4cfad5ae0f
- 全新ui - 全面优化websocket逻辑，提高数字人和ui连接的稳定性及资源开销 - 全面优化唤醒逻辑，提供稳定的普通唤醒模式和前置词唤醒模式 - 优化拾音质量，支持多声道麦克风拾音 - 优化自动播放服务器的对接机制，提供稳定和兼容旧版ue工程的对接模式 - 数字人接口输出机器人表情，以适应新fay ui及单片机的数字人表情输出 - 使用更高级的音频时长计算方式，可以更精准控制音频播放完成后的逻辑 - 修复点击关闭按钮会导致程序退出的bug - 修复没有麦克风的设备开启麦克风会出错的问题 - 为服务器主机地址提供配置项，以方便服务器部署
363 lines
13 KiB
HTML
363 lines
13 KiB
HTML
<!DOCTYPE html>
|
|
<html>
|
|
<!-- Created by GNU Texinfo 7.0.1, https://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
|
<title>FFmpeg Resampler Documentation</title>
|
|
|
|
<meta name="description" content="FFmpeg Resampler Documentation">
|
|
<meta name="keywords" content="FFmpeg Resampler Documentation">
|
|
<meta name="resource-type" content="document">
|
|
<meta name="distribution" content="global">
|
|
<meta name="Generator" content="makeinfo">
|
|
<meta name="viewport" content="width=device-width,initial-scale=1">
|
|
|
|
<link href="#SEC_Contents" rel="contents" title="Table of Contents">
|
|
<style type="text/css">
|
|
<!--
|
|
ul.toc-numbered-mark {list-style: none}
|
|
-->
|
|
</style>
|
|
|
|
|
|
</head>
|
|
|
|
<body lang="en">
|
|
|
|
|
|
<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-Resampler-Options" href="#Resampler-Options">2 Resampler Options</a></li>
|
|
<li><a id="toc-See-Also" href="#See-Also">3 See Also</a></li>
|
|
<li><a id="toc-Authors" href="#Authors">4 Authors</a></li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="chapter-level-extent" id="Description">
|
|
<h2 class="chapter">1 Description</h2>
|
|
|
|
<p>The FFmpeg resampler provides a high-level interface to the
|
|
libswresample library audio resampling utilities. In particular it
|
|
allows one to perform audio resampling, audio channel layout rematrixing,
|
|
and convert audio format and packing layout.
|
|
</p>
|
|
|
|
</div>
|
|
<div class="chapter-level-extent" id="Resampler-Options">
|
|
<h2 class="chapter">2 Resampler Options</h2>
|
|
|
|
<p>The audio resampler supports the following named options.
|
|
</p>
|
|
<p>Options may be set by specifying -<var class="var">option</var> <var class="var">value</var> in the
|
|
FFmpeg tools, <var class="var">option</var>=<var class="var">value</var> for the aresample filter,
|
|
by setting the value explicitly in the
|
|
<code class="code">SwrContext</code> options or using the <samp class="file">libavutil/opt.h</samp> API for
|
|
programmatic use.
|
|
</p>
|
|
<dl class="table">
|
|
<dt><samp class="option">uchl, used_chlayout</samp></dt>
|
|
<dd><p>Set used input channel layout. Default is unset. This option is
|
|
only used for special remapping.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">isr, in_sample_rate</samp></dt>
|
|
<dd><p>Set the input sample rate. Default value is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">osr, out_sample_rate</samp></dt>
|
|
<dd><p>Set the output sample rate. Default value is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">isf, in_sample_fmt</samp></dt>
|
|
<dd><p>Specify the input sample format. It is set by default to <code class="code">none</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">osf, out_sample_fmt</samp></dt>
|
|
<dd><p>Specify the output sample format. It is set by default to <code class="code">none</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">tsf, internal_sample_fmt</samp></dt>
|
|
<dd><p>Set the internal sample format. Default value is <code class="code">none</code>.
|
|
This will automatically be chosen when it is not explicitly set.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">ichl, in_chlayout</samp></dt>
|
|
<dt><samp class="option">ochl, out_chlayout</samp></dt>
|
|
<dd><p>Set the input/output channel layout.
|
|
</p>
|
|
<p>See <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#channel-layout-syntax">(ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual</a>
|
|
for the required syntax.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">clev, center_mix_level</samp></dt>
|
|
<dd><p>Set the center mix level. It is a value expressed in deciBel, and must be
|
|
in the interval [-32,32].
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">slev, surround_mix_level</samp></dt>
|
|
<dd><p>Set the surround mix level. It is a value expressed in deciBel, and must
|
|
be in the interval [-32,32].
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">lfe_mix_level</samp></dt>
|
|
<dd><p>Set LFE mix into non LFE level. It is used when there is a LFE input but no
|
|
LFE output. It is a value expressed in deciBel, and must
|
|
be in the interval [-32,32].
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">rmvol, rematrix_volume</samp></dt>
|
|
<dd><p>Set rematrix volume. Default value is 1.0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">rematrix_maxval</samp></dt>
|
|
<dd><p>Set maximum output value for rematrixing.
|
|
This can be used to prevent clipping vs. preventing volume reduction.
|
|
A value of 1.0 prevents clipping.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">flags, swr_flags</samp></dt>
|
|
<dd><p>Set flags used by the converter. Default value is 0.
|
|
</p>
|
|
<p>It supports the following individual flags:
|
|
</p><dl class="table">
|
|
<dt><samp class="option">res</samp></dt>
|
|
<dd><p>force resampling, this flag forces resampling to be used even when the
|
|
input and output sample rates match.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp class="option">dither_scale</samp></dt>
|
|
<dd><p>Set the dither scale. Default value is 1.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">dither_method</samp></dt>
|
|
<dd><p>Set dither method. Default value is 0.
|
|
</p>
|
|
<p>Supported values:
|
|
</p><dl class="table">
|
|
<dt>‘<samp class="samp">rectangular</samp>’</dt>
|
|
<dd><p>select rectangular dither
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">triangular</samp>’</dt>
|
|
<dd><p>select triangular dither
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">triangular_hp</samp>’</dt>
|
|
<dd><p>select triangular dither with high pass
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">lipshitz</samp>’</dt>
|
|
<dd><p>select Lipshitz noise shaping dither.
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">shibata</samp>’</dt>
|
|
<dd><p>select Shibata noise shaping dither.
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">low_shibata</samp>’</dt>
|
|
<dd><p>select low Shibata noise shaping dither.
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">high_shibata</samp>’</dt>
|
|
<dd><p>select high Shibata noise shaping dither.
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">f_weighted</samp>’</dt>
|
|
<dd><p>select f-weighted noise shaping dither
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">modified_e_weighted</samp>’</dt>
|
|
<dd><p>select modified-e-weighted noise shaping dither
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">improved_e_weighted</samp>’</dt>
|
|
<dd><p>select improved-e-weighted noise shaping dither
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp class="option">resampler</samp></dt>
|
|
<dd><p>Set resampling engine. Default value is swr.
|
|
</p>
|
|
<p>Supported values:
|
|
</p><dl class="table">
|
|
<dt>‘<samp class="samp">swr</samp>’</dt>
|
|
<dd><p>select the native SW Resampler; filter options precision and cheby are not
|
|
applicable in this case.
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">soxr</samp>’</dt>
|
|
<dd><p>select the SoX Resampler (where available); compensation, and filter options
|
|
filter_size, phase_shift, exact_rational, filter_type & kaiser_beta, are not
|
|
applicable in this case.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp class="option">filter_size</samp></dt>
|
|
<dd><p>For swr only, set resampling filter size, default value is 32.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">phase_shift</samp></dt>
|
|
<dd><p>For swr only, set resampling phase shift, default value is 10, and must be in
|
|
the interval [0,30].
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">linear_interp</samp></dt>
|
|
<dd><p>Use linear interpolation when enabled (the default). Disable it if you want
|
|
to preserve speed instead of quality when exact_rational fails.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">exact_rational</samp></dt>
|
|
<dd><p>For swr only, when enabled, try to use exact phase_count based on input and
|
|
output sample rate. However, if it is larger than <code class="code">1 << phase_shift</code>,
|
|
the phase_count will be <code class="code">1 << phase_shift</code> as fallback. Default is enabled.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">cutoff</samp></dt>
|
|
<dd><p>Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float
|
|
value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr
|
|
(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">precision</samp></dt>
|
|
<dd><p>For soxr only, the precision in bits to which the resampled signal will be
|
|
calculated. The default value of 20 (which, with suitable dithering, is
|
|
appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a
|
|
value of 28 gives SoX’s ’Very High Quality’.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">cheby</samp></dt>
|
|
<dd><p>For soxr only, selects passband rolloff none (Chebyshev) & higher-precision
|
|
approximation for ’irrational’ ratios. Default value is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">async</samp></dt>
|
|
<dd><p>For swr only, simple 1 parameter audio sync to timestamps using stretching,
|
|
squeezing, filling and trimming. Setting this to 1 will enable filling and
|
|
trimming, larger values represent the maximum amount in samples that the data
|
|
may be stretched or squeezed for each second.
|
|
Default value is 0, thus no compensation is applied to make the samples match
|
|
the audio timestamps.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">first_pts</samp></dt>
|
|
<dd><p>For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.
|
|
This allows for padding/trimming at the start of stream. By default, no
|
|
assumption is made about the first frame’s expected pts, so no padding or
|
|
trimming is done. For example, this could be set to 0 to pad the beginning with
|
|
silence if an audio stream starts after the video stream or to trim any samples
|
|
with a negative pts due to encoder delay.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">min_comp</samp></dt>
|
|
<dd><p>For swr only, set the minimum difference between timestamps and audio data (in
|
|
seconds) to trigger stretching/squeezing/filling or trimming of the
|
|
data to make it match the timestamps. The default is that
|
|
stretching/squeezing/filling and trimming is disabled
|
|
(<samp class="option">min_comp</samp> = <code class="code">FLT_MAX</code>).
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">min_hard_comp</samp></dt>
|
|
<dd><p>For swr only, set the minimum difference between timestamps and audio data (in
|
|
seconds) to trigger adding/dropping samples to make it match the
|
|
timestamps. This option effectively is a threshold to select between
|
|
hard (trim/fill) and soft (squeeze/stretch) compensation. Note that
|
|
all compensation is by default disabled through <samp class="option">min_comp</samp>.
|
|
The default is 0.1.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">comp_duration</samp></dt>
|
|
<dd><p>For swr only, set duration (in seconds) over which data is stretched/squeezed
|
|
to make it match the timestamps. Must be a non-negative double float value,
|
|
default value is 1.0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">max_soft_comp</samp></dt>
|
|
<dd><p>For swr only, set maximum factor by which data is stretched/squeezed to make it
|
|
match the timestamps. Must be a non-negative double float value, default value
|
|
is 0.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">matrix_encoding</samp></dt>
|
|
<dd><p>Select matrixed stereo encoding.
|
|
</p>
|
|
<p>It accepts the following values:
|
|
</p><dl class="table">
|
|
<dt>‘<samp class="samp">none</samp>’</dt>
|
|
<dd><p>select none
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">dolby</samp>’</dt>
|
|
<dd><p>select Dolby
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">dplii</samp>’</dt>
|
|
<dd><p>select Dolby Pro Logic II
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>Default value is <code class="code">none</code>.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">filter_type</samp></dt>
|
|
<dd><p>For swr only, select resampling filter type. This only affects resampling
|
|
operations.
|
|
</p>
|
|
<p>It accepts the following values:
|
|
</p><dl class="table">
|
|
<dt>‘<samp class="samp">cubic</samp>’</dt>
|
|
<dd><p>select cubic
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">blackman_nuttall</samp>’</dt>
|
|
<dd><p>select Blackman Nuttall windowed sinc
|
|
</p></dd>
|
|
<dt>‘<samp class="samp">kaiser</samp>’</dt>
|
|
<dd><p>select Kaiser windowed sinc
|
|
</p></dd>
|
|
</dl>
|
|
|
|
</dd>
|
|
<dt><samp class="option">kaiser_beta</samp></dt>
|
|
<dd><p>For swr only, set Kaiser window beta value. Must be a double float value in the
|
|
interval [2,16], default value is 9.
|
|
</p>
|
|
</dd>
|
|
<dt><samp class="option">output_sample_bits</samp></dt>
|
|
<dd><p>For swr only, set number of used output sample bits for dithering. Must be an integer in the
|
|
interval [0,64], default value is 0, which means it’s not used.
|
|
</p>
|
|
</dd>
|
|
</dl>
|
|
|
|
|
|
</div>
|
|
<div class="chapter-level-extent" id="See-Also">
|
|
<h2 class="chapter">3 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="libswresample.html">libswresample</a>
|
|
</p>
|
|
|
|
</div>
|
|
<div class="chapter-level-extent" id="Authors">
|
|
<h2 class="chapter">4 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>
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|