Klues are designed to hold short-form content. With a standard account, the maximum storage capacity is 5 megabytes per Klu and with a business account, the maximum storage capacity increases to 20 megabytes per Klu. You can find out more about the difference between account types here. In this post, we will share tips and tricks to compress your media to the ideal file size.
Terminology
Bitrate
Bitrate refers to the amount of data within each second of a video file, this is measured in megabytes per second (Mbps) and impacts both video quality and file size.
Encoding
Encoding is the process of changing a file’s format from one to another (e.g. .mp4 to .mov) and involves two components: CODECs and Containers. CODECs (short for coder/decoder) are programs which encode and decode data, this is the program that changes the file format (encoding) and opens the file to view or edit in video editing software (decoding). Popular CODECs include H.264, H.265 and ProRes 422. Containers refer to the specific file format of a video file such as .mp4, .avi and .mov.
Frame Rate
Frame rate refers to the number of images presented per second (fps) of video footage. There are two types of frame rates relevant to compression. Recorded frame rate, which is the number of frames recorded by your camera and project frame rate, which is used to edit, export and present your final project.
Resolution
Resolution is the number of pixels across each dimension of a computer screen that can be displayed. It is described as ‘width x height’, such as ‘1920 x 1080’ or ‘1080 x 1080’. Larger resolutions will drastically increase file size because there are more pixels being used to display the video.
Tips for Compressing Videos for Klu
Encoding
Adjusting the bitrate of your render has a tremendous effect on file size. Generally speaking, lower bitrates lead to smaller file sizes and poorer image quality. Therefore, Your choice of CODEC will impact the minimum bitrate required to render a high quality video. For instance, H.264/AVC (Advanced Video Coding) is considered the industry standard CODEC for uploading videos on social media. Therefore, we recommend 3mbps as the minimum bitrate required to render a h.264 video at HD 720p.
H.265/HEVC (High Efficiency Video Coding) is a new CODEC that is designed to be more efficient than h.264. This is achieved through an innovation in how h.265 processes frames. Since H.264 processes frames using Macroblocks, this method segments each frame into uniform blocks of pixels (from 4×4 to 16×16 pixels) to encode and decode videos. Whilst h.265 uses Coding Tree Units (CTUs), which divides the frame into pixel blocks of various sizes (from 4×4 to 64×64). In doing so, CTUs will use large pixel blocks (64×64) to capture backgrounds, whilst using small pixel blocks (4×4) to capture movement and details in the foreground. As a result, h.265 can render the same video file as h.264 at approximately half the bitrate and file size. Therefore, we recommend 1.5mbps as the minimum bitrate required to render a h.265 video at HD 720p.
Display Resolution
Videos don’t need high resolution because Klues are designed to be viewed from mobile devices. This means you can minimise your file’s size by rendering at a smaller display resolution, such as standard definition ‘720 x 480p’. Alternatively, rendering at ‘1280 x 720’ pixels can be used for HD viewing.
Frame Rate
The last strategy to reduce video file size is to reduce the number of frames in your video. Cameras have a recorded frame rate of 50fps within the UK. The frame rate is cut in half to 25fps for broadcast television and for cinema, it’s slightly lower at 24fps. Therefore, lowering your project’s frame rate to 24 or 25fps will save on file size during the render and ensures that your final video meets the required standards for public display.