Why convert video files?
Video files, especially those recorded in high definition, can be very large. This can cause issues for sharing and uploading, as there may be limits on the file sizes you can store. Depending on what the purpose of the video is, it may not be necessary to work with such large files.
How can video file size be reduced?
If HD cinema quality is not your main priority, you can vastly reduce the file size by one or more of the following:
- converting to a video file format that uses good compression (e.g. MP4)
- reducing the output resolution (i.e. making it a smaller frame dimension)
- reducing the frame rate (number of frames shown per second) – a last resort unless your video is fairly static, e.g. a simple narrated PowerPoint slideshow.
Read on to learn how to do all this with Handbrake software.
Set up Handbrake software to convert video
HandBrake is an open source application that can be used to reduce video size. Firstly, download and install HandBrake on your PC – (on a University PC you can do this via AppsAnywhere). Contact IT Service Desk if you need any help installing HandBrake.
Launch Handbrake. The Source Selection screen comes up (if not, click Open Source), and looks like this (click image to enlarge):
As it suggests, you can either drag and drop the video file from your PC (known as the “source file”) onto the specified area, or you can use the options on the left side to navigate to a file location. You can open one file at a time, or if you have many videos to convert, an entire folder full of video files. This guide will focus on converting a single file.
Handbrake will scan the source file – if very large, this may take a little time.
When the main screen comes up, note the highlighted sections:
- Source: shows information about your original file – filename, resolution, frame rate, audio track, subtitle track.
- Presets: a quick selection of commonly used file conversion configurations. For maximum reduction in file size, click and choose General > Very Fast 480p30.
- Format: shows what file type your converted video will be. Leave this as MP4. Below this, also tick Web Optimized if you will be putting your video online.
- Save As: specify a location and a name for your converted file (click Browse to choose the folder).
Audio boost (optional)
If the volume on your video is very low (e.g. this can sometimes happen with recordings made on the Zoom cameras), you can boost it up at the same time as you convert your video:
5. Click on the Audio tab.
6. Click the chevron to expand the information about the audio track.
7. Gain: insert a number from 0 – 20 (max) to indicate how much you want to boost the audio.
Convert your video!
You are now ready to encode (convert) your video:
8. Click on Start Encode to start the process.
9. A progress bar and information including time remaining will appear at the bottom of the window. The encoding may take a while to complete, and may use your PC’s resources quite intensively.
When the message changes to Queue Finished, your video conversion is complete!
Advanced tips
This guide has explained the very basic procedure to convert a video file. Handbrake has much more functionality that you may wish to explore further, including:
- Presets: do experiment with the different presets – there may be times when you want slightly better video quality, even if it does mean a slightly bigger video file size. Sometimes converting from one format to another (e.g. MOV to MP4) is enough to reduce file size sufficiently without needing to sacrifice any other settings.
- Audio: As well as boosting audio as above, you can even delete the audio track completely if it is not necessary – this will also help reduce file size.
- Queue: if you have more than one file to convert, you can add them to a queue to be processed consecutively. For each file, when you have configured the settings, click Add to Queue. Once you have queued them all up, you can start encoding, go and have a cup of tea, and leave Handbrake to work its way through the files.
- Batch conversion: if you have a number of video files to which you want to apply the same settings, you can add them to the queue to be processed automatically. You’ll first need to edit Tools> Preferences > Output Files to enable automatic file naming and a default location to save the output files to.
- Top and tail: use the Range > Seconds settings to specify a start and end time for the converted video. You’ll need to make a note of the timestamps on your original video to work this out, but this can be a quick way to chop off the unwanted bits at the beginning/end of a video, thus making your video shorter and reducing file size.
