swresample

swresample is a resampling library from the FFmpeg project. It is designed to resample audio data between different sample rates and channel formats. The library provides efficient and flexible audio resampling capabilities, allowing developers to convert audio streams to various formats without significant loss of quality.

The primary function of swresample is to change the sample rate of an audio stream. This means altering the number of audio samples per second. For instance, an audio file recorded at 44.1 kHz (CD quality) can be resampled to 48 kHz (common for video) or 16 kHz (for voice applications). The library employs various algorithms to perform this conversion, aiming to minimize aliasing and distortion.

In addition to sample rate conversion, swresample can also handle channel layout changes. This involves modifying the number of audio channels or their arrangement. For example, it can convert stereo audio (two channels) to mono (one channel) or to surround sound formats. The library supports a wide range of channel layouts.

swresample is part of the larger FFmpeg multimedia framework, which is widely used for audio and video processing. Its integration within FFmpeg means it benefits from the project's extensive codec support and ongoing development. Developers can use swresample directly in their applications or leverage its functionality through the FFmpeg command-line tools. The library is known for its performance and its ability to provide high-quality audio resampling.