Video Bitrates and the iPad (H.264 and MPEG-2)

The video formats the iPad can support are (from the tech specs page):

H.264 video up to 720p, 30 frames per second, Main Profile level 3.1 with AAC-LC audio up to 160 Kbps per channel, 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, 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

I've seen bit rates of up to 4000kbps recommended for 720p on the iPad, but I haven't experimented with any since I haven't had any HD content I wanted to convert.

I know it supports at least 5000 kbps since that is what I've been ripping my blu-ray movies to. Quality at that bitrate is fantastic, though size is another matter. Since I'm ripping once for multiple devices I wanted to rip at the maximum I could only once and use iTunes to sync everywhere (ATV, iPhone 4, iPad).

Glor

DVD's use bitrates generally between 2000-8000. Encoding into an H.264 Video file at around 5000-6000 would give you a very good quality rip.

With regards to what the iPad supports, I have a 720p HD Camcorder that encodes ate 12000Mbps. So when I edited the movies files together and was happy I exported into a MOV file using the standard iMovie export options for 720p.

After encoding iMovie spat out a MOV file that had a bitrate of just under 10,000Mbps, and my iPad plays that fine with no problem.

I believe the Main Profile of 3.1 allows bitrates upto 14,000Mbps at 30FPS/720p.

Off course with bitrates like this you could get some amazing quality from the iPad, which in theory could also be applied to Video files for the new ATV.

cheers
G

Apple's Tech specs are WRONG. I've encoded both Mp4 and h264 movies at 720x480 at 10,000 and even as high as 15,000 kbps, and the ipad plays them back with zero issues what so ever. I did this on accident one day when typing in the bitrate when ripping a DVD. Then I tried 15K for the heck of it. The file sizes are absurdly large. So you'd never want to really go that high. I've found 1500-2000Kbps works fine for a standard 720x480 DVD.

I've also ripped blue ray discs (and yes you can rip Blue Rays. It's a cat and mouse game. The CP gets broken then a new version of Blue ray comes out, then it gets broken, etc, etc) at 1920x1080p, I've done them at 5K and the ipad played back just fine. Although for a decetly sized file, I would stick to 1500-2500Kpbs.

I don't think the ipad really has a bitrate limitation. I think it has more of a framerate limitation based on the resolution of the video.

Message was edited by: TallBearNC