untrunc vs DataRecover Pro for a broken MP4/MOV

How untrunc works, and why the reference clip matters

An MP4 or MOV is two things: the media data (the mdat box, holding the compressed video and audio samples) and the index (the moov box, holding the sample table — where each frame starts, how big it is, its timing, and the codec configuration). Most cameras write the mdat as they record and write the moov at the end. Cut the power and you get a file full of perfectly good frames with no index telling a player where any of them are.

untrunc solves this with a clever trick: you give it a healthy clip from the same camera at the same settings, it learns the track layout and codec parameters from that clip's moov, then it walks the broken file's mdat and writes a new moov to match. When the reference is a good match, the result is often a clean, fully seekable file. It's free, open source, and has rescued an enormous amount of footage. If you have the reference clip and you're comfortable at a command line, it's a genuinely great tool.

Where untrunc gets hard

The reference requirement is the catch. You don't always have a healthy clip from the same device — the footage came from a phone you no longer own, a rental camera, a friend's drone, a download. Even when you do, it has to match: change the resolution, frame rate, bitrate mode, or audio settings between the reference and the broken clip and the rebuilt index can be wrong in ways that show up as stutter, drift, or a file that still won't open.

There's also the workflow. untrunc is a compiled command-line program; on a Mac you'll typically build it yourself or use a third-party graphical wrapper someone else maintains. And it assumes you already have the broken file in hand. If the clip was deleted, or the card was formatted, untrunc can't help until something else has found it.

How DataRecover Pro approaches the same file

DataRecover Pro's repair engine works in three tiers. When the index exists but is damaged — bad offsets, a truncated atom — it performs a clean repair and fixes the structure in place. When the index is missing entirely, it does a structural rebuild: it scans the media data itself, and where the video and audio streams carry enough self-describing structure (H.264 and HEVC in MP4/MOV are the common case), it reconstructs the sample table from the stream without needing a reference clip. When neither is fully possible, it falls back to partial salvage and returns the longest playable portion rather than nothing.

The honest limit: some codecs don't mark their own frame boundaries in the stream. A ProRes MOV that lost its moov is the frequent example — there's nothing in the bytes that reliably says where one frame ends and the next begins, so a rebuild needs an external template. In that case DataRecover Pro needs a reference clip too, and untrunc, which was designed around exactly that idea, is the right tool for the job. We'd rather say so than have you buy a license expecting a miracle.

What DataRecover Pro adds around the repair is the rest of the recovery. It finds the clip first — a deleted MOV on an APFS volume comes back through the filesystem parse with its name intact; a clip on a formatted card is carved by signature, anchored on the file's ftyp header. You can preview it before paying, repair it in the same workflow, and the repair runs in a sandboxed worker process on your Mac; nothing is uploaded. The same engine also rebuilds JPEG, PNG, GIF, PDF, and DOCX files, and pulls intact frames out of damaged RAW, HEIC, and TIFF images.

Which one to reach for

You have the broken file and a healthy clip from the same camera at the same settings, and you're fine with a terminal: use untrunc. It's free and built for precisely this.

You don't have a reference clip, the clip was deleted or lost, or the footage is H.264/HEVC from a phone, action camera, drone, or screen recording: run DataRecover Pro's free scan and see what the preview shows.

The file is a ProRes or other intra-frame professional codec with no moov: you'll need a reference clip either way. Try untrunc first. If it doesn't take, DataRecover Pro's partial salvage may still return some of the footage.

Whatever you use, copy the broken file somewhere safe first and work on the copy. A failed rebuild should never cost you the original.

The verdict

untrunc is the better tool when you have a matching reference clip and just need an index rebuilt. DataRecover Pro is the better tool when you don't have one, when the clip still has to be found, or when you'd rather have a preview and a guarantee than a build toolchain. A license is $89 lifetime or $59 a year for 3 Macs, buying needs no account, and if it can't recover your files, you don't pay.