<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>Ffmpeg on kenji.blog</title><link>http://kenji.blog/en/tags/ffmpeg/</link><description>Recent content in Ffmpeg on kenji.blog</description><generator>Hugo -- gohugo.io</generator><language>en</language><copyright>kenjinote</copyright><lastBuildDate>Sun, 02 Mar 2025 04:16:07 +0900</lastBuildDate><atom:link href="http://kenji.blog/en/tags/ffmpeg/index.xml" rel="self" type="application/rss+xml"/><item><title>ffmpeg Parameters for iOS</title><link>http://kenji.blog/en/p/ios-%E5%90%91%E3%81%91%E3%81%AE-ffmpeg-%E3%83%91%E3%83%A9%E3%83%A1%E3%83%BC%E3%82%BF/</link><pubDate>Sun, 02 Mar 2025 04:16:07 +0900</pubDate><guid>http://kenji.blog/en/p/ios-%E5%90%91%E3%81%91%E3%81%AE-ffmpeg-%E3%83%91%E3%83%A9%E3%83%A1%E3%83%BC%E3%82%BF/</guid><description>&lt;img src="http://kenji.blog/p/ios-%E5%90%91%E3%81%91%E3%81%AE-ffmpeg-%E3%83%91%E3%83%A9%E3%83%A1%E3%83%BC%E3%82%BF/img.png" alt="Featured image of post ffmpeg Parameters for iOS" />&lt;h1 id="ffmpeg-conversion-parameters-optimized-for-ios">ffmpeg Conversion Parameters Optimized for iOS
&lt;/h1>&lt;p>Here is an &lt;code>ffmpeg&lt;/code> command to convert videos so they can be played smoothly on iOS devices (iPhone and iPad).&lt;/p>
&lt;div class="highlight">&lt;div class="chroma">
&lt;table class="lntable">&lt;tr>&lt;td class="lntd">
&lt;pre tabindex="0" class="chroma">&lt;code>&lt;span class="lnt">1
&lt;/span>&lt;span class="lnt">2
&lt;/span>&lt;span class="lnt">3
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&lt;td class="lntd">
&lt;pre tabindex="0" class="chroma">&lt;code class="language-bash" data-lang="bash">&lt;span class="line">&lt;span class="cl">ffmpeg -i input.mp4 &lt;span class="se">\
&lt;/span>&lt;/span>&lt;/span>&lt;span class="line">&lt;span class="cl">&lt;span class="se">&lt;/span>-c:v libx264 -profile:v high -level 4.1 &lt;span class="se">\
&lt;/span>&lt;/span>&lt;/span>&lt;span class="line">&lt;span class="cl">&lt;span class="se">&lt;/span>-vf &lt;span class="s2">&amp;#34;scale=1920:-2&amp;#34;&lt;/span> -r &lt;span class="m">30&lt;/span> &lt;span class="se">\
&lt;/span>&lt;/span>&lt;/span>&lt;span class="line">&lt;span class="cl">&lt;span class="se">&lt;/span>-crf &lt;span class="m">20&lt;/span> -preset slow &lt;span class="se">\
&lt;/span>&lt;/span>&lt;/span>&lt;span class="line">&lt;span class="cl">&lt;span class="se">&lt;/span>-c:a aac -b:a 128k -ar &lt;span class="m">48000&lt;/span> &lt;span class="se">\
&lt;/span>&lt;/span>&lt;/span>&lt;span class="line">&lt;span class="cl">&lt;span class="se">&lt;/span>-movflags +faststart output.mp4
&lt;/span>&lt;/span>&lt;/code>&lt;/pre>&lt;/td>&lt;/tr>&lt;/table>
&lt;/div>
&lt;/div>&lt;h3 id="meaning-of-each-option-brief-explanation">Meaning of Each Option (Brief Explanation)
&lt;/h3>&lt;table>
&lt;thead>
&lt;tr>
&lt;th>Option&lt;/th>
&lt;th>Description&lt;/th>
&lt;/tr>
&lt;/thead>
&lt;tbody>
&lt;tr>
&lt;td>&lt;code>-i input.mp4&lt;/code>&lt;/td>
&lt;td>Input file (source video to be converted)&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-c:v libx264&lt;/code>&lt;/td>
&lt;td>Encode video with H.264 (iOS compatible)&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-profile:v high -level 4.1&lt;/code>&lt;/td>
&lt;td>Widely compatible profile and level for iOS&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-vf &amp;quot;scale=1920:-2&amp;quot;&lt;/code>&lt;/td>
&lt;td>Resize width to 1920px, auto-adjust height maintaining aspect ratio&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-r 30&lt;/code>&lt;/td>
&lt;td>Convert to 30fps frame rate&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-crf 20&lt;/code>&lt;/td>
&lt;td>Video quality (lower value means higher quality, recommended 18-23)&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-preset slow&lt;/code>&lt;/td>
&lt;td>Balance between encode speed and compression ratio (slow means high compression/high quality)&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-c:a aac&lt;/code>&lt;/td>
&lt;td>Encode audio in AAC format&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-b:a 128k&lt;/code>&lt;/td>
&lt;td>Set audio bitrate to 128kbps&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-ar 48000&lt;/code>&lt;/td>
&lt;td>Set audio sampling rate to 48kHz (recommended for iOS)&lt;/td>
&lt;/tr>
&lt;tr>
&lt;td>&lt;code>-movflags +faststart&lt;/code>&lt;/td>
&lt;td>Places the index at the beginning of the video, &lt;strong>speeding up streaming playback on Web and iOS&lt;/strong>&lt;/td>
&lt;/tr>
&lt;/tbody>
&lt;/table>
&lt;hr>
&lt;p>Videos converted with these settings can be expected to have high compatibility and smooth playback on Apple devices such as iPhones and iPads.&lt;/p>
&lt;hr>
&lt;p>You can adjust file size and image quality by changing the resolution and bitrate as needed. Try setting &lt;code>-crf&lt;/code> to around 18 if you need high quality, or 22-25 if you want to reduce the file size.&lt;/p></description></item></channel></rss>