VCU Libraries

Research Guides

Convert Video Formats

This guide will help you understand digital video formats and convert them to suit your needs.

Conversion Glossary


Bitrate
: Bitrate is the amount of data being decoded per second. Depending on your pixel dimension and delivery method,  the bitrate will vary.  One way to reduce file size is to lower the bitrate, but you may actually notice a difference in quality. Here are some recommended bitrates:

Dimension
Delivery
Avg Bit Per Sec
320X240   Web 400 kbps
720X480   DVD 4000-5000 kbps
1920X1080   Blu-ray 50,000 kbps
(50 mbps)
3840×2160   HDTV 85 mbps
7680×4320   HDTV 360 mbps

 

Pixel Dimension (or Video Resolution): In short, this is the width and height of your video, and it can be resized to suit your needs.  Here are some examples:

Format Dimension Aspect Ratio
PDA    320x240 4:3
VGA    640x480 4:3
DVD (NTSC)    720x480 4:3
DVD (PAL)    720x576 4:3
XGA   1024x768 4:3
HD   1280x720 16:9
FULL HD   1920x1080 16:9
4K ULTRA   3840×2160 16:9
8K ULTRA   7680×4320 16:9


Another thing to consider is if you to try to show a widescreen video on a standard display, it could either have the ends cropped off or be squished down to fit the size.  By Letterboxing a 16:9 video, you recreate the 4:3 aspect ratio.  

Image of Aspect Ratios
Here is a handy aspect ratio calculator for determining your resolution, or vice-versa.

Interlace: When video is intended for television, it is interlaced. Each frame is made up of two fields of interlaced lines. On a computer monitor this is seen as a comb effect because one field is 1/60 of a second ahead of the other. If your video program provides the option, interlaced video should be deinterlaced before encoding..

Two-pass: Videos can be encoded in one sweep (single pass), but some tools can also encode videos in two passes. In the first pass, the video is analyzed to see which sections require a higher or a lower bitrate. In the second pass, the actual encoding is done. Two-pass encoding takes longer but creates a video roughly 75% to 95% of the original file size at the same quality.

Converting Video Formats

Media conversion software, or transcoders, come in all shapes and sizes. Many are free, many are cross-platform. Some will only import certain formats, while others may have limited output options. Some will handle batch processing and others offer editing options.  

On this page are video examples of how to convert video file formats and how to rip a DVD using Format Factory, one of the many free transcoders available for Windows.

When converting video from one format to another, it is essential to note the following three settings:

  • Bitrate - Basically, this is how fast data travels between the file and the screen, and also the setting most responsible for quality.
  • Pixel dimension - This is the length and width of the video in pixels.
  • Frame rate - How many frames per second the video will deliver.

Refer to the glossary on the left as a guide for these settings.

Converting Video Formats Using Format Factory

Ripping DVD Clips Using Format Factory