EVS Codec Software
- Super-wideband Audio Coding with Backward Compatibility for Narrowband/Wideband Operation
- Mobile, VoIP and Voice Conferencing for LTE
- Optimized for DSPs, RiSC, CISC processors
- 3GPP TS 26.441-451 compliant
VOCAL offers the EVS codec software as a standalone algorithm, as part of a modular software library suite, as well as with a VoIP stack. VOCAL’s software is written in ANSI C and does not make use of any GPL licensed software components.
EVS
Enhanced Voice Services (EVS), standardized by 3GPP, is a multi-rate audio codec supporting an audio bandwidth up to 20kHz with supported use for conversational speech and music. This codec provides enhanced voice quality, better compression rates, and network features over previously standardized 3GPP codecs. EVS codec software was designed for integration with LTE and packet-switch mobile communication networks.
In order to support efficient compression of both speech and music input audio signals, EVS has separate compression modes. Algebraic Code-Excitation Linear Prediction (ACELP) is used for speech signals and the Modified Discrete Cosine Transform (MDCT). For backward compatibility with previous 3GPP standards for narrowband and wideband voice, AMR-WB Inter-Operable mode is implemented. The EVS software also offers a channel-aware mode for additional robustness to channel errors. This is achieved by combining the jitter buffer management (JBM) with partial redundancy. The redundant information is used to synthesize a lost frame or packet.
Features
- Transcoding Support
- Compliant with 3GPP TS 26.442 Source code
- Narrowband, Wideband, Super-wideband and Fullband Modes Supported
- Detailed Algorithmic Description (3GPP TS 26.445)
- AMR-WB Backward Compatible Functions (3GPP TS 26.446)
- Error Concealment for Lost Packets (3GPP TS 26.447)
- Jitter Buffer Management (3GPP TS 26.448)
- Comfort Noise Generation (3GPP TS 26.449)
- Discontinuous Transmission (3GPP TS 26.450)
- Voice Activity Detection (3GPP TS 26.451)
- IP Multimedia Subsystem (IMS) (3GPP TS 26.114)
- Performance Characterization (3GPP TR 26.952)
- Multichannel implementation
- Multi-tasking environment compatible
Use Cases
- Session Border Controller
- Lawful Intercept Software
- WebRTC Software
- Media Gateway Control Protocol (MGCP) Software
- Speech Coder and Compression Software
- Speech Vocoder Software
Custom use cases are also available. Please contact us to discuss your custom EVS requirements.
VOCAL’s solution is available for the above platforms. Please contact us for specific supported platforms.
