Encoding

There are quite a number of formats for storing digital video. The format to use very much depends on the way you want to store or distribute your movies. This article will present a couple of different format, which one to use and how to transform one format to another. For more detailed technical information about video formats please refer to one of our articles in the section Tech Info.

1. Compression

Once you have completed your project on the timeline, you're are ready to create a file containing the final video. Some editing programs allow you to save the file in different formats directly form the timeline. However, you can also choose to first save the file as a DV-AVI and use a separate program to transform it to the format that you want. Because of its size, DV-AVI is not very suitable for archiving or distribution of video, so you want to compress it to smaller size format. For storage on like VideoCD and DVD you even must do it, because they need a certain format. Compressing the video to another format is called encoding. A piece of software to compress or decompress a vide file is called a CODEC (COmpressor/DECompressor). In order to play back a certain format on a PC you need to have the appropriate codec installed on your system. Some codecs are incorporated in the operating system but others you will need to install separately.

2. Common types and which to use

In the table below a number of common video formats is given with their specific use:

DV-AVI

This is the format used in digital camcorders using miniDV or Digital8 tapes. It offers very good quality. Standard DV-AVI takes about 2GB for 9 minute of video and it is therefore not very suitable for permanent storage or distribution of your final movie. However, it is very suitable as a working format for video editing and it is needed to put your final movie back to tape. Of course if you edit in DV-AVI you don't need any conversion; you just save it directly from the timeline.

DivX

This codec is very popular for distribution of video over the Internet. It is not standard incorporated in Windows, but the codec can be downloaded all over the Internet. The original codec DivX;-) was a hacked freeware version of the MPEG-4 codec. Later releases are developed from scratch to give them a more legal status. The quality is quite good. Once you installed the codec you may be able to create DivX movies directly from the timeline. If not, you can use a freeware program like VirtualDUB to convert your movie to DivX or one of the specially designed programs like Dr. DivX.

Other AVI types

There are many other codecs which are used in AVI type files. In your Device Manager window (for Windows XP select System from the Configuration Screen and select the hardware tab, then select Videocodecs from Sound, video and game controllers controllers) you can check which ones are installed on your system. The older codecs like Cinepack, Indeo are slowly becoming less popular and their use is not recommended. Non-standard ones, like MJPEG codecs, should not be used at all for distribution, because others that don't have these codecs installed will not be able to play these files.

Like with the DivX codec, you may be able to export your movie using any of the codecs directly from the timeline. Alternatively, you can use VirtualDUB to create a file with the desired codec.

MPEG-1

This is the first de facto standard developed by the Motion Pictures Expert Group. At its commonly used compression levels it offers VHS level quality and then takes about 10MB per minute. It is standard playable on Windows PC’s and therefore suitable for storage and Internet distribution. This format is also used in VideoCD’s. In order to create MPEG-1 you need a special MPEG-encoder. Some video editing programs include such an encoder, usually as a third party plug-in. This enables you to create an MPEG-1 directly from the timeline.

If your editing program does not include an MPEG-encoder or you are not happy with the quality, you can install a separate encoder. A popular MPEG-encoder is the freeware program TMPGEnc; a commercial stand alone encoder is the Mainconcept MPEG-Encoder. If you create an MPEG-1 for VideoCD you have to make sure to use settings that fall within the VideoCD specification.

A third way to create MPEG-1 is by using CD burning programs that can generate VideoCD's and which have a built in MPEG-1 encoder. The latest versions of Nero for example do have such a built in encoder.

MPEG-2

This is an enhancement of the previous MPEG-standard and offers possibilities to create better quality than MPEG-1. MPEG-2 video is used in a wide variation of compression. It’s main purpose is to store video on SVDC (at higher compression rates) or DVD (at lower compression rates). The codec is patented and not free and MPEG-2 files are therefore not standard playable on PC’s. The codec is incorporated in software DVD players (like PowerDVD and WinDVD).

MPEG-2 encoding is done similar as MPEG-1 encoding but because of the patent you will not find freeware MPEG-2 encoders. You will find built-in encoders in video-editing programs, but also stand alone encoders. The freeware version of TMPGEnc has MPEG-2 encoding as a 30 days free trial.

Another option is to import your video into a DVD authoring program which will encode your movie to MPEG-2 before burning the DVD.

WMV

This is one of the latest format developed by Microsoft as part of its strategy to close the gap between PC's and home video equipment. It is standard playable by Windows Media Player 7 and higher versions. It is both useful for file sharing over the Internet, but the standard also allows high quality video. The encoder to create WMV is free of charge and can be downloaded from Microsoft.