A frame rate or frame frequency, which is measured in frames per second (FPS), represents the number of individual frames presented to video viewers within a certain time. That rate is an important measurement in video production, requiring an understanding of how the human eye and brain perceive moving images. The frame rate at which you can distinguish individual stills projected as part of a series is lower than 12 FPS. Faster rates, such as 20 or higher, would cause images to appear as if they were moving.
Depending on the industry, standard frame rates vary. For example, cinema experts usually apply the following:
- The standard 24 FPS for traditional films.
- A refresh rate of 30 Hz., which depicts the number of times a monitor display is refreshed, for digital video.
- Interlaced scanning, a technology that raises the frame rate without increasing the data rate while maintaining the resolution.
This post, part of a series on video formats, addresses the following topics:
- How Frame Rate Relates to Resolution
- How You Should Choose the Best Frame Rate
- How Frame Rates Affect Video File Size
- How Automation With Cloudinary Fosters Video Management
How Frame Rate Relates to Resolution
Resolution depicts an image size in pixels. This scenario, for example—
- HD: 1920 x 1080 or 4K: 3840 x 2160 pixels, which can achieve a 16-megapixel (MP) resolution in total
- A 30 FPS refresh rate on the display
—means that you must update 16 million pixels in each of the 30 frames every second, and that it would take 0.033 second or 33.3 milliseconds to render a frame. The rendering time must never exceed the frame rate.
The resolution multiplied by the frame rate sets the system-required data rate. For example, an HDMI v1.3 supports delivery of 1,080p at 120 FPS, but a 4K resolution supports only up to 30 FPS.
Resolution and Frame Rate in the Gaming Industry
In video games, scene complexity might overwhelm the rendering task and impact the resolution because you must lower the resolution or frame rate to properly render the image. The rendering of the image is made easier by dropping the resolution from 16 MP to 4 MP, 2 MP, or half of the maximum resolution, thereby reducing the quality.
Since 30 FPS is most commonly available in displays (30 Hz.), many developers prioritize resolution over frame rate. They consider anything above 30 to be high end, which typically prevails in niche markets of gamers and graphics aficionados.
On the other hand, even though, under typical viewing conditions, you might notice the difference in resolution between 720p and 1080p, you definitely cannot see the difference in higher resolutions like 4K and 8K.
How You Should Choose the Best Frame Rate
The appropriate frame rate is determined by several factors, such as the video type and the delivery context.
The frame rate of a video defines how realistic the video can be, significantly affecting the video’s style. Since humans perceive motion as being slightly blurry, the frame rate must mimic that blurriness for a touch of realism.
If the frame rate is too high, the “soap-opera effect” might apply to your video, displaying too many details and making the scenes seem unnatural. Conversely, if the frame rate is too low, the scenes might look choppy, leading to a rotten viewing experience.
Motion-filled videos might benefit from a high frame rate. However, due to legacy electricity and television standards, 30 FPS is the standard for TV viewing.
Before choosing a frame rate, consider the means of delivery for the video and the viewing device. Remember, not all broadcast TV and viewing devices support certain frame rates; do your research before pinning down the rate.
You can deliver video online with various frame rates. No specific standard—like the 24 FPS for cinema—applies. Instead, guidelines vary according to the platform. YouTube, for example, accepts all frame rates but recommends encoding and uploading at exactly the same rate at which you captured the video.
Even though motion-heavy videos can benefit from a high frame rate, that does not mean that you must capture motions at that rate. Instead, capture them at a higher frame rate for more details and for greater flexibility in editing. An example is sports games, which are usually recorded at a high frame rate to enable a display of crisp and clear recaps in slow motion.
How Frame Rates Affect Video File Size
According to a study by Larry Jordan on 8K videos with the Apple ProRes codec, higher frame rates require more storage, bandwidth, and consumption—regardless of frame size. For example, for a video set to 24 FPS with storage at 100%, the table below shows how a higher frame rate increases the video’s file size, necessitating more storage capacity and bandwidth:
|Frames Per Second (FPS)||File-Size Increase Compared to 24 FPS|
As shown above, 60 FPS requires 2.5 times the capacity and bandwidth of 24 FPS.
How Automation With Cloudinary Fosters Video Management
Cloudinary is great for optimizing and delivering video and adapting it to accommodate the user device and network speed. You can set up the appropriate parameters in several ways without having to learn the nitty-gritties of frame rates and the related lingo.
Let’s have a look at some of Cloudinary’s remarkable video-management capabilities.
Automatic Format Selection and Transcoding
By setting the
f_auto parameter in video URLs, you direct Cloudinary to automatically select the best format for the user device with optimal bandwidth and speed. For example, Chrome users would receive an AV1-encoded WebM file; Safari users, an HEVC-encoded MP4 file.
If those formats do not work on the user device, Cloudinary delivers the video as an H.264-encoded MP4 file, which enjoys universal support.
Cloudinary identifies the best, must-show sections of videos by analyzing those videos with advanced AI and machine-learning techniques, churning out intelligently downsized footage in any aspect ratio.
To take advantage of that capability, set
crop mode to
auto. The cropped video then follows its most interesting content throughout the play session, retaining all the features you desired during the filming process and filling the screen—no matter the aspect ratio.
Cloudinary is a breeze to work with for nontechnical folks, too. Its rich, verbose Media Library uploads and manages videos from the UI, as well as offers numerous intuitive, versatile, and rich features. Do check them out.