Understanding the World of Blu-Ray
by Paul M. Krasnodenski
PISCATAWAY, N.J.-June, 17 2008-
With HD-DVD no longer around to compete with Blu-ray for dominance as the High Definition format of choice, more and more people are looking at Blu-Ray players for additions to their Audio/Video systems to supply their HD content. However, when considering the transition from DVD to Blu-ray with all the new terms and products, it can sometimes be discouraging and lead one to decide to not make the transition and miss out on all the amazing improvements that Blu-ray has to offer. So this month we will go over some key points of this technology to hopefully help you successfully make the transition to enjoying a full HD experience. It all comes down to understanding not only what you can get out of Blu-ray, but what you will need to get it.
First, let’s briefly introduce this newest candidate for an addition to your home theater or media room. The name Blu-ray comes from the blue colored laser that is used to read the content on the discs. The most simplistic explanation of the difference over a standard DVD is that a Blu-ray disc can store more than five times the amount of information. This extra space translates to Blu-ray’s ability to provide advanced, uncompressed HD audio and video resolutions of up to 1080p. This format is now being accepted by the majority of the major film studios. Multiple manufacturers have also jumped on this technology producing Blu-ray players at varying price points. With all these different models it is important to know what you want out of your player and what you need to get it.
Perhaps the most important requirement is having an HD television. While having a TV with a 1080p resolution is by far the preference, it is not necessarily mandatory. Depending on your seating distance and the size of your screen you can get quite an amazing picture from a TV using a resolution of 720p or 1080i. What is mandatory however is HDMI connectivity. And again, though a standard HDMI connection is acceptable to truly exploit all that this format has to offer today as well as tomorrow, an HDMI version 1.3 connection is needed. Version 1.3 is an advanced HDMI connection that is pretty much standard on all current TVs and is necessary for transmission of the most current and upcoming High Definition audio and video formats. Not having the most up-to-date display does not exclude you from being able to experience the breathtaking visuals that Blu-ray has to offer. Additionally, when purchasing a new TV you should be looking for the features that will give you the most out of your investment today and tomorrow.
Hand in hand with Blu-ray’s stunning visuals is its breathtaking High Definition audio. This too has requirements to achieve the maximum level of performance. Though you can get your basic audio from the HDMI connection to your TV, to be able to get the immersive surround sound experience, you will need a receiver to process the audio signal from your Blu-ray player. There are three ways to transmit audio from your player to your receiver and each has a certain level of performance. There are more variables in regard to the audio than the video, but again once you know what you can have, what you want, and what you need to get it, it becomes easier to understand.
In addition to the standard left and right audio outputs there are three advanced audio outputs that most Blu-ray players use. These outputs are a digital audio output in the form of a Tos-link or Coaxial SPDIF jack, HDMI which we touched on earlier, and a multi-channel output. A Tos-link connection is a fiber optic wire that transmits the audio signal via light. A Coaxial SPDIF connection is similar to a standard RCA connection. These are the two most common connections and which one you use usually comes down to what you have available on your receiver unit and how far you are running the cable (i.e. through walls or from separate rooms) as the Tos-link tends to be a bit more delicate than the Coaxial SPDIF. When you use the multi-channel output, the Blu-ray player does the work by processing the soundtrack and then sending the signal to the receiver for amplification and routing to the speakers only typically without any processing done by the receiver. Conversely, when you come across the statement that a player transmits the audio bitstream, it means that the signal is sent to the receiver which in turn does the work of processing the signal. The multi-channel output on your Blu-ray player may support either a 5.1 or 7.1 speaker set up depending on the model you have. Last but not least, we have the HDMI connection. When you use this connection you will need to connect not only your Blu-ray player to the receiver via HDMI, but your receiver to your TV or projector via HDMI so the HD video signal can be received. And just like with video, having equipment that supports HDMI v1.3 increases the capabilities and quality you are able to enjoy.
Dolby Digital and DTS are mandatory formats found on every Blu-ray disc and will support up to a 5.1 soundtrack. These formats are available when using any of the above mentioned connections. However unless you are using the multi-channel output, you must have a receiver that will support processing these formats.
The next step up is the Dolby Digital Plus and DTS-HD High Resolution formats. These soundtracks can support up to a 7.1 speaker set up but are considered optional and are not required to be supported by all Blu-ray players. These formats cannot be fully transmitted over a Tos-link or Coaxial connection, so in turn they will be sent as a standard DTS or Dolby Digital signal. This signal can pass over any version of HDMI or the multi-channel output, but how it is sent is decided by the model Blu-ray player you have.
Up next is the PCM soundtrack. This is an exact replica of the studio soundtrack. A Tos-link or Coaxial connection is unable to carry 5.1 PCM signals, however it can be successfully sent over either HDMI or HDMI v1.3. The multi-channel output can also be used but the quality of the audio then is determined by the player as it will be doing the processing instead of your receiver.
At the top end of the list are the Dolby TrueHD and DTS-HD Master Audio formats. Unfortunately these too are considered optional and not every player is required to support them. These formats are supposed to be identical to the studio master soundtrack and are considered to be rather identical in quality to each other. These soundtracks are not able to be sent over Tos-Link or Coaxial connections and the player will default to the standard Dolby Digital or DTS signal. If you are using a standard HDMI connection, the player may only send the standard formats as with a Tos-link and Coaxial connection or it may convert the signal to PCM (see above). When using an HDMI v1.3 connection, the audio bitstream may be sent to the receiver to be processed where your receiver supports the format. When using the multi-channel output, either the standard Dolby Digital or DTS signal will be sent or the player will do the decoding for the TrueHD or Master Audio and then send it to the receiver for amplification. When given multiple possibilities, it is the specification of the player that designates which action is taken.
To be sure you have the ability to get the best audio Blu-ray has to offer, you will want three things. First is an HDMI v1.3 connection on your Blu-ray player, receiver, and TV. You will also need a player that can at least send the Dolby TrueHD and DTS-HD Master Audio bitstream to your receiver, and finally, a receiver that can decode Dolby TrueHD and DTS-HD Master. So the high definition video and audio provided by Blu-ray players sounds great but what about all of your DVDs? There is no need to worry as your DVDs will play just fine in a Blu-ray player. Not only will it play them, but most Blu-ray players can upscale your standard DVDs to a high definition resolution of up to 1080p when using an HDMI connection.
The last thing to consider is the profile your player supports. The three profiles are Profile 1.0, Profile 1.1 and Profile 2.0. Profile 1.0 is basically the first generation of players. They lack features that have now become mandatory for a Blu-ray player to have and cannot be upgraded to Profile 1.1. Profile 1.1 is considered the standard for Blu-ray players. Profile 2.0 is brand new and not widely available and will also have internet connectivity. The primary difference comes down to the special features you can access on the Blu-ray movie. If you have a Profile 1.0 you do not need to run out and upgrade unless you want to exploit the special features. Profile 1.1 is probably your best bet if you are looking to purchase your first player. But if you want the latest and greatest you may want to wait for Profile 2.0, or at least make sure that the player you buy today can be updated to future profiles like Profile 2.0.
Again, we will end on a very similar note as before which stresses that this technology is ever-changing. What is the standard today may evolve into something different tomorrow. So, to get the most out of your investment, try to be ready for tomorrow today. Just as we mentioned before that having HDMI v1.3 connections is almost a must, so is knowing if your Blu-ray player is able to be updated and how it accomplishes this. There is so much more that Blu-ray offers than we covered here and I hope this information encourages you to enjoy what this great form of media has to offer. Thank you for reading this month. Next month we will continue with a product overview of the Integra DTR-7.8 a THX Ultra 2 Certified, 7.1-Channel, 3-Zone Home Theater Receiver.
Questions or Comments?
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