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XOOM vs Ipad 2 HD Video playback

Guest Justus Chia

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Guest Justus Chia

The bad news is that Apple didn't increase the resolution. ... The iPad 2 sticks with the same 9.7-inch screen with 1024 x 768 pixels. ... The Motorola Xoom sports a 10.1-inch panel with 1280 x 800 pixels. Still, we prefer the iPad 2's screen because it has wider viewing angles ... and does a slightly better job resisting fingerprints. ... It's still a mono speaker. ... [it] has plenty of audio oomph, but the Xoom's stereo speakers are more impressive. ... The camera quality isn't great. ... Don't expect great video quality ... You also don't get a flash, which the Xoom has

Ipad 2:

Video formats supported: H.264 video up to 720p, 30 frames per second, Main Profile level 3.1 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 by 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 by 720 pixels, 30 frames per second, audio in ulaw, PCM stereo audio in .avi file format


If you stick with H.264 Baseline Profile, you can achieve up to 1920x1080p at 30 fps at 20Mbps.

Baseline Profile means:

- No CABAC entropy coding.

- No B frames

- No 8x8 transforms (DCT)

- No Weighted Prediction

For 1280x720p at 30 fps, you can go up to 20Mbps and Motorola XOOM should still be able to handle it. More Realistically, depending on the content, you can get away with 4Mbps and up with varying degrees of quality. If you are tight on space, use 4Mbps. If you want something to look good you can use 10/12 Mbps. At some point though the higher the bitrate will only translate to decreasing amounts of quality improvement. In other words, 20Mbps will probably look as good as 15Mbps, but will just use up more space. Ultimately, there is really no one size fits all solution and it may take a little experimentation to find the settings that work best for the content you wish to view.

(Tips: we always use this Blu-ray Ripper to rip Blu-ray DVD movies onto iPad 2 and Xoom)

Additionally your device does not have a limitation on certain types of B frames (Main profile tool). So you can add in B frames and not affect performance that much. If you are using a encoding tool that uses B frames, such as QuickTime Pro, you should be able to achieve main profile encoding.

If you are using a lower resolution that 720p (such as 720x480 resolution size) in order to encode longer length video , you can get away with using more tools (High and Main profile tools). However, encoding become more complex and may require more experimentation to achieve acceptable results.

In general, if you are concern about performance, use baseline tools and possibly b-frames (with no weighted prediction). This will give you the best performance.

Also as side note, if you are upscaling from a DVD to 720p try to use the best upscaling algorithm provided and don't expect to get true 720p quality from upscaled DVD.

Looks like Xoom is a tad bit better in terms of supported Hardware video decode capabilities.

In terms of GPU - it seems that the Ipad 2 may have a bit of an edge with the new power VR 543 - though this is not official as there are no direct comparisons yet.

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