Can I just rename .RSV to .MP4?

Usually it doesn't help. The extension changes, but the map is still missing.

I have no technical background. Can I do this myself?

Most of the time, yes. The program works like any other: open it, pick two files, press a button. Nothing to type. The part that needs attention is the check at the end.

How long does it take?

It depends on the file size: a few minutes for a short file, longer for an hour or more. The program works on its own, you can leave it and come back.

Sony .RSV file won't open? The footage is probably still there

Windows File Explorer in the CLIP folder of a Sony card: two healthy MP4 files, two XML files, and the file C2000.RSV of 153,600 KB marked with an orange frame — What it looks like on the card: the broken file is marked. Full size, just a different extension, and no player opens it.

In short

What happened: the camera managed to save the picture and sound, but not the small “map” that tells a player where each frame sits. Without the map the file won't open, but the footage is inside.
What not to do right now: don't format the card, don't keep shooting on it, and don't run repair tools on the original file.
What to do: copy the file to a computer, take a healthy clip from the same camera, and rebuild the map with a free program. Four steps, below.
Don't want to deal with it? Send me the file. The check is free, and if I couldn't recover it, you get your money back. How to send it.

What to do, step by step

Copy everything to the computer. The .RSV file, and while you're at it a healthy clip from the same card (an MP4 that opens normally). From now on work only on the copies. The card stays aside.
Prepare a “sample clip”. A healthy recording from the same camera at exactly the settings the broken file was shot with: same resolution (4K, say), same frames per second (25, 50 or 100), same recording quality. Simplest: a clip you shot the same day, just before or after the broken one, without changing settings in between. The clip you copied from the card usually fits. If there isn't one, put a card in the camera, lens cap on, and record 30 seconds.
Run a free program called untrunc. It takes the map from the healthy clip and builds a new one for the broken file. Download it here (Windows. A normal program with buttons, nothing to type). On the page that opens, download untrunc_x64.zip, unzip it, and run untrunc-gui.exe (not untrunc.exe, which is the version without the window). Open the program's Settings and tick the option for .RSV files. Pick the sample clip, pick the .RSV file, and run. If the file that comes out won't open, run it once more, that happens. How you know it worked: a new MP4 appears, and it opens in a player.
Check the whole file, not just the start. The length should match what you shot. Scrub to five or six points along the video, especially near the end. At each one stop, play a few seconds, and check the picture moves smoothly and the lips match the speech. If the picture jumps or the sound drifts: the sample clip doesn't match closely enough. Find a closer match and run again. Don't switch programs.

The untrunc-gui window on its Settings tab, the RSV recovery mode option marked with an orange frame — untrunc’s Settings tab: tick RSV recovery mode before you run. Without it the program does not recognise the file.

Why it happened

While recording, the camera writes picture and sound to the card the whole time. One thing it saves for the moment you press stop: a small map that tells a player where each frame starts and ends. If the power went before that, all the footage stayed there without the map, and the camera left the file under a temporary name ending in .RSV instead of .MP4.

That's why renaming it to .MP4 doesn't help: the extension changes, the map is still missing.

The next time you switch the camera on with that card, it may show “Image Database File error. Recover?”. You can accept: it tidies the camera's own records, and by Sony's guide deletes nothing. But it won't repair the recording itself.

When this won't help

If the file reached you by transfer (WeTransfer, Drive, a download) and not straight off the card: first check its size matches the original. A stalled transfer leaves a file that looks fine and is empty inside, and no program repairs that. Ask for the file again.
If you kept shooting on the card after it happened: whatever was overwritten is gone. Whatever wasn't can still be saved.

Short answers

Can I just rename .RSV to .MP4? Usually it doesn't help. The extension changes, but the map is still missing.
I have no technical background. Can I do this myself? Most of the time, yes. The program works like any other: open it, pick two files, press a button. Nothing to type. The part that needs attention is the check at the end.
How long does it take? It depends on the file size: a few minutes for a short file, longer for an hour or more. The program works on its own, you can leave it and come back.

If you're stuck

If the file is big, if the second run also came out jittery, or you just don't have the head for this right now, send me a link to the file and to a healthy clip from the same camera. I first check whether the footage is actually in the file and tell you where you stand. That check is free. If there's something to recover and you want to go ahead, you get a price for the file. You pay, and then the work starts. And if I couldn't recover it, you get your money back, all of it or part of it, depending on the result.

Prefer email? avihaiteram@gmail.com

Who I am

Avihai Teram adjusting a camera on a tripod, a softbox behind him

Avihai Teram, videographer and video editor. I shoot on a Sony FX3 and work with camera files like these every day, so I know how a camera writes them and what breaks when it shuts off mid-recording, and I have brought files like these back from Sony and DJI cameras. Send me a file that won't open: the first check is always free, and if I couldn't recover it, you get your money back. You can also find me on Instagram: @avihai.teram.