VOD Video Quality Comparison

In earlier Video On Demand posts, I've talked about using the Netflix Watch Instantly capability to stream movies and TV shows to your computer or — via a TiVo, a Sony PlayStation 3, or any other "Netflix-ready" device — directly to your HDTV screen. I've also talked about using the Amazon Video On Demand store to rent or purchase videos and then watch them in your computer browser or download them to a TiVo or other "Amazon-ready" device.

I haven't said much yet about the ability to rent or buy videos at the iTunes Store, via the iTunes application on your Mac or PC, as opposed to your web browser. The iTunes Store offers video content for iPhones and iPods, for the Apple TV, and for play on your desktop in iTunes.

I recently rented the 1958 classic horror flick The Fly at Amazon and iTunes and compared the quality of the video with that at Netflix. All these are standard-def versions.

Here is how a particularly useful frame of the movie looks in the Netflix version:




In the iTunes version:




And in the Amazon version:




To see what the differences are, you'll need to click on each of these images to enlarge them in your browser window. The best way to do that is to open each in a new tab in the same browser window, then click on each tab in turn to note the rather obvious differences.

First, rapidly alternate between the Netflix and Amazon versions. They're similar in frame size, but the Netflix covers just a tad more of the original 2.35:1 CinemaScope film frame — compare especially the amount of the grid of the depicted window screen that you can see at the left edge of the picture.

The Netflix image is also sharper. Look at the Roman numeral date MCMLVIII in both images. It's a little more legible in the Netflix than in the Amazon.

Now switch to the iTunes version. The MCMLVIII is downright blurry. The frame is stretched vertically to yield a subtly incorrect picture geometry. The left edge of the picture reveals less of the depicted screen than the Netflix version does — about as much as the Amazon version does. Also, the iTunes version looks duller and darker; the reddish brown background color isn't as vibrant.

In other words, the iTunes image is geared to the low available resolution and nonstandard aspect ratio of an iPhone/iPod screen. The subtle vertical stretching allows the image to use more of the mobile device's limited screen area than would otherwise be the case, given that (nearly) the entire width of the original (extremely wide) film frame is being shown.

Most users probably prefer the slight geometric distortion to having wider black bars at the top and bottom of the iPhone/iPod screen, so this is a compromise that makes some sense. However, if you are watching on a big computer monitor, the soft, stretched image looks pretty bad when compared, in full-screen mode on the same monitor, with the Netflix version — which, after all, is free to anyone with a Netflix-ready TV setup and a standard Netflix account.

Meanwhile, the Amazon version is just a tick inferior to the Netflix version, and far preferable to the iTunes version on any reasonably large screen. If you lack a Netflix-ready setup but have one that is Amazon-ready, you will lose little in terms of video quality (though you will have to pay for each rental or purchase).

Strictly speaking, this comparison applies only to this one movie; it may be that Amazon is better than Netflix for other titles. However, I think it likely that iTunes will be generally unable to match either Netflix or Amazon in terms of video quality, simply because it targets iPhones/iPods first, and bigger, higher-resolution viewscreens second.

An exception: HD content. You can buy or rent certain titles in HD from an Apple TV, for use on the Apple TV. I'll deal with that in a subsequent post.

Another exception: standard-def videos from the iTunes Store, when rented directly from an Apple TV (see this Apple Support document). They can have up to 720x480-pixel widescreen resolution, while the same titles rented from a computer or iPhone/iTouch max out at 640x480. (I rented The Fly from my computer.)

This exception applies only to iTunes Store rentals of videos. iStore video purchases are stuck with 640x480 resolution, no matter what device you use to make the purchase. 720x480 supposedly won't play on an iPhone/iTouch, only on an Apple TV. If you bought a video on your Apple TV and later tried to move it to your iPhone, it wouldn't play ... and Apple doesn't want to deal with the customer complaints when that happens.

An aside for techies:

(The main part of the article is done. If you don't want to be bored by a raft of technical detail, you can stop reading now.)

640x480-pixel anamorphic resolution squeezes a 16:9 widescreen picture into a nominally 4:3 video frame that uses "square" pixels: the individual pixels are exactly as wide as they are tall. The decoder expands the frame again into its original 16:9 aspect ratio, a process that is relatively easy when the pixels are square. Of course, after the pixels are "unsqueezed," they're no longer square, but having square pixels prior to the unsqueezing allows the decoding to be done by a processor of quite limited power, such as is found in an iPhone/iTouch.

720x480-pixel anamorphic widescreen, unsqueezed to 16:9, has non-square pixels both for the input to the decoder and for the output, so the strain on processing capacity is much greater — too great for an iPhone/iTouch. But the Apple TV has (somewhat) greater processing capacity, so 720x480-pixel anamorphic widescreen input works with it.

There are other potential ways in which videos that work on an Apple TV can be incompatible with an iPhone/iTouch. For example, if a video has a bitrate of over 1,500 kbps, iPhone/iTouch won't touch it. iPhone/iTouch can't use videos encoded with bidirectionally predictive frames (B-frames), either. B-frames allow for more compact files and hold down transmitted bitrates. If B-frames were allowed, 1,500 kbps could yield a sharper, more artifact-free image.

But the iPhone/iTouch, because of its tiny, low-resolution screen, can't render any sharper and better images than it does. Plus, higher bitrates require larger memories and faster processors in a decoding device, while B-frames likewise tax the decoding processor and require the frames of displayed video to be held in memory after they have been displayed, "wasting" available memory space. Apple made the compromises that it did in order that the processor speed and memory size of the iPhone/iTouch could be held within reason.

Now, these considerations don't apply at all to Netflix video streaming, for the simple reason that the list of Netflix-ready devices includes no mobile or portable devices.

What about Amazon VOD? Again, Amazon's official list of ways to watch their videos conspicuously fails to mention mobile or portable devices.

In its earlier incarnation as Amazon Unbox, the Amazon VOD service supported Microsoft PlaysForSure portable devices. Those were non-PC devices that were certified by Microsoft to be able to play anything their Windows Media Player app could play on a real computer. PlaysForSure certification was rebranded as "Certified for Windows Vista" in 2007.

Meanwhile, Microsoft had come out with it's own iTouch competitor, the Zune portable media player — and Zune cannot play all PlaysForSure content!

Remind you of anything? Such as: the iPhone/iPod Touch can't play all the content an Apple TV can play (including HD content).

The message here is that it is as yet extremely difficult — nay, impossible — to stream highest-quality video content that "plays for sure" on all manner of devices that turn out to be price-competitive in a competitive, real-world marketplace.

Amazon VOD Rentals

In Amazon's Video On Demand I talked about buying videos from Amazon's VOD store. You can also rent many titles. As this is written, there are 17,327 rental titles and 23,459 titles that can be purchased.

Many of the rentals and to-buy titles are the same. For example, Borat, the 2006 Sacha Baron Cohen hit, costs $2.99 to rent, $5.49 to buy:



When you buy a TV show or movie, it goes permanently into your video library at Amazon.com:



But when you rent, the title is only temporarily in your library until it is downloaded to a device you own that can play it. After the download, you have 30 days to begin playing it on that device. Once you begin watching it, you have 24 hours to finish. When the 24 hours are up, the downloaded copy goes poof.

You can also play the rental on your computer, right in your web browser. Again, you have 24 hours to finish before it vanishes forever.

Here's me renting The Phantom of the Opera (2004). First, I search for "phantom of the opera" at the Amazon VOD store and get:




I click on "The Phantom of the Opera (Rental — 2009)" and see:



(I still have the option to buy the video, as you can see.) At this point I need to already have an Amazon.com account with a credit card or other default payment method on file, and 1-Click ordering enabled. After I click on "24 hour rental with 1-Click $2.99," after a few seconds during which Amazon is processing my order, I see:



I opt to click on the "Your Video Library" link at this point, to see:



Notice that this entry is truly a phantom. Come Dec. 26 at 4:01 PM, if I haven't watched it, it will vanish!

Going back to the "Thank you for your purchase" panel: it gives the options to "Watch Now," "Watch Later," or "Download." You should choose one of these very, very carefully, bearing in mind that "Once you download or start to watch this rental you can't change your viewing choice." That means your choice of a device such as a TiVo to download the rental to is irrevocable. You can't change your mind later and move it to a different device, or decide to play the rental instead in your browser window.

Likewise, if you start playing the rental in your browser, you can't change your mind and download it to your TiVo.

"Watch Now" is what you click to play the rental right in your browser window. "Watch Later" does nothing except leave the rental sitting in Your Video Library, awaiting further disposition. "Download" is the way to initiate a download to your TiVo or other device compatible with Amazon VOD. For purposes of this example, I'll click "Download."

Before I click it, I need to make sure the download is going to go to the right device, so I need to make a selection from the download device drop-down menu:



In this menu I see my two TiVo units, "Living Room TiVo" and "Bedroom," and one Windows computer, "Clone of winxp," running Amazon's Unbox viewer in Windows. (The Unbox software won't run on a Mac.) I want to send my download to my "Living Room TiVo," so I select that, click "Download," and see:



At this point the download has begun. My TiVo box shows a blue LED on its front panel, and if I look in its Now Playing list, I see "The Phantom of the Opera" with a simulated blue LED next to it. The same item appears (redundantly) in the folder representing my "Amazon Video On Demand" group.

I can begin playing the video almost immediately, thanks to the fact that this is a "progressive" download that does not require me to twiddle my thumbs until the whole video has been downloaded.

(If at this juncture I look, in my computer browser, again at my Amazon "Your Video Library," I note that "The Phantom of the Opera" has disappeared from it. Once the rental has begun downloading, that's it: it's no longer in the library.)

Getting back to my Living Room TiVo: whenever I begin playing the rental, before it actually starts I have to wade through a warning to the effect that I'll have just 24 hours to finish watching. When I confirm that starting the 24-hour clock ticking is what I truly intend to do, the video starts playing, just like any other video I have on the TiVo.

If I like, I can temporarily stop playing it — planning to come back to it later — whereupon it acquires a flashing red flag next to its entry in the Now Playing list. This is a warning that at a time 24 hours from when I began watching the rental, it will cease to exist — even if I haven't finished watching it! And sure enough, exactly 24 hours after I first hit Play, the downloaded file disappears from the TiVo.

Amazon's Video On Demand

So far in my Netflix Streaming series, I've talked about the ability to stream Netflix video to your home computers-slash-HDTV screens. Now I'd like to branch out and discuss Amazon Video On Demand.

At Amazon.com's main page you can set the Search drop-down menu to Video On Demand, leave the search box empty, and click Go. If you do, you'll see this. As this post is being written on Nov. 26, 2009, there are 40,691 results, each a movie or TV show that you can rent or buy.

Many titles can be rented or bought — for example, Borat, the 2006 Sacha Baron Cohen hit:



This post covers buying. I'll talk about renting in a subsequent post.

Amazon VOD used to be called Amazon Unbox (Get it? It's a video you can buy, like a DVD or a Blu-ray. But it's not a DVD, so you can't hold it in your hand, it doesn't come in a box, there's no shrink wrap, etc.). Amazon Unbox has been around since Fall 2006; since Fall '08 it's been rebranded Amazon Video on Demand. Where Unbox required you to use a software player that worked only on Windows PCs, Amazon VOD works on PCs and Macs. You don't even need a special player now; a web browser is all you need. (Plus, there is still an Amazon Unbox player that you can use in Windows. Download it here.)

Say you'd like to watch every show in the entire first season of The West Wing. At Amazon's VOD shop, you type "West Wing" into the search box and see various seasons of the late, great NBC political drama at the top of the results:



If you click on Season 1, you'll see (click the image to enlarge):



Here's a close-up of the "Order Now" panel:



Assuming you already have an Amazon account with a credit card and 1-Click buying enabled, purchasing just the first episode for $1.99 is pretty straightforward — it's the default purchase, shown as "Now Playing" in the "Preview" column in the episode list. Scroll down in the list, and you can select other first-season episodes, either singly or as a group, by putting check marks by those you want. Each episode, purchased singly, is $1.99.

But you are interested in the entire season, so you would just click "Buy Season 1 with 1-Click $17.99."

Once you enter your Amazon password and confirm your purchase, all the videos become a permanent part of your online video library at Amazon. To see them listed there, click on "Your Video Library" in the Video On Demand menu bar in your browser window. You'll see a graphic labeled "The West Wing Season 1." Here is mine for Season 2 (I don't own Season 1):



(You can click on the screen image above to enlarge it. The "Your Video Library" tab at upper right is what you clicked on to arrive at this screen in the first place.)

Clicked on, the thumbnail graphic will expand to show all the individual episodes of The West Wing for that particular season:



Clicking on one of the episodes brings up:



You can elect to download the selected episode, or you can watch it right away.

Choosing the download option gives you:



In this case, my download destination is a TiVo video recorder in my "Bedroom." (I'd already downloaded it to my "Living Room TiVo," as the "Locations" entry indicates.)

You can download the videos you buy to various compatible computers and devices in your household, but you have to initiate the download from a computer browser. You can't manipulate your Amazon Video Library from a device such as a TiVo itself.

"Bedroom" is an available download destination for me, since I have already registered that TiVo with Amazon. To do that in my computer browser I went here, then clicked on Refresh list of registered TiVo DVRs. (Go here to confirm what TiVos you have already registered with Amazon, if any.) You can also register the TiVo from the TiVo box itself by selecting "Video on Demand" from the main TiVo menu, selecting "Amazon Video On Demand" from the next menu, and then following the on-screen registration instructions.

Once you have initiated an Amazon VOD download, within a minute or so the destination device will actually begin receiving the video. If the device is a TiVo, a blue LED lights up on its front to indicate that a download is in progress. You can go into its Now Playing list and see the video already listed there. While it is downloading, it will display an imitation of the blue front-panel LED next to its name.

If you want, you can start watching the video even while the download proceeds. This capability of watching an in-progress download is called "progressive download."

If you have a slow Internet connection, it is possible that the progressive download will not keep up with the playback — in which case you will be returned to the TiVo menu screen for the video. You can resume playback of the video at will, but you may have to wait a bit for enough of the video to be transferred to avoid further interruption.


If you prefer, you can bypass downloading the video to a TiVo or other compatible device and just watch it instantly on your computer, in your web browser:



(Click on the image above to see it full size. The grain in the image is a byproduct of my screen capture software and does not appear in the actual video.)

The Adobe Flash Player plugin must be installed in your browser for this to work.

Once the purchased video is in your Amazon VOD library online, you can play it in your browser any time you want, as often as you want.

Remember, watching an Amazon VOD video in your browser starts instantly, since the whole file is not actually downloaded. This is different from a progressive download, for which you may have to wait five minutes or so before beginning to watch the video. That's why if you elect to use the Amazon Unbox player on a Windows PC, you have to wait for enough of the video to be downloaded, before starting to watch.

You don't have to pay extra for each use of the video, whether in a browser window, in the Unbox player, or on a device like a TiVo. You can also re-download it at any time for free; if you delete it from Unbox or your TiVo you can get it back at will. This is the advantage of buying rather than renting.

However, if you will only be watching a video once or twice, and if Amazon offers it for rental rather than purchase, renting can save you money. Renting will be the topic of my next post ...