Child pages
  • Media Format Guidelines
Skip to end of metadata
Go to start of metadata

This section outlines the guidelines for submitting media files to PBS LearningMedia via the CMS tool.  Please adhere to these guidelines to ensure the content submission process goes smoothly. Media files that can be included in your resource include:

Key:  (tick) = supported   (error) = not supported 


Acceptable audio file format:  MP3. 


The following document formats are supported for import:

Supported document formats
Import File TypeSupported

DOC (Microsoft Word) / DOCX

TXT (Text)(tick)
PDF (Adobe's Portable Document Format)(tick)
XLS (Excel File) / XLSX(tick)
OpenDocument (ODT)(tick)
  • Because documents need to be downloaded for use, they will not be converted and will maintain their original format. 
  • If you do not want your document to be editable and you would like it to retain the layout and formatting you've applied, submit it in the print-ready PDF format PDF-A (
  • If your document should be editable, you can:


Mezzanine images (1920 x 1080) are preferred, however, lesser quality images are acceptable if mezzanine is not available.

Acceptable image formats
File TypeSupported


Type of ImageRequirements
Poster Images (and thumbnails)
  • LearningMedia requires a poster image for all assets.

  • Poster images should be 1920 pixels wide by 1080 pixels high and have a 16:9 aspect ratio.  Minimum image size accepted is 700 pixels wide by 394 pixels high.
  • The poster image is resized automatically for lists (thumbnail size) and resource pages (poster image size, i.e. the image you see before you hit the play button).
  • For videos, a representative frame should be chosen.
  • For interactives, we recommend using a screenshot.
  • For documents and audio, we would like to have a representative image, or icon.
  • See more about poster images
  • We strongly recommend including at least one logo on each resource (typically the Contributor logo).

  • You can submit any size/ratio logo and we will automatically resize to a width of 150 pixels or height of 90 pixels, maintaining the image's original proportions.

  • All logos should be in vector format.

  • All logos should be full color:
    • .PNG (Must be transparent)
    • .JPG
    • .EPS
    • .AI (Adobe Illustrator)
  • Only submit .AI and .EPS files if you are unable to provide .JPG or .PNG files.  .AI and .EPS files require reformatting by our design department and may take more time to process.)
  • All brand logos should be in color and all other logos should be grayscale.
  • You can include an unlimited number of Brand, Contributor, Funder, and Producer logos.

  • See more about logos

Station website banner
  • Banner image should be 1260 pixels wide by 162 pixels high. 


HTML Guidelines

  • HTML may be written according to the HTML 4.01 Transitional, XHTML 1.0, or HTML5 doctype.
  • All HTML files must declare a valid doctype. (HTML will be validated against W3C guidelines. It is suggested that all files are validated before submitting to PBS.  There are free utilities available to achieve this.)
  • HTML must be Section 508 compliant.
  • Interactive developers should follow best practices of web development for HTML, CSS, JavaScript and Flash/Action script including the use of non-blocking JavaScript loads and supporting the widest array of browser technologies possible.
  • When targeting a version of Flash, it is suggested that interactive developers target the lowest version number that supports the technology needed to produce the interactive.

Keep in mind that schools and institutions do not always run the most cutting-edge version of the Flash Player.  Also keep in mind that .swf files do not work on many tablets.

Target browsers

The following is a list of target browsers:

  • Google Chrome
  • Internet Explorer 8.0+
  • Firefox 3.6+
  • Safari 5.0+

LearningMedia Technical Requirements can be found here:

Interactive Package Construction 

  • Interactives that contain multiple files should be delivered in ZIP archives containing all required files and directory structures needed to experience the object.
  • At the root of the ZIP archive should be a manifest file called manifest.txt. The manifest should contain the following information, and nothing else:
    • Title: Title of interactive
    • Creator: Creator of interactive Creator
    • Email: Email of interactive Creator
    • Description: Short description of interactive
    • Date Created: Date interactive was created
    • The ZIP archive should also contain an index.html file at the root of the archive
  • Only the index.html and the manifest.txt files should be located in the root of the archive. All other files should be contained in a subdirectory called content.
  • Within the content directory, interactive creators may use whatever directory structure they choose, as long the guidelines outlined below are followed:
    • Reference files and directories with the correct letter case.  Filesystems are case sensitive. Capital letters may be used, but it is imperative for developers to realize that they must reference files and directories with the correct letter case. If the HTML, JavaScript, CSS or Actionscript of your interactive references "filename.jpg" and the actual file is called "fileName.jpg" then your interactive may appear broken to the end user. This would cause your interactive to be rejected by PBS staff. (This is generally only a problem for developers working on case insensitive platforms such as Windows.) To avoid complications with filename references, it is recommended to avoid any uppercase letters in filenames.
    • Do not include spaces or special characters in file or directory names.  No spaces or special characters are allowed in file or directory names. The only special characters that are permitted are: dash ( - ), underscore (_), and period (.). So this-file_name.txt is valid, but this file~name.txt is not valid.
    • All linkage in any interactive should be self-contained and relative to the pathing within the zip archives. For example, the index.html file may embed the object content/swf/main.swf as a valid path and file. However, /content/swf/main.swf will not be a valid path or file on the production system.
  • All interactives will be loaded via the index.html file in the root directory. This file should bootstrap the interactive to run for the user.

The structure of the content directory may take on a much wider variety of appearances. Figure 1 demonstrates a sample content directory.

Figure 1



UI/UX Guidelines

It is imperative to realize that the interactives will be experienced through many different platforms and devices. In addition to designing the interactive for the appropriate audience, it is helpful to keep in mind some tips to make the interactive accessible for a variety of platforms and interfaces.

(tick) TIPS
Variable display resolutions The interactives may be viewed on a wide variety of displays with varying resolutions so, where possible, use vector graphics. Vector graphics are especially friendly for developers when using Flash, although features such as SVG and the canvas tag enable HTML-based interactives to leverage scalable graphics. It is recommended that wherever possible, HTML-based interactives utilize a fluid layout in order to make the best use of available display resolution.
Avoid hover events A hover event is any event that occurs upon hovering the mouse cursor over an object on the screen. Both JavaScript and Flash allow for this type of event.  These types of events should be avoided in order to better support touch-based interfaces. If an onHover event does not impact the actual functioning of a interactive, it is allowed. However, if an onHover event prevents users on a touch-based device from experiencing the core functions of a interactive, then those onHover events will require alteration.
Provide user -friendly interfaceAlthough mouse pointers and other interface devices provide a high level of accuracy, it is recommended that interactive developers try not to position linked objects too closely together. Give some room to linked elements of your interactive, and allow hot zones to be as large as possible. This will make the interactive more accessible to differently abled users, will ease interaction with the interactive on touch-based devices, and will expand the audience to a wider age range (younger children tend not to be as precise with the mouse as adults and older children).
HTML links When featuring HTML links as assets, provide the URL that takes the user closest to the media. PBS LearningMedia intentionally tries to avoid cataloging entire websites since we aim to feature discrete resources, so please avoid URLs to home pages, especially if the websites are large.


Videos should not contain web links or hash tags.



File Format

MPEG-4 (.mp4)

*.mov files are acceptable, however, .mp4 is the preferred format.

Total Stream BitRate5 Mbps  
Video Stream  


AVC (H.264)  

Frame Size

  • 16/9: 1280 x 720
  • 4/3: 960 x 720 
Frame Rate30 fps

Video Standard

Scan TypeProgressive  
Video Stream BitRate4808 Kbps  
Video Stream BitRate ModeVBR  

Video audio

Mezzanine is the preferred format, however, web delivery is acceptable if mezzanine is not available.

Audio Stream


Web Delivery/COVE Spec


Audio Stream BitRate192 Kbps 48 Kbps

Audio Stream BitRate Mode


Number of Audio Channels

2 (Stereo) 1 (Mono)
Audio Channel's PositionsL, RC
Sampling Rate48 KHz44.1 KHz 
Bit Depth16 bits16 bits 

** Preferred format.

Closed Captioning

When you use one of the caption formats that are supported for ingest, your caption file is automatically converted and stored in the CMS as DFXP.

Acceptable caption formats
File TypeSupported for ingest


SAMI  (tick)
QuickTime text(error)

** Preferred format.

 How can a viewer tell if my video has captions?

When a user mouses over your video, a bar appears at the bottom of the video. If the bar contains a CC icon (Figure 1.1), that means your video contains closed captions. If the CC icon does not appear in the bar, closed captioning is not available for your video.  Users can format their captions by clicking the icon in the upper left side of the video (Figure 1.2).  Learn more about closed captioning

Figure 1

FCC Online Captioning Regulations

Full-length and chapterized video programming shown with closed captions on TV must now have captions when distributed online within 45 days of the original broadcast date. Captions of online video programming must be at least the same quality as the captions shown on TV. The FCC requires the copyright holder of the content to notify the distributor as to whether captions are needed for a particular program and to provide the digital captioning file if needed. In addition, digital closed captioning will be required to be present and accurate for clips, excerpts and segments as of January 1, 2016. The following exemptions apply as of January 1, 2016 for all clips, segments, and excerpts that are lifted from a broadcast television program:  

  • Captions are not required for montage clips online that excerpt multiple programs that were televised, until January 2017.
  • Captions are not required for online clips from near live or live broadcasts, until July 2017.
  • Captions are not required for clips and segments broadcast before January 1, 2016.

Full text of the online closed captioning regulations can be found here: FCC regulations


Acceptable caption formats
File TypeSupported for ingest

What is ASCII?