Understanding Digital Video
We understand that it can get very confusing just trying to understand all of the words and codes used by companies to try and sell us their latest gadgets. You are likely to have come across terms like 720P, 1080HD or 4k – but may not know what any of the numbers or letter stand for. This part of the guide should help you navigate through the jargon and make the process easier.
With this in mind, please read the guidance below in full to help you have the best chance of submitting a video that we can accept for submission and allow you complete your RSL exam successfully.
RSL AWARDS VIDEO EXAMS-HOW TO GUIDE
What frame size should I set my equipment to use?
As a very rough rule, the larger the number stated, the more detail is captured within each video frame you record – but there is a downside. More detail often means bigger digital files – which require more storage and take longer to upload to the internet.
4k video can, and often does, look fantastic – but the file sizes are big and can cause some compatibility issues too. At the other end of the spectrum, if the frame size is too small, the images can look blurry or pixelated when you try and view them on computer monitors or tablets, so it is best to go for a happy medium – striking a balance between detail and file size.
Full HD (often referred to by the names 1080i or 1080P) is a very good happy medium. However, 720HD video can still look very good (720i or 720P) and will produce noticeable smaller file sizes. As a result, RSL is asking for a minimum of 720HD videos and currently setting a maximum of 1080HD, to ensure your picture quality is good whilst keeping the file sizes manageable. Please note that the current file size limit is 2GB.
What does the ‘i’ and/or ‘P’ after the numbers mean?
The ‘i’ stands for ‘interlaced’, meaning that the video file captured refreshes every other line of pixels every frame, so the video file actually contains half the amount of data. It refreshes very quickly, so you can’t see the interlacing in a perfectly set up system. However, most mobile phones and cameras now only give you the option to record in a progressive format – meaning every line is captured. It’s probably best to avoid interlaced formats if you can. If your settings don’t mention it and your equipment is relatively modern, it’s more than likely to be a progressive video format.
But what do those numbers actually mean?
Look at the chart below to see how each frame size relates to each other. This should also explain why 4K is so detailed, but why the file sizes are so big:
What frame rate should I use?
This figure refers to how many frames your camera captures every second. A camera that captures 30 frames per second (30fps) is essentially capturing 30 images which, when played at the correct speed, gives a good impression of natural movement.
Frame rate has an impact on the perceived quality of video to an extent – a very low frame rate will result in jerky video. However you don’t need a huge amount of frames per second before things start to look pretty smooth. Feature films, for instance, typically use 24 frames per second. This is important, because mobile phone and camera manufactures are currently increasing the frame rates that their devices can capture, largely so extreme slow motion video can be produced. Whilst this is impressive, Rock School don’t need this – and the more frames your video contains, the bigger the file sizes get again.
So, its for this reason RSL is asking you to set your frame rate to somewhere between 24 fps (frames per second) and 30fps. Typically this will be a choice between 25fps and 30fps, depending on the hardware. This will generate video that is smooth but should keep your video file size manageable.
What video format should I use?
Mobile phones and consumer cameras largely gather video and process them and store them in a file, which makes it easier to share using the internet. The results vary, but a well designed video format can do an excellent job of retaining a good sound and image while squeezing it into a small package. The most common formats are .MP4 files which are a good choice, as they are both quite small and open across lots of devices, but .mov files and .avi files are also pretty well supported. If you are at all confused or concerned, it may be worth contacting RSL to check that your submitted video files will open.