While "720p" suggests high definition, the "900MB" file size indicates heavy compression. Release groups like Ganool used the x264 codec to shrink 20GB-40GB Blu-ray discs into files small enough to be downloaded quickly on slower internet connections of the late 2000s and early 2010s. The Group (Ganool):
While the "Ganool" release was efficient, it came with trade-offs compared to the original Blu-ray: Compression Artifacts: In dark scenes or fast-moving jungle sequences (of which Apocalypto has many), blockiness or "noise" would be visible. Audio Quality: Apocalypto -2006- BluRay 720p 900MB Ganool