I'm capturing some old 8 mm tape videos using dvgrab on Linux, saving them to disk as raw video files. I'm playing the tapes with a Sony digital 8 mm camcorder, using a Firewire/PCIe interface. Some of the tapes were recorded on the same camera in Digital8 format, and others were recorded on an analog Sony camcorder (which I no longer have). Most of the latter are in Hi8, but a couple are in Video8 format.

The Digital8 videos play as expected after capture. The Video8 and Hi8 tapes play fine on the camcorder, but when I play the captured .dv file, there is no video or audio. I play them using VLC Player, the video program that comes with Linux, and a Plex Server running on a Synology DS218 NAS. In all those players, there is no video or audio.

Apparently a codec problem, but I don't know what to do about it. When I look at the codec info in VLC, it's the same for the files that play properly and the ones that don't. It says "Codec: DV Video (dv ). I attached a screenshot of the codec info. I tried running the dv files through all the conversion profiles available in VLC, and that didn't help. What must I do differently to capture the video from these analog tapes?