Stereoscopic Metadata

Introduction

Whenever you open a 3D movie for the first time, Stereoscopic Player needs some information about the file or DVD before starting playback. At least, you have to specify the layout– how left and right view are encoded (e.g. side-by-side, over/under, interlaced, ...). In addition, you can specify aspect ratio, preview image, source and textual information. Optionally, Stereoscopic Player allows you crop the video and adjust parallax. All mentioned values and a few more bits of information are stored in the library for each video you have already played back. Click File->Video Properties in the main window or right-click on a library item and select Properties to view or edit these values. Since we are referring to information about video data but not the video data themselves, the term metadata is used.

Entering metadata in the video properties dialog

When opening a video again, all necessary information is already available in the video library. Stereoscopic Player starts playing without posing any questions. It would certainly be better if no configuration is necessary at all, even the first time. Instead, it should the vendor's task to provide all metadata. Stereoscopic Player implements two mechanism, both based on stereoscopic metafiles, which allow vendors to provide metadata. They are discussed in the following two chapters.

Stereoscopic Metafiles

Library items can be exported to individual files, called stereoscopic metafiles. The extension of stereoscopic metafiles is *.svi. To create a stereoscopic metafile, click File->Export->Stereoscopic Metafile in the main window or right-click on a library item and select Export->Stereoscopic Metafile. The metafile will be created in the same directory as the video file. Both share the same filename, except file extensions.

When Stereoscopic Player encounters a unknown 3D video, it searches for the metafile of the same name. If the metafile exists, Stereoscopic Player reads in its information and plays the file without showing the dialog to select the stereo format.

Stereoscopic Metadata Server

If no metafile can be found, the second mechanism to automatically assign metadata is used: In this case, Stereoscopic Player queries a metadata server on the Internet. Using the original configuration, Stereoscopic Player accesses the official metadata server with the following address:

The official metadata server holds information for most commercial 3D-DVDs and some 3D video files available for free on the Internet. You can add your own servers. Click File->Settings->Servers, enter server name and address and click Add. Users without Internet access should uncheck the option Contact server when opening a unknown file in File->Settings->Playback to avoid delays by unsuccessful attempts to establish a server connection.

The video library can be synchronized with the metadata servers at any time. To update the whole library, select File->Update Video Library. Distinct items can be updated using their context menu. Select Internet Update and one of the submenu options to update the whole library, selected items only or new items (never updated before) only.

Settings up your own metadata server is fairly easy, because metadata servers are ordinary http servers that provides stereoscopic metafiles for download. Filenames do not correspond to video filenames,  instead a hash value (unique key derived from video file content) is used. Hash values are advantageous because they allow to locate the metafile even if the user has renamed the video file. Metafiles for servers can be created using Stereoscopic Player export feature as described above. You just have to select Metadata Server File instead of Stereoscopic Metafile. In addition to the metafiles, there must be the file UpdateLibrary.dat on the server. UpdateLibrary.dat is a plain text file containing the text Stereovideo-Updateserver[V1.0]. Stereoscopic Player uses this file to verify that the server provides metadata server functionality and is responsive.

If you are a 3D video vendor, you should keep playback for users simple as possible. Therefore, distribute your video files together with stereoscopic metafiles. We also offer to put your metadata server files on the official metadata server. If your 3D videos are available free of charge  (e.g. for download), we will also offer this service for free. Please verify that the information you entered is correct and complete before you send us the files.