Bitrate Configuration is a useful tool for managing the file size and export quality of your Highlight Reel. This gives you more control over compression and allows you to maintain space on your GNARBOX and devices. In addition, you may have received errors in previous app versions if you tried to export too large of a Highlight Reel. Bitrate Configuration is here to the rescue to help negate this issue and support your compression needs!
Whether you're creating a large Highlight Reel or trying to compress your video for a social platform, this feature can make it possible to export to your phone and upload successfully.
How to Control Bitrate on the GNARBOX
To control the bitrate settings on your GNARBOX, tap the Settings button and scroll down and select "Video Bit Rate":
Next, select the bitrate you'd like to export your Highlight Reel and trimmed clips at:
GNARBOX will then export your next Highlight Reel or trimmed clip at the selected bitrate!
It's import to remember to select your bitrate before you export your video from the Highlight Reel.
What is bitrate & how does it affect my video file?
In this use, bitrate refers to the amount of information that is processed during playback over a specific period of time. Bitrate is most commonly measured in Megabits Per Second (Mbps) or Kilobits Per Second (Kbps) when referring to video and audio compression. 8 bits of data is equal to 1 byte of information. Generally speaking, bitrate can best be understood in this sense:
Higher Bitrate = Higher Quality Video + Larger File Size
Bitrate directly affects your file in 2 key ways: file size and quality. We've all witnessed a poor broadcast or watched a low quality YouTube video. The reason this occurs is due to poor bitrate compression. There are several different variables that can also affect what bitrate you should use. This includes resolution, frame rate, codec and even movement in your video. We'll talk more in a second how each of those affects the quality of your video.
Here's a visual side-by-side comparison of a screenshot taken from the same video exported in 3 vastly different bitrates:
Notice how the low bitrate appears to be blocky while the high bitrate produces a sharper image. In this example, you can especially see this in the sky.
On the GNARBOX, we've provided you with four different bitrate options to help you with your compression needs. They are:
GNARBOX uses a Constant Bitrate (CBR) versus a Variable Bitrate (VBR), which means you choose one bitrate option that affects the entire video on export. To date, the default has been 65Mbps but after Release 1.4.0 it is 45Mbps.
Bitrate versus Resolution
Resolution is definitely one of the determining factors in choosing which bitrate you use to export your video. A high resolution video exported at 10Mbps will show more compression than a lower resolution video exported at 10Mbps. There is more information stored in the high resolution video and therefore, more data that is being compressed on export.
In the diagram above, you can see how the information in a 4K video is much greater than a 720p video and thus making the compression quality of the 4K video much lower than the 720p video.
Bitrate versus Frame Rate & Codec
Similar to resolution, frame rate and codec have a direct correlation to bitrate and file size. More frames per second results in a greater amount of information in a video file. The more information your file contains, the higher the bitrate you will need to use when exporting.
Codec has the same affect: a better or newer codec will result in a greater amount of information, thus requiring a higher bitrate on export for better quality video.
Bitrate & Movement
If you've ever watched a sporting event or a concert, you may have noticed that a large amount of fast moment can cause a video to appear blocky. This can be a result of low bitrate.
If your video contains a large amount of movement, we definitely recommend opting for a higher bitrate to reduce poor compression.
For a great visual representation of this, check out this YouTube video.
Calculating File Size
In some instances, you may be utilizing bitrate to simply lower your file size. The basic formula to figure out what your exported file size will be is:
Using Bitrate with GNARBOX
GNARBOX is currently formatted as a FAT32 drive, which limits exports to 4GB or less. Lowering your bitrate will enable you to export a longer Highlight Reel. The chart below will show you the maximum Highlight Reel length you can export at each bitrate setting. So although you can export an 8min video at 65mbps, you can also export a 44min video at 10mbps. The important thing to note here is that there will be a significant quality difference between 65mbps and 10mbps.
Which Bitrate Should You Choose?
Based on resolution and Highlight Reel length, here are our GNARBOX recommended minimum bitrate suggestions for export to get acceptable video and minimal compression:
Minimum Recommended Bitrate
If your video is long, you many need to go below these suggestions or export your file at a lower resolution in order to keep your file below the 4GB limit.
Example User Test
As an example, here's a test we ran to show the impact bitrate can have on your file size. Here you can see the final export size of a 2min 4k Highlight Reel exported to 4K:
Social Media Bitrate Suggestions
YouTube and Instagram stories are pretty popular places that GNARBOX users love to upload there content. As you may have noticed from past trials and errors, these two social platforms often compress your video automatically during your upload. Based on our research and testing, here are suggested bitrates on GNARBOX for each platform:
Instagram automatically does quite a bit of down-compression to a story on upload. Based on our tests, 30Mbps exports at any resolution seem to perform at the highest quality for Instagram Stories.
As always, we're here to help solve your GNARBOX related issues, so if you're unable to find the answer you're looking for on help.gnarbox.com, feel free to shoot us a message using the chat window found in the bottom right corner of the page!
Marlena is the Customer Support Manager at GNARBOX. Talk to her about Canon cameras, travel and adventure photography! You can see her personal work at instagram.com/marlenapearlphoto and marlenapearlphotography.com