Video Formats

The format of a video needs to be considered when planning to deliver video media targeted at different audiences. Different formats and resolutions exist which are better suited for different delivery choices.

After a video is recorded in digital video, on a DV Camera, it can be uploaded to a computer for editing. During editing using simple applications, such as Windows Movie Maker which is installed with Windows, scenes can be rearranged, shortened or cut and transitions applied between scenes. The audio from the video can be muted and replaced with an alternative audio track or both audio tracks can be audible, for example if adding music. Titles and credits can also be added.

After editing, the video is rendered which creates a new video file containing the full contents of the edited timeline. The render format is very important to suit different end products.

An uncompressed AVI format file has a large file size, but if the resolution is kept the same, the quality is very close to the original. It is good practice to keep a copy of the project as uncompressed AVI at full resolution. Many commercial video editing applications and camera combinations support uploading an edited and rendered video back to tape on the camera. Uncompressed AVI is unlikely to be your distribution format for the wide audience.

Some examples of good commercial applications are:

Ulead Video Studio (Windows – Low cost)

Pinnacle Studio (Windows – Low cost)

Sony Vegas (Windows – Medium cost)

Final Cut (Mac – High Cost)

Mpeg2 is the format used for DVD. When an mpeg2 is rendered, the audio track and video track can be split into two files, this can provision for multiple sound tracks and can be added to the DVD, for example for a multi-lingual DVD or for when an additional sound track that contains a detailed commentary is an optional audio. To produce a DVD like this, it will need to be authored using an application such as Ulead DVD Workshop, which also supports creation or import of multiple subtitles. When producing a DVD the resolution of the film should normally be kept the same as the original, but as mpeg2, the output format of DVD, is a compressed format, the quality will be less than the uncompressed AVI and have a file size which is much smaller.

Ulead DVD Workshop also has features which can be used to create menus. Menus are useful when the author wishes to include a number of short films for distribution on a single DVD.

SVCD, super video CD format is an alternative mpeg2 format choice. CD authoring software is required to produce a SVCD layout CD which is automatically recognised and played by a CD or DVD player. Neros DVD/CD burning software will author a SVCD format CD and can also render a mpeg2 video file from an uncompressed AVI in a single burn option. The standard resolution for a SVCD is less than you would choose for DVD, but the video will be roughly half the file size. Just under 40 minutes will fit on a single CD. 

This format is suitable for distribution to those likely to have lower specification computers and/or with only a CD drive. CDs are also cheaper to reproduce than DVD so there are also cost benefits. For both mpeg2 formats a computer will need to have an mpeg2 codec installed. This are not freely downloadable for Windows Media player, but is installed when a DVD Player software is installed. AVS DVD Player is a free player which will install the required codec to enable Windows Media player to play mpeg2 format video files. You could of course use AVS DVD Player as your default media player, and why not!

The format for VCD, Video CD, is mpeg1, a different format to mpeg2. Windows Media Player will play mpeg1 format video files without the need to install any additional software. The quality and resolution are less than for SVCD and the file size is roughly half again supporting films up to 70 minutes on a single CD. This format is also suitable for slow computers with only a CD drive.

If VHS cassettes are digitized using low end capture devices, such as USB or PCI TV cards, the resolution and quality are unlikely to warrant burning to DVD. Rendering the final output as VCD will not detract from the quality of the video significantly. The advantage of using DVD, for this case, is that multiple videos can be stored on a single media, with a menu or a film longer than 70 minutes can be distributed on a single disc.

When rendering video for the web or YouTube the major consideration is watchability. Videos of higher quality can be streamed, but without very high speed connections, both serving and receiving the video will not stream well. There are recommended template formats for web distribution when rendering from most video editing applications. These mainly reduce resolution and increase compression to lower bandwidth requirements. In addition the number of frames per sec can also be changed, for example from 25fps to 12.5fps. Typically audio quality is also reduced or converted to mono to decrease the overall file size. The render file format that would be best suited to YouTube and these compression settings would be mpeg1, mp4 video or wmv, all common formats supported cross platform and by many media players.