Producing Conference Video Pt. 4: Live Delivery and Postproduction

Hungry for Editing Speed

Once the footage is ready for editing, the next factor in editing speed is the computer itself. The combination of CPU speed, RAM, and hard drive speed used to be the most important components but, as we'll soon find out, there is a fourth component that is emerging as an equally, if not more important component for some NLEs and software video encoders.

First, let's have a look at the individual components to get a better understanding of how they work together. The Computer Processing Unit (CPU) is to the brain as the computer is to the human. Just as our brains have many parts that work in harmony, a CPU has different elements that work together to process data. In a modern Intel CPU, these elements are the number of cores, clock speed, front side bus, L2 Cache, Hyper threading, and Turbo boost. To help illustrate the roles let's think of our computer as your local grocery store.

Now think of the CPU as the store's checkouts. The number of cores is akin to the number of checkouts that are open. The higher the number, the faster customers can check out. So a dual-core computer can handle twice as many customers as a single-core, and a quad-core four times as many.

CPUs are rated by their core or clock speed, so think of the core speed as the speed in which each cashier can process items. A slower core speed is like a cashier that has to manually punch in each item and a faster core speed is like a cashier who works at a grocery store with a scanner and every item has a bar code.

The next element is the front-side bus (FSB). Think of it as the conveyor belt at the grocery store that is running at a constant speed. Using a small FSB is like having a narrow belt so it takes longer for the load of groceries to arrive, while working with a higher FSB is like having a wider belt as it can deliver more groceries to the cashier to process. The final benefit of a wider conveyor belt is that the groceries can be arranged and scanned more efficiently.

The L2 cache is like the float (change in the till) with which the cashier makes change. Now imagine that every customer paid in cash with bills only. The larger float allows the cashier to give the most efficient change (a quarter instead of 25 pennies), and means that the cashier doesn't have to break as often to replenish the float.

Hyperthreading is what allows the computer to act like it has twice as many core as it appears to have. In our analogous grocery store, this looks like a cashier that now has two cash registers, two lines, and a trainee to operate the second register. So a modern quad-core computer with hyperthreading will display 8 cores in the task manager.

The final element in new CPUs is Turbo-Boost technology and it is the equivalent of giving the cashiers cans of RedBull so that they can process customers faster for short bursts when things get busy. All of these elements contribute to CPU speed but, without the next two elements in sufficient quantity, a computer would be operating under capacity.

The next element in our computer is RAM, or Random Access Memory. In our grocery store our inventory manager has a boardroom table that represents the RAM in our computer. His department managers gather around this table to discuss inventory-level reports and to place orders to replenish stock. A larger store requires a larger boardroom table with additional managers to keep up with the groceries that the cashiers are checking out. Modern computers paired with 64-bit operating systems can address more RAM than ever before, and having 12-24GB of RAM on an editing system is very common.

Finally, the size of the grocery store is akin to the size of the hard drive and the hard drive speed is how fast the stock boys can replace goods on the shelf at the same time as shoppers are loading their carts. If they run out of food, the whole process slows down. To speed up the process our grocery store features wider aisles, which is akin to joining hard drives in a RAID array.

What's important in our grocery store is that all these components work together to get the groceries from the supplier and into our customers' hands as quickly and efficiently as possible. If one of the systems has a lower capacity than another, it becomes a bottleneck in the process. So the fastest CPU in the world won't run at capacity if it doesn't have enough RAM, just like our grocery store can't checkout customers if the shelves are bare.

From CPU to GPU

Up until recently these three components were the most important considerations for video editing speed. This all changed about a year ago with developments in both NVIDIA CUDA Graphics Processing Units (GPUs)and the ability of Adobe's Premiere Pro CS5 to utilize this capacity. Adobe was the first NLE to offload much of the video editing work from the CPU to the GPU and this difference accounts for a dramatic speed increase over the previous CS4 release.

GPUs are found on video cards and offer parallel processing that is much more efficient for video editing than that of a CPU. The speed improvements are nothing short of dramatic, especially in multi-layer compositions and those with effects. And even if you aren't editing on Adobe Premiere Pro CS5, Sorenson Media is allowing Avid and Final Cut Pro users to take advantage of GPU processing improvements with their Squeeze 7 encoder, which works as a stand-alone or direct plugin on those editing systems.

These speed improvements have helped reduce the traditional postproduction bottlenecks, tape capture, and computer processing time, and video production turnaround time is now more a function of the editing speed of the operator as opposed to computer speed. The result is the growth of the same-day-edit market, where the video producer will edit one or even several videos on the day they were filmed, and play them back to the attendees. The SDE is very common in wedding videographer circles, but as far back as four years ago, EventDV writers Chris and Laura Randall of Edit1Media recounted to me their SDE experiences with corporate clients.

Two years ago, I filmed a conference in Walt Disney World and the Disney Institute led my client's attendees through a team-building activity that involved creating mock commercials during the day, and their editors quickly turned the videos around for playback in the evening. So popular were the videos that the attendees asked that the videos be replayed again that same evening. But what if you're asked to perform your video live, in real time, as the event in happening?