What exactly is a video codec and how does it impact local film playback?

12 Eki 14:45

I've been digging into why my locally stored movies sometimes stutter or look blocky, and I keep seeing the term 'codec' everywhere. Can someone break down what a video codec actually does, how it compresses and decompresses footage, and why the choice of codec matters for playback on a phone? Also, are there any general tips for picking a codec that balances quality and performance? 🤔