Using Multimedia in a PDF

PDF files have long been used for their versatility and convenience, working well both on the web and in print. While predominantly text and image based, there is also the opportunity to use video and audio. This advice document outlines the considerations for using and embedding multimedia in PDFs.

Introduction

PDF (Portable Document Format) files are popular for a number of reasons including:

• Simple to produce from a wide-range of applications
• Can produce low to high-end quality output suitable for all types of delivery
• Can easily be uploaded to the web
• Work well in print
• Viewable on most platforms and devices
• Searchable
• Ability to include security measures

Why add multimedia?

PDF files can be quite lengthy if they cover a topic in great depth. Using multimedia – images, video, audio and interactive Flash content - can greatly add to the context that the content of the PDF file is attempting to convey. For example, a graphic can often illustrate or communicate a scenario more elegantly than text. For more information, please refer to our advice Using Images in Education and Using Video in Teaching and Learning.

Please note: the inclusion of Adobe Flash content (other than Flash-based video file types) within PDFs is beyond the scope of this document (due to the technical skill set required).

Example uses

• Student induction pack with multimedia exemplars
• Add context to a text-based PDF report or student exercise
• A ‘Talking Head’ video which performs in a similar way to a podcast
• Using video to provide walkthroughs, e.g. ‘how to’ guidance to support the text-based PDF material
• Video text-based reports may have been delivered at an event and thus can be added as a potential enhancement
• Course prospectus promotional material may benefit from additional uses of multimedia to explain what a course or module entails

Requirements

There are a number of considerations that will support your use of multimedia in PDF files:

• Adding video and audio to a PDF requires Adobe Acrobat 7+ which is NOT the freely downloadable version and a video converter tool may also be required.
• File formats – a PDF is a container file (imagine it as a box with multimedia acting as pieces of content within the box) which means that it is flexible and accepts quite a few file formats including Windows movie video, QuickTime and Flash SWF/FLV. The ‘container’ nature of a PDF however means that any video or audio used in the PDF is effectively independent of the PDF and it cannot compress the video and audio as it can with text and images. A third-party player and codec is required.
• File size – consider what additional media resources will add to the file size of a text-based PDF. As noted above, a PDF file is unable to reduce the file size of audio or video. This has practical implications for choosing to embed the video or access it from the web. If using Flash for video (SWF/FLV) it is possible to deliver multiple versions of varying quality e.g. by default it will attempt to play the high resolution but if no internet connection is available then it will use the in-built low resolution version. Adobe has more on this topic: making a video version that detects if you are online (delivering the full quality version) or offline (delivering the low resolution version).
• User experience – use multimedia where it provides additional context to the text-based copy and understand how the PDF will be used by the students. The use of multimedia, with the exception of images means that this type of PDF is aimed at those viewing on a computer rather than print. If you think it will be printed, then consider a hybrid design that works for both or alternatively a separate print version.

When not to use multimedia PDFs

PDFs have excellent rendering for text and images and the ability to output varying quality files means we have great flexibility for the final file size. A key strength of the PDF format is its portability, yet the addition of video or audio media resources will increase file size, as it has the inability to alter the quality and therefore file size – making them typically too large to email, rendering them no longer portable.

File sizes

To get an idea of the file size increase when adding video we produced a sample to show the various file size differences using the same text, 20 paragraphs, 2070 words of Lorem Ipsum:

File format	File size
5 page Microsoft Word	95 kb
5 page Adobe PDF	93 kb
1 Adobe PDF file AND 4mins 48 seconds of Mpeg-4 video with audio	15.8 MB + 272 KB for the PDF

How to embed video and audio

Below we have provided a step-by-step guide showing you how to add video to your own PDF files.

Adding video to a PDF

1. The purpose of this video is to demonstrate how multimedia is added to a PDF using Adobe Professional, which is the paid for version of the popular free Adobe reader, with additional tools such as the ability to add video and audio.
2. On screen now is a sample 1 page PDF with text and an image that we’ll be adding video and audio to
3. The video is just under 5mins in length and the audio 30 secs. Adobe Professional accepts a range of file formats, we chose to use the Windows Movie video file format and Mp3 as they are both widely supported on institutional computers
4. Adding images to a PDF is done at the initial creation stage, typically in Microsoft Word along with the text and then the document is exported as the PDF file format.
5. To add video, leave a space in the PDF for the video and then using Adobe Professional Go to Tools > Advanced > and select the Movie tool Find the video and click insert. You will return to the PDF and should notice that the cursor has changed to a selection tool, drag a rough square at the location that you wish to place the video. A placeholder image of the video will appear and you can fine tune its location.
6. Here is the final file, notice the file size difference from the original and the multimedia version? the PDF is a container file, and is unable to compress the audio and video, so any audio or video will increase the PDF file size by its own file size – Potentially making it less portable and usable for sending via the internet if that was to be your chosen delivery method.
7. TIP As the file size increases substantially with audio and video, it can be a good idea to keep the original PDF before any multimedia was added and save any multimedia version with a different file name. This not only gets you a highly portable version for email and printing, but also enables you to quickly add different multimedia in the future.

Adding audio to a PDF

To add audio, leave a space in the PDF for the audio player and then using Adobe Professional Go to Tools > Advanced editing > and select the Sound tool, You will return to the PDF and you should notice that the cursor has changed to a selection tool, drag a rough shape at the location that you wish to place the audio. An add sound dialogue box will appear, Find the audio file and click select and then ok. An outline box will appear that represents the audio player. Fine tune its location and then save the PDF.

Published in: Delivering and using

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