December 30, 2006
AACS cracking - here's the deal
Earlier this week, news broke that someone had "cracked" the AACS DRM system used by both HD-DVD and BluRay. At this point, there hasn't been independent verification of any of this, but here's the deal as best as I understand.
A guy named muslix64 on the Doom9 forums figured out a way to extract title keys from HD-DVD discs, very likely using a vulnerability in Power DVD 6.5. He then wrote a decryption tool based on the publicly available AACS specifications. He released the software, including source, but did not release any title keys. He made hints that there is a fundamental flaw in the way title keys are handled, and that player revocation is unimportant. With player revocation, a flawed player (such as Power DVD, if indeed it is vulnerable) can be disabled from playing future discs.
It's interesting, if indeed it's true. There is no evidence that the AACS encryption itself is flawed, and indeed, that seems unlikely as it's essentially an implementation of AES. However, we know that using encryption for DRM on untrusted hardware is likely to have some vulnerability, if you're willing to dig deep enough. That is apparently what's happened here.
What does it mean? Not much right now. Muslix64 has disappeared, and nobody has been able to discover the relevant title keys at this point. If someone does recreate a title key extraction method, it would be an interesting alternative to the world of DVD cracking. Instead of having a DMCA-violating circumvention device in the form of DeCSS or any of the later decryption programs, you could instead have a totally legitimate decoder tool paired with some title keys. The legality of the title keys would be questionable - the court case would be very interesting. In any case, it's likely that you'd get your HD-DVD, check online to get the title key, paste it into your ripper and be done.
Give it 6 weeks and check again. This could be a blip, this could be the death of BluRay and HD-DVD. We'll see.
Posted by at 6:44 PM
December 28, 2006
Sony HVR-1500 deck breaks my heart to little pieces
So first off, I find it shocking that the first mention I get of a new HDV deck is via a DVD mailed to me by Sony. I'm speaking of the HVR-1500, a new half-rack studio HDV deck. No links here, because Sony has no mention of it on their website. It sounds like it was announced in conjunction with the HVR-V1U camera.
So why does it break my heart? Because it's SO close to being what I really want. It's got expandable input and output options. One of those options is HD-SDI output. But input? Oh, I'm sorry, I'm afraid it's limited to SD-SDI. What?!
This is such blatant marketing-driven stupidity on the part of Sony. We can't have folks using HDV as a record format in a professional setting, that'd be crazy! So we best cripple the product.
I'm encoding the video they sent me to post here, so you can marvel at the greatness that Sony almost achieved. I'm going to be doing some shin-kicking at NAB this year ...
[Edit: Video Posted Below]
Posted by at 5:01 PM
December 25, 2006
The truth of depth of field
A number of sites have linked to this article about depth of field, which looks at the commonly held belief that zooming in creates a shallower depth of field.
The article isn't super clear, but the essential fact is that zooming in doesn't actually change depth of field, it just makes the stuff in the background bigger. The stuff is no more blurry, it's just easier to see the blurriness.
He's absolutely right of course, but it's really splitting hairs. In the end, it doesn't really matter.
Posted by at 12:52 AM
December 21, 2006
HDV is dead, long live HDV
There have been a few articles in the past week stating that the end of HDV is near. This article in particular goes into depth about the emerging intraframe formats which are vying for the low-end professional market.
I agree that AVC-Intra (note: AVC could be either inter- or intra-frame, don't assume!) and JPEG2000 are good options for compression going forward. They're both good steps forward, but I don't think they're HDV competitors. Let me explain.
At this point there are no "professional" HDV cameras on the market. The closest you get are the XDCamHD products from Sony, which are more or less HDV wrapped in MXF going onto an optical disc, with the ability to bump up the bitrate a little bit. All the other HDV cameras on the market are, in my opinion at least, consumer or pro-sumer level. JVC might argue a bit, but they're JVC so who cares?
The products being discussed in the Nordahl article are most closely related to the XDcamHD products. Neither AVC-Intra nor JPEG2000 are particularly well suited to tape based storage, at least miniDV style cassettes. The Panasonic and Grass Valley (respectively) cameras instead make use of different direct-to-disk recording options. AVC-Intra is just an i-frame-only version of H264, which itself is just a further development of the technology from MPEG-2. JPEG2000 uses wavelet compression and could be pretty impressive. I've never used it in production. Both are solid choices for higher-bitrate recording.
I don't think HDV is going anywhere soon. Getting away from LongGOP compression is a good idea in the long run, but for the low end of the market I think it'll have to wait until flash memory becomes much larger and much cheaper. I'm a firm believer that it will be difficult to penetrate the low end of the market without the ability to easily swap media in the field, without lugging along a laptop. That means being able to carry a pocket full of flash cards, preferably of some variety that can be purchased at a local Target or Best Buy when you're shooting in the field. P2 is a start down that path, but I think widespread adoption is still a ways off. Products like the Firestore are just bridging the gap until we can have proper direct-to-memory capture.
From a technical standpoint, I think we're just starting to see what HDV can do. For example, read Steve Mullen's article on smart GOP splicing. If you can avoid the generational issues of reencoding HDV, the remaining issues are based on processing speed. I wouldn't be surprised to see realtime HDV output over firewire in the next version of Final Cut.
Here's my predictions for recording formats in 2007 and 2008. For cameras under $10,000, HDV will remain the dominant force. The HVX-200 and successors will continue to embrace P2, but I think it'll be 2009 or 2010 before P2 is really practical in all situations.
For cameras from $20,000 - $50,000, you'll see a few formats. AVC-Intra will replace DVCProHD, as NLEs add support for that format. AVC-Intra has major benefits over DVCProHD with no downsides. XDCamHD will stick with the current setup through 2007, but in 2008 I'm expecting to see a higher bitrate recording system (XDCamHD2 or some such) which will add a non-GOP recording format. It'd be nice if it was JPEG2000, but I'm guessing it'll be SONY2000 or something stupid and proprietary like that. JVC will continue to push ProHD long past its sell-by date, and the HD100 will become a faded memory.
Above $50,000, I think what we've got today is pretty much where we'll stay, with the exception of DVCProHD being replaced by AVC-Intra. HDCam, HDCam-SR, D5 and the other "big tape" formats are with us for the long haul at this point. Various direct-to-crazy-raid turnkey solutions will probably begin to creep into this market space as well, but it'll be a slow process.
And me? I'll just go back to shooting Hi8.
Posted by at 2:34 PM
December 20, 2006
Greatest Email Ever
This has nothing to do with video, but I just got this email from my polisci professor and can't stop laughing. The paper was about Iraq policy ...
We have one final exam paper that doesn't have a name. The paper has no title page, all the class info in the upper left-hand corner of the first page, and the first sentence reads: "The strapping hero stands, sword in hand, ready to slay the mighty dragon; two powers evenly matched."
I'm assuming this is a final exam and not a review of "Eragon," so please send an email to me and the two TAs (Cc'd above) if this is your paper.
Posted by at 12:56 PM
December 19, 2006
Panasonic AV-HS300G - Portable HiDef switcher
Panasonic is now shipping the AV-HS300G, a DC powered HD/SD switcher. I don't know much about this product, but I've very interested. It doesn't look like it's as all-in-one as the Anycast, but the MSRP is $7999 which puts it in a whole different price range. This could be an ideal solution for doing field shoots with the canon XL-H1. You still need a separate way to record the video,
This demands more investigation.
Posted by at 10:20 AM
December 18, 2006
The Life of a Travelling Freelancer
Stefan Sargent has written a good article for DV.com about his life as a traveling producer. He's a one man shooter-editor, and writes about his experience flying with gear, lighting on location with limited options and limited time. This gives a really good taste of one type of lifestyle in this business. Check it out.
Posted by at 9:06 AM
December 16, 2006
The $13 dimmer
FresHDV has a little blurb about portable dimmers for field lighting. Turns out, Harbor Freight (they of the $20 miter saw) has a router speed control which can handle up to 15 amps. Perhaps for most lighting equipment that you'd be plugging into a home circuit. $12.49 is a heck of a lot better than the $100-$150 that a lighting supply house will charge.
Posted by at 3:27 PM
Pirates of the Caribbean Effects Work
ILM has launched a website about the effects work in Pirates of the Caribbean: Dead Mans Chest. It's a bit cheesy, but hey, it's a Saturday.
Posted by at 3:06 PM
December 14, 2006
Alex Lindsey has been Antiqued (Sony releases new 4:4:4 camera)
Sony has announced a new 4:4:4 1080p camera, the F23. It's essentially a modified F950 which adds the ability to dock with an HDCam-SR deck, and also support more camera attachments. The F950 and F23 live in the same market space as the Arriflex D-20, Grass-Valley/Thompson Viper and Panavision Genesis. Essentially, if you don't have at least a half million dollars, don't bother asking.
Posted by at 11:42 AM
December 12, 2006
HDV Camera Rundown
Creativemac has a nice little overview of the current HDV cameras on the market. They don't really draw any conclusions, but they've got nice pictures. So, that's something I guess.
Posted by at 4:29 PM
December 9, 2006
Best. Toy. Ever.
So I bought a mini-RC Helicopter and it is the single greatest thing of all time, ever. Everyone needs one of these. Mine came from RadioShack, but there are apparently lots of different brands.
Dig the video (click to play):
Posted by at 5:02 PM
December 8, 2006
Youtube allows web-based recording
Wow. This is huge. Arstechnica has an article about the addition of a tool called Quick Capture to YouTube. Quick Capture allows you to record video directly within your webbrowser, storing it to youtube. No more capture->edit->upload steps, just record and go.
Frankly, I was always impressed that so many people were willing to go through the various steps needed to post a video on YouTube. This is going to be a huge addition to YouTube, especially for video bloggers.
They're making use of the various media abilities of Flash 9 in a pretty serious manner. I've seen similar apps for web conferencing (Breeze, etc) but this is a huge deployment. I wonder how they're dealing with media server licensing...
If only it would let me log in ...
Posted by at 4:44 PM
December 7, 2006
Apple Patent for Dynamic mpeg encoding
Macnn has a post about a recent patent granted to Apple for dynamic field/frame encoding of MPEG. It's not terribly exciting, but I figured I'd comment since I've seen some other sites mischaracterizing it.
Basically, when you have interlaced video, you get better codec efficiency if you compressed each field separately, instead of compressing a frame made up of two fields combined. The reason is pretty straightforward. A field is more or less a picture of your scene, taken once every 60th of a second. So, two sequential fields can be very different if there's fast motion or the camera is moving. MPEG encoding works in terms of macroblocks - 16x16 blocks of pixels. If there's lots of continuity among the pixels in that block, you'll get good compression. However, if every other line in that block is totally different, you'll either get terrible compression or have terrible quality. So, with interlaced video, field based compression is great. With progressive video, or animation, or other non-interlaced video, you'll get better efficiency with frame-based encoding.
That's great if you're able to tell the compressor in advance about the source video. However, with many video codecs, it's not easy to programatically determine whether the video is interlaced or progressive. It gets even worse when both formats are mixed within a single video!
What Apple's patent proposes is a compression process that dynamically selects between field-based and frame-based encoding with each macroblock. The only bit that really matters is the discrete cosine transform on the luminance macroblock. So, Apple does two DCTs on the macroblock (actually double that, but then it gets confusing), one treating the block as if it were field based, and one treating it as if it were frame based. Because a DCT can easily be vectorized, you can do multiple DCTs in parallel. Then you just check to see which block has the most zeros and use it.
With H.264, the entropy encoding (CABAC or CAVLC) takes far more CPU than the DCT, so this is a pretty clever way to get better efficiency with a really simple addition.
Posted by at 7:34 PM
December 4, 2006
Large Scale P2 Production
Check out this article from kenstone.net regarding large scale p2 production. One of the challenges with P2 based cameras (like the Panasonic HVX-200) is that you can't feasibly maintain your footage on the original media. Even on a major production, burning through $30,000 in p2 cards every day isn't a realistic option. So, you've got to come up with a workflow to offload that content as it's being shot. The article goes into great detail about the process being used on the production of a significant TV pilot.
Posted by at 1:00 PM
December 1, 2006
I totally forgot to post the cake that some of the student crew made me for my birthday. Thanks everyone!
Posted by at 2:34 PM
Panasonic HPX2000 Camera announced
The Panasonic AJ-HPX2000 has been re-announced (sorry, can't find the official press posting). It's a 2/3" HD camera in an ENG body. It makes use of P2 cards, so it's sort of a big brother to the HVX-200. 24p is included as expected. There's one interesting item, which is that it can be switched between DVCProHD (their normal, 100mbps HD codec) and AVC-Intra, a codec of which I have no prior knowledge. It sounds like it's an H264 based intraframe codec which can achieve half the bitrate of DVCProHD at the same quality level. That's important for Panasonic, as the P2 card format puts a real limit on recording times. Note that AVC-Intra and AVCHD are not the same formats. Helpful!
Posted by at 11:49 AM
There are a number of choices in this part of the market, including the Indie-Dolly, the Microdolly and the Losmany Spider Dolly. There are pros and cons to each. The Microdolly is definitely hte most portable, with its tent-pole style track. However, I wasn't convinced it would hold up to student use. The Losmany dolly uses flexible track, which is very cool in concept, but which I haven't been happy with in reality. It seems like there's always just enough movement in the track so as to be noticeable. The Indie-Dolly uses a collapsable track system which is significantly more robust than the Microdolly, but which is still reasonably portable.
The pricing for the Indie-Dolly system is pretty straightforward. You purchase the dolly itself, for around $1000, and then buy sections of track as desired. So far, we've got one straight track kit ($500, 12 feet) and have ordered a curved track kit ($600, 13 feet).
Everything comes in very nicely constructed bags. The bag for the dolly has wheels and a handle, similar to many luggage bags. It's a good thing the wheels are there, as the bag weighs nearly 50lbs. The track bag is slightly lighter, though much larger.
Assembling the dolly is relatively straightforward, but it's not an instant task by any means. It took me about half an hour the first time, though I imagine future setups will go much quicker.
Though the kit includes a seat, I think most operators will chose to just walk with the dolly. There is also a push bar included.
Unfolding the track is rather analogous to collapsing a flexfill. Even after watching the demo video a few times, it was still a bit confusing. I suppose it just takes practice.
Once you've got it all assembled, the movement of the dolly is very smooth. There's no jitter when moving between pieces of track, and the individual trucks don't seem to be shifting on the track at all. I'm looking forward to getting the curved track to do some longer moves.
In the end, I think the Indie-Dolly is a great option for those seeking an affordable, portable dolly. I believe other folks have come to this conclusion as well, as it took nearly a month for our order to arrive.
Posted by at 11:25 AM