How to fix a corrupted Canon video file

By the FixMP4 engineering team · Updated October 9, 2026 · Tested on real H.264, HEVC and AAC recordings

A Canon video that will not open after the battery died, the card filled up or the camera locked up is usually an MP4 or MOV whose index was never written. If the clip is H.264 or H.265 (most EOS R, EOS M, PowerShot and DSLR video), you can rebuild the index from a short reference clip recorded on the same camera with the same movie recording size, frame rate and compression setting. Canon's RAW (CRM) and XF-AVC (MXF) formats are not supported. The FixMP4 repair tool rebuilds supported files in your browser with a free preview first.

Which Canon files can be repaired

Canon has used several video formats over the years, and the repair approach only applies to the MP4 and MOV containers with H.264 or HEVC inside:

ALL-I (intra-frame) recordings are especially robust: every frame is a keyframe, so even damaged data affects only individual frames.

Why Canon recordings lose their index

Canon cameras write frames to the card as they are encoded and finalise the file when recording stops. The finalisation step writes the moov atom, which lists every frame's size, timing and position. A battery that empties mid-take, a card that fills, a card that is too slow for the selected bit rate (the camera then stops with a "buffer" or card warning), overheating on long 4K or 8K takes, or a firmware lock-up all prevent that step. The frames are on the card; the table of contents is not.

First: protect the card

Do not record anything else on that card and do not format it. Some Canon bodies offer to "recover" or rebuild the image database at power-on; if your camera shows such a prompt, let it complete. Copy the whole DCIM folder to a computer with a card reader rather than over USB from the camera.

Record the right reference

On the same camera body, record five to ten seconds with identical settings. The settings that matter are in the movie recording size menu and the shooting mode:

• Resolution and frame rate, for example 4K UHD 25p or FHD 59.94p.
• Compression: IPB, IPB Light or ALL-I.
• Codec and bit depth: H.264 8-bit versus H.265 10-bit (enabled by C-Log or HDR PQ).
• Canon Log or HDR PQ on or off.
• Crop mode (for example 4K crop versus full-width), which changes the encoded size on some bodies.
• High frame rate or time-lapse movie modes if used.

If you no longer remember the settings, inspect an intact clip from the same shoot in VLC under Tools, Codec Information, or with MediaInfo, and match the resolution, frame rate, codec and profile. More advice: how to choose a reference file.

Rebuild the index

1. Open the repair tool on a computer.
2. Drop the broken MP4 or MOV and the reference clip.
3. Watch the free preview and check colours and motion.
4. Export the full file with a subscription.

A preview with heavy blocking means the reference does not match: the usual culprit is IPB versus ALL-I or 8-bit versus 10-bit. A preview with flat, grey colours is expected for Canon Log footage and needs a LUT in your editor.

Audio

Canon MP4 recordings normally carry AAC audio, which is rebuilt along with the video. MOV recordings from many DSLRs and some higher-end modes use uncompressed linear PCM audio, which this tool does not rebuild. The scan then has to step over the PCM chunks between video frames; you may get the video without camera audio, or, for some layouts, a partial result. Check the free preview before exporting. If you recorded separate audio on an external recorder, sync it in your editor.

Dual card slots

On bodies with two slots (R5, R6, 5D IV and others), check whether you recorded to both cards simultaneously. If so, the second card may contain a clip that was finalised normally, or one that failed at a slightly different moment.

What to expect

You usually get back everything up to the last second before the failure. Metadata such as lens information and timecode that only lived in the lost index may not be restored. If the clip ends earlier than you expect, the card itself may have stopped accepting data; check the card for errors and see our guide on recovering video from a corrupted SD card.

Common mistakes

• Recording the reference with a different compression option; IPB and ALL-I clips are structured very differently.
• Leaving Canon Log or HDR PQ off for the reference when the broken clip used it, which changes 10-bit HEVC into 8-bit H.264 on some bodies.
• Copying the file with the camera connected over USB while it was still busy; use a card reader.

Prevention

• Use cards that meet the required speed class for your mode (V60 or V90, or CFexpress for high bit-rate 8K and ALL-I).
• Format cards in the camera before each shoot.
• Carry spare batteries; LP-E6 batteries drop quickly in the cold.
• Watch the overheating indicator on long 4K/8K takes.
• Keep firmware up to date.

Related guides

• Fix Sony video and fix Nikon video
• Repair a MOV file
• All device guides

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