The line of compression schemes is stretching out. Soon, we could potentially have MPEG-2 through to HEVC in use in a single program chain. All this complicates workflows and calls for careful planning to avoid unnecessary transcoding.
Do we need all these compression standards? Well, yes. As resolution increases, the demand for more efficient compression will increase in step. MPEG-2 started out for SD but has been stretched for HD.
MPEG-4 was going to be the answer to everything, from small phones up to movie screens. That has only worked by adding a new Part for a new compression scheme. Video started out as Part 2 — Visual Objects. That didn’t prove much more efficient than MPEG-2, so AVC was born — MPEG-4 Part 10. However, the demands for mobile video and the advent of 4K have led to the need for an even more efficient codec than AVC, and that has come to fruition as HEVC, or H.265.
Where does that leave camera makers? One benchmark is record time. In the days of tape, shooters came to expect three or four hours of record time; that’s probably one day’s work. Wind forward a few years, and writing camera files to memory cards gives a record time somewhere between 30 minutes and two hours; it all depends on how much compression you use. Some cameras have multiple card slots to give longer record times.
That’s going to mean a handful of cards to manage and offload to backed-up disk storage each day. I can hear the film guys thinking, “A luxury — we had 10-minute reels. We had to stop, change reels and check the gate before you were off again.”
After a period of limited record times, solid-state memory cards, with 128GB and larger capacities, have eased those restrictions.