Tuesday, 27 September 2011

Bang & Olufsen and 3rd party products



It is a common misconception that integrating Bang & Olufsen Televisions and HiFis with other products is hard work.

The technical department in Struer have worked tirelessy to now make Bang & Olufsen products the easiest to integrate with a wide variety of systems and products.

Take a look at the publication above and see how easy it can be.

Alternatively call Bang & Olufsen of Winchmore Hill to find out more;

+44 208 360 5088

email winchmorehill@bang-olufsen.co.uk

Thursday, 22 September 2011

Servers and Streaming-some clarification


For some time now Bang & Olufsen of Winchmore Hill have been suppliers of the superb Kaleidescape Movie and Music Server. There is a lot of confusion about electronic delivery of home entertainment. Streaming is a method for delivering movies by which the movie is presented to the viewer as it is being delivered over the Internet. The movie is not stored locally, so the quality is limited to what your Internet connection can deliver in real time, and you must be online to watch the movie. Netflix uses streaming for their electronic rental business.

An Internet download works differently. The movie is copied to local storage from which it is played back later. For example, a movie purchased from the iTunes store can be downloaded to an iPad and viewed offline. Downloads work well for movies you purchase because you can view your collection without relying on a service "somewhere in the cloud." Both streaming and downloads are growing, but not nearly as fast as Blu-ray Disc purchases.

We believe that people will continue to collect movies for a long time, just as they collect books and art. We buy movies we love. We buy movies our children love. We sometimes buy a movie to ensure that it will be possible to watch it, even outside of an "availability window." Children watch the same show over and over, which makes buying more economical than renting. Another great reason to purchase is that DVD and Blu-ray offer the best video and audio quality.

In this context, our view on downloads is quite simple: It is just another delivery mechanism for purchasing movies. Today, DVDs and Blu-ray Discs offer the broadest selection and the best fidelity. If you buy movies you must store them, and we believe a movie server is the best place to keep your treasured collection of movies. A natural evolution for the Kaleidescape movie server — one that we have planned from the beginning — will be to support downloads in the future. Indeed Kaleidescape plan to provide online purchasing of Bluray quality movies early in 2011.

The selection of movies available via streaming suffers from the same limitations as other movie rental services: restrictive availability windows and studio licensing deals. In addition, streaming services limit video and audio quality to save bandwidth. Today, streaming is a convenient source of entertainment when immediate availability is more important than quality and choice. Streaming serves important needs, but it does not take the place of a high-quality movie collection. Will the Kaleidescape movie server support streaming in the future? Maybe, but it's not a high priority for us because streaming is already supported by various devices in the home, and because Kaleidescape is focused on transforming your personal collection into a magical experience.

Monday, 12 September 2011

Mulichannel Audio

Below is a very interesting article from the Bang & Olufsen technical team re Dolby DTS surround sound

Multichannel Audio
People familiar with movies in the cinema or on DVD-Video will know that “surround sound” is comprised of what is known as 5.1 channels of audio. The 5 channels are sent to the Left, Centre, Right, Left Surround and Right Surround loudspeakers, and the .1 channel refers to the LFE (Low Frequency Effects) channel which is usually produced by a subwoofer. This channel is called a .1 channel since it has about one-tenth of the frequency content of the other 5 channels.
The current high-performance medium for distributing films is BluRay which is a disc capable of supporting up to 8 channels of audio. This is typically used as a 7.1-channel system which includes the 5.1 channels of DVD-Video plus an additional 2 channels, probably used for extra surround information. There are different options for the placement of the two extra loudspeakers, depending on the movie’s mix.
In order to get the 7.1 channels of audio from your BluRay player into your surround processor - a name for a very fancy volume knob with a switch to allow you to choose between your BluRay and other players,- you can either connect 8 separate wires that send analogue audio signals between the two devices, or one single cable called an HDMI cable which supports not only the 8 channels of audio, but also the video signal for your television. If the audio signal is sent on the HDMI cable, then it is transmitted as a digital signal, a stream of 1’s and 0’s, referred to as a PCM (Pulse Code Modulation) signal. PCM is probably the most common method of using a digital signal to represent an audio signal. It is the method used in compact discs, but in fact has been used for decades before the introduction of the CD. When the PCM digital audio signal on the HDMI cable contains more than one channel, it is known as a “multichannel PCM” signal.

Audio Compression
In order to send a large document via email, it is common to compress the file in advance, usually using a .zip format, to reduce its size for sending. You create the document, “zip” it to shrink it, and send it. The person receiving the file “un-zips” it to return it to its original size and content. The same is true for audio on a BluRay – in order for all 7.1 channels to fit into the storage available on a BluRay, the audio signals must be compressed to make them smaller. There are a number of compression formats that are available with different levels of quality for fitting the audio on the BluRay disc. Some of these compression systems are “lossy” which means that they throw away information to make the storage requirements smaller. Some of the systems are “lossless” which means that, although they reduce the amount of storage space required, they do so without any loss in information.
Two examples of these “lossless” compression systems are Dolby TrueHD and DTS-HD Master Audio

Dolby TrueHDTrueHD is Dolby’s system for lossless compression and is optional as a format on BluRay movies and players. This means that not all players are able to decode a movie that uses the TrueHD compression algorithm, and that not all BluRay movies have audio that uses the format. In order to ensure that, in either of these cases, you will still be able to hear audio from your film, the soundtrack is always available in Dolby Digital format, the same lossy compression format used on DVD-Video, as a “backup” solution.
Some quick facts about Dolby TrueHD:

- it is a successor to the Dolby Digital, also known as “AC-3”, lossy compression format
- it can support up to 14 channels of audio, although most films are mixed in either 5.1 or 7.1
- if higher-resolution audio is used, then the number of channels is reduced. 8 channels of 96 kHz, 24-bit audio or 6 channels of 192 kHz, 24-bit audio


DTS-HD Master Audio
The competitor for Dolby TrueHD is from DTS (Digital Theatre Systems) and is called DTS-HD Master Audio. It is an extension of the original DTS lossy compression format available on some DVD-Videos. This means that the original format forms the “core” of the new format. If your player cannot play the DTS-HD Master Audio format, it will play the portion of the audio signal that is in the DTS signal, however, more capable players can decode the entire stream and give you a lossless stream equivalent to the original signal.
Some quick facts about DTS-HD Master Audio:

- it is an extension of the DTS compression format
- like Dolby TrueHD, if higher-resolution audio is used, then the number of channels is reduced (8 channels of 96 kHz, 24-bit audio or 2 channels of 192 kHz, 24-bit audio

Summary
It is important to not confuse “multichannel PCM” with either Dolby TrueHD or DTS-HD Master Audio. The latter two are the compression systems used to fit the audio on the distribution medium, like BluRay, for example, whereas multichannel PCM is the format that is probably used to transport audio on your HDMI cable between devices in your home. For example, it is likely that your BluRay player reads either the Dolby TrueHD or the DTS-HD Master Audio file on the disc, decodes it, and then sends it to your surround processor on the HDMI cable using multichannel PCM digital audio.