ffmpeg downmix and bitrate

ipython_audio.html

@@ -12438,7 +12438,7 @@ sox in.wav out.wav trim 75 30</code></pre>
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 <div class="inner_cell">
 <div class="text_cell_render border-box-sizing rendered_html">
-<p><a href="https://www.ffmpeg.org/">ffmpeg</a> is a framework to convert among different audio and video file formats.</p>
+<p><a href="https://www.ffmpeg.org/">ffmpeg</a> is a framework to convert among different audio and video file formats. Use <code>ffmpeg</code> if you want to convert WAV to MP3.</p>
 
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 </div>
@@ -12462,6 +12462,17 @@ sox in.wav out.wav trim 75 30</code></pre>
 
 <pre><code>ffmpeg -i in.wav out.mp3 </code></pre>
 
+</div>
+</div>
+</div>
+<div class="cell border-box-sizing text_cell rendered"><div class="prompt input_prompt">
+</div>
+<div class="inner_cell">
+<div class="text_cell_render border-box-sizing rendered_html">
+<p>Down-mix all input channels to mono with a bitrate of 128k:</p>
+
+<pre><code>ffmpeg -i in.wav -ac 1 -ab 128k out.mp3</code></pre>
+
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ipython_audio.ipynb

@@ -612,7 +612,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "[ffmpeg](https://www.ffmpeg.org/) is a framework to convert among different audio and video file formats."
+    "[ffmpeg](https://www.ffmpeg.org/) is a framework to convert among different audio and video file formats. Use `ffmpeg` if you want to convert WAV to MP3."
    ]
   },
   {
@@ -633,6 +633,15 @@
     "    ffmpeg -i in.wav out.mp3 "
    ]
   },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Down-mix all input channels to mono with a bitrate of 128k:\n",
+    "\n",
+    "    ffmpeg -i in.wav -ac 1 -ab 128k out.mp3"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},