Question about exporting to iPod

[Tim Dashwood]

Originally Posted by Nate Schmidt

Tim, when I installed your presets the mp4's worked great but my iPod won't recognize the h.264 ones any ideas?

I forgot to mention that the Apple specs for H.264 and ipod are "baseline profile." I don't know how to specify baseline profile in compressor.

However, once you add your .mov files to iTunes, just select them and then choose "Convert Selection for iPod" from the advanced menu. iTunes will then do something to the H.264 files to make them compatible. iTunes then changes the extension to ".m4v" but the quality and bitrate stay the same. H.264 is technically a MP4 format.

Now the files will transfer to the ipod.

[Sergio Perez]

Originally Posted by Tim Dashwood

I've been doing alot of research on encoding video for ipod and discovered some interesting things. (iLounge is a great resource for this info.)

Apple posts max specs of 320 x 240 at 768kbps in H.264 or 480x480 at 2500kbps in MP4.

The great thing is that you can break the pixel dimension rules in many ways to achieve higher quality video. Of course everything gets downscaled to 320 horizontal rez on the actual ipod screen, but the native rez is output to a TV when you use the video cable.

Here's the secret to ipod video: The actual resolution limits are 300 macroblocks for H.264 or 900 macroblocks for MP4.

For example
-320 pixels divided by 16 = 20
-240 pixels divided by 16 = 15
- 15 x 20 = 300, therefore 320 x 240 meets the 300 macroblock limit for H.264.

That's great for 4x3, but let's say you want to encode something that is 16x9. Why waste space on black bars when you only need to encode the actual 16x9 content?

The dimensions I found that work well for 16x9 in H.264 are 368 x 208.
So 368 pixels divided by 16 = 23
208 pixels divided by 16 = 13
23 x 13 = 299 macroblocks. Therefore under the 300 macroblock limit.

Now, for MP4 the macroblock limit is much bigger at 900.

So for 4x3 MP4 you could go as high as 553 x 416
For 16x9 MP4 you can go up to 640*360 --- that's DVD quality!!!!

Just remember to keep the bitrates under 768kbps for H.264 or 2500kbps for MP4.

Tim, are your presets optimized for the best output? Can we have some presets that gives us optimal output?

I suggest you name them " Tim Dashwood Ipod presets" you deserve it!

[Tim Dashwood]

Originally Posted by Sergio Perez

Tim, are your presets optimized for the best output? Can we have some presets that gives us optimal output?

Well, with Compressor 2 you can turn on 2-pass encoding for H.264 to get the best VBR use out of the available bandwidth. Other than that, the presets I created use the maximum bitrate and macroblocks allowed on the iPod.


As soon as I have time I will create some additional settings to pull a 16x9 from a letterboxed 4x3, as well as pull a 2:35:1 from 4x3 or 16x9.
2.35:1 will allow even more horizontal resolution. I just calculated that 720x306 would work for MP4 2.35:1 ratio.

[Tim Dashwood]

I've created some new settings for 2.35:1 extracted from 4x3 or 16x9 and 2-pass H.264. I created these ones in Compressor 2, but I'm not sure if they are backwards compatible with Compressor 1.
I used the MP4 compressor within the quicktime wrapper instead so the extension of MP4 files is .mov. This doesn't seem to affect anything. The ipod still plays it no problem.
I was also able to "use current frame rate" in compressor 2, so there's no need for separate 24P or 60i settings anymore. These will also be NTSC or PAL compatible. The 2.35:1 settings may need slight crop adjustment for PAL because of the higher vertical rez.

You can look at a frame grab of the updated settings here:
http://homepage.mac.com/timdashwood/...d_settings.jpg

You can download the settings here:
http://homepage.mac.com/timdashwood/...ompressor2.zip

Just move the 4 folders to your user name/Library/Application Support/Compressor folder before you launch Compressor 2.

Please try them out and let me know how they work. Also watch the large MP4s on a TV with the video out cable from the ipod and let me know how it compares to DVD. The resolution should hold, but I'm sure you'll see many more compression artifacts than DVD quality Mpeg2.

[Sergio Perez]

Will do, Tim. Thanks for all the hard work. I'll check this out and report to you tomorrow (hopefully :)

[Dave Perry]

Tim,

I've learned a lot this weekend by following this post. Just got my iPod this weekend and have had a crash course in encoding for it thanks to your and others posts.

I'm using MPEGStream Clip for my encoding because unfortunately Compressor 1 does not do H.264.

[Tim Dashwood]

Originally Posted by Dave Perry

I'm using MPEGStream Clip for my encoding because unfortunately Compressor 1 does not do H.264.

Compressor 1 will work with H.264 if you have QT7 installed. These are my old Compressor 1 presets.
http://homepage.mac.com/timdashwood/.Public/iPod.zip

[Dave Perry]

Thanks Tim,

I'll check those out tonight. I opened Compressor 1 to see if it had presets and didn't se any for H.264. I guess that's why I need to get yours and install them :)

[Sergio Perez]

Tim, the video i did using one of your presets looked very good indeed. However, the encoding, for best quality, on my 1.65 powerbook took really a lot of time! I believe I'll try to do the conversions on my Powermac for definite analysis. I'm posting this in a hurry, not an in depth analysis, and seing footage straight from the Ipod. I'll post tv output opinion latter (Ipod picture looks better than default ëxport to ipod"from quicktime pro".)

[Tim Dashwood]

I just found out that running the ipod update included with iTunes 7 will allow the iPod Video (5th Generation) to play H.264 files at up to 640x480 resolution. Previously the limit was 320x240.

This is good news for those of us who want to use our iPods as portable media players to connect to external monitors or TVs.

Originally Posted by Tim Dashwood

I just found out that running the ipod update included with iTunes 7 will allow the iPod Video (5th Generation) to play H.264 files at up to 640x480 resolution. Previously the limit was 320x240.

This is good news for those of us who want to use our iPods as portable media players to connect to external monitors or TVs.

Thanks Tim,

This is also good news for helping to consolodate the flow and options for exporting movies to the web and iPod at the time. I like 480 x 270 for the web, so this new option will reduce the number of steps I need to take to prepare a movie for both.

I appreciate your update. { edit from post #27 comment - thanks Tim }

[Tim Dashwood]

Originally Posted by Derek West

I appreciate your update... Even though this is just for the new 5th Generation of iPod's.

What I mean by 5G iPods is the iPod "Video" that was released last year. I bought mine in January. The new configurations released on Sept 12, 2006 are still 5G, but they come preloaded with the new firmware. Running this update will bring the year-old iPod Video up-to-date.

[Heath McKnight]

Why is iTunes 7 the best so far (I've been using since I figured out what it was 5 years ago--I wasn't used to mp3 players in a computer, or a device for that matter)? NO GAPS BETWEEN SONGS! Sorry for the all caps, but I've always been annoyed when I hear a gap between my favorite albums' songs, like OK Computer, etc.

heath