Technical Requirements
Compression for iTunes U:
There are a variety of software packages that allow you to compress content for distribution on the Web including iTunes U. Commercial packages such as Sorenson Squeeze, Compressor, and QuickTime Pro, open source alternatives, and hardware options from companies such as Elgato provide considerable control over codec settings and enable you to balance image quality and file size. Below are Apple’s general recommendations for encoding iTunesU audio and video:
Audio files (AAC, MP3)
with appropriate file extensions (.m4a, .mp3)
For best results during playback, Apple recommends converting MP3 files larger than 32MB to AAC format. For AAC audio files, use the following specifications:
- Audio format: AAC-LC (Music)
- Data rate: 128 Kbps
- Channels: Stereo
- Output sample rate: 44.100 kHz
- Encoding quality: Better
Video files (MPEG-4 with H.264 compression)
with appropriate file extensions (.mp4, .m4v, .mov)
For best results with iPod, use MPEG-4 with H.264 compression with the following specifications:
- Video format: MPEG-4 with H.264
- Data rate: 256 Kbps
- Image size: 320 by 240
- Frame rate: 30
- Key frame: Every 24 frames
If you use QuickTime to create and edit video content, Apple recommends that you export your videos by choosing “Movie to iPod” from the Export pop-up menu in QuickTime Pro. You can also select other options such as “Movie to AppleTV” and “Movie to iPhone.” Keep in mind, however, that selecting other options may reduce the number of devices that can view your content.
- More information on compression settings for common Apple devices.
Thumbnail image
A thumbnail image (JPEG, PNG, or GIF) to accompany your video or audio is required and must be sized to 320 x 240px or greater.
Contact NSIT Academic Technologies or CMIG for assistance with compression settings or to arrange to have your media compressed for you.