed (e.g., MP3 at 320 kbps) to the server.
2. Automated Conversion: The server ingests the master feed and transcodes it in real time into your configured MP3 and AAC+ sub-bitrates.
3. Synchronous Delivery: All listeners receive the identical audio programming simultaneously, regardless of which bitrate option they select in their web player or mobile app.

You do not need multiple encoders or extra studio upload bandwidth to supply diverse quality tiers to your listeners.

Understanding Platforms, Codecs, and Protocols

Clear distinction between terminology helps ensure proper station configuration:

• Audio Codecs (MP3, AAC, OGG): Define how audio signals are compressed and encoded into digital bytes.
• Streaming Protocols (Icecast 2, SHOUTcast v1/v2, HLS): Govern how audio bytes are transported across the network to listeners.
• SPCast: The complete management and server platform orchestrating AutoDJ playback, transcoding pipelines, listener metrics, server relays, and APIs.

On the protocol layer, SPCast delivers streams over classic HTTP streaming (Icecast, SHOUTcast) as well as modern HLS (HTTP Live Streaming) for frictionless integration with Apple iOS devices, modern web browsers, and Android apps.

Recommended Broadcaster Setup

For everyday web radio operations, we suggest the following multi-bitrate configuration:

• Channel 1 (Web Player & Desktop): MP3 at 192 kbps (ideal balance between fidelity and bandwidth).
• Channel 2 (Mobile Apps & On the Go): AAC+ at 48 or 64 kbps (crystal-clear audio with reduced cellular data requirements).
• Channel 3 (Audiophile / Hi-Fi): MP3 at 320 kbps for discerning listeners on broadband connections.

Check technical details at SPCast or contact support for configuration advice.