ProRes

ProRes is Apple's line of intra-frame (I-frame only) codecs designed as edit-friendly intermediates rather than delivery formats. Each frame is compressed on its own, so scrubbing and trimming are fast and the picture stays high quality through many edits. It comes in tiers: Proxy and LT for lightweight offline work, standard 422 and 422 HQ for mastering, and 4444 with alpha for graphics and VFX. Bitrates are high, so files are large compared with H.264, but the trade is responsive editing and minimal generation loss. Editors transcode camera footage to ProRes for smooth playback on modest hardware, deliver masters in 422 HQ, and use 4444 when they need an alpha channel or maximum color fidelity. It is a de facto standard across post houses, especially on Mac-based pipelines.