How to Recover Corrupted Videos with Untrunc: A Free Guide

<p>The sinking feeling. It’s a universal dread for anyone who creates video content: a corrupted file. Recently, while recording an impromptu episode of <a href="https://www.pabloyglesias.com/podcast/">enCLAVE DIGITAL</a> with my Sony ZV-E10 and Hollyland Lark M2 mics, that nightmare became reality. The battery died mid-interview.</p>

<p>Selecting “Recover video” on the camera seemed to save the day. We continued recording, but a nagging worry persisted. And rightly so. When I transferred the file to my computer, no player – VLC, Windows Media Player, or QuickTime – could open it. A 32GB MP4, seemingly lost.</p>

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<p>This article details how I recovered the file using Untrunc, a free, open-source tool, and shares lessons for content creators using mirrorless cameras for podcasts, vlogs, or interviews.</p>

<figure class="wp-block-image size-full"><img decoding="async" loading="lazy" src="https://www.pabloyglesias.com/wp-content/uploads/2026/01/untrunc-ejemplo.jpg" alt="Untrunc Screenshot" /></figure>

<h2>The Technical Setup for enCLAVE DIGITAL</h2>

<p>While I typically record enCLAVE DIGITAL videos with a camera connected to a dummy battery and a microphone connected to the computer, this special episode required a different setup. I used my <a href="https://amzn.to/4ppRPvH" target="_blank" rel="noreferrer noopener">Sony ZV-E10</a> in 4K at 30p with stereo recording, connecting <a href="https://www.pabloyglesias.com/hollyland-lark-m2-mejor-calidad-audio-contenidos-audiovisuales/">Hollyland Lark M2</a> mics to separate my voice (left channel) and the interviewee’s (right channel). Stereo recording was intended to simplify post-production.</p>

<p>The Lark M2 receiver was in stereo mode (blue LED), with Audio Rec Level set to -12dB to prevent clipping. I recorded directly to a SanDisk Extreme Pro UHS-I U3 SD card, compatible with the ZV-E10’s speeds (up to 170-200 MB/s read).</p>

<p>Strategic lighting was also in place. Everything seemed perfect for a high-value interview discussing <a href="https://www.pabloyglesias.com/3-aprendizajes-negocios-familia-charla-elia-guardiola/">navigating 2025 and lessons learned from 2024</a>.</p>

<p>But at the 11-minute mark, the original NP-FW50 battery died. I swapped in a spare, and the camera prompted: “Recover Image DB?” I selected “Yes,” and continued recording for another 8 minutes, but with a growing sense of unease.</p>

<p>Upon copying the files to my computer, the first video – containing the bulk of the interview – was unplayable.</p>

<figure class="wp-block-image aligncenter size-full"><img decoding="async" loading="lazy" src="https://www.pabloyglesias.com/wp-content/uploads/2026/01/video-corrupto.jpg" alt="Corrupted Video File" /></figure>

<p class="has-text-align-center"><em>(Video C0087 plays fine, but C0086 is corrupted due to battery loss during recording and is therefore unplayable.)</em></p>

<h2>Why Did the MP4 File Become Corrupted?</h2>

<p>Cameras like the Sony ZV-E10 write videos in MP4 containers using the H.264/XAVC-S codec. When the battery dies abruptly, the file becomes “truncated”: the final metadata (MOOV atom), which indexes frames, audio, and duration, is missing. The content is still there, but the player lacks the guide to read it.</p>

<p>Initial attempts to fix the file failed:</p>

<ul>
    <li><strong>VLC advanced settings:</strong> Tools &gt; Preferences &gt; Input/Codecs &gt; Always fix.</li>
    <li><strong>Shutter Encoder:</strong> Rewrap and H.264 re-encode.</li>
    <li><strong>DaVinci Resolve:</strong> Crashed at 30%.</li>
    <li><strong>Wondershare Repairit:</strong> Stalled at 83.70% after three hours.</li>
</ul>

<p>This led me to explore GitHub and discover Untrunc.</p>

<figure class="wp-block-image size-full"><img decoding="async" loading="lazy" src="https://www.pabloyglesias.com/wp-content/uploads/2026/01/herramienta-untruc-recuperacion-video.jpg" alt="Untrunc Tool Screenshot" /></figure>

<h2>Untrunc: The Free Video Recovery Savior</h2>

<p>Untrunc, developed by <a href="https://github.com/anthwlock/untrunc" target="_blank" rel="noreferrer noopener">Anthwlock</a>, reconstructs truncated MP4s using a healthy reference video from the same device. It’s free, cross-platform (Windows, Mac, Linux), and effective in 80-90% of cases involving battery drain on Sony ZV-E10, A7III, or FX30 cameras.</p>

<p>It works by analyzing the internal structure of the reference file (headers, video/audio tracks) and copying it to the corrupted file, completing the missing metadata.</p>

<h3>Step 1: Prepare Files and Download Untrunc</h3>

<ol class="wp-block-list">
    <li><strong>Record a reference video:</strong> Use the same camera, resolution, framerate, and audio setup.</li>
    <li><strong>Download Untrunc:</strong> <a href="https://github.com/anthwlock/untrunc">https://github.com/anthwlock/untrunc</a></li>
    <li>Copy <code>reference_sana.mp4</code> and <code>corrupto.mp4</code> to the Untrunc folder. <strong>Do not modify the originals!</strong></li>
</ol>

<h3>Step 2: First Attempt – Basic Recovery (8 Minutes)</h3>

<p>Open CMD in the folder (Shift+Right Click &gt; Open terminal):</p>

<pre class="wp-block-preformatted">text<code>untrunc.exe referencia_sana.mp4 corrupto.mp4</code></pre>

<p>This created <code>fixed.mp4</code>, which played in VLC, but only for 8 minutes and 13 seconds – the length of the reference video. The corrupted file was over an hour long.</p>

<h3>Step 3: Activate Step Mode (-s) for Complete Recovery</h3>

<p>The <code>-s</code> (step mode) flag reconstructs progressively, predicting MP4 structures byte-by-byte and bypassing errors without relying solely on the reference.</p>

<pre class="wp-block-preformatted">text<code>untrunc.exe -s referencia_sana.mp4 corrupto.mp4</code></pre>

<p>With -s activated, the process took around 15 minutes, resulting in a 31GB video – the complete interview with intact stereo audio! Verification in Premiere confirmed the separated voices and no glitches.</p>

<h2>Lessons Learned for Content Creators</h2>

<p>Here are some preventative measures:</p>

<ul>
    <li><strong>Proxy Recording:</strong> MENU &gt; Camera Settings2 &gt; Proxy &gt; On.</li>
    <li><strong>Dummy Battery:</strong> Use a dummy battery and power bank.</li>
    <li><strong>Audio Signals:</strong> Enable low battery beep. MENU &gt; Setup &gt; Audio Signals &gt; On.</li>
    <li><strong>Short Clips:</strong> Limit file length to 12 minutes.</li>
    <li><strong>Fast SD Cards:</strong> Use UHS-I U3/V30 cards.</li>
</ul>

<h2>MP4 Recovery Tool Comparison</h2>

<figure class="wp-block-table"><table class="has-fixed-layout"><thead><tr><th class="has-text-align-left" data-align="left">Tool</th><th class="has-text-align-left" data-align="left">Free</th><th class="has-text-align-left" data-align="left">Needs Reference</th><th class="has-text-align-left" data-align="left">Recovers &gt;Ref</th><th class="has-text-align-left" data-align="left">Ease of Use</th><th class="has-text-align-left" data-align="left">Success Rate</th></tr></thead><tbody><tr><td>Untrunc (-s)</td><td>Yes</td><td>Yes</td><td>Yes</td><td>Medium</td><td>90%</td></tr><tr><td>Shutter Encoder</td><td>Yes</td><td>No</td><td>Partial</td><td>High</td><td>70%</td></tr><tr><td>VLC Fix</td><td>Yes</td><td>No</td><td>No</td><td>Low</td><td>30%</td></tr><tr><td>Wondershare Repairit</td><td>No (~30€)</td><td>No</td><td>Partial</td><td>High</td><td>80%</td></tr><tr><td>DaVinci Resolve</td><td>Yes</td><td>No</td><td>Partial</td><td>Medium</td><td>50%</td></tr></tbody></table></figure>

<p><strong>Did you know?</strong>  A full battery isn't always enough.  Sudden power loss can still corrupt files, even with a seemingly charged battery.  Regularly backing up your footage is crucial.</p>

<p><strong>Pro Tip:</strong> Always test your recovery workflow *before* a critical shoot. Knowing your tools and having a backup plan can save you hours of frustration.</p>

<p>Have you ever experienced a corrupted video file? Share your story and recovery tips in the comments below!</p>

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