Aug/090
Difference between 1080i and 1080p
While high definition has become a reality for many consumers, the technical jargon associated with this exiting new technology is causing much confusion. Just as we were beginning to understand the differences between Blu-ray and HD DVD along comes a new high-definition format, 1080p.
But why do we need another high-definition format anyway? Many of us have bought our HD Ready screens and were ready to sit back and enjoy this new viewing experience, but now we are all wondering if we bought the right kit in the first place.
Many of the more recent HD Ready flat screens feature a resolution of 1,366×768 pixels. This will display the commonly used 720p and 1080i formats, although 1080i/1080p signals will be downscaled to fit. To display 1080i/1080p signals in their entirety, you’ll need a screen with a resolution of 1,920×1,080 pixels, coined ‘Full HD’ by the marketing men.
However, just because a screen has 1,920×1,080-pixels it does not necessarily mean that it will accept 1080p input – so check before you buy.
Remember, 720p, 1080i, 1080p are formats in which ‘Sources’ of high definition content are presented for viewing on a particular output device such as your LCD/Plasma screen. The source could originate from your TV cable provider for example, or your xbox 360. To restate the point, 1080i/1080p needs a screen resolution of 1,920×1,080-pixels to display in its entirity, but you don’t have to have a screen with this resolution to display a 1080i/1080p signal – lower resolution screens downscale the signal to fit.
Taking a step back, 720p and 1080i were initially set out as the two key standards for High Definition content, with Sky HD, HD DVD and the Xbox 360 supporting these formats. Any TV that supports 720p and 1080i is classed as HD Ready. Let’s take a step back for a moment and take a quick look at the development of TV technology to see how we arrived at these standards.
In a CRT display (the TV you grew up with), a stream of electrons is generated by a gun, and is scanned across the face of the tube in scan lines, left to right and top to bottom. The face is coated in phosphors, which glow when hit by the electron stream. A method of scanning was required that would reduce the transmitted TV picture’s bandwidth and work in accordance with the electricity supply frequency (50Hz in the UK and Europe and 60Hz in the US). The result was interlaced scanning.
A method of reducing bandwidth was required because early sets were not able to draw the whole picture on screen before the top of the picture began to fade, resulting in a picture of uneven brightness and intensity. To overcome this, the screen was split in half with only half the lines (each alternate line) being refreshed each cycle. Hence, the signal is interlaced to deliver a full screen refresh every second cycle. So if the interlace signal refreshes half the lines on a screen 50 times per second this results in a full screen (or frame) refresh rate of 25 times per second. The problem with interlacing is the distortion when an image moves quickly between the odd and even lines as only one set of lines is ever being refreshed.
As TV screen technologies have progressed another system called Progressive Scan has also been developed. With progressive scanning the frames are not split into two fields of odd and even lines. Instead, all of the image scan lines are drawn in one go from top to bottom. This method is sometimes referred to as ’sequential scanning’ or ‘non-interlaced’. The fact that frames are shown as a whole makes it similar in principle to the way film is shown at the cinema.
At this point it is worth considering what we mean by resolution in relation to TVs;
Resolution: HD-Ready TVs need to be able to display pictures at the resolution set by the new standard. Resolution can be described either in terms of “lines of resolution,” or pixels. The resolution you see on your TV depends on two factors, namely the resolution of your display and the resolution of the video signal you receive. Because video images are always rectangular in shape, there is both horizontal resolution and vertical resolution to consider.
Vertical resolution: This is the number of horizontal lines that can be resolved in an image from top to bottom. The old familiar CRT TV displays 576 lines, while Digital HD television operates at a resolution of either 720 or 1080 lines. This is the most important resolution as it is most noticeable to the human eye.
Horizontal resolution: This is the number of vertical lines that can be resolved from one side of an image to the other. Horizontal resolution varies depending on the source. The number of horizontal pixels is not quite so critical as vertical resolution as it is not as obvious to the human eye during normal viewing.
An analogue TV signal in Europe, where the PAL standard is used, has 625 horizontal lines of which 576 lines are displayed and the image (or frame) is refreshed 25 times a second. This is the standard we have been used to for years.
A High Definition Digital TV signal delivers significantly more picture detail and audio quality than a standard signal, producing pictures that are significantly better, sharper and clearer;
720p: 1,280×720 pixel resolution. High-definition picture that is displayed progressively. Each line is displayed on the screen simultaneously, therefore it is smoother than an interlaced picture.
1080i: 1,920×1,080 pixel resolution. High-definition picture that is displayed interlaced. Each odd line of the picture is displayed, followed by each even line, and the resulting image is not as smooth as a progressive feed. 1080i is therefore a more detailed picture suited to documentaries and wildlife footage, but less suitable for action-oriented material such as sports and movies.
1080p: 1,920×1,080 pixel resolution. High-definition picture that is displayed progressively. Each line is displayed on the screen simultaneously, therefore it is smoother than an interlaced picture. This is the ultimate high-definition standard — the most detailed picture, displayed progressively.
There are two main formats for HDTV, namely 720p (i.e. a 720 line picture progressively scanned 50 times a second) and 1080i (1080 lines interlaced at 50 cycles per second). The picture resolution of a high definition digital TV is about 4 times greater than a typical 576 line TV picture.
not having a screen which is able to display 1080p may not be important to you. However, there are exceptions, and if you are a serious game player you will probably already know one of them, or to be precise two of them. The xbox360(with a little tweak) and the playstation 3 produce output at 1080p. Also, the new High Definition DVD format, blu-ray has also been designed for 1080p ouput. Is the difference worth the extra investment? Maybe, something you will have to judge for yourselves …
Aug/090
RealNetworks loses critical ruling in RealDVD case
A federal court has found enough evidence to decide that RealDVD, the software that enables users to copy DVDs and store digital duplicates on a hard drive, violates U.S. copyright law.
U.S. District Court Judge Marilyn Patel on Tuesday issued a preliminary injunction that will prevent RealNetworks from selling the $30 software until a jury can decide the issue. That will undoubtedly keep RealDVD and Facet, Real’s prototype DVD player, off store shelves for an indefinite period. Facet also makes digital copies and stores them to a built in hard drive.
The decision represents a major victory for the film studios, which had accused Real of violating the Digital Millennium Copyright Act (DMCA) and breach of contract in a lawsuit filed last fall. Had the decision gone against the film studios and its trade group, the Motion Picture Association of America (MPAA), it would have been an affirmation that consumers have the right to copy their DVDs for personal use. Right now, when a DVD owner loses or breaks a disc, they conceivably must purchase another copy. RealDVD and Facet eliminate the need for discs once copies are made.
But the MPAA argued that Facet and RealDVD are pirate tools that enabled users to copy and redistribute movies and could cost the industry billions. The MPAA has maintained that under the DMCA, consumers do not have the right to copy films–ever.
“We are very pleased with the court’s decision,” MPAA Chairman and CEO Dan Glickman said in a statement. “This is a victory for the creators and producers of motion pictures and television shows and for the rule of law in our digital economy. Judge Patel’s ruling affirms what we have known all along: Real took a license to build a DVD-player and instead made an illegal DVD-copier.”
“We are disappointed that a preliminary injunction has been placed on the sale of RealDVD,” Real said in a statement. The company that makes entertainment software said it would have more to say after it had reviewed Patel’s decision.
The big question for Real is whether it has the stomach to continue the fight. The legal fees have already set Real back more than $6 million.
“RealDVD makes a permanent copy of copyrighted DVD content,” Patel wrote in her decision, “and by doing so breaches its (Content Scramble System) License Agreement with the (DVD Copy Control Association, the group that oversees the protection of DVDs for the major Hollywood studios) and circumvents a technological measure that effectively controls access to or copying of the Studios’ copyrighted content on DVDs.”
In her decision, Patel made a play on words using Vegas–Real’s code name for RealDVD–to illustrate how the software could lead to the mass pirating of movies.
“Had Real’s products been manufactured differently, i.e., if what happened in Vegas really did stay in Vegas,” Patel continued, “this might have been a different case. But, it is what it is. Once the distributive nature of the copying process takes hold, like the spread of gossip after a weekend in Vegas, what’s done cannot be undone.”
Patel’s decision is unlikely to surprise anyone who followed the case. During last year’s hearings on a temporary injunction and last spring’s proceedings on the preliminary injunction, Patel appeared highly skeptical of Real’s arguments.
In her questions to both sides’ attorneys, Patel seemed concerned about the potential for people to use RealDVD and Facet, to copy rented discs without compensating the creators, a practice known as “rent, rip, and return.”
One glaring hole in Real’s argument was its assertions that RealDVD didn’t circumvent ARccOS and RipGuard because they really aren’t anticopying software; and that Real had licensed CSS, the technology designed to prevent unauthorized copying of DVDs, so it was essentially authorized to do what it wanted with it.
The MPAA crushed these arguments in proceedings. The studios showed that both ARccOS and RipGuard are anticopying technologies used by some of the major film studios as a layer of piracy protection in addition to CSS. The studios’ lawyers produced documents that revealed ARccOS and RipGuard were effective enough copy protections to stymie Real’s engineers, as well as a group of “Ukranian hackers,” from cracking them.
One other important detail: ARccOS and RipGuard are not included in the CSS license. By circumventing the technology, Real had risked violating the DMCA, which prohibits the cracking of antipiracy technologies. And that’s exactly what happened.
“Real was aware of ARccOS and RipGuard during the development of the RealDVD products,” Patel wrote in her 58-page decision. “Real software engineers identified ARccOS and RipGuard as both copy protection systems and barriers to their development of a DVD copying device from the outset of the RealDVD project.”
While the courtroom showdown was first billed as a fight over RealDVD, it soon became clear that what was really at stake for Real was Facet.
Real CEO Rob Glaser demonstrated the device in court last spring and showed how an owner could move between films–it holds more than 70–in a way similar to how someone scrolls through an iTunes playlist. I wrote that the device could have helped spur flagging DVD sales and given DVD collectors, such as myself, a way to revitalize their movie collections.
Hollywood, however, is working on its own programs to give consumers access to digital copies after buying a CD. But the studios typically want additional money for the digital copy.
So, now we wait to hear whether Real will carry on the fight. However it turns out, the company has earned kudos from anticopyright proponents for waging the campaign. The question is whether carrying the flag for the free-content crowd is enough of a payoff.
Aug/090
Logitech Harmony 900: Best remote ever?
When we reviewed Logitech’s Harmony One universal remote last year, we gave it an enthusiastic Editors’ Choice award and really lamented only the fact that there was no RF option for users who had components hidden in cabinets or in closets. Well, more than a year later, Logitech has given us what we asked for–and even a little more–in its Harmony 900.