Why did the N70 automatically stop shooting in less than 30 seconds?

The storage speed can't keep up with the recorded data. For example, the speed of writing into the card is 1M/s, the recording speed of the data you shot is 2M/s, and your mobile phone has 30M cache. Then, after 30 seconds, the data can't be written into the card, and there is no cache to store, so it can only be stopped by itself.

Mitigation measures: 1. Buy high-speed cards.

2. Reduce the resolution and fps of the image.