Tobi Creating or Modifying EPUB Media Overlays
The basic structure of the EPUB book is different from that of the DAISY book. Where we have a single XML file containing the entire textual data in a DAISY book, there are generally more than one text files (XHTML files) in an EPUB book. So, Tobi handles both of them differently. It creates one project for each file of the EPUB book, and all of them are enumerated in XUKSPINE file.
Thus, a Tobi project for EPUB book is a collection of sub-projects containing the textual, graphical, and audio data required to create EPUB media overlays. At one point of time, Tobi will display data of single sub-project only. To work on another sub-project, you should invoke the Project Spine dialog by pressing Ctrl+U. It displays the list of all the sub-projects of the current project; select the required project from the list and press Enter to open it. You can also use the Search bar over the list to find the required one quickly. The figure below displays the Project Spine dialog.
Before going further, it is advisable to run through User Interface of Tobi that will acquaint you with the components of Tobi’s GUI.
Tobi enables you to import the following EPUB formats:
- Text-only EPUB book for converting it into EPUB audio media overlays
- Existing EPUB 3 media overlays for updations.
- A stand alone HTML 5.0 file for generating EPUB media overlays from it.
Follow the instructions below to import a text document or EPUB book:
- Click File->Import on the menu or press Ctrl+I. Tobi opens a dialog box to let you browse for EPUB media overlays, EPUB text-only book, or XHTML document.
- Select the .opf/.epub file for EPUB publication, or .xhtml/.html file for XHTML document.
- Click on the Open button. Tobi will then open a dialog box to select the audio format for the project, as shown in the figure below. Please note that the same format will be used for all the sub-projects.
- Choose the sampling rate for the project from the combo box.
- Check the checkbox, Stereo, if you wish to use stereo channels in your project; leave it unchecked for mono channel.
- To preserve the audio format used by the source publication, check the checkbox Preserve source format. In this case, Tobi will override any selections made in this dialog by the audio format of the publication being imported.
- Recheck the selections made by you; once selected, the audio format can not be changed for the project.
- Click on the OK button.
Tobi will create one project for each XHTML file and store all of them in the _XUK folder in the same directory as that of the imported publication. The textual and graphical data will also be imported and stored in the data folder of the respective sub-project. If you import EPUB media overlays, the audio data will be imported too. Thereafter, it will open the Project Spine dialog enumerating the sub-projects. Choose the one you wish to view and click on the OK button to load it in Tobi.
Once you open a sub-project in Tobi, it will be treated as any Tobi project and all the operations explained in Tobi project and DTB Creation may be used to work on its data. To understand how to export to EPUB Media overlays, please refer to the section Exporting as EPUB.
To select another sub-project of the current project, perform the steps listed below:
- Press Ctrl+U. The Project Spine dialog opens.
- Select the sub-project from the list box. You may also use the Search bar on the top of the list to find the matching entry prior or subsequent to the current selection.
- Click on the OK button.
Tobi will close the currently opened sub-project, and open the sub-project you selected in the application window.
As EPUB project is a collection of sub-projects, you will have to use the project spine for exporting it and updating the metadata. The project spine can be accessed using the Project Spine dialog, which can be invoked by any of the following methods.
- If a sub-project is open, press Ctrl+U.
- Otherwise, press Ctrl+O and select the file with .xukspine extension from the project directory.
To update the metadata of the book, do the following:
- Click File->Open on the menu or press Ctrl+O. Tobi opens a dialog to browse for a file.
- Select the file with .xukspine extension from your project directory, and click on the OK button. Tobi loads the project spine and opens the Project Spine dialog.
- Press Esc to close the dialog box.
Please note that even if the application window does not display the usual project data, but the XUKSPINE file is opened in Tobi. You can also open the XUKSPINE file by clicking the Open Spine button in the Project spine dialog (Ctrl+U).
Once the project spine is loaded in Tobi, you can update the book metadata by pressing Edit->Edit metadata on the menu or by pressing F11, which will invoke the Metadata Editor. For information on updating book metadata, refer to the section Book Metadata.
To export the project as EPUB 3 media overlays, follow the instructions given below:
- Press Ctrl+U to launch the Project Spine dialog.
- Click on the Export full EPUB button therein. Tobi will open the Export dialog enabling you to select the audio format for the exported book.
- Select the sampling rate from the combo box.
- If you wish to have stereo channels in the exported book, check the checkbox Stereo; leave it unchecked for mono channel.
- To encode the exported audio files in MP3 format, click the checkbox Encode MP3.
- To instruct Tobi to include image descriptions in the EPUB book, check the checkbox Include/Merge image descriptions. Otherwise, the descriptions will only be exported to the DIAGRAM descriptions directory. Checking this checkbox will enable some more controls as listed below.
- aria-describedby: Check this checkbox if the description should lie in the same page in an IFrame.
- aria-details: Check this checkbox if the link should point to an external page.
- Click on the OK button to start the export. Tobi opens a dialog box to browse for a folder where the exported book will be stored.
- Select a folder from the tree view, and press Enter.
Tobi will export the project as per EPUB specifications and store the exported book in the folder selected by you.
After exporting the project to EPUB, Tobi will enable you to perform EPUB check to ensure conformity of the exported book with the EPUB 3 specifications. Click Yes to perform the check or No to ignore.
Please note that Tobi also enables you to convert existing DAISY books to the latest accessible EPUB 3 standard. To know how, please visit Upgrading DAISY books to EPUB.Tags: Tobi