1. The New Formats of the Millenium
   DVD, DVD-A and SACD - what are the differences?
2. 5.1 Technology and Where it’s Going
   Dolby Digital vs. DTS
3. What is Authoring?
4. Full Production Services
   What are the benefits?
5. The Common 5.1 Setup

The New Formats of the Millennium – DVD, DVD-A and SACD - what are the differences?

DVD is an absolutely brilliant invention… it’s the next generation of optical disc storage technology. In a nut shell, it’s a bigger and faster CD that can hold quality video, 5.1 Dolby Digital, 5.1 DTS, Dolby Digital stereo or PCM stereo audio as well as computer data. These items could be music videos or concerts, interview footage, behind the scenes, pictures or artwork, biographical info, discographies, home movies – it’s limitless… you need only your imagination.

Shortly after the conception of DVD-video was the introduction of DVD audio, or DVD-A. These discs are an easy parallel to CD’s as they contain mostly audio content, with minimal graphic menus to aid in navigation. They are also authored in a way that allows easy playback in DVD-equipped automobiles. The main difference with DVD-A titles is the audio encoding technology. MLP audio (Meridian Lossless Packing) contains multi-channel, uncompressed PCM audio similar to CD’s, only at a higher bit-rate and sample rate. Never before has digital audio been so close to the sound of the original audio master recordings. Currently, the only disadvantage to DVD-A is the majority of set-top DVD players are not capable of playing back the MLP audio. Dedicated DVD-A players are available, but lower-priced DVD players are currently being introduced that support standard DVD’s as well as DVD-A’s.

SACD parallels the compact disc even more-so than DVD-A. It has less of a home theatre appeal than DVD-A and is geared more towards cars and traditional home stereo playback. The discs lack the visual navigation of DVD-A’s and behave in the same manner as CD’s, allowing an easy transition for consumers into a higher-fidelity audio experience. SACD’s can contain 5.1 surround and/or high resolution stereo audio and depending on the authoring, can be backwards compatible with CD players, a component that is in the works for, but not yet available with DVD-A’s. The audio encoding process for SACD is very different from DVD’s, as the technology introduced a new standardized audio format called Direct Stream Digital, or DSD, which rivals the MLP audio on DVD-A’s. The technologies of SACD and DVD-A offer such similar qualities that it is unknown as to which of the two will prevail as the “standard” multi-channel replacement to CD’s, however the discs and players are readily available at retail superstores, catapulting them into the mainstream market.

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5.1 Technology and Where it’s Going. Dolby Digital vs. DTS

The larger capacity of DVD’s allows for multiple audio formats on the same disc. Standard stereo audio streams are very common for reasons of compatibility, however DVD technology is capable of so much more than CD quality stereo audio. There are two competing formats of 5.1 surround audio, both of which have their advantages and disadvantages. Dolby Digital 5.1 audio is created in a way that allows the soundtrack to adapt to the listener’s environment. This is an ideal scenario for film DVD’s, allowing the dynamics of the audio to be selected by the listener. Music DVD’s can suffer in that respect, as it allows the listener to alter the audio from the way the mix engineer intended.

This is where DTS comes in… A very limited amount of playback parameters makes DTS a close parallel to CD audio, only in brilliant 5.1 surround sound. The encoding process is less audible with DTS, making it more appealing when the audio is the priority of the project. The consequence of using DTS is a much higher file size, limiting the amount of content that can fit on the disc. Dolby Digital provides a solution when 5.1 surround audio is desired, but there is simply too much video content to house both. Another factor in the decision of Dolby vs. DTS is the demographic of the DVD. When pristine audio quality is much less of a concern for the listener than the amount of video content, Dolby Digital is an easy solution.

Proper planning in the early stages of the project can allow the best elements of all technologies to live on one disc. The Metalworks DVD team is well aware of the limitations of each technology and can monitor the capacity of your DVD throughout the entire process, which is an essential service in the developmental stages of your DVD project.

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What is Authoring?

Authoring, although it is your final step in production, is one of the key components. How your project is authored will affect the final outcome for the consumer. A good reputable authoring company will work with you from pre-production right through to final completion – managing ALL elements to ensure the perfect fit.

The key factor in authoring is encoding and navigation (the way one moves through the disc). Both picture and audio live on two separate streams… not married together the way we’ve been accustomed to with VHS. Therefore, both must be encoded separately and must match identically in time code to remain in sync with one another. Once authored you can check for these potential issues. You can look at authoring as a marriage ceremony. You go to the church (authoring suite) and unite the pieces together, but how well they stick is left up to how much care and effort have gone into the pre-planning and the courtship. If there has been solid communication and exploration of needs, your end result should be everything you expected! Isn't love grand?

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Full Production Services – what are the benefits?

DVD’s consist of various assets - mainly speaking they are audio and video streams with menus (either still or motion).

Most, to date, have been produced by three different parties –
1 - the re-mixer/studio
2 - the video production house
3 - the final authoring company

This can prove to be quite costly, confusing and could create delays in delivery - digital files need to shipped back and forth creating time delays and potential sync issues, also conflicting schedules between production facilities may create unforeseen time delays.

At Metalworks we work with you from conception right through to final completion. Our team of talented developers will bring their expertise and limitless imagination to your project. From conceptual state to authoring we manage your project with the utmost attention to detail – especially sync. Sync has already proven to be a potential issue and managing both the video and audio assets is a benefit to all parties preventing any last minute derailment and major time delays due to re-edits and re-encodes.

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The Common 5.1 Setup

In order to hear a 5.1 surround mix the way the mix engineer intended, it is crucial that you have at least the key components of a 5.1 playback system. The arrangement of the speakers is crucial as well, but is limited to the size and shape of the room. A proper 5.1 system consists of a DVD player and receiver capable of decoding Dolby Digital 5.1 and/or DTS 5.1 audio streams. Six speakers are required for proper playback. 3 speakers are positioned in front of the listener, referred to as Left, Center, Right (or LCR). The main content of a music feature or film resides in these 3 channels. There should be 2 speakers positioned to the rear of the listener, towards the side walls of the room. These are referred to as Left and Right Surround (or LS & RS). These channels can contain ambient sounds, sound effects, special effects in music or to give a sense of three-dimensional direction in films.

Finally, a subwoofer should be positioned towards the front of the listening environment. The subwoofer, or LFE (low frequency effects) contains any bass-heavy content such as explosions or rumbles in films. For music programs, it can contain any low frequency instruments such as kick drums or bass, giving them more breathing room. Lower frequency material is usually routed to the subwoofer channel to reduce the amount of work required by the other five speakers, which in most home-theatre situations aren't capable of reproducing a wide frequency range.

The aforementioned refers to the common material that is found in each speaker, but DVD technology allows for endless possibilities of sound placement. With 5.1, it is possible to literally sit in the middle of a performance in the comfort of your living room. With conventional stereos, correct speaker placement was disregarded in most homes, but 5.1 requires more precise positioning to experience everything the format has to offer.