For computer-based video recording in general and with LECTURNITY in special, many parameters have to be taken into consideration. They all have an impact on the quality of the recording. This document suggests reasonable settings for common scenarios.

Scenarios

The replay scenario is the most important parameter for the video settings appropriate for video recording. LECTURNITY documents may be replayed by using two substantially different methods:

• either by using web technologies and streaming media, i.e. with Real Media, Windows Media or Flash,
• or by using the LECTURNITY Player for offline content replay.

The main difference between the two replay possibilities is that in order to replay a document in the LECTURNITY Player, the video does not have to be recoded, but may be recorded in a suitable format directly within LECTURNITY. With the three streaming solutions, the video is recoded into a streaming media format. This means that the video recorded by LECTURNITY is a temporary product and should thus be of the highest quality possible.

Goals

The most common goal of a video recording is to achieve the best quality possible with as little bandwidth (file size) as necessary. This is always a difficult task, and in most cases it is not possible to achieve both at the same time.

It is also common to edit your LECTURNITY recording by using the Edit View prior to publication (with the Publisher). This also has to be taken into account when defining the video parameters for the recording. Editing a document means that the video has to be recompressed, and this may lead to a video quality degradation. As a consequence, the source media quality, in the first place, has to be as good as possible.

As stated above, editing a recording prior to the final publication is desirable in most cases, e.g. in order to cut out mistakes or to split the recording into multiple parts.

In case it is foreseeable that the video is to be edited after the recording, it makes sense to choose a high quality for video recording although this might lead to a high data rate. This data rate is however not decisive for the final product. In the following editing phase the data rate can be influenced in the Edit View as well as in LECTURNITY Record View.

Recording

You should decide before the recording which codec is appropriate for the final document and use this one - if necessary with different settings - for all recordings in your project. Mixing different codecs in different production phases may lead to quality losses. One reason is that different codecs interpret some characteristics of the video (color intensity, image details etc.) differently.

The following settings are reasonable for the recording in LECTURNITY when the recording is to be post-edited:

Please note here that for recording with the codec iv50 (Indeo Video 5) the Quick Compress option of the Indeo Codec should always be activated in order to avoid problems.

The codec settings of the divx codec have to be adjusted in the configuration dialog of the codec. Its appearance may vary from version to version. Here's an example of the 5.0.5 version.

The suggested codec settings produce quite large video files. This is intended as editing can be done with source documents of good quality. When exporting the edited project the video can be adapted to the desired target data rate without a noticeable loss of quality.

Export

For the export from the LECTURNITY Edit View you again have to keep the desired scenario in mind, i. e. whether the document (after the conversion into an LPD format by the LECTURNITY Publisher) is to be replayed by the LECTURNITY Player or whether a Streaming Media document is to be created for the use in the Web. Please continue reading in the respective sections:

• Replay in the LECTURNITY Player
• Replay via Streaming Media

For documents replayed by the LECTURNITY Player you have a free choice of video settings. In this section the settings of two common codecs Indeo Video 5 (iv50) and DivX (divx) are suggested as an example. These codecs allow for videos of different quality and data rates.

*) Requirement when recording with this setting directly; when recoding by the LECTURNITY Edit View this setting is without influence.

*) Requirement when recording with this setting directly; this is not important when recoding with the LECTURNITY Edit View.

The stated data rates are estimated values. They may vary up or down by some 20 % depending on the content of the video.

When converting LECTURNITY documents into a streaming media format, it is important that the source material has a high quality. Audio and video will be compressed using a Windows Media, RealMedia or Flash codec, and the better the quality of the source material, the better the outcome of this compression. For the streaming media export, the same recommendations are valid as for the recording.