joshua/joshua.seigler.net
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Updates

Browse source
This commit is contained in:
Joshua Seigler 2025-06-26 19:12:39 -04:00
parent 07cf2aec06
commit 1fe29b8b1a
53 changed files with 651 additions and 161 deletions
Download patch file Download diff file Expand all files Collapse all files

4
posts/authority-consents-blind-spot/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -93,7 +93,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>July 2, 2020</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 0" href="/tags/ethos">ethos</a>
</span>
</div>

4
posts/embracing-mysticism/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -93,7 +93,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>October 16, 2021</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 4" href="/tags/faith">faith</a>
<a class="tag" style="--tagIndex: 0" href="/tags/ethos">ethos</a>
</span>

205
posts/ffmpeg-audio-cleanup/index.html Normal file
View file

@ -0,0 +1,205 @@
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
font-family: "Inter Variable";
font-style: normal;
font-display: swap;
font-weight: 100 900;
src: url(/fonts/inter-latin-wght-normal.woff2)
format("woff2-variations");
unicode-range:
U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC,
U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193,
U+2212, U+2215, U+FEFF, U+FFFD;
} /* inter-latin-wght-italic */
@font-face {
font-family: "Inter Variable";
font-style: italic;
font-display: swap;
font-weight: 100 900;
src: url(/fonts/inter-latin-wght-italic.woff2)
format("woff2-variations");
unicode-range:
U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC,
U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193,
U+2212, U+2215, U+FEFF, U+FFFD;
}
</style>
<script
defer
src="https://stats.apps.seigler.net/script.js"
data-website-id="ccb4bd94-2a71-47fe-8eea-d85bf75b7f6d"
></script>
<script defer src="/scripts/effects.js?v=d86d3b7642f1"></script>
<link rel="me" href="https://github.com/seigler" />
<link
rel="webmention"
href="https://webmention.io/joshua.seigler.net/webmention"
/>
<title>FFmpeg audio cleanup - joshua.seigler.net</title>
<meta name="description" content="" />
<meta name="keywords" content="posts, technical, ffmpeg" />
<meta property="og:title" content="FFmpeg audio cleanup" />
<meta property="og:type" content="" />
<meta
property="og:url"
content="https://joshua.seigler.net/posts/ffmpeg-audio-cleanup/"
/>
<meta name="twitter:title" content="FFmpeg audio cleanup" />
<meta name="twitter:description" content="" />
<meta name="twitter:card" content="summary" />
<meta name="generator" content="Eleventy v3.1.0" />
</head>
<body data-font="english" data-path="/posts/ffmpeg-audio-cleanup/">
<script>
const savedTheme = localStorage.getItem("theme");
if (savedTheme != null) {
document.body.setAttribute("data-theme", savedTheme);
}
</script>
<header>
<nav>
<div class="nav-row">
<div class="nav-home"><a href="/">joshua.seigler.net</a></div>
</div>
<div class="nav-categories">
<a class="nav-active" href="/posts/">/posts</a>
<a class="" href="/about/">/about</a>
<a class="" href="/now/">/now</a>
<a class="" href="/uses/">/uses</a>
<a class="" href="/recipes/">/recipes</a>
<a class="" href="/music/">/music</a>
<a class="" href="/books/">/books</a>
<a class="" href="/search/">/search</a>
</div>
</nav>
<h1>FFmpeg audio cleanup</h1>
<div class="header-meta">
<author>Joshua Seigler</author><date>June 26, 2025</date>
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 5" href="/tags/technical"
>technical</a
>
<a class="tag" style="--tagIndex: 10" href="/tags/ffmpeg">ffmpeg</a>
</span>
</div>
</header>
<header class="toc"></header>
<main data-pagefind-body="data-pagefind-body">
<p>
I recently needed to process 20+ phone audio recordings. The audio is
mp3 recordings in stereo, made in an environment with echoes and noise
from fans/heaters.
</p>
<p>
Although I could do it easily with
<a href="https://tenacityaudio.org/" target="_blank" rel="noopener"
>Tenacity</a
>
I didn’t want to use a manual process, since it would take days. So I
tried using FFmpeg filters and Bash scripting.
</p>
<p>
I found an FFmpeg filter called
<a
href="https://ffmpeg.org/ffmpeg-filters.html#compand"
target="_blank"
rel="noopener"
>compand</a
>
which lets you map an input decibel range to an output decibel range. I
also used the
<a
href="https://ffmpeg.org/ffmpeg-filters.html#anlmdn"
target="_blank"
rel="noopener"
>anlmdn</a
>
filter to reduce noise, and the
<a
href="https://ffmpeg.org/ffmpeg-filters.html#highpass"
target="_blank"
rel="noopener"
>highpass</a
>
filter to help with clarity.
</p>
<p>I ran into a couple gotchas.</p>
<ol>
<li>
<code>mpv</code> does something special for audio playback that
prevents audio from clipping. <code>vlc</code> plays the file as it
is.
</li>
<li>
Because the compressor has an attack and decay (which is necessary for
things to sound good) it can cause clipping if the volume rises
sharply. Applying a <code>delay</code> parameter with half the
duration of the attack length fixed this.
</li>
</ol>
<p>Here is the script:</p>
<pre
class="language-bash"
><code class="language-bash"><span class="token shebang important">#!/bin/bash</span>
<span class="token keyword">if</span> <span class="token punctuation">[</span> <span class="token string">"<span class="token variable">$#</span>"</span> <span class="token operator">==</span> <span class="token string">"0"</span> <span class="token punctuation">]</span><span class="token punctuation">;</span> <span class="token keyword">then</span>
<span class="token builtin class-name">echo</span> <span class="token string">"Error: no arguments provided."</span>
<span class="token builtin class-name">echo</span> <span class="token string">"Usage: <span class="token variable">$0</span> file1 file2 file3 ..."</span>
<span class="token builtin class-name">echo</span> <span class="token string">" or: <span class="token variable">$0</span> *.ext"</span>
<span class="token builtin class-name">exit</span> <span class="token number">1</span>
<span class="token keyword">fi</span>
<span class="token builtin class-name">trap</span> <span class="token string">"exit"</span> INT
<span class="token keyword">while</span> <span class="token punctuation">[</span> <span class="token string">"<span class="token variable">$#</span>"</span> <span class="token operator">!=</span> <span class="token string">"0"</span> <span class="token punctuation">]</span><span class="token punctuation">;</span> <span class="token keyword">do</span>
<span class="token assign-left variable">base</span><span class="token operator">=</span><span class="token string">"<span class="token variable">${1<span class="token operator">%%</span>.*}</span>"</span>
<span class="token assign-left variable">ext</span><span class="token operator">=</span><span class="token string">"<span class="token variable">${1<span class="token operator">##</span>*.}</span>"</span>
<span class="token assign-left variable">outfile</span><span class="token operator">=</span><span class="token string">"./normalized--<span class="token variable">$base</span>.<span class="token variable">$ext</span>"</span>
<span class="token keyword">if</span> <span class="token punctuation">[</span> <span class="token operator">!</span> <span class="token parameter variable">-f</span> <span class="token string">"<span class="token variable">$outfile</span>"</span> <span class="token punctuation">]</span><span class="token punctuation">;</span> <span class="token keyword">then</span>
<span class="token builtin class-name">echo</span> <span class="token string">"Processing <span class="token variable">$1</span>"</span>
ffmpeg <span class="token parameter variable">-i</span> <span class="token string">"<span class="token variable">$1</span>"</span> <span class="token parameter variable">-v</span> warning <span class="token parameter variable">-ac</span> <span class="token number">1</span> <span class="token parameter variable">-af</span> <span class="token string">"compand=attacks=0.3:decays=0.3:delay=0.15:points=-80/-300|-45/-25|-27/-15|0/-12|20/-12,anlmdn=s=10,highpass=f=500"</span> <span class="token parameter variable">-threads</span> <span class="token number">4</span> <span class="token string">"<span class="token variable">$outfile</span>"</span>
<span class="token keyword">else</span>
<span class="token builtin class-name">echo</span> <span class="token string">"Skipping <span class="token variable">$1</span>, already processed."</span>
<span class="token keyword">fi</span>
<span class="token builtin class-name">shift</span>
<span class="token keyword">done</span>
</code></pre>
<p>
If this is useful to you please leave a comment or send an email, I
would love to hear about it.
</p>
</main>
<script
data-isso="//comments.apps.seigler.net/"
src="//comments.apps.seigler.net/js/embed.min.js"
></script>
<section id="isso-thread" data-title="">
<noscript>Javascript needs to be activated to view comments.</noscript>
</section>
<footer>
&copy; Joshua Seigler 2025. -
<a rel="me" href="mailto:joshua@seigler.net?subject=Hello">Contact</a>
-
<a href="/feed.xml">RSS</a>
-
<a href="/unoffice-hours/">Unoffice Hours</a>
-
<a href="/webrings/">Webrings</a>
</footer>
<div id="effects"></div>
</body>
</html>

4
posts/finally-a-coherent-worldview/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -93,7 +93,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>July 14, 2023</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 4" href="/tags/faith">faith</a>
<a class="tag" style="--tagIndex: 0" href="/tags/ethos">ethos</a>
</span>

39
posts/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -81,18 +81,33 @@
</nav>
<h1>Posts</h1>
<div class="header-meta">
<span class="tags" style="--totalTags: 10"></span>
<span class="tags" style="--totalTags: 11"></span>
</div>
</header>
<main>
<section data-pagefind-body></section>
<ul class="collection">
<li>
<a href="/posts/ffmpeg-audio-cleanup/">FFmpeg audio cleanup</a>
<aside>June 26, 2025</aside>
<aside>
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 5" href="/tags/technical"
>technical</a
>
<a class="tag" style="--tagIndex: 10" href="/tags/ffmpeg"
>ffmpeg</a
>
</span>
</aside>
<p></p>
</li>
<li>
<a href="/posts/july-21-2025/">War</a>
<aside>June 21, 2025</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 6" href="/tags/zeitgeist"
>zeitgeist</a
>
@ -107,7 +122,7 @@
>
<aside>June 15, 2025</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 2" href="/tags/how-to"
>how to</a
>
@ -128,7 +143,7 @@
<a href="/posts/tools-of-the-trade/">Tools of the trade</a>
<aside>May 15, 2025</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 5" href="/tags/technical"
>technical</a
>
@ -143,7 +158,7 @@
<a href="/posts/thinking-machines/">Thinking machines</a>
<aside>April 24, 2025</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 6" href="/tags/zeitgeist"
>zeitgeist</a
>
@ -156,7 +171,7 @@
<a href="/posts/site-design-updated/">Site design updated</a>
<aside>June 05, 2024</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 5" href="/tags/technical"
>technical</a
>
@ -170,7 +185,7 @@
>
<aside>July 14, 2023</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 4" href="/tags/faith">faith</a>
<a class="tag" style="--tagIndex: 0" href="/tags/ethos">ethos</a>
</span>
@ -181,7 +196,7 @@
<a href="/posts/embracing-mysticism/">Embracing Mysticism</a>
<aside>October 16, 2021</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 4" href="/tags/faith">faith</a>
<a class="tag" style="--tagIndex: 0" href="/tags/ethos">ethos</a>
</span>
@ -197,7 +212,7 @@
>
<aside>May 26, 2021</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 3" href="/tags/communication"
>communication</a
>
@ -214,7 +229,7 @@
>
<aside>April 03, 2021</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 1" href="/tags/learning"
>learning</a
>
@ -234,7 +249,7 @@
>
<aside>July 02, 2020</aside>
<aside>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 0" href="/tags/ethos">ethos</a>
</span>
</aside>

4
posts/july-21-2025/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -87,7 +87,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>June 21, 2025</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 6" href="/tags/zeitgeist"
>zeitgeist</a
>

4
posts/my-very-own-github-pages/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -93,7 +93,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>June 15, 2025</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 2" href="/tags/how-to">how to</a>
<a class="tag" style="--tagIndex: 5" href="/tags/technical"
>technical</a

4
posts/needs-based-communication/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -93,7 +93,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>May 26, 2021</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 3" href="/tags/communication"
>communication</a
>

4
posts/site-design-updated/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -87,7 +87,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>June 5, 2024</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 5" href="/tags/technical"
>technical</a
>

4
posts/the-trivium-a-tool-for-learning-anything/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -104,7 +104,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>April 3, 2021</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 1" href="/tags/learning"
>learning</a
>

4
posts/thinking-machines/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -102,7 +102,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>April 24, 2025</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 6" href="/tags/zeitgeist"
>zeitgeist</a
>

4
posts/tools-of-the-trade/index.html
View file

@ -6,7 +6,7 @@
name="viewport"
content="width=device-width, initial-scale=1.0, viewport-fit=cover"
/>
<link rel="stylesheet" href="/site.css?v=6a81398da707" />
<link rel="stylesheet" href="/site.css?v=658836c9b392" />
<style>
/* inter-latin-wght-normal */
@font-face {
@ -87,7 +87,7 @@
<div class="header-meta">
<author>Joshua Seigler</author><date>May 15, 2025</date>
<span class="tags" style="--totalTags: 10"
<span class="tags" style="--totalTags: 11"
><a class="tag" style="--tagIndex: 5" href="/tags/technical"
>technical</a
>