OK- so now that aTV is out, how long before someone writes a program to rip dvds to itunes and grab cover at so that you can scroll through your movies on yoru television with coverflow, click a button, and watch the movie?

I see aTV taking off huge if it is what "media center adapters" were supposed to be- machines that just work. No company seems to understand (besides apple) that if you make something that just works for the average person, you will sell a lot of them. So aTV seems to jsut work, now we just need an convenient (not muli-part) program to rip dvds in to itunes.

The "average person" doesn't rip their movies to their PC. In fact, I don't know of anyone who does this out of all my friends.

Not until congress repeals the DMCA. Apple can't put (legally) DVD ripping in iTunes.

Of course I wouldn't be surprised if Handbrake (or its offshoot), or MacTheRipper implements a one step rip-to-iTunes-in-aTV-format feature.

I for one am not interested in converting my MPEG2s to an aTV format. I love the concept of the aTV, I applaud Apple for developing aTV and I understand why they are not supporting MPEG2 (the media industry would probably go bezerk). I guess I"ll just have to wait for someone else to step up and copy Apple, but with more Codec support.

Well, they've already hacked the thing to play DIVX, etc., as well as to take a larger hard drive. If there is a hack to make it see and play Video_ts DVD rips, I am ordering one as an extender for my bedroom. I'd be surprised if such hack isn't available within a month or two.

Then ATV would totally make sense to me:-)

It will be running anything a Mac can very soon. The VisualHub creator got VLC running on it today.

It will be running anything a Mac can very soon. The VisualHub creator got VLC running on it today.

If they got VLC running on it within the Front Row interface I'm sold.

If they got VLC running on it within the Front Row interface I'm sold.They're working on putting osx*86 (OS X on generic PC hardware) right now (not sure if it will work, but everybody's learning as they go). VLC and other apps are running instead of BackRow (for limited duration as the WatchDog reboots the box when it detects BackRow is down). It's still rough right now. Kind of like wading up the amazon.

We know that QuickTime in the Mac OS can't pass an AC3 stream to the optical port. Can anyone confirm that the [apple]TV is crippled in the same way?

(If the [apple]TV *can* passthrough AC3 data, then converting ones' DVD library just got a whole lot more realistic/efficient)

media fork (hand break) will rip a dvd to an ATV acceptable h.264

media fork (hand break) will rip a dvd to an ATV acceptable h.264

But at what cost? ARe we losing resolution? Digital audio?

Resolution is selectable. What we lose is surround as far as I can tell.

Is this confirmed? I hadn't heard this before about the Apple TV. What good is the optical port if you can't get Dolby Digital or DTS out of it? According to the specs on my Macbook, you can send DD or DTS from the optical port (I guess at least for the DVD Player.app). I never heard anything saying you can't get DD or DTS from a quicktime (xvid or divx or whatever) file. ???

I never heard anything saying you can't get DD or DTS from a quicktime (xvid or divx or whatever) file. ???

I guess you are new here ;)

The problem is that QT does not pass the 5.1 sound to the optical audio port. It can decode the sound, but only passthrough in stereo.

Sorry.. I've been reading more on this.. very disappointing :(

Okay but we don't need or even want the Apple TV to "decode" the sound. Only pass it through to the AVR for decoding there. I was reading something about being able to play 5.1 sound from QT or iTunes. You would hear static locally from stereo speakers, but as long as the volume was at 100% the 5.1 was passed through the optical port to the avr. Has this all be tested on the AppleTV now that it has been shipping?

Sorry.. I've been reading more on this.. very disappointing :(

Okay but we don't need or even want the Apple TV to "decode" the sound. Only pass it through to the AVR for decoding there. I was reading something about being able to play 5.1 sound from QT or iTunes. You would hear static locally from stereo speakers, but as long as the volume was at 100% the 5.1 was passed through the optical port to the avr. Has this all be tested on the AppleTV now that it has been shipping?

The only way I have read of getting 5.1 sound actually working in QT is a very time-consuming process where you have to import each of the soundtracks separately and then save it to one movie. I believe even then, you need to have 5.1 discrete outputs for this to work.

A better solution at the moment is the AppleTV hack project which has successfully gotten VLC loaded onto AppleTV and VLC has successfully played back 5.1 on the AppleTV.

Okay, but what about this?

http://trac.cod3r.com/a52codec/

A52Codec - Features
* Multi-channel decoding of AC3 audio (can do full 5.1 decoding).
* Implemented as a core-audio component so it is available to both Quicktime and Core Audio components.
* Includes an AC3 importer so QuickTime can read .ac3 files directly.
* Includes a preferences file to enable or disable dobly surround encoding as well as dynamic range compression.

I have been using A52 for a while in quicktime to play my xvid files that have ac3 soundtracks. Works great, though I do not know if it outputs the 5.1 to the optical port for playback on a 5.1 receiver. I might have to test that.

A better solution at the moment is the AppleTV hack project which has successfully gotten VLC loaded onto AppleTV and VLC has successfully played back 5.1 on the AppleTV.

I don't see the need for VLC. Once A52 is installed in a Mac, Quicktime will play the AC3 soundtrack. Again, I don't know if it passes through 5.1 as well to the optical port or if it just passes stereo, but someone could check real quick (I'm not at home). I would think if it is possible to run VLC on an AppleTV, it is possible to install A52 and just use the AppleTV as normal.

Um, really?

http://trac.cod3r.com/a52codec/

A52Codec - Features
* Multi-channel decoding of AC3 audio (can do full 5.1 decoding).
* Implemented as a core-audio component so it is available to both Quicktime and Core Audio components.
* Includes an AC3 importer so QuickTime can read .ac3 files directly.
* Includes a preferences file to enable or disable dobly surround encoding as well as dynamic range compression.

And where in this list do you see "passthrough to optical output"?

Trust me, this question has been discussed to death here. This plugin, as well as others, permits QT to playback (in stereo) files that contain only AC3 information.

Gotcha. So you are saying VLC will pass the AC-3 information through the optical out?

Gotcha. So you are saying VLC will pass the AC-3 information through the optical out?

Actually, I'm not, but the guys working on hacking the AppleTV are saying that they have accomplished ".vob(DVDrip) with VLC (Menu, subtitles, 5.1 surround working)".

You can keep up with their projects and progress here (http://wiki.awkwardtv.org/wiki/).

But, if you mean playing back on a regular Mac (not AppleTV), then yes, AFAIK VLC plays back .divx and other file formats with AC3 correctly.

Danny, I don't think that does what you think it does. Read through the help tickets, especially #4:

http://trac.cod3r.com/a52codec/ticket/4

Gotcha.
:)

Interesting, the arstechnica "In Depth Review" (http://arstechnica.com/reviews/hardware/appletv.ars/4) on the apple tv states that..


Although Apple makes no claims regarding Apple TV's ability to play "full" surround sound, it is emerging as a major sticking point among audiophiles. To be sure about the Apple TV's audio capabilities, we enlisted the help of a friend of ours, one of our readers, and fellow forum member John Averitt. What we found confirmed most people's fears: Apple TV is limited to playing files that are present in iTunes, which limits the number of 5.1 file types. A 5.1 AAC QuickTime movie gave only 2-channel sound through the Apple TV, or (at best) Dolby Digital Pro Logic II when played through the optical connection. This is different than Front Row behavior on a Mac mini—Front Row uses QuickTime and all of its associated plugins. With Front Row, Dolby Digital (AC3) encoded audio can be output through the optical cable, giving "true" surround sound. Since there is no way (that we know of) to play Dolby Digital or DTS encoded audio in iTunes, that leaves AAC 5.1 for the Apple TV, which the device treats the same way as a default 10.4 QuickTime install does—by putting all five channels into two. So, there is no 5.1 surround sound, just the older Pro Logic II, two-channel Dolby format.

Is this just flat out wrong? This review is saying that Front Row (which uses Quicktime and it's components) can output Dolby Digital (AC3) encoded audio through the optical cable with true 5.1 output.

Interesting, the arstechnica "In Depth Review" (http://arstechnica.com/reviews/hardware/appletv.ars/4) on the apple tv states that..



Is this just flat out wrong? This review is saying that Front Row (which uses Quicktime and it's components) can output Dolby Digital (AC3) encoded audio through the optical cable with true 5.1 output.

No, it is not wrong, however, they have left something out. While FrontRow uses QT for playing certain file types, it uses Apple DVD Player to play DVDs (not QT and not iTunes). Apple's DVD Player can indeed output AC3.

AppleTV, OTOH, I don't believe has ever claimed to be able to play DVDs. Therefore, no AC3. I think most of us believe that Apple will eventually be selling, via iTunes, HD movies, very possibly with 5.1 audio. How exactly the AppleTV will play them back we don't know since iTunes does not yet offer them.

No, it is not wrong, however, they have left something out. While FrontRow uses QT for playing certain file types, it uses Apple DVD Player to play DVDs (not QT and not iTunes). Apple's DVD Player can indeed output AC3.

AppleTV, OTOH, I don't believe has ever claimed to be able to play DVDs. Therefore, no AC3. I think most of us believe that Apple will eventually be selling, via iTunes, HD movies, very possibly with 5.1 audio. How exactly the AppleTV will play them back we don't know since iTunes does not yet offer them.I don't now how, but somehow through my addition of Perian and a52, and maybe some other stuff, months ago (pre-aTV), I totally mangled the ability of DVD player to pass AC3 through the optical of my MB, if in fact it ever could. It only passes stereo (or maybe dolby pro, but I didn't care enough about that to test it--maybe I will) I didn't followup to resolve it, because I just switched to VLC, and it worked fine, and offered a better viewing experience.

I don't now how, but somehow through my addition of Perian and a52, and maybe some other stuff, months ago (pre-aTV), I totally mangled the ability of DVD player to pass AC3 through the optical of my MB, if in fact it ever could. It only passes stereo (or maybe dolby pro, but I didn't care enough about that to test it--maybe I will) I didn't followup to resolve it, because I just switched to VLC, and it worked fine, and offered a better viewing experience.

I think adding all those other codecs can have consequences -- my Mini started doing strange things, so I removed them.

What I realised however, is that, since VLC can play almost anything without adding codecs (not to mention has a lot of other cool features), why bother using QT at all? (BTW, have you discovered the Shoutcast TV feature?)

I think most of us believe that Apple will eventually be selling, via iTunes, HD movies, very possibly with 5.1 audio. How exactly the AppleTV will play them back we don't know since iTunes does not yet offer them.

Apple's movie trailers that are HD currently have 5.1 AAC sound.
So unless the ATV can transcode AAC to AC3 on the fly or if Apple starts using AC3 instead, we aren't going to have true surround sound.

Apple's movie trailers that are HD currently have 5.1 AAC sound.
So unless the ATV can transcode AAC to AC3 on the fly or if Apple starts using AC3 instead, we aren't going to have true surround sound.You've hit the nail on the head. And if aTV is given support for AC3 support from Apple, most likely iTunes (and QT, and Mac OS X) will have to get support too. This then presents Apple with the problem of re-doing FairPlay to include AC3, and all of the licensing and contract issues embedded in that. And when the Mac fully supports AC3, the content providers will complain loudly, as it brings things like xvid and video_ts into the forefront, as users will not have to go to such lengths to get these formats running.

My guess is that this issue is one of the stumbling blocks for Apple bringing HD to the iTS. And it's a pretty big one. Not that the other issues aren't big either. But by definition, Apple can't offer HD content without offering 5.1 audio that will decode on the aTV and the Mac.

I doubt Apple will go the transcode AAC -> AC3 route, as it will entail more overhead than is needed on the Mac or aTV. And I don't know how well the first gen of HD video-capable Macs could handle a transcode on top of everything else. Anyone know how much effort it takes to dynamically transcode audio like this? But this gives them a way around the AC3/FairPlay issues.

My bet is that all of this will be taken care of in Leopard somehow, and this is when we will see HD content at the iTS, the resolution of the audio surround sound issues, release of the next gen Mini, and an upgrade in aTV abilities. Included in this will be upgrades to Front Row and DVD player (or a replacement). Whether or not FR and player issues will be significant is another matter.

Roughly Drafted had a well reasoned take on the whole situation. In a nutshell AC-3 and MPEG2 are inefficient codecs for "internet-based" content. He claims AAC has a more efficient 5.1 implementation and that DPLII was used for backwards compatability. I agree on the latter but I'll have to look into AAC.

We all wish we could implement a Kaliedescape system for $300, incremental to our Mac investments, and we know the hardware could do this. Reality is, its not entirely legal (yet- love to see KaScape win their case) and I'm sure Apple doesn't want to alienate the Studios by allowing people to play .vob files easily.

I bought one anyway and will report back after I have a chance to connect it. Merely as a front end for iTunes, its worth my money and the iPhoto player is a nice extra. Not expecting much from the video. Yet. On this version.

Cheers,

Roughly Drafted had a well reasoned take on the whole situation.When Roughly Drafted starts to referring to those of us here at AVS as:
"These same gold plated adapter people"
and again:
"Users without a fancy home stereo won't hear any difference"
I tend to lose interest in anything else he has to say.

In some previous articles of his I commented on how all we are asking for is what we get with a DVD: 5.1 AC3. He isn't willing to listen to anyone who undertands what quality vieo and audio is all about. He is an apologist of the worst sort when it comes to justifying Apple's current use of technology as acceptable because it is a small minority who know/hear/see the difference in AV formats. I mean, why in the world would anybody want to try and defend Apple's current content offerings' formats?

While there is some value in RD'd articles, more often than not they are chock full of errors, inconsistencies, and personal opinions masquerading as fact and truth. You only have to read the multitude of "Readers write back" articles where the author hand picks those that uphold his positions, or that correct him on obvious technicalities. Any efforts to get him to see things from the viewpoint of the "gold plated adapter" crowd are brushed off as being elitist and unrealistic.
-------------------
And on that note, here's an interesting read on 5.1 audio on the Mini and aTV at This Much I Know:

So does the Apple TV support 5.1 audio? (http://www.thismuchiknow.co.uk/?p=34)

And on that note, here's an interesting read on 5.1 audio on the Mini and aTV at This Much I Know:

So does the Apple TV support 5.1 audio? (http://www.thismuchiknow.co.uk/?p=34)

Thanks for this! The link describes quite clearly what kinds of multichannel audio are supported in aTV's basic operation right now.

Hopefully, someone will figure out how to get the DVD Player app to run in aTV -- this could be the fastest way to get true Dolby and DTS 5.1 out of aTV when playing a DVD from a folder. When there's no transcoding and multichannel audio, I'm in.

SCD

I think adding all those other codecs can have consequences -- my Mini started doing strange things, so I removed them.

What I realised however, is that, since VLC can play almost anything without adding codecs (not to mention has a lot of other cool features), why bother using QT at all? (BTW, have you discovered the Shoutcast TV feature?)

VLC has it's downfalls as well IMO. I haven't figured out a way to play more than one video simultaneously in VLC, whereas QT can do this quite easily, just open a second file and click play.

I didn't followup to resolve it, because I just switched to VLC, and it worked fine, and offered a better viewing experience.

What is this better viewing experience over DVD Player.app? Obviously that is subjective, but I much prefer DVD Player over VLC.


All that aside, it is great news that folks have gotten VLC to run on the aTV. I just wonder how that works from a user interface standpoint. Does it automatically run Full Screen? Does it take over certain video file types for playback instead of QuickTime (or whatever aTV is running for video playback)?

VLC has it's downfalls as well IMO. I haven't figured out a way to play more than one video simultaneously in VLC, whereas QT can do this quite easily, just open a second file and click play.

What you say is correct, however, why on earth would you need to play two films at the same time, only one of which would have sound(!)? I wouldn't call this a downfall at all since I have never found any use for playing more than one film at a time.



What is this better viewing experience over DVD Player.app? Obviously that is subjective, but I much prefer DVD Player over VLC.


And I'm the opposite. I don't like that DVD Player will not let me skip over the junk that studios put on DVDs. VLC will let me, though. VLC also has many more controls for tuning the video output than DVD Player. OTOH, I do like the user interface better on DVD Player than VLC, however, VLC is in active development, while DVD Player seems to be updated only rarely. Also DVD Player is a DVD player, while VLC is a media player. That makes it more useful.

Wildrock-

Agreed on his misunderstanding of our hobby but he does make a good argument why Apple has "crippled" this device by not offering MPEG2 / AC3 decoding, among other things. Regardless of the vlaidity of some of his arguments, he did provide me with a fresh perspective on what Apple is doing.

But perhaps he's placing too much emphasis on the download model. I'm not even sure the product is built around a download model. I've only bought about 5 songs from the iTunes store in three years. Some say its like an iPod for the TV but the inability to rip your collection invalidates that idea.

My bet is the device can decode MPEG2 / AC3 but it doesn't yet, probably for legal/negotiating reasons.

I think the people really want a cheap Kaliedascape. That's the killer app, not downloading sub-DVD quality video. Wonder what's going on in the background and if the DVD consortium will change the rules to keep the format alive. I think DVD sales are starting to decline. Update the DVD rules to allow managed copy?

<Update the DVD rules to allow managed copy?>

Absolutely. Then we would see Apple immediately incorporate the import features they use for CDs.

Please, don't litter this thread--or this forum--with entire articles copied and pasted from that dope and his Roughlydrafted site. It's a copyright violation, for one; if you actually have a point or two to make, or just want to say, hey great article, excerpt a few quotes and share a few of your own comments--ok, hltr?

Like what wildrock just did a few posts ago when he wrote:

While there is some value in RD'd articles, more often than not they are chock full of errors, inconsistencies, and personal opinions masquerading as fact and truth.

This I agree with 100%. His latest 5.1 piece, I'm afraid, trumps the usual blind leading the blind, because now it's obvious he's 1) deaf as well and/or 2) has very cheap AV equipment. (The real problem, I think, is he has very little appreciation for cinema or music, but that's a separate issue.)

while receivers that can decode Pro Logic can extract all four channels to distribute as surround sound.

He fatally misunderstands that Pro Logic isn't decoding anything; PL is post processing that's applied by modern AVRs to anything it receives that isn't initially detected as AC-3 or DTS.

When he says:

the difference between Pro Logic and AC3/DTS content is not dramatic over the same set of 5.1 speakers

he is revealing himself to be a clueless neophyte when it comes to audio, video and home theater experiences. Hands on experience with audio and video--apart from what he's read about computer specs--isn't his strength.

The Apple TV does something special with AAC 5.1 audio: it mixes it into a format Pro Logic receivers can split into multiple channels of sound, with a separate center channel and front and rear stereo.

No, it doesn't--it decodes it into two channel stereo and then Pro Logic receivers receive it and do their magic no matter what, there's nothing special being sent, and nothing special being received. A limited, confused, mixed signal will always be heard from the center channel--it won't be the kind of discrete separation that the director and sound engineers intended. The difference between Pro Logic and 5.1 audio with discrete channels is massive, even complete newbies would hear a dramatic difference.

(And not that Daniel would have access to an AVR with HDMI in, he most assuredly doesn't have an HDTV with HDMI in, but aTV doesn't even pass the separate streams as PCM into the HDMI connector which fully supports it.)

Apple TV does its best to deliver AAC 5.1 audio to receivers using Pro Logic, and when audio systems begin supporting the modern, multichannel AAC format natively, Apple will be able to deliver it optically in full quality

I'm not sure what the longer wait will be--Daniel to get some actual hands on experience under his belt, with a Mac connected to an HDTV, rather than relying on his cobbled together trio of RCA cables which he's using to connect an aTV to his (likely) old tube TV

or

AVR manufacturers to implement AAC 5.1 support.

Agreed on his misunderstanding of our hobby but he does make a good argument why Apple has "crippled" this device by not offering MPEG2 / AC3 decoding, among other things. Regardless of the validity of some of his arguments, he did provide me with a fresh perspective on what Apple is doing.

I understand where you're coming from on this, Soundkernel, and to a certain extent I agree. I do think the 5.1 piece that wildrock linked to previously was better and I think the portion of the aTV review on Ars technica which dealt with audio was the clearest of all. These folks have a different, more informed perspective, because they've actually had a mini hooked up to an HDTV and ALSO have some knowledge and experience as typical audio and video home enthusiasts.

Their pertinent page about surround sound limitations here:

http://arstechnica.com/reviews/hardware/appletv.ars/4

The main problem with RD, on the other hand, is he starts from an assumption why Apple did something--then works forward from what likely could be the "correct" conclusion why: that AC-3 and DTS audio is too large for downloading and Apple wants something less large and more forward-looking. He knows where he has to end up, it's actually getting there while wearing the Apple shill hat that is more than a little bumpy.

The RD author is obviously not an AVphile and maybe he's wrong on many points. I'll follow up next week with qualitative judgements from my own evaluation.

I'll buy some content this weekend from iTunes and download some of the HD trailers. Maybe I can find something that's also available on HD-DVD for reference and can compare the A/V quality of Apple TV (playing iTunes video content) with DVD and HD-DVD. Later I'll use Handbrake to do some .vob conversions and compare those as well.

Cheers,

Personally, where I think that RD's author went wrong was when he tried to follow Apple into the CE world. RD built its following based on the author's historical understanding of Apple and its competition with Microsoft, sprinkled with anecdotal knowledge of the growth of the PC industry. He is at heart an IT guy. I enjoy reading his historical pieces, not because they're well written or accurate (he desperately needs a good knowlegeable technical editor), but because they give me insight on how the industry got to where it is today.

But but as Apple strays outside of the traditional PC market, and moves into the CE space, complete with iPods, iPhones the aTV, and the iTunes Store, so does it leave many of those who understood the company behind. Most of the analysts (and the daily armchair bloggers) who built a reputation either fanning or flaming Apple based on their understandings of the rise and current state of the PC fail miserably when they try to understand Apple outside of that realm.

RD is a case in point where an Apple fan-boy gets it so terribly wrong, playing cub reporter in a CE industry he has no experience in. And so he uses his blog as a way of throwing out his understandings, without any editorial review, and then takes in the flak and either learns from it, discounts it, or ignores it. It is a very odd sort of journalism; one that I am not so comfortable with. But it shows how very wrong a person can be, when they, as chefklc notes, start with their mistaken conclusions and then work smoke and mirrors to justify how they got there.

I finally finished reading the pieces late last night after my initial dismissal, (must have been feeling overly masochistic), and about choked when I got to his conclusion that the answer to Apple's dilemma with 5.1 sound is for Apple to do nothing at all, but for all of the "gold plated people" to go out and buy AAC compatible receivers. That's kind of like saying that if eating bad food makes you fat, but you like how it tastes, go buy some larger trousers.

Just as it is true that Apple is moving in the CE industry, it has taken some very large steps in our area. Adding the digital audio output, dvi, AppleTV, the iTunes Store -- all of these are addressed to ht people.

Right now, though, the high-end stuff almost all comes from other companies. I think it will stay like that. I think Apple will continue to make high-end consumer products. If we want more or want better, we will probably have to look someplace else.

However, the fact that Apple made ATV so hackable is quite interesting. I think the next big question is what will happen with the iPhone? Will that also be so easily hacked? And whether or not it is hacked, will Apple offer, perhaps through another company, a remote control program (perhap Sailing Clicker) for the iPhone? With the hacked ATV and a remote control iPhone, there are some very interesting possibilities.

I think the next big question is what will happen with the iPhone? Will that also be so easily hacked?Without straying too far off thread, I think that the iPhone will be much more difficult to hack, for a couple of reasons.

First off, it is flash based, and the OS X variant is likely much more different than the aTV OS X, and further removed from Mac OS X. Running OS X on ARM vs. running OS X on a Pentium M (or current Mac Intel procesors) is going to be a bit harder to decipher. The first point of entry for the aTV hacks was to remove the drive and mount it on a regular Mac. This won't be near as easy with the flash-based iPhone OS X.

Secondly, I think that apple will take much greater care with the iPhone platform than the aTV. It's market goals are, even as modest as they are (10 million devices through 2008), quite higher than the aTV's (somewhere between 800,000 and 2 million according to analysts in the next year). The iPhone will have much higher visibility, and Apple has already indicated a desire to limit third party development. While for the aTV, Apple has already scheduled developer workshops at WWDC.

Thirdly, I don't think that a lot of the techniques used hacking the aTV--moving standard Mac OS X and open source apps onto the platform to see how they run and interact--will be easily accomplished. A lot of apps and routines require certain OS and hardware dependencies to run, and the iPhone strays further from the current known environment. There will a lot more miss than hit, than with the aTV's attempts.

That being said, I have no doubt that the iPhone will be subject to intense scrutiny (read hacking), probably moreso than the aTV. And the efforts at hacking the aTV will assist those who work on the iPhone, as people become more familiar with Apple's moving OS X to new architectures. And as with the OP's orignal intent with this thread, everything pertaining to ripping DVDs to the aTV holds true for the iPhone. I think that the iPhone will only serve to accelerate the desire and drive to have Apple's AV platform diversified by third parties and open source advocates. This is a good thing and should hopefully help to resolve problems like the 5.1 audio issues and video file format support.

[edit: one more thing]
The aTV is based on adapting current OS X 10.4.7 technology. The iPhone most likely will be built on an OS X 10.5 base, judging by the comments Jobs had last year about Leopard, and the iPhone features he showed off at MacWorld this year. In addition to building off a relatively unknown version of OS X, the iPhone will bring new technology (like Multitouch) to play, that may or may not exist in the first shipping version of mac OS X 10.5. The realm of the unknown in the iPhone will far outweigh the unknown in the aTV.