<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <!-- Created by , GNU Texinfo 7.0.1 --> <head> <meta charset="utf-8"> <title> Libswresample Documentation </title> <meta name="viewport" content="width=device-width,initial-scale=1.0"> <link rel="stylesheet" type="text/css" href="bootstrap.min.css"> <link rel="stylesheet" type="text/css" href="style.min.css"> </head> <body> <div class="container"> <h1> Libswresample Documentation </h1> <div class="top-level-extent" id="SEC_Top"> <div class="element-contents" id="SEC_Contents"> <h2 class="contents-heading">Table of Contents</h2> <div class="contents"> <ul class="toc-numbered-mark"> <li><a id="toc-Description" href="#Description">1 Description</a></li> <li><a id="toc-See-Also" href="#See-Also">2 See Also</a></li> <li><a id="toc-Authors" href="#Authors">3 Authors</a></li> </ul> </div> </div> <ul class="mini-toc"> <li><a href="#Description" accesskey="1">Description</a></li> <li><a href="#See-Also" accesskey="2">See Also</a></li> <li><a href="#Authors" accesskey="3">Authors</a></li> </ul> <div class="chapter-level-extent" id="Description"> <h2 class="chapter">1 Description</h2> <p>The libswresample library performs highly optimized audio resampling, rematrixing and sample format conversion operations. </p> <p>Specifically, this library performs the following conversions: </p> <ul class="itemize mark-bullet"> <li><em class="emph">Resampling</em>: is the process of changing the audio rate, for example from a high sample rate of 44100Hz to 8000Hz. Audio conversion from high to low sample rate is a lossy process. Several resampling options and algorithms are available. </li><li><em class="emph">Format conversion</em>: is the process of converting the type of samples, for example from 16-bit signed samples to unsigned 8-bit or float samples. It also handles packing conversion, when passing from packed layout (all samples belonging to distinct channels interleaved in the same buffer), to planar layout (all samples belonging to the same channel stored in a dedicated buffer or "plane"). </li><li><em class="emph">Rematrixing</em>: is the process of changing the channel layout, for example from stereo to mono. When the input channels cannot be mapped to the output streams, the process is lossy, since it involves different gain factors and mixing. </li></ul> <p>Various other audio conversions (e.g. stretching and padding) are enabled through dedicated options. </p> </div> <div class="chapter-level-extent" id="See-Also"> <h2 class="chapter">2 See Also</h2> <p><a class="url" href="ffmpeg.html">ffmpeg</a>, <a class="url" href="ffplay.html">ffplay</a>, <a class="url" href="ffprobe.html">ffprobe</a>, <a class="url" href="ffmpeg-resampler.html">ffmpeg-resampler</a>, <a class="url" href="libavutil.html">libavutil</a> </p> </div> <div class="chapter-level-extent" id="Authors"> <h2 class="chapter">3 Authors</h2> <p>The FFmpeg developers. </p> <p>For details about the authorship, see the Git history of the project (https://git.ffmpeg.org/ffmpeg), e.g. by typing the command <code class="command">git log</code> in the FFmpeg source directory, or browsing the online repository at <a class="url" href="https://git.ffmpeg.org/ffmpeg">https://git.ffmpeg.org/ffmpeg</a>. </p> <p>Maintainers for the specific components are listed in the file <samp class="file">MAINTAINERS</samp> in the source code tree. </p> </div> </div> <p style="font-size: small;"> This document was generated using <a class="uref" href="https://www.gnu.org/software/texinfo/"><em class="emph">makeinfo</em></a>. </p> </div> </body> </html>