Quality and efficiency, the two keywords of Dolby Digital Plus
During a recent press conference in Milan Dolby through his European managers Díaz-Valdés Alonso and Philip Arletti, after drawing some fundamental audio concepts, passed on to the basic contemporary idea that of "how to increase the audio experience in sporting events" in the shade of the most recent advancements in Dolby technology.
The description outlined an historical description of the qualitative criteria that characterize the audio from the days of the Stereo 7 cassette until today, passing inevitably from the CD and inevitable practices of compression and bandwidth, with related considerations on the ability or inability of each media to reproduce the dynamic range required.
Evidently we have gone far from the initial simple ability to be able to broadcast tv audio in the form of sufficiently intelligible information in mono, to the present situation in which the sound travels often in stereo and in 5.1-channel, especially at sporting events: the audio program here really assumes a crucial importance.
The most critical part in the broadcast chain is not in the section of on field production (EFP) but it is in the segment that covers the transmission, where it is essential to compress the signal with an encoding process and to operate a balance between efficiency (ie bandwidth) and quality conveyed. These two parameters are closely interrelated; the broader the bandwidth, the more expensive the transmission and the result will be more qualitative. The typical solution of MPEG1 Layer2 is not so terrible but it certainly can be improved much and especially can not stand the multi-channel operation.
The need to use a very efficient encoding in terms of bandwidth usage and quality is decisive and Dolby has always been able to help broadcasters and telcos in this difficult task of optimizing the resources of spectrum and bandwidth. Decreasing the bandwidth despite an increase in the quality or freeing up space for other channels, is the dilemma. And this is the typical situation in Europe.
DDPlus
Dolby Digital is the standard that has spread to meet the needs of multi-channel operation and Dolby now offers the latest Dolby Digital Plus that can cope with all the audio information that we expect in a proper HD broadcast.
The DDPlus is now widely available in consumer products, TVs and set-top-boxes, and in addition to being supported in the broadcast area it is also available in mobile applications and online. The same format is suitable in many worlds and so it proactively addresses the desired digital convergence between mobile and broadcast in the multi screen offer.
The DDPlus realizes the bandwidth savings required for the typical profile of multi-channel and multi-platform delivery of the today's media. In practice it is a codec and a technology that can be used by the broadcaster on traditional tv channels, and both online and on mobile platforms.
The DDPlus is also convenient because a channel with 5.1 audio signals also provides metadata by with which the TV set operates the stereo downgrade, so perfectly adaptable to the existing situation.
The DDPlus allows to apply approximately 50% data reduction while maintaining the same quality and this means that the benefits can be felt in a special way in the segment on the transmission even more than in segments of storage and data transport infrastructure.
There are also worth-mentioning studies that indicate that when the audio perception is better, the viewer even distinguishes visual details that would otherwise have been lost when sound is not optimal.
In other words, the same visual quality is perceived even better if the sound is really better.
In this direction, much has been done especially in international events with live high-quality audio 5.1 channels. Starting with the past and forthcoming Olympic Games in Russia, the Champions League, the San Remo Festival, the Moto GP, Formula 1, the Oscars, the Music Festival of the Eurovision.
For instance, SKY has recently launched a whole bouquet of channels dedicated to Formula 1 in HD and since the launch of just a few months ago they have focused a great deal of their own promotion on the audio multichannel surround concept "for an all-encompassing experience".
