It seems new AmCrest cameras or new version firmware can support .mp4 video format. Please upgrade your camera's firmware to the latest version. After that, you might be able to change the video format to .MP4, which can be played on any browser or our mobile viewer apps.
If you cannot change the video format, unfortunately, .dav is a proprietary video format. You can use our cloud recording service, but you can only view it with AmCrest's player software.
Another option is to use our image recording service. You can configure the camera to upload image snapshots instead of video clips. You can then use our browser-based viewer or mobile viewer app to view recorded images. It can be played just like video.