CodecLib — For Easy Integration of Multiple Speech and Audio Codecs on any Floating-point Platform At VoiceAge, our extensive experience as developers of multimedia codec implementations for various platforms and environments has inspired us to develop a tool that makes it easy to implement multi-codec applications like IP phones, call center monitoring, or audio players/recorders. We're pleased to offer CodecLib, an application programming interface (API) developed as an integration tool for deploying multiple combinations of speech and audio codecs. CodecLib provides the same interface on any floating-point platform, including the Linux, Intel®/Windows®, Sun Solaris™ and Mac OS® X platforms.

Supported Codecs • G.711 (A-law or µ-law) • G.722 (ADPCM) • G.722.1 • G.722.2 (AMR-WB) • G.723.1 • G.726 • G.728 • G.729 • G.729a • G.729b • G.729d • G.729e • AMR • AMR-WB (G.722.2) • AMR-WB+ • GSM-EFR • GSM-FR • GSM-HR • Microsoft® GSM • QCELP-13 (IS-733) • EVRC (IS-127) • VMR-WB • ACELP®.net Supported Platforms • Intel®/Windows® • Linux/Unix® • Sun Solaris™ • Mac OS® X

CodecLib lets you operate in two “modes” — “generic” or “open.” In generic mode, CodecLib makes it easy to integrate speech and audio codecs in your application through built-in logic. We've designed the logic to automatically address the individual characteristics and capabilities of the different codecs so that you don't have to. You can, if you wish, “operate blind.” For example, CodecLib automatically manages the buffer for input and output. On the input side, speech frames are automatically buffered until the buffer meets the requirements of each codec regarding frame size. And on the output side, CodecLib provides a simple handshake with the application to manage overflow of the audio output buffer.

On the other hand, if you're a developer who has expertise in the audio codec domain, the open interface allows you to fine-tune the individual capabilities of any and all codecs in your application. The CodecLib open interface allows you to directly query and use supported libraries to retrieve codec-specific properties and capabilities. You can then configure your application code to use individual codecs in a selective way.

Resampling
You can use the resampler codec library (sampler) to adjust the sampling rate of an audio file to one of the following rates (in Hz):