Depends on resolution and JPG codec. A 1080p PNG frame is typically 2 to 5 MB; a 1080p JPG at quality-85 is 200 to 500 KB; a 4K PNG is 6 to 15 MB. At the extreme, every-frame PNG extraction of a 10-minute 1080p MKV produces ~50 GB total. JPG 丢失: 图像转换为 DCT, 量化和加密, 质量控制了丢弃多少 。