ENCODING: Unlocking the Mystery!
Part One
Remember the days, when you brought in your film to the colourist and he put up the reel, transferred the film to Digital Beta and then you cut your project? Upon finish, you on-lined your project on Digital beta, and sent the master to your client along with the bill! In those days, that was the deliverable.
Today, we are finishing in High Definition, then down converting to Standard Definition. Sometimes, the project delivers with a SD center cut version, other times letter boxed SD versions. It can include HD versions, two DVD’s, a Blue Ray DVD, high resolution Quick Times and uploadable web versions.
Today, those are the deliverables. All of a sudden, delivering a project has become considerably more complicated and time consuming. The information that follows might ease the pain just a little.
After editing for twenty years, I’ve seen a lot of different encoding processes and software. To date, nothing works as well as Premiere’s Media Encoder. I’ve used Cleaner, Squeeze, Compressor, Media Composer, and many others. Premiere out performs the others by far.
Still, it can be a long journey to correctly encode a 1920×1080 uncompressed HD file for use on your iPhone or on a website. As discussed in our previous newsletter “HD 101,” we need to consider two things when encoding: The file format and aspect ratio.
FILE FORMAT & ASPECT RATIO
Currently, people are requesting two kinds of file formats: a Quicktime or Media Player format that is of high quality and a smaller, low resolution file that works with their website or media delivery system. Unfortunately, the aspect ratio or image area of the picture file can be many different sizes. For example, the frame width and height can be anything. Often, a website tries to make all of its videos uniform. Our site (which contains HD and SD projects) are all sized down to 720×406. The reason is that we wanted to maintain the 16×9 aspect of the HD work we’ve done and we wanted our SD work to match it. We lose a lot of image when encoding SD (4×3) projects this way. But, watching our work and sending reels via Wiredrive makes the viewing experience much cleaner.
If you don’t have a solid media delivery system and you need one try Wiredrive, by Iowa Interactive. It’s a wonderful product. It allows us to send videos to our clients and send demo reels to our potential clients. You can also upload, change the video presentations and work on our website.
What’s so cool about Premiere Pro CS 5.5, is that Adobe media encoder comes with the editing software and has many presets already set with all the parameters you need.
You first select the format you want to encode to the file. You are probably already working with a file created from an Avid or Final Cut Pro software. It is usually an uncompressed quicktime because that is also a requested deliverable. But, where do you go from here?
Your client must tell you which encoding format they want and oftentimes they don’t really know, because it’s complicated. I always try to get a frame size and codec or compression type.
CODEC OR COMPRESSION TYPE
A codec is a device or computer program capable of encoding and decoding a digital data stream.
Compression of data or source coding is the process of encoding information using fewer bits than the original representation would use while maintaining acceptable image quality!
This is where it begins to get complicated. Here’s a break down: Think of the file format as the container and the codec as the compression type, or you can think of it as making a big image smaller in both image size and data size.
The trick to encoding is finding the right format and compression type that creates the image quality you prefer. However, the file size has to be small enough to upload to the web, your iPhone or to store for future reference. The average size of our files on our site are around 3.5 to 5 megabits or MG. This was our target file size, not image size. Remember, our image size was 720×406. We accomplished this by using a quicktime codec called H264 and mpeg 4 compression.
Premiere Pro CS 5.5 gives you many preset compression types for many uses, such as Apple TV, iPod, Ipad, Vimeo, YouTube, Tivo, etc. You can also create your own presets. At the top of the example, you can see that we have a FP HD to Web preset. Here you can customize your settings to match any scenario.
Part of having a successful encode, is knowing the frame rate of your original video file (24 progressive, interlaced, 30fps, 29.97, etc.) You can make the encoded video into anything you want, but often it looks better to use the same frame rate and image aspect ratio. You don’t want to distort your image. Remember, the goal is to encode a great looking video at the lowest file size possible. You can also set up several presets for a particular client and encode all of them at the same time.
I hope you’ve found this information helpful. I go into greater detail in Part two of Encoding: Unlocking the Mystery.