It depends on the quality.
3:11 sec.
The answer depends on 800 MB of WHAT: low quality audio or high definition video?
That really depends a lot on the video's size and quality. Take a sample of a video in the desired quality, and look how many MB it takes, and for how many minutes it plays. From there, you can extrapolate. (1 GB = 1024 MB)
It depends on the quality of the video.
If its not class six or higher, you can't even record hd video. If not, maybe i'd say 10 minutes max if low definition.
It depends on if the video is compressed or not. A loose guideline for uncompressed video is about a Gigabyte every ten minutes. So, a 5 minutes video should use about 500MB of space. If a video were compressed or reduced in size, it could be much smaller.
The answer depends on what you wish to store? Low or high quality audio, or low or high quality video.
I have a DV520 Camcorder, It will only video for 2 minutes.
A Skype video call download is about 10 MB per minute. This would equate to about 600 MB an hour.
Using the average audio rate (128k per second), 10 minutes takes up a mere 10 megabytes, or a scarce 100th of a gigabyte. Remeber: It is usually 1 minute for 1 megabyte.
You're either asking how many minutes of sound or video can be stored in 244.92 MB. Unfortunately, different audio and video formats have very different storage requirements. Without further information, it's impossible to tell if 244.92 MB would store several hours or several seconds of data.