Elvis 4 API - Previews

For all supported file types, Elvis generates previews to display in the Desktop client and in API clients. The previews are all based on lightweight Web formats and can therefore be quickly displayed and navigated.

Generated previews

Previews are generated in the following formats:

• JPEG previews for images and PDFs
• MP4 previews for videos
• HTML previews for most documents

Default preview formats

Previews of an asset can be requested by using the asset ID or the assetPath, using the following syntax:

• Example using the asset ID:

http://demo.elvisdam.com/preview/5LMAQTW9qfhANn7f6JJVpl

• Example using the assetPath:

http://demo.elvisdam.com/preview/Demo%20Zone/Images/Travel/Architecture/Domein%20Hofstade.jpg

The default previews are equal to the previews in the Desktop client.

• maxWidth_1600_maxHeight_1600.jpg (for an image)
• maxWidth_1600_maxHeight_1600_page_0.jpg (for a PDF or PowerPoint)
• maxWidth_480_maxHeight_360.mp4 (for a video)
• maxLength_600000.flv (for audio)

Customized preview formats

By altering the preview URL, customized preview formats can be requested from the server such as a smaller JPEG preview, a different page of a PDF or a video preview in FLV format.

Note: Custom preview formats are not supported for HTML previews.

If these previews have not been generated yet, they will be generated on-the-fly by the server and cached in the <Elvis Data>/previewFilestore folder.

• Example using the asset ID:

http://demo.elvisdam.com/preview/5LMAQTW9qfhANn7f6JJVpl/previews/maxWidth_1600_maxHeight_1600.jpg

• Example using the assetPath:

http://demo.elvisdam.com/preview/Demo%20Zone/Images/Travel/Architecture/Domein%20Hofstade.jpg/previews/maxWidth_1600_maxHeight_1600.jpg

• Default preview with different extension:

preview.tiff

• Smaller preview for use on a Web page:

maxWidth_500_maxHeight_350.jpg

• Preview for page 3 of a PDF or slide 3 of a PowerPoint:

maxWidth_1600_maxHeight_1600_page_3.jpg

• HD (720p) preview for a video:

maxWidth_1280_maxHeight_720.mp4

• Flash video format preview:

maxWidth_640_maxHeight_480.flv

Using a custom file name

By default the file name of the requested image contains the parameters as supplied in the URL.

Example: maxWidth_1600_maxHeight_1600.jpg

To use a custom file name, add the following to the end of the URL:

For Elvis 4.0 – 4.6.15:

file name////extension

For Elvis 4.6.16 and higher:

file name/*/extension

• Examples using the asset ID:

http://demo.elvisdam.com/preview/5LMAQTW9qfhANn7f6JJVpl////my-custom-name.jpg

http://demo.elvisdam.com/preview/5LMAQTW9qfhANn7f6JJVpl/*/my-custom-name.jpg

• Example using the assetPath:

http://demo.elvisdam.com/preview/5LMAQTW9qfhANn7f6JJVpl/previews/maxWidth_1600_maxHeight_1600.jpg////my-custom-name.jpg

http://demo.elvisdam.com/preview/5LMAQTW9qfhANn7f6JJVpl/previews/maxWidth_1600_maxHeight_1600.jpg/*/my-custom-name.jpg

Changing the file name separator

Info: This feature requires Elvis 4.6.16 and higher.

In case a different separator needs to be used (for example by changing it back to 4 forward slashes), add the following property to the <Config>/config.properties.txt file:

downloadUrlFilenameSeparator=

Example: downloadUrlFilenameSeparator=////

Supported properties

The following properties are supported:

maxWidth and maxHeight

• Description: Sets the maximum width and/or height of the preview. The aspect ratio will always remain the same. If the original asset fits within the supplied dimensions, the original width and height will be used for generating the preview. It is allowed to just supply one of the dimensions.
• Applicable file types: Images, videos, PDFs, presentations and layouts.
• Value: numeric.
• Example:

maxWidth_800_maxHeight_600.jpg

scale

• Description: Sets the width and height of the preview relative to the original size. The scale is in percentages from 1 to 100. If used in combination with maxWidth or maxHeight the image will be scaled with a maximum size.
• Applicable file types: Images.
• Value: 1 – 100.
• Example:

scale_50.jpg

PPI / DPI

• Description: The pixels per inch / dots per inch can be set to any desired value. When not set, the original PPI / DPI value of the file will be used. .
• Applicable file types: Images.
• Value: numeric.
• Example:

maxWidth_800_maxHeight_600_ppi_72.jpg

compression

• Description: TIFF compression.
• Applicable file types: Images.
• Value: uncompressed, packBits, LZW, ZIP and JPEG.
• Example:

maxHeight_600_compression_packBits.tiff

quality

• Description: JPEG compression quality 1 - 100.
• Applicable file types: JPEG images.
• Value: 1 – 100.
• Example:

scale_75_quality_12.jpg

maxLength

• Description: Limits the length of audio previews. The value is in milliseconds.
• Applicable file types: Audio files.
• Value: numeric.
• Example:

maxLength_60000.mp3

page

• Description: The page of the PDF or presentation to create a preview from. The value can range from 1 to the number of pages in the document. The preview will always have .jpg as extension.
• Applicable file types: PDFs, presentations and layouts.
• Value: numeric.
• Example:

maxWidth_1600_maxHeight_1600_page_3.jpg

embedMetadata

• Description: When set to true the metadata embedded in the original asset will also be embedded in the generated preview. Note that for certain file types the embedding of metadata is not supported, for example for PNG files. By default the original metadata is not embedded.
• Applicable file types: Images, PDFs, presentations and layouts.
• Value: true or false
• Example:

maxWidth_800_maxHeight_600_ppi_72_embedMetadata_true.jpg

Extensions

• Description: The extension of the generated preview can be different from the original.
• Applicable file types: Images, PDFs, presentations and layouts.
• Value:
• Images: jpg, png, tiff
• Videos: flv, mp4
• Audio files: mp3, flv
• PDF, presentation, layout: jpg
• Example:

maxWidth_800_maxHeight_600.png