Export to AVI

Overview

mediaCam captures are stored in a proprietary format. This format has been developed to allow the efficient lossless compression of screen based information. The recommended means of viewing redistributed mediaCam captures is to do so using mediaPlay, netu2's freely redistributable application. mediaCam AV also has the ability to convert its captures to the AVI format. These captures can consist of screen, audio, cursor and annotation streams. Data can be exported in uncompressed and compressed form using any compatible codecs.

A note about Codecs

The set of codecs displayed by mediaCam displays in the export wizard reflect those currently installed on the PC. The codecs are produced by third parties and not under the control of netu2. Whilst the export wizard attempts certain validation of the capabilities, presence of a codec in the list does not guarantee that an export can be successfully performed. If an AVI creation failed because of a problem with a particular codec it may be worth adjusting some of the options and retrying.

You may want to download the Windows Media Video 9 VCM from Microsoft it has endless settings plus a very useful help file.
Windows Media Video 9 VCM

Issues effecting Codecs

A video codec maybe enabled or disabled depending on whether it can manipulate an input stream of a particular dimension or output an AVI of a particular dimension. If a codec becomes unavailable it may be because either of these dimensions is not supported by the codec in question. Other options, such as the restriction of the data rate, key framing and the output quality are enabled or disabled on a per codec basis.

Why won't my capture convert ?

The first thing to try is to set the number of colours to True Colour (24 bit), this can be found in the compression page of the AVI export wizard. This may be needed as some codec's won't work correctly with High Colour (16 bit). If this fails to rectify the problem first try ticking the Force resolution to be a factor of 8 x 8 option in the settings page of the wizard, or choose one of the predefined resolutions. Finally try using a modern codec, for example Microsoft Video 9.

AVI File size and quality

Codecs may be used to compress both the audio and video elements of a mediaCam capture. There are two ways of reducing the size of AVI files:

The first is by the omission of video Key Frames. Key frames are frames in the AVI that contain a complete screen at that pointing time as opposed to only the difference between it and the last. They are useful to include in AVI as they make it easier to move forward and backwards through the file. Where file size is an issue or the file is to be streamed the omission of key frames can reduce the size of the output AVI.

The second way in which file size can be reduced is by using compression techniques. The use of lossless compression techniques maintains quality but the scope for reduction in file size is limited. If a compression method is chosen that results in data loss, further reductions in file size can be achieved, but at the cost of a loss of quality in the resulting AVI. The reduction in quality can be configured in the export wizard, if the codec in question supports this feature.

It is important to note that the relation between data loss and quality will depend on the chosen codec. How a codec behaves in these circumstances can depend on what type of data the codec was designed for. For example a codec designed to compress movies may not work as well on screen captures.

Export to Quicktime

mediaCam does not support the QuickTime file format directly. If you wish to export to Quicktime download and purchase QuickTime Pro from www.apple.com/quicktime/download for around $30.

Export to VideoCD

take a look at this site for some useful tips and software for converting your captures to VideoCD format, http://home.cogeco.ca/~avi2vcd.