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skunkworker

macrumors regular
Original poster
Sep 9, 2007
182
20
I have been noticing recently that the iTunes Store Movies have been looking unusually good for their size. Is it they take the HD source and oversample it down to 720x400? or are they using better h.264 b-frames?
 
Yeah I would surmise that Apple has access to better sources than DVD from which to do their master encodings, plus the fact that they wouldn't be going through multiple encodings... I.E. going from some high quality source to H.264 instead of high quality source to MPEG-2 to raw to H.264 (two levels of compression artifacting).
 
Their encoding algorithms may be more sophisticated than what is available for free to the public. They may also have the ability to manually increase bit rates or change compression algorithms for certain sections of the movie to get better image quality. I've heard that even for DVDs they don't just feed it into a program to do it, they actually spend quite a bit of time to make the movie look as good as they can.
 
I don't think it is Apple that is doing the encoding. I think that they get it that way from the distributor/studio. Other than that, all the points above would apply to the distributor.
 
I was thinking about this the other day as I watched a movie I had ripped on my Apple TV. I sure would love to know how Apple do it - as in what their process is.

pac
 
I was thinking about this the other day as I watched a movie I had ripped on my Apple TV. I sure would love to know how Apple do it - as in what their process is.

pac

I heard that Steve spends his evenings encoding content for the iTMS, using the latest HandBrake snapshot :D
 
lol

"I heard that Steve spends his evenings encoding content for the iTMS, using the latest HandBrake snapshot"

Made my day, him and a tin of ben an' jerry's!

Well, I have had some good rips and some bad rips, if you look at "sleepy hollow'" on iTunes it looks like crap, same with the original pirates, before they upped it to HD.

As for us using handbrake, we have limited systems compared to duplication/encoding houses, but I think if we tweak a bit and put more time in it we can get some nicer stuff too.
 
The recent update to HD also brought Anamorphic Encoding w/ 5.1 Dolby Surround Sound to SD content as well. As stated by Apple at NAB 2007 (or '06, don't remember), they use Compressor to encode all video content on the store.

To answer your question, any of the recently encoded content from within the past year looks just as good as a DVD Handbrake rip (HD obviously better) due to the anamorphic encoding.
 
No mystery. Sources much higher res than even blu ray. Bring a macpro octo to its knees running that source through hb. Nothing more and nothing less. To think you can duplicate it from a 480p dvd source (or even come close) is craziness.

Realize that transcoders like hb can only calculate compression based upon what they are given for sources. each transcode drops the visual quality. Thats why blu ray rips transcoded down to 480p look so much better than the sd dvd 480p source transcoded to a 480p hb encode and on and on.

I would say that *if* you had access to the sources the studios had, you could get close if not comparable output (maybe even better?). Of course you might need a server farm to do it in any meaningful amount of time.
 
Yeah, with iTunes, its consistent file size but inconsistent quality.

Most of the movies look very good. Some, even at 640x480, I can't distinguish from an upscaled DVD (not that I go out of my way to try to compare. If it looks good, it looks good and I leave it at that).

However, as someone mentioned, there are a few times when something looks crap. It's not often, and the filesize and consistency of filesize overrides any issues I have with that.

Meanwhile, movies I encode with Handbrake at the universal setting, look good but are wildly inconsistent in filesize. When I go the iPod legacy route, I end up with similar filesize to that of the iTunes store. I find most films (dramas, non-animated) are perfectly fine with the iPod legacy preset in Handbrake. However, I go with Universal anyways.

With TV shows, that's an entirely different story, especially with animated and older comedies. They look like crap from the iTunes store. I encode those myself.

Like I said, file size is significantly larger (some episodes of The Simpsons ring it at a whopping half a gig per episode), but that also includes two or three audio tracks.
 
I would imagine that If Apple encode them themselves, they do it direct from the master tapes rather than ripping from DVDs.

Although I doubt it's literally "tapes," Apple likely has access to the master video copies, or at least uncompressed. Don't forget that DVDs are compressed video, which means some data was already lost going from master to DVD. Apple's software for encoding is probably written better since it's not some open-source "we're trying our best" effort like HandBrake.

What's hilarious is I bet there's a room somewhere that uses Blu-ray Discs since those are lossless media. I know zip about the movie industry, but that sounds like an easy way to give Apple an uncompressed copy.
 
....I bet there's a room somewhere that uses Blu-ray Discs since those are lossless media. I know zip about the movie industry, but that sounds like an easy way to give Apple an uncompressed copy.

The video content on Blu-ray video discs is compressed.

Blu-ray discs are only "lossless" in the sense that ANY digital storage medium is lossless - you read from them exactly whatever you write to them, but what gets written to them is a compressed version of the original images.

You admit you know "zip" about the movie industry, but please don't inadvertently start an apocryphal tale that "Blu-Ray is lossless" - like the tale that everybody latched onto about ten years ago that "DVD was a good medium for archiving movies". Both completely untrue.
 
I have been noticing recently that the iTunes Store Movies have been looking unusually good for their size. Is it they take the HD source and oversample it down to 720x400? or are they using better h.264 b-frames?
LOL what does "oversample it down" mean? :confused: DVD native resolution is 720x480 in the US and 720x576 in europe.

They will look exactly the same as a DVD ISO image. If you're using something like Handbrake to rip a DVD and make it into a smaller file size, you are compressing the crap out of your DVD and killing the quality.
 
Audio on many DVD's is lossless too.
Er, lossless vs. what ? The original master the film was shot in ? Even DTS is compressed from the original. AC3 (which the dvd spec requires) is also compressed. Not sure what you mean by "Lossless".
 
Spice Weasel - Thank you. That has made my day. I've got this great image of Steve Jobs in a turtle neck, boxers, and rabbit slippers, eating a bologna sandwich, a coke can with a straw sticking out of it next to him, staring at an apple cinema display, shaking his head because Handbrake isn't supporting Blu-ray subs. Maybe even throw in the Woz walking into the room in a bathrobe and black socks eating a slice of pizza asking if Jobs wants to go outside and play Segway polo... (by the way, in my cartoon bubble, Jobs and Woz aren't gay, just roomies in the same apartment.)
 
Not actually. PCM is not compressed. However, I believe that DVDs are limited to 2.0 sound if using PCM.

I guess I was referring to MLP (lossless encoding) for pcm which is quite common. Though afaik pcm tracks generally lend themselves to music dvd's etc. especially when they were originally recorded in stereo.

To the OP: apologies for derailing the thread. But to the point of the title.

in terms of video, the extremely high quality of the *video* source lends itself to the relatively excellent quality. Yes, even blu ray is compressed (video) though with better codecs (like h.264, etc.) than the mpeg-2 used on standard dvd's.
 
But surely the very act of taking any analogue signal, be it audio or video, and converting it to digital results in some form of loss, unless you can sample it with an infinate resolution. Or am I just talking rubbish ;)
 
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