David Kong of David Kong.net does a super job of explaining video compression.
Here’s an outline of what he covers in this tutorial:
- What a codec is – And how it differs from a container.
- Different types of codecs – And why I frequently use 4 different codecs on a single project.
- Bit Depth – What it means and why it matters.
- Chroma Subsampling – 4:4:4, 4:2:2, and 4:2:0, and when it becomes an issue.
- Spatial Compression and Blocking – One of the most common artefacts you see with normal work.
- Temporal Compression – Long-GOP codecs, inter-frame compression, and ALL-I codecs.
- Lossless vs. Lossy compression – How image compression differs from data compression.
- Bit Rate – How to calculate bit rates and the differences between kbps/kBps/Mbps/MBps.
- Raw – Briefly, the difference between Raw, compressed, and uncompressed (this could have been a 40-minute tutorial on its own!)