The Difference Between Bitrate, Resolution, and Frame Rate (and Why It Matters When Streaming Video)
When you run videos on reputable streaming services like Netflix or HBO Max, you don’t have to think much about it; you just press the play button and enjoy. However, if you (ahem) pirate this video, you may notice that you have tons of video options to choose from: bitrate, resolution, and framerate. What are these options and how do they differ? (Not that you ever need to know, I’m sure.)
Perhaps you already have some idea; when you adjust these settings, the quality of your video stream changes. If you lower the quality, the stream may also work better, especially if you have a slower internet connection. But knowing the difference between frame rate, bit rate, and resolution (especially the last two) can help you fine-tune the quality of your stream to best match your internet connection and your TV or screen.
Frame frequency
Let’s start with a simple one: frame rate. All video is a collection of individual images or frames. Frame rate refers to the speed at which these frames are arranged to create video, usually per second (fps). Standard frame rates include 24 frames per second (movies and some TV programs), 30 frames per second (mainstream TV), and 60 frames per second (Internet content).
Your best bet is to try and match the frame rate of the original file when streaming content online. In many cases, the video player will show you this, or even give you no option to change it. The main exception is 60 frames per second – this high frame rate is usually used for online content and not for traditional movies and TV shows. When someone uploads a 60fps video file to a streaming service, you often have the choice of streaming it at its original framerate or dropping it down to a more manageable 30fps.
If your internet speed can handle it, streaming is always better. However, if you’re having chugging issues, you can lower the frame rate. As you reduce the number of frames in the stream, this can reduce latency and buffering. However, this will also result in image shaking. Instead, you can start with the following two options.
Bitrate
Video bitrate refers to the amount of data that the video contains. Generally, the higher the bitrate, the higher the quality of the video as it contains more video information to work with. When streaming video, bitrate is usually measured in megabits per second (or Mbps). The higher the number, the more megabits per second the video will play.
In an ideal world, you’d like to watch videos at as high a bitrate as possible so you don’t lose quality (which is partly why enthusiasts love physical media like Blu-ray). However, the higher the bitrate, the larger the video size. Video is already a large file format and it takes a lot of power to stream these large files. Even if you have an internet speed capable of transferring lossless video files, it’s horribly inefficient. Often there are completely static video fragments, such as a long shot of a still background, where it just doesn’t make sense to send each frame of that video one by one.
This is where reducing the video bitrate comes into play. This is also known as compression and its job is to reduce the overall size of the video by removing video information to save space. Yes, this can result in a reduction in video quality, but not always in the perceived quality of the video. Let’s look at this example of a static background – if a character is moving in the foreground, compression will save and send that part of the image. However, since the background doesn’t change, it just sends one frame until the image changes again. It’s sneaky, but you never notice.
Of course, sometimes reducing the bitrate too much can noticeably affect the quality. The more you reduce the bitrate, the less detail you will see in the image. However, if your stream is lagging, lowering the bitrate might be one way to find it; try testing a few different bitrate options to see if you can live with the lower quality, especially if it contributes to overall stream stability.
However, before you do so, you may want to consider the following.
Video resolution
Video resolution is often confused with bitrate; but while they both affect how the video looks, they are not responsible for the same thing. Resolution is a measure of how many pixels a video contains. You may be familiar with resolutions such as 1080p and 4K; 1080p video is 1920 pixels wide and 1080 pixels high, while 4K video is 3840 pixels wide and 2160 pixels high.
4K video may look sharper because it contains more pixels than 1080p or other video resolutions such as 720p and 480p. When you reduce the resolution of a video stream, you are reducing the number of pixels that the stream sends to your display.
This reduction in the number of pixels can be an effective way to improve the performance of a stream when your internet connection cannot handle it, and may be preferable to lowering the data rate. After all, if you’re trying to stream 4K on a 1080p or 720p TV, you won’t be able to take advantage of those extra pixels properly.
Even if you have a 4K TV, lowering your frame rate may be the best first step. You’ll probably prefer high bitrate 1080p video over low bitrate 4K video; the former may not match your TV’s pixels, but it will contain more video information than a low-bitrate 4K file, which may seem more detailed on your part.