iTunes U for web audio and video specifications
Keep in mind that your content is available on iOS devices (iPad, iPhone, and iPod touch) and to a broad worldwide audience with varying server bandwidth and performance. To ensure a good experience, consider appropriate file size and compression when encoding your audio and video file content.
Apple recommends using the following specifications for your audio and video content:
Audio files
Frequency response: 20Hz to 20,000Hz
Audio formats: AAC (8 to 320 Kbps), Protected AAC (from iTunes Store), HE-AAC, MP3 (8 to 320 Kbps), MP3 VBR, Audible (formats 2, 3, 4, Audible Enhanced Audio, AAX, and AAX+), Apple Lossless, AIFF, and WAV
User-configurable maximum volume limit
Some MP3 audio files, specifically ID3 version 1.x tagged files, have known issues displaying item artwork information. To use specific artwork with these audio files, Apple recommends either converting the files to MP3 files tagged as ID3 version 2.4 or converting the files to the AAC file type format (.m4a).
iTunes U does not support the downloading of WAV or AIFF file formats on the iPod, iPhone, or iPad.
Video files
Video mirroring and video out: Up to 1080p through Lightning Digital AV Adapter and Lightning to VGA Adapter (adapters sold separately)
Video formats: H.264 video up to 1080p, 60 frames per second, High Profile level 4.2 with AAC-LC audio up to 160 Kbps, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats; MPEG-4 video up to 2.5 Mbps, 640 x 480 pixels, 30 frames per second, Simple Profile with AAC-LC audio up to 160 Kbps per channel, 48kHz, stereo audio in .m4v, .mp4, and .mov file formats; Motion JPEG (M-JPEG) up to 35 Mbps, 1280 x 720 pixels, 30 frames per second, audio in ulaw, PCM stereo audio in .avi file format
AirPlay mirroring and video out to Apple TV (2nd and 3rd generation)
If you are using QuickTime to create and edit video content, it is recommended that you export your videos by choosing Movie to iPod from the Export pop-up menu in QuickTime Pro. See QuickTime Player User Guide.
Due to video file profile level requirements, iTunes U might not play some files on the iPad without re-encoding the files. See the iPad audio playback and TV and video requirements in the iOS Technology Overview documentation.