Here at vzaar support, we see a lot of videos! I’ve noticed recently that a lot of videos we’re delivering for customers are much bigger than they need to be which can lead to playback problems and uses up bandwidth faster than needed. Using the wrong encoding settings can actually increase the size of your videos, so let’s take a look at why that can happen and how to avoid it…
Source video vs. target video
When you upload your video to vzaar, the video you are uploading is referred to as the ‘source’ video. In most cases, we’ll re-encode your video for online delivery (because the quality and size of video used in desktop editing and viewing can be too high and too big for viewing over an average internet connection).
Once your video is encoded, that’s the version we deliver to your viewers and we refer to it as the ‘target’ video. In some cases (if you’re using iOS Optimized Streams or Dual Encoding) we’ll create more than one target video – we call those different renditions.
Bitrates and bandwidth
Like any other digital media, video is made up of bits and bytes of data. The bitrate of your video is the number of bits that are conveyed per unit of time. In online and desktop video, you’ll normally see it measured in Kbits per second (Kbps).
Very generally speaking, the higher the bitrate, the better the quality of the video. However, you can’t add quality to a video after the fact. If your video is recorded at, say, 2,000Kbps, you can’t just re-encode it at 4,000Kbps and make it look twice as good – you’ll just end up with a much bigger file which looks the same (or worse) and eats up bandwidth twice as fast!
Playback bandwidth is the data streamed – from us to your viewer – when a video is played. For example, if you have a video that is 10Mb and it is watched from start to finish once you would have used 10Mb of your monthly playback allowance (actually, you’ll have used just a little more than that because we have to deliver a player and the poster frame for your video).
When you upload your source video using our upload page, you’ll see that you have the ability to change the size and bitrate of the video:
The settings under “video dimensions” such as ‘Small’, ‘Medium’, ‘Large’ and ‘High Definition’ are pre-sets for convenience. ‘Original’ will use the original settings of your source and ‘Custom’ let’s you set the width and bit rate for your target video explicitly.
It’s important that you always choose a Kbits value which is the same or smaller than that of your source so that you don’t increase the size of your video during encoding.
If you look under the title of any of your videos on the video manage page, you’ll see “Content storage”. Click on the small, green downward arrow and you’ll see something like this:
In this case, I chose a bitrate – 4000Kbps – which was significantly higher than that of the source. Now the target file is 3 times the size which means we’re using 3 times as much bandwidth as we need to!
And it looks no better.
The source video in that example was encoded at 780Kbps. If I upload the file again and choose 512 for Kbits, you see this:
Now we have a smaller file size which uses less bandwidth, less money AND still gives your viewers a great quality video.
Here’s the two examples so you can compare the difference for yourselves:
512Kbps: smaller size & less bandwidth
4000Kbps: large size & more bandwidth
What if I don’t know my source file bit rate?
If you’re creating and editing the video, you’ll normally set the bitrate of the source video in the final export settings. In Adobe Premiere, it looks like this:
Find out the bitrate of your source video and, when uploading to vzaar, set the Kbits rate to a number which is the same or smaller.
Experiment with different bit rates to find a setting which makes your videos look great during playback and keeps the target video size as low as possible. That way, you’ll provide your viewers with a great viewing experience (and save yourself some money while you do it).