By Justin Moon
So, you’ve cut together a video in Adobe Premiere Pro and you are ready to export it for your intended use. You select one of the presets from the dropdown menu and export, and your 20-minute video is 2 gigabytes in size! This article will explain what is happening in the export process and how to balance file size with quality.
First, here is a shortcut to access the media encoder. Control-M (command-M for mac) will open the Media Encoder window from within Premiere – so long as you have the sequence window active. Now that you have this window open, let's run through some important options.
Format
There are multiple options for different types of uses. For the most part, H.264 is the type you will be using. Without going into too much detail, H.264 will output an mp4 filetype, and this is what you should use for any web-based video.
Presets
Presets can be great guidelines. However, they are generally intended to produce something in the correct file type for an intended use. "Match Source, High Bitrate" is an enticing option. After all, it doesn't change anything and seems to promise high quality. Or even "High Quality 1080p HD" sounds like what an editor is probably seeking for the video they have created. This menu is where novice media creators lean on suggestions from Adobe to select the encoding type for them, and generally end up with an unnecessarily large file.
Uses
Let's briefly touch on uses for media outputs. For the most part, if you are reading this article, it is unlikely that you will have the need to produce and deliver a full resolution, high-bitrate output to deliver to a production house for final color correction and mastering that will ultimately be re-encoded for intended audiences. That is the purpose of high-bitrate encodes. To leave headroom for other processes and compression that would take place in that workflow. Generally we are creating media for our courses and websites. This media is best suited with an encoding profile that balances high quality with low file size. This would be the final encode in a production house anyway - encoding for your audience. So let's work on that.
Balancing Quality and Size
Take a look at this export setting. I have a 3:16 video of some slides with a voice over. I have selected "High Quality 1080p HD" as the preset. If you notice in the bottom left of the window, the estimated file size of this video is 476 MB. Let's see what we can do about that.
First notice there are several tabs within the encoder itself. Effects, Video, Audio, Multiplexer, Captions, and Publish.
We will mostly work with the Video and Audio tabs here.
I have the Video tab selected here, let's take a look at some of the options.
Scrolling down, we come to the bitrate settings section. We have VBR, 1 Pass and the target bitrate is set to 20. VBR stands for variable bit rate, and we have a target set to 20Mbps. A variable bitrate is going to apply varying amounts of, let's call it power, to the encode, and the target is how much of that power is applied. So, think of it like a hose and we are watering a small plant. In this case, 20 would be like turning your hose to near full power, and selecting the "jet" setting on your sprayer. Will the plant get wet? Yes. Its survival of the encounter is another question however.
By lowering the target bitrate to 5Mbps, we can immediately observe a drop in file size from 476MB to 124MB.
We can also make some adjustments to the audio tab to decrease the overall size without adversely impacting quality.
Above are the default settings. AAC is the standard codec for streaming video, and the companion to H.264 video. This should be left as is. The sample rate can alternate between 48000 and 44100 Hz. In most cases it is best to leave this as-is as well. Now, Stereo indicates 2 channels, left and right. Are there elements of music, or other spatially important aspects to the audio that would require independent left and right channels? In my case, it is a voice over. Also, depending on the way your audio is recorded, a mono track may only play through the left speaker in the final product. So in this case, I'm going to change to mono, which will reduce the file size further.
Like video, audio is also encoded using a bitrate which can be reduced. The default setting for mono audio in this preset is 160. We will drop it to 96.
Checking in on the impact these changes have had, we see that our output is now estimated to be 119MB. This is a much more manageable file size, and is more appropriate for the intended audience. Benefits also include a faster upload/download time for sharing or posting to the LMS, and less bandwidth required to stream it. All of these changes, while encoding and compressing at a lower rate, do not adversely impact quality to a discernible level for this particular audience.
Lastly, you can save this (or any of your own creations) as a preset of your own! Just click the icon with an arrow pointing downward to a hard drive, name, and save your preset for easy access next time. It will appear in the dropdown window with the others.
Explore different combinations of bitrate and audio settings to achieve the best quality/file size balance for your projects. If you have any questions about editing in Premiere or other advanced topics, email This email address is being protected from spambots. You need JavaScript enabled to view it..
