iTunes and the new Apple TV have finally been updated to support High Profile 4.0 H.264 video, Ars Technica has discovered.
The site noticed that when downloading the new 1080p videos from iTunes the file sizes weren't as big as expected. This is because of a switch from encoding H.264 video using the "Main" profile to the "High" profile.
The profile indicates what kind of decompression algorithms the H.264 decoder has on board-the "High" profile obviously has some tricks up its sleeve that the "Main" or "Baseline" profiles known to previous devices don't support. The level value indicates how many blocks or bits per second a device can handle.
The previous generation Apple TV only supported playback of 720p video using the Main Profile level 3.1 which meant bigger files and incompatibility with a lot of web accessible video. The new Apple TV supports 1080p video encoded with the High or Main Profile level 4.0 or lower. This allows for significantly smaller file sizes and much more compatibility with downloadable video. Meaning, you may not have to re-encode videos as often for use with iTunes and Apple devices.
Unfortunately, Apple chose not to support the newer 4.1 profile with the new Apple TV; although, the iPad and iPhone do support it. Also the iPod touch still only supports the Main Profile level 3.1. So, if you want a video to display universally across all Apple devices, you will still need to re-encode.
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The site noticed that when downloading the new 1080p videos from iTunes the file sizes weren't as big as expected. This is because of a switch from encoding H.264 video using the "Main" profile to the "High" profile.
The profile indicates what kind of decompression algorithms the H.264 decoder has on board-the "High" profile obviously has some tricks up its sleeve that the "Main" or "Baseline" profiles known to previous devices don't support. The level value indicates how many blocks or bits per second a device can handle.
The previous generation Apple TV only supported playback of 720p video using the Main Profile level 3.1 which meant bigger files and incompatibility with a lot of web accessible video. The new Apple TV supports 1080p video encoded with the High or Main Profile level 4.0 or lower. This allows for significantly smaller file sizes and much more compatibility with downloadable video. Meaning, you may not have to re-encode videos as often for use with iTunes and Apple devices.
Unfortunately, Apple chose not to support the newer 4.1 profile with the new Apple TV; although, the iPad and iPhone do support it. Also the iPod touch still only supports the Main Profile level 3.1. So, if you want a video to display universally across all Apple devices, you will still need to re-encode.
Read More