Lazaclip

A7 V RSV file: recovering a video that didn't finish saving

Updated 7 November 2026

You were recording on the A7 V when the battery ran out, the camera was switched off, or a card was pulled a moment too early. The clip isn't in playback, and on the card there is a file ending in .RSV that no player wants to open. The video is usually still inside that file. This guide shows how to keep it safe and get it back as a normal .MP4.

What the .RSV file is

During recording, the camera writes your video and sound into a working file with the .RSV extension. When recording stops normally, it writes the index (a list of where each frame and each piece of audio is stored) and renames the file to .MP4. A power cut skips that last step. The recorded data is there, but without the index nothing can play it. Background: What is an RSV file?

The A7 V records XAVC S and XAVC HS (and, depending on settings, XAVC S-I) into .MP4 files, so an interrupted video in any of these formats is left as an .RSV.

Protect the card first

  • Don't format the card, whatever the camera or the computer suggests.
  • Don't record anything else on it. Switch to another card for the rest of the shoot.
  • Don't delete the .RSV.
  • Make a copy. Put the card in a card reader and copy the whole PRIVATE folder to your computer. Videos are stored in PRIVATE/M4ROOT/CLIP; photos are in DCIM and aren't affected.

Two card slots: check both

The A7 V has two slots: slot 1 takes a CFexpress Type A or an SD card, slot 2 an SD card. If you record to both cards at the same time, look at the second card before repairing anything: if only one card was removed, the other may already hold a finished .MP4 of the same video. After a dead battery, both cards will normally have an .RSV; copy both.

If you use the second slot for photos or as overflow, the video is on the card that was recording at the moment of the cut.

Try the camera first

Some Sony cameras try to recover an interrupted clip on their own when you put the card back into the same camera with a charged battery. Whether your A7 V does this for your clip we can't say in advance, and it doesn't always work, but it is free. After copying the card, charge the battery, put the card back into the same camera and slot, and switch on. If a message about recovering data appears, wait for it to finish without switching off. Then look in the CLIP folder for a new .MP4.

Turn the .RSV into an MP4 on Windows

If the .RSV is still there, it needs a new index. Lazaclip is our Windows 10/11 program for exactly that (we make it, so this is our own product). It works offline and doesn't upload your video:

  1. Open the card or the folder you copied. The program lists each .RSV and whether it can be rebuilt.
  2. Click Preview 10 s: the first ten seconds of your video open, watermarked, in your video player. Scanning and the preview are free.
  3. With a license, save the full video as an .MP4 on your PC.

The video and audio are not re-encoded. The program keeps the recorded data as it is and only rebuilds the missing index around it. Your original .RSV stays untouched.

Has it been tested with the A7 V?

No, not yet. Our tests so far are on A7S III recordings (XAVC S, XAVC S-I and XAVC HS, rebuilt without a reference clip, with frames and audio identical to the original up to the last unfinished group of frames) and on the original a7S. The A7 V uses the same XAVC S / XAVC HS recording format; the free preview shows whether the program can read your file before you pay.

What you get back

  • The video up to the last second or so before the cut. That final moment was never fully written and can't be rebuilt.
  • The original sound, from the built-in microphone or the mic you used.
  • An .MP4 about the size of the .RSV, so keep enough free space on your PC.
  • Footage in XAVC HS needs an editor or player with H.265 support.

Making it less likely next time

  • 4K recording uses a lot of battery. Start long takes with a full battery and carry a spare.
  • Recording to both slots at once gives you a second copy of every clip.
  • Don't open the card door or switch off until the camera has finished writing.
  • In the cold, keep spare batteries warm in an inside pocket.

Coming from the previous generation? See the A7 IV guide. For the compact body, the A7C II guide.