Future of Digital Music in Windows
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Introduction
In recent years, games have driven the majority of the innovation in PC audio. The Microsoft Windows operating system now provides rather sophisticated methods for modeling sounds in immersive, 3-D environments using the Microsoft DirectSound3D API. Additionally, the PC also delivers a comprehensive method of developing interactive music, which can add substantial emotional impact to any multimedia title. Microsoft DirectMusic is the name of this new technology.
At the same time, traditional music playback continues to be a multi-billion dollar business in the United States alone. The growing popularity of high-quality audio compression is destined to forever change the way that consumers use recorded music. Given that the most popular form of compression can reduce a high-fidelity piece of music from 40MB to 4MB, the distribution of this media is now an order of magnitude easier. From the viewpoint of a consumer using today's storage capability, music has transcended dedicated physical media. It is now entirely practical to store your favorite music on a reasonable-sized hard drive of even flash memory. It is also practical to download an entire high-quality piece of music from the Internet using a 56k modem. This is a paradigm shift in the making.
This article describes the digital music market and the product opportunities it presents. It highlights the technological challenges of current and future scenarios and describes Microsoft's plans to address them.
There are four distinct models of music playback that relate to PCs. The first and most conventional is already widely in use. Using the PC's audio system, users play music stored on the Internet or local hard disk. The next model involves the use of portable players. These devices connect to PCs to obtain their source material. Another approach is to embed a PC into the form factor of a consumer electronics device. This enables new product category called a Virtual Jukebox, which can deliver much more convenience than previous product lines. Lastly, the way that these new consumer electronics devices connect to other devices must be considered.
PC as Music Player
Currently, most PCs only utilize the most basic capabilities of digital music. Typically, a single application performs the music importation, song data tracking, play list generation, and file playback. Users rely on the existing Internet browser to download music files from the Internet. Two problems plague this scenario: song management and security. The compression format is also an issue that will be covered later in this article.
Users quickly notice the lack of a centralized service tracking the music files and their associated meta data. Almost every music application keeps a list of available music files and the artist and title information in a proprietary database. The downside is that this information can rarely be shared between applications. The next-generation operating system must keep track of the location of all music files, stored on fixed and removable media. It must also maintain a centralized table of contents to facilitate references to material that may not be currently available.
In addition to music management, there must be some form of content protection for those publishers and artists who want it. This protection should have many facets under the control of the content owner. Options include controlling the permissible distribution, limiting or preventing the number of copies that users can make, and controlling the number of times a particular song will play before expiring.
PC as Music Host for Portable Player
The next obvious step is connecting the PC to a portable music device, so users can take their music with them. Many devices require that consumers store the audio on the PC and transfer it to the portable device using the PC's parallel port or Universal Serial Bus (USB). As with the previous model, a centralized service needs to do the work of referencing all available media and administering the content protection scheme, as desired by the content provider. In addition, the system must be able to extend these services to portable devices from any manufacturer.
The biggest technological shortcoming for the portable model is the lack of standards to interface the portable device to the PC and any relevant music application. The system must deliver this support with a new application programming interface (API). The benefit to consumers is that they can quickly and easily use their portable device with all music available to the PC.
Virtual Jukebox
Another possible scenario involves dedicating a PC to perform music playback and management. This enables manufacturers to build a cost effective and very focused product. It will be designed to do one thing well and the user interface will be optimized to match. The Virtual Jukebox has the potential to really fit the mold of a consumer electronics device. It does one thing well and can be easily understood by consumers.
The compelling consumer benefit is the convenient integration of CD and Internet audio. A single, smart device tracks all the available music that a consumer owns and offers a variety of ways to play it. The Virtual Jukebox can group music by artist, or mood, or style--or it could intelligently select from a list--whichever makes the most sense for the given circumstance.
The biggest challenge lies in assembling the all the necessary subsystems, including the file system, CD audio, user interface, and so on. Microsoft Windows CE can address many of the needs. Additional information is contained in the following sections.
Connected Virtual Jukebox
The next level of consumer benefit in digital music is the interconnection of these smart music devices. Having CD and Internet audio integrated in one place is a good start. Making your music available to you in other rooms, at work, in the car, and on the move is the next important step.
Many of the challenges of the connected Virtual Jukebox have already been addressed. However, there are new issues that will extend the scope of existing plans. Home Networking is beyond the scope of this article and offers method to interconnect devices like the Virtual Jukebox. The Digital Content Management scheme mentioned in the "PC as Music Client" scenario will need to scale across the home network to create a single unified repository of available music.
Underlying Technology
While most of the necessary support already exists, Microsoft is committed to delivering all the technology needed to address the digital music revolution. Many of the components are also relevant to other forms of media. The next sections cover the major items in more detail.
High-Quality Music Compression
The enabling factor of music on PCs is high-ratio compression of audio that is indistinguishable from the original. Many forms of compression can provide 10:1 reduction in size with no perceptible loss in sound quality. Moving Picture Experts Group (MPEG) Version 1 Layer 3, commonly known as MP3, can encode a stream of full-fidelity audio at 1378kbps into 128kbps with results acceptable to a very discriminating listener. Second generation codecs are coming to market now. They offer the ability for users to get full fidelity from an even smaller data rate. Many codecs offer great sound quality at 64kbps.
The Microsoft DirectShow architecture is a modular approach to audio and video processing. Its inherent strength lies in its flexibility to adapt to a number of applications. DirectShow can obtain data from the Internet, hard disk, or a variety of other sources in such a way that the downstream components need to have no knowledge of the origin.
Digital Content Management
The next major release of Windows will contain a new technology called Digital Content Management (DCM). Its charter is to integrate the vast assortment of audio, video, pictures and other data into a single catalog. For music, DCM will automatically track the importation of songs from all available sources, including Internet downloading, CD, and file transfers across a network. Additionally, the system will be able to reference catalog entries even for files that are stored on removable media. This will provide the conceptual integration that the current generation of sound, video, and picture applications desperately need.
Content Access System
Microsoft is committed to a long-term strategy that delivers a technical framework for content protection. The system employs a secure container that can encapsulate any type of data, including images, books, music, and video. Future versions of Windows will allow content owners to set certain rules for materials they distribute to consumers. Rules such as copy restrictions, expiration dates, and more are configurable by the content owner. Using the scheme it is still possible for the owner to specify that content have no restrictions whatsoever.
Portable Player APIs
Microsoft recognizes the consumer benefit of connecting portable audio players to the PC. It is important to extend the Content Access Scheme mentioned above to all devices that connect to the PC, such that the content owner's rules are followed. Microsoft will be delivering hardware abstraction layers that enable music applications to address portable music devices in a uniform manner.
Microsoft Windows CE and Digital Music
Currently, Windows CE offers many of the necessary services to build a Virtual Jukebox. At the most basic level, Windows CE already provides a graphical user interface, a multithreaded kernel, audio APIs, and a development kit. Upcoming releases will add support for DirectShow and compatible audio codecs. For more information, please visit the Windows CE web site: http://www.microsoft.com/windowsce/.
Home Networking
The Virtual Jukebox is even more compelling when you hook it to other devices. One way to think of it is as a centralized music repository. You could use a stereo in any room and have access to the entire collection of music stored on your Virtual Jukebox. For more information on home networking, see the web site at: http://www.microsoft.com/homenet/.
Call to action for Digital Music:
| • | For more information, please see the web site available at http://www.microsoft.com/whdc/device/audio/default.mspx. |