Question about MeGui/x264 settings for iPod

[Xodarap]

So I've read that iPods (I'll be using 5.5g) can only take AVC video at baseline @1.3. I don't know what 1.3 means (new to AVC), so I'm wondering what options I can change in the encoder settings, specifically. I navigate to the ipod 5.5g preset, and the baseline setting grays some things out. But I'm wondering if I can change, say, motion estimation settings -- that shouldn't affect output recognition, would it? Or quant settings? What macroblock options can I set (besides adaptive DCT and I8x8, which are greyed)? Can I enable deblocking?
Of course, as I should have asked to start, is there an option-by-option guide on ipod compatibility?

Addition: So I went to the wiki article, and it says 5.5 can take level 3, whereas I read in the x264 guide something about 1.3. But it doesn't matter because I have no clue what this macroblocks/second deal is. Also, to add to my questions: I read that the max width for 16:9 iPod video is 624, not 640 -- is that right (doesn't make sense to me)?

[check]

just use the ipod profiles :)

[simonhowson]

I read that the max width for 16:9 iPod video is 624, not 640 -- is that right (doesn't make sense to me)?
It's 640, but the vertical resolution varies depending on the aspect ratio.

I would just stick to the profile. Or turn on the deblocking filter, but apparently this requires 20% - 30% more CPU power, and thus will decrease battery life.

I've had no problems using the auto threads option with the iPod profile, so I'd turn that on if especially if you have a dual core CPU.

[giandrea]

It's 640, but the vertical resolution varies depending on the aspect ratio.

I would just stick to the profile. Or turn on the deblocking filter, but apparently this requires 20% - 30% more CPU power, and thus will decrease battery life.

I've had no problems using the auto threads option with the iPod profile, so I'd turn that on if especially if you have a dual core CPU.

Does the iPod plays back 640x480 anamorphic 16:9 clips, or is it too much for its small CPU? I have some examples if you want to test it, but I don't have an iPod by myself...

[Xodarap]

just use the ipod profiles :)

Well, honestly, I'm quite a quality whore -- plus I plan to watch these same movies on my own LCD monitor, which is sharp enough to make even the subtlest artifacts glaring. Which is why I was wondering if I could just turn up M.E. and quant settings, which shouldn't affect the playback of the file (I would think).

And to the other comment, let me get this straight: the deblocking option applies to the playback itself? IE, it takes more CPU power to play it back or to encode it? I don't mind if my encodes take two days each if it eeks out another couple percentage points of quality. I'm that bad :P

[foxyshadis]

ME mode definitely has no effect on playback, and reference frames usually don't. (Some devices have a maximum, but I think ipod's is at least higher than the profile's.) Those two, along with tweaking deblock settings, should have the largest effect.

[giandrea]

Well, honestly, I'm quite a quality whore -- plus I plan to watch these same movies on my own LCD monitor, which is sharp enough to make even the subtlest artifacts glaring. Which is why I was wondering if I could just turn up M.E. and quant settings, which shouldn't affect the playback of the file (I would think).

And to the other comment, let me get this straight: the deblocking option applies to the playback itself? IE, it takes more CPU power to play it back or to encode it? I don't mind if my encodes take two days each if it eeks out another couple percentage points of quality. I'm that bad :P


Let me explain... if you have a 640x480 clip with an aspect ratio of 2.42:1, the scaling processor of the iPod might be not powerful enough to handle the video. If you are doing not anamorphic or slightly anamorphic there should be no problem. Someone should test if the first case is supported, you can find a sample here (13.6 MB) (http://motoriweb.com/public/test_ipod.mp4), if you can tell me if it plays on the iPod without reencoding, it would be much appreciated.

(The file was edited with QuickTime and remuxed with MP4Box, and has a special atom to view it anamorphically even in QuickTime, that doesn't support anamorphic video, so it is not certain that it will play on an iPod, but it if does, then I know how to rip all my DVDs :sly: )

[NWDaniels91]

Let me explain... if you have a 640x480 clip with an aspect ratio of 2.42:1, the scaling processor of the iPod might be not powerful enough to handle the video. If you are doing not anamorphic or slightly anamorphic there should be no problem. Someone should test if the first case is supported, you can find a sample here (13.6 MB) (http://motoriweb.com/public/test_ipod.mp4), if you can tell me if it plays on the iPod without reencoding, it would be much appreciated.

(The file was edited with QuickTime and remuxed with MP4Box, and has a special atom to view it anamorphically even in QuickTime, that doesn't support anamorphic video, so it is not certain that it will play on an iPod, but it if does, then I know how to rip all my DVDs :sly: )

For the file you provided, iTunes reports "'test_ipod.mp4' was not copied to the iPod because it cannot be played on this iPod."

All I know is that iTunes won't copy it, but I can't be completely sure why iTunes won't copy it. I can tell you this though: if I use iTunes to convert the clip for the iPod, it makes a 640x265 file. I thought I read somewhere that the iPod can only handle files with a SAR of 1:1, but don't quote me on that . . .

[giandrea]

For the file you provided, iTunes reports "'test_ipod.mp4' was not copied to the iPod because it cannot be played on this iPod."

All I know is that iTunes won't copy it, but I can't be completely sure why iTunes won't copy it. I can tell you this though: if I use iTunes to convert the clip for the iPod, it makes a 640x265 file. I thought I read somewhere that the iPod can only handle files with a SAR of 1:1, but don't quote me on that . . .

Thanks, I've read that too, but I have reports from people that confirm that the iPod supports SARs different than 1:1... so I guess I'll have to wait untill I have a new iPod to test ;)