itunes U 애플

http://deimos.apple.com/rsrc/doc/iTunesUAdministratorsGuide/Introduction/chapter_1_section_1.html#//apple_ref/doc/uid/AdminGuide-CH1-SW3

Apple recommends using the following file formats for iPod and iTunes content:

• AAC (Advanced Audio Coding) for audio content. AAC is a state-of-the-art, open (not proprietary) format. It is the audio format of choice for Internet, wireless, and digital broadcast arenas. AAC provides audio encoding that compresses much more efficiently than older formats, yet delivers quality rivaling that of uncompressed CD audio.

• H.264 for video content. H.264 uses the latest innovations in video compression technology to provide incredible video quality from the smallest amount of video data. This means you see crisp, clear video in much smaller files, saving you bandwidth and storage costs over previous generations of video codecs.

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iTunes U supports the distribution of compressed audio and video files. Apple recommends using the following formats for your iTunes U audio and video content:

• Audio files (AAC, MP3) with appropriate file extensions (.m4a, .mp3). For best results during playback, Apple recommends converting MP3 files greater than 32 megabytes (MB) to AAC format. For AAC audio files, Apple recommends the following specifications:

  • Audio Format: Baseline Low-Complexity Profile with AAC-LC (Music)

  • Data Rate: Up to 160 Kbps

  • Channels: Stereo in .m4v, .mp4, and .mov formats

  • Output Sample Rate: 48 kHz

  • Encoding Quality: Better

• Video files (MPEG-4 with H.264 compression) with appropriate file extensions (.mp4, .m4v, .mov). For best results with iPod, Apple recommends using MPEG-4 with H.264 compression with the following specifications:

  • Video Format: MPEG-4 with H.264

  • Data Rate: Up to 1.5 Mbps

  • Image Size: 640 x 480 pixels

  • Frame Rate: 30 frames per second

  • Key Frame: Every 24 frames

  • Audio Tracks: Baseline Low-Complexity Profile with AAC-LC audio up to 160 Kbps

You can also use iTunes U to distribute Portable Document Format (PDF) files.

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.

Note: Some MP3 audio files, specifically ID3 version 1.x tagged files, have known issues displaying track 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).