With FFmpeg version 1.1 comes the option of high-quality audio resampling using ​The SoX Resampler library ('libsoxr').

To build FFmpeg with libsoxr, it must first be installed. On unix-like systems, it may be available as an installable package from your OS provider; otherwise, libsoxr should be installed from source code downloaded from ​here—either a versioned tar-file, or a git 'clone'. Once downloaded (and unpacked, in the case of a tar file), it should be built and installed according to the instructions in the INSTALL file (included in the source distribution).

With libsoxr installed, ./configure --enable-libsoxr instructs the FFmpeg build system to use libsoxr.

To invoke ffmpeg with the SoX Resampler, the option -af aresample=resampler=soxr should be given; e.g.

ffmpeg -i my-48000.wav -af aresample=resampler=soxr -ar 44100 my-44100.wav

Further options may be given to change the default resampling bit precision and preserved bandwidth—see the manual page ​ffmpeg-resampler for details.