IPod touch support 720x400 ?!

[haoqfu]

I ripped off a 50 seconds chapter from Fight-club from handbrake, and chose 720*400 (h264, low complexity), average bit rate is 2500, the file size is about 16.9Mb, surprisingly it worked great on ipod touch (guess it would be working on iphone as well).

according to the official spec, don't ipod touch & iphone & ipod classic only support up to 640*480 with 2500 bitrate? anyone has got any idea?

 

[Jade Cambell]

I ripped off a 50 seconds chapter from Fight-club from handbrake, and chose 720*400 (h264, low complexity), average bit rate is 2500, the file size is about 16.9Mb, surprisingly it worked great on ipod touch (guess it would be working on iphone as well).

according to the official spec, don't ipod touch & iphone & ipod classic only support up to 640*480 with 2500 bitrate? anyone has got any idea?

It simply downscales it on the device....

 

[haoqfu]

It simply downscales it on the device....

since the official spec says the max. resolutioni is 640*480, i assume the ipod shouldn't sync with iTunes on movie with better resolution..

 

[Fuchal]

since the official spec says the max. resolutioni is 640*480, i assume the ipod shouldn't sync with iTunes on movie with better resolution..

resolution doesnt matter. as long as it is a valid file under the limit of total pixels.

it counts the total pixels - 640 * 480 = 307200

720 * 400 = 288000

 

[cjmal]

since the official spec says the max. resolutioni is 640*480, i assume the ipod shouldn't sync with iTunes on movie with better resolution..

I remember reading that as long as it's under a certain amount of total pixels, it will work, it's not nevessarily just about the resolution. I had 640 x 352 videos working on the 5th gen iPod before the update even came that supported 640. Try a bigger height, and I can guarantee you that it wont work

 

[cwolves]

urg...the specs are wrong.

it supports FULL level 3 baseline h264 video. Max video settings are:

720x480 @ 30.0 fps w/ 6 ref frames
or
720x544 @ 26.4 fps w/ 5 ref frames
or
720x576 @ 25.0 fps w/ 5 ref frames

10mbit/sec video
40,500 macroblocks per second
1,620 macroblocks per frame

The "max video sizes" are calculated based on the macroblocks. Encoding at high sizes will force 16x16px macroblocks, thus lowering your quality a bit. Unfortunately with baseline 3 you'd need to cut your video size to 480x216 before most encoders would use 8x8 blocks.

16x16 x 1,620 = 414,720 max pixels per frame.
414,720/720 = 576. Thus 720x576 is max possible video size.
40,500 / 1,620 = 25. Thus at 720x576 your max framerate is 25 fps.

 

[haoqfu]

you are right, i remember i heard of the "total pixel count" theory before as well..

by the way, do you think 720*400 looks better on the computer than 640*480? i'm only going to keep one copy of each movie I have, so that i can view on both my ipod and mac.

 

[cwolves]

by the way, do you think 720*400 looks better on the computer than 640*480? i'm only going to keep one copy of each movie I have, so that i can view on both my ipod and mac.

720x400 and 640x480 are different aspect ratios. If you're going for a universal fit and have 1.3333 ratio video (which is what 640x480 is), use 720x544

 

[haoqfu]

720x400 and 640x480 are different aspect ratios. If you're going for a universal fit and have 1.3333 ratio video (which is what 640x480 is), use 720x544

sorry, i should have clarified that i'm comparing 720x400 and 640 x356 which are of the same ratio.