Portable Content Formats

This section includes detailed descriptions of the typical formats used for portable media content, with suggestions for the best file formats and tools to use for specific formats. The section also includes information about the post-production tasks (i.e. after the recording process is complete) to put the finishing touches on the content for the chosen format.

Emory's Center for Interactive Teaching (ECIT) is your resource for podcasting production. Contact ECIT to set up an appointment for production help or for consultation on your podcasting project.

Choosing the best format to use is often as much an art as a science. While it would seem obvious in some cases that having more visuals with audio is better, the tradeoff may be a limit in portability (for students who do not have 5th generation "video" iPods or other media devices capable of playing back enhanced media formats) or in longer download times for students with slower network connections or who are participating in online courses. It is important to be aware of the technical capabilities of users of your materials and weigh those against the pedagogical benefits of more robust content forms.

If you have existing content in a format that is not in an iTunes ready format, conversion to another format may be possible. All questions about content formats should be directed to ECIT.

Content format	Advantages	Best for
Audio only	Smallest files; most portable (in .mp3 format) to different devices or by copying to audio CD or to a flash drive	Shorter recordings or for student populations who do not have good access to networked computers. Long speeches or lectures, where the video files do not offer additional understanding.
Enhanced audio	The inclusion of images or graphics in addition to audio and chapter markers can help illustrate content more fully	Content that benefits from visual support for satisfactory comprehension
Narrated slideshow	Simulates the classroom experience of a PowerPoint-type slideshow with narration	Summary or overview narrations of content with graphic and text visuals
Full movie	Full-motion video can convey context and nonverbal content more effectively than any other format; screen capture movies can provide very effective technical documentation	Content or situations where providing the full audiovisual experience can significantly enhance understanding and retention of an important concept, idea or experience

Audio-only files

This format is the most flexible to implement because audio-only files can be accessed in so many different ways on a computer and on many different kinds of portable devices (including burning to audio CDs).  This format is ideal for shorter recordings that focus on a single topic. However, for longer recordings, or for shorter recordings that cover multiple topics, the absence of bookmarks or chapter markers can make it difficult for the listener to cue up specific parts of the recording quickly. This can reduce the effectiveness of the recording for review purposes.

Primary file formats for portable playback	MP3 (Emory Recommended Format) - This compressed format works on both Macintosh and Windows computers and in software programs such as iTunes and Windows Media Player. It also works on iPods and other portable media devices, including many cell phones (for smaller files). Many audio files can be saved in compressed MP3 format without significant loss of sound quality. WAV – This uncompressed format provides good sound quality but produces a much larger file than other formats, which will cause a significant increase in download times for students on slow network connections.
Suggested tools	Audacity - Recording, editing and export of digital audio files. QuickTime Pro - Recording, editing and export of digital audio files. iTunes - Quick conversion of existing digital audio files to MP3 or iPod format and for input of labels (metadata) useful to iPod users. SoundForge – Higher-end digital audio reocording and editing software package with more sophisticated (and harder to learn) editing interfaces and capabilities. These programs may be overkill for many recording and editing situations.
Post-recording tasks	Edit the digital audio file name so that it is meaningful to the user who downloads it and complies with the standard naming convention for your project. For public materials, add approved intros and exits. Add the descriptive information for the track in iTunes by choosing Get Info in the File menu and then adding in text labels for track Title, Album, Genre, Year and any other fields that describe the content. See Emory's tagging recommendations. Retain a copy of your final product as your archival copy.

Enhanced audio (for playback on iPod/iTunes only)

Enhanced audio is an audio podcast/file with images and/or chapter markers embedded within the content. The image files are not limited to chapter artwork as with audio books. You can also embed links to Web sites; these links could then be clicked and browsed if the podcast file is being viewed on a computer with a live network connection. When viewed on an iPod, the link address will display during playback and can be opened directly on an iPod Touch or iPhone.

Primary file formats for portable playback	M4A - This format can be played back only on iPods, iTunes (Mac/Windows) and Quicktime. These files will not play in Windows Media Player or on portable devices that are not iPods. Can be burned to audio CDs if needed; in this case only the audio would be accessible to the person listening to the CD.
Suggested tools	GarageBand - This software is part of the iLife suite for Macintosh. Its interface allows you to easily add images and web links to audio files and create an enhanced audio file that can be used as a podcast or for regular download for playback in iTunes or for synching to an iPod on Mac or Windows. It also includes a wide variety of background music loops you can add to your file. PDF Tutorial, "Creating an enhanced podcast with GarageBand. QuickTime Pro - This software (Mac/ Windows) allows you to build an enhanced audio file. Given the number of manual steps, however, this is not the best software to use if you have GarageBand available. Camtasia Studio - Camtasia can be used to produce movie files that function like enhanced audio, but are technically distinct (format will be .M4V and cannot be copied to an audio CD). Powerpoint (Mac only) - The basic concept is that you play back your PowerPoint presentation using a tool that allows you to simultaneously record your voiceover narration. The program captures everything that shows on the screen during your presentation and saves your voiceover as well. This can be saved as a .MOV file on a Mac and then exported to a .M4V. The primary consideration in this content format is the design of the presentation slides. Content that is very text heavy or has small print will not be easily viewable on an iPod, although students who play the content back using a computer should not have difficulty viewing slide content.
Post-production tasks	Assemble your images into a folder then import them into your chosen program. Adjust the display time of the images to coordinate with the appropriate segments of the recording. Add chapter information and/or Web links if desired. Export to M4A. For public materials, add approved intros and exits. For iPod format: import into iTunes and add metadata by choosing Get Info in the File menu and then adding in labels for Album, Genre, Year and any other fields that describe the content. See Emory's tagging recommendations. Retain a copy of your final product as your archival copy.

Full Movie

This is the most full-featured type of content format, as it can contain video as well as still images, graphics, audio and text. It also results in the largest files, which may have an impact on students with slow network connections. For this reason, you may wish to consider offering multiple ways for students to access movie content, including downloadable and streaming options, although careful consideration of the copyright implications is important before making content available in downloadable format.

The primary recommendation for video work is to make sure that you save your video project space (in whichever video editing program you use) in addition to saving the exported file in iPod or other formats. This will allow you to go back later and make additional edits or export to a new format.

Primary file formats for portable playback	MP4 (Emory Recommended Format) - This compressed format works in software programs such as iTunes and Quicktime. It also works on iPods and some other portable media devices, including cell phones. M4V - This Apple-proprietary format can be exported for playback on iPods and iTunes (Mac/Windows). These files will not play in Windows Media Player or non-iPods. MOV - An Apple proprietary format that can be created by some programs. Though usable in iTunes, it will not synchronize and play to an iPod..
Suggested tools	iMovie - Ready out of the box to export digital video for iPod playback. QuickTime Pro - This software (Windows/Mac) can take video in AVI format from Windows-based video editing programs and export it in iPod format. Camtasia Studio - This Windows program is great for making screen capture movies (ideal for documentation) or for narrating presentations.  It can export files in M4V format for iPod/iTunes playback. iTunes - Can convert movies into different QuickTime formats, including format for synchronization with an iPod.
Post-recording tasks	Use your preferred video editing program to create a video file. Export in iPod format or use QuickTime Pro to transfer to iPod format. For public materials, add approved intros and exits. Add metadata in iTunes by choosing Get Info in the File menu. See Emory's tagging recommendations. Retain a copy of your final product as your archival copy.

Original: Center for Instructional Technology, Duke University Libraries
Modified by Emory University, Emory's Center for Interactive Teaching

Unless otherwise specified on this page, this work is licensed under a
Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.

iTunes U Home | User Guides | Contribute | Feedback