libavresample

libavresample is a component of the FFmpeg project that provides software-based audio resampling and sample format conversion. It enables tasks such as changing the sample rate (upsampling or downsampling), converting between channel layouts (for example from stereo to surround or vice versa), and converting between different sample formats (interleaved versus planar layouts, integer and floating point representations).

The library offers a resampling context configured with input and output parameters, including input and output sample rates, channel layouts, and sample formats. The resampler accepts audio frames from a source and produces frames in the destination format, handling buffering and timing to manage partial frames across calls. It supports a variety of resampling algorithms and aims to preserve audio quality while performing the conversion.

Libavresample has been part of FFmpeg for many years, but development has shifted toward the separate library libswresample. In newer FFmpeg releases, libavresample is considered deprecated or kept primarily for compatibility, with migration guidance toward libswresample. Applications that work with FFmpeg’s decoding and transcoding pipelines may still interact with libavresample directly or indirectly through FFmpeg’s higher-level interfaces, but new development is generally oriented around libswresample.

See also: FFmpeg, libswresample, audio resampling, sample format conversion.