Video Compression Best Practices and Tools
Doris Sooläte avatar
Written by Doris Sooläte
Updated over a week ago

When filing issues for runs we must record videos. Oftentimes, these videos exceed the 10MB allotted per file on the Testlio platform. To get around this we must decrease the size of the file, while also ensuring that the quality is not dramatically decreased. Here are some tips on how to accomplish that. 

Best practices: 

a) Ensure there is no audio unless you are giving verbal instructions 

b) Make sure the text in the video is still legible 

c) It is often easier to change the settings of the recording software you are using to get the initial recording compared to compressing it later

Example: Decreasing resolution or bitrate in the screen recording settings

d) Keep videos as concise as possible to limit the file size. Don’t record anything that is not necessary for the developer.

a) can be used to convert to mp4 format, strip audio, and decrease the file size.

b) Click on Select Files and navigate to your source video

c) Once the file has been added to the Queue, we need to make sure the target file will be mp4 by selecting mp4 from the Dropdown menu:

d) Next click on the Wrench Symbol to bring up additional Conversion Options

e) From the Conversion Options modal we can remove the audio track by selecting none in the Audio Codec dropdown

f) Furthermore, we can change the video Quality by adjusting the RF factor to a higher value, 28 in this example:

g) The Resolution and Frames per second can also be reduced: 

h) Other Settings can be changed as needed, but this sums up the most useful adjustments.

i) Click on the Start Conversion button and Download video when the conversion is finished

2. The open-source Software Handbrake can be used to compress videos to small file sizes while retaining high quality.

a) Download and Install Handbrake from 

b) When you open the software it will look like this: 

c) You can either open your Source File by clicking “Open Source” and navigating to the file or just drop your source file anywhere on the App

d) Generally, the first step would be to remove (if not necessary) or compress Audio (if necessary for the issue report)

To remove Audio Navigate to the Audio Tab and switch all tracks to “None

To compress the Audio to a fraction of its initial size you can, for example, change the Mixdown to Mono and the Bitrate to 56.

e) Next, we will turn up the compression of the Video. The easiest way to adjust this is by turning up the Rate Factor in the Video Tab. The default value is 22. From my experience, anything below RF 28.5 still yields very good quality. I would advise not to select an RF above 31 as the quality will rapidly decrease with higher values. 

f) Another way to reduce the video size without degrading the quality much is to reduce the frame rate. By default, a recording from your cell phone camera will have 30 frames per second. We can reduce this to 15 frames per second without much of a visible change.

g) Lastly, in the Dimensions tab we can also change the resolution of the video to reduce the file size. Most cellphone camera recordings will be in Full HD, which is 1920 x 1080 pixels. It's often better to reduce the dimensions of videos to 1280 x 720 or 800 x 450 pixels. The change in resolution will have a dramatic effect on the file size, and the loss in quality is often negligible for our purposes. (note: before adjusting the dimension make sure Keep Aspect Ratio is checked and Anamorphic is turned off.

h) After changing some or all of these settings click on the Start button and your video will be transcoded.



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