|What is DVD-Audio?|
DVD-Audio is an audio media format that is similar to DVD-Video which is what movies and the like are on. It's the same size as a DVD-Video disk as well as looks the same. But a DVD-Audio (Also written as DVD-A) is for high resolution multichannel audio.
By high resolution I mean it can playback audio at up to the 192kHz sample rate and 24-bit depth (stereo only). It can playback 5.1 audio at 96kHz/24-bit depth. Compare that to a normal audio CD which has a set samplerate of 44.1kHz and 16-bit depth. The maximum data bandwidth for DVD-A is greater than that of DVD-Video: 9.6 Mb for DVD-A and 6.14 Mb for DVD-Video. The bit depths supported by the spec are 16, 20, and 24 bits of resolution.
In fact a DVD-A supports a number of different sample rates and bit depths.
*In order to accomodate 6 channels the audio must be compressed using the MLP lossless compression method.
The DVD-Audio specification also allows the use of normal DVD-Video to be accessed from the DVD-A partition. This way an artist can have a link/button that will play their normal DVD-Videos or play AC-3/DTS 5.1 surround sound files. So you can have both versions on a single DVD. Of course there is a maximum of 4.38 GB (4.7 GB Disc) of room on the DVD disc. NOTE: DVD's use 1000 bytes to equal 1k where a computer uses 1024 bytes. There is actually a bit less than 4.3 GB because of formatting and all the other picture, text files.
There are many more options for DVD-A for audio. For instance you can mix different sample rates for different songs as well as use different bit depths. You can also use different sample rates and bit depths for front or Surrounds and subwoofer. This is mainly for use if you are running out of room and say the subwoofer channel doesn't necessarily require the full 96kHz/24-bit depth (this may be an arguable point). There are two different types of groupings used for DVD-A. These grouping allow you to mix sample rates and bit depths with no prolbems.
Equipment needed to create a DVD-Audio Disc for PC:
It's gotten much simpler in the past year or so to create a DVD-Audio disk. At the moment there are two software programs that will allow you to create a simple DVD-A disc.
The first is called Bronze by Minnetonka. It is for Windows and will allow you to create a high resolution dvd-audio disc from PCM (wav) files. It doesn't accept MLP encoded tracks which limits it to 6 channels of 48kHz/24-bit audio or you can use 2 channels of 192kHz/24-bit audio. The program accepts both AIFF and WAV file uncompressed file formats. This is probably the least expensive way to get into High Resolution Audio. It outputs to DVD-R/RW burners.
Another program for DVD-Audio creation is from Steinberg called WavLab. This program does much more than burn DVD-Audio discs. It's an audio editor with the ability to edit multichannel sound files. It supports ASIO sound cards as well as others and has many DVD-Audio tools include playlist editing, onscreen video menu creation, picture slide show and DVD text.
There can be a number of different sample rates and bit depths placed on the same DVD media (DVD-R, DVD-RW, and molded DVDs). The supported sample rates are 44.1kHz, 48kHz, 88.2kHz, 96kHz, and 192kHz.
DVD-Audio takes advantage of the large storage capacity, speed and flexibility possible with DVD. DVD-Audio provides for audio in stereo and in multi-channel surround in a wide range of specifications. In addition to audio, a DVD-Audio disk can contain a limited amount of video, which can be used to display text, such as lyrics or notes; or stills such as a photo album. Up to 16 graphic stills can be associated with each track and on-screen displays can be used for lyrics and disc navigation. As an option, a DVD-Audio disc can also include audio tracks recorded in the DVD-Video specification (Dolby Digital and DTS) for compatibility with DVD-Video players.
A DVD disc is capable of recording video, audio and data information of many different types and formats. An industry group, named the DVD Forum has responsibility for establishing the industry standards and formats for DVD. In 1996, The DVD Forum released the DVD-Video format, which was designed to deliver video at a quality exceeding VHS tape with surround sound and better than CD audio. Before defining a DVD format optimized for audio, the DVD Forum sought the opinions of the music industry and audio equipment manufactures. In January 1998, the DVD Forums Working Group 4 released a draft DVD-Audio standard. In July 1998, the DVD Forum released the preliminary 0.9 version. In March 1999, the DVD Forum released the final version 1.0 of the DVD-Audio specification.
Is DVD-A really better?
I listened to the demo disk that came with a Panasonic DVD-A player. It had a variety of tunes recorded in a number of different formats. The one that really struck me was called "Dancing Drums" and has lots of cymbals and other percussive instruments. It's a stereo recording done at 24-bits and 192 kHz. The attacks and transients are oh-so-sweet, and the imaging is rock solid. This is definitely a step beyond CD.
Can my DVD-Video player or my CD player play DVD-Audio discs?
To provide compatibility with DVD-Video players, most DVD-Audio discs are including Dolby Digital (some also include DTS) audio tracks that satisfy the DVD-Video specification. These tracks are playable on DVD-Video players. A DVD album which includes these features will carry the DVD-Audio and DVD-Video logo.
In order to play the DVD-Audio ultra-high fidelity PCM and MLP encoded audio tracks from DVD-Audio disk, a DVD player is required that meets the DVD-Audio specification. These players can be identified by the DVD-Audio logo.
Unfortunately, a DVD-Audio disc is NOT playable on a CD player.
What's Up with DVD-Audio?
What's so special about DVD-A? The disk holds 4.7 GB of data where as a CD only holds about 700 MB of data. This means you can put about 6 hours of redbook audio (44.1k - 16bit - Stereo) on a DVD-Audio. DVD-Audio also supports 24-bit bit resolutions and bitrates upto 192 kHz for stereo and 96 kHz for 6 channels (5.1 surround or 6 channels - There is a difference). This will allow for better quality recordings to be heard by the masses.
It will also allow for different formats to be on the same DVD-Audio. This means that one track can be a 192 kHz stereo file and the next be a 48 kHz 5.1 surround file. You can also have different bit rates in the same song. For instance you can have 96 kHz in the Front speakers and 48 kHz in the surrounds. This is useful if you are only using the surround for playback of an audience response or for ambience found in the theater. This will save some space on the disc, still leaving enough room for other tracks.
DVD-Audio still has a maximum transfer rate of about 9.6 Megabits-per-second. If you record 6 channels at 24/96, your data rate is 13.8 Megabits-per-second, which exceeds the limitation. How do you get around this problem?
MLP - Meridian Lossless Packing is the data-reduction technique selected for DVD-Audio. MLP sounds better because it is a lossless data algorithm. It is not like MP3 for instance. You get back exactly what you put it, so it does not distort or change any of the audio information. MLP on average reduces the size of the file by about 50%. So, with MLP you can put 6 channels of 24/96 on the disk, and still not hit the 9.6 Mbs data limitation. MLP can also be used to simply get longer recording times onto the disk.
Putting together a DVD-Audio Disk:
At first there was only one game in town - Sonic Solutions Their light version runs around $6,000 with their full version aroud $20,000. These are out of range for most project or mid-level studio's. Minnetonka Audio has now come out with two affordable DVD-A authoring systems, a basic discWelder STEEL starting at $499 and a full featured discWelder CHROME at $2495. Minnetonka Audio also offers the SurCode MLP encoder at $2495 with the exclusive Rebit feature not found in any other MLP encoder. Please check out Minnetonka Audio's discWelder and SurCode sites for more info.