Microsoft Windows Media Resource Kit (Pro-Resource Kit)

To provide movies, trailers, and other video on their site, Contoso Movies Online must convert the video into Windows Media files. Then the files can be sent to the hosting service, and end users will be able to link to the files from the Contoso Web site and stream the digital media to their computers. To convert the video, the company will use two or more production workstations.

The basic components of a workstation are a playback VCR and a computer system. The VCR plays back the video, and the computer converts the video and stores it as a file. Contoso plans to use the workstations to convert all of their video. In the initial phase of the site, the company will need to convert many hours of video in order to have a broad enough catalog to open business. The company plans to have no less that 100 titles available before going online. That means that over 200 hours of video must be encoded. To help convert the initial volume of titles, Contoso may contract with outside encoding services.

In the early stages of business planning, the management team asked the questions: “Why not send out all conversion work? Why not keep the core business of the company focused on acquiring and renting movies?” The company decided to use a service to handle the hosting of the site and streaming content, an e-commerce provider to handle the purchase process, and a license service to handle issuing and maintaining DRM licensing. Why not farm out conversion as well?

The Contoso team is made up of people interested in the production of movies. As part of their charter, they decided that they want to have direct control over the quality of their content in order to provide the best user experience. By encoding their own material using the Windows Media codecs, tools, and services, they can work with the codec and encoder configurations to achieve the cleanest image and sound. And by contracting with a prominent CDN, they hope to provide their customers with the highest-quality stream. Other online sites may promote price or the size of their catalog. Contoso hopes to build their reputation on the quality of the end-user experience. The decisions were based on the vision and goals of this particular company. For your company, you may decide to use third-party encoding services exclusively, but handle your own e-commerce or focus on acquiring content only. The approach you take depends on your business model.

Today, video can be stored in a wide variety of formats. The company could receive material from a studio in several videotape formats, including Betacam SP, Digital Betacam, and S-VHS. Other popular formats include MiniDV, DV, DVCPro, DVCAM, Hi8, and Digital8. Video can also be stored on discs, such as DVDs, CD-ROMs, laser discs, and removable hard disc drives. Each format has its advantages and disadvantages, which help define how and when it is best used.

Contoso will standardize on the Digital Betacam format. This format is considered to be an industry standard for storing professional-quality video. However, the company will also purchase S-VHS and DVD decks to cover their bases. Again, quality is important to the company, so they will make the considerable investment in Digital Betacam decks.

Each workstation, therefore, will include a Digital Betacam deck and a computer system to store the converted video. The Betacam decks are fairly large, heavy, and expensive, so they will be permanently located at each workstation. The S-VHS and DVD decks are lighter and less expensive, so they will be made portable. For example, the DVD deck could be used for capturing on a workstation, and then moved to another area and used to view material.

Workstation Overview

Contoso will make the necessary investment in the workstations to ensure the highest-quality conversions. However, this does not mean they must purchase a lot of expensive production hardware and software. The company does not need to get in the business of editing and processing video and designing sound. They only need to convert video using methods and systems that provide the best possible quality. Therefore, they do not need dedicated video or sound editing tools. The Contoso staff will take the audio and video exactly as it comes from the studio and convert it to files, striving to make the finished files look and sound as close as possible to the original.

To that end, Contoso will require playback decks that reproduce good-quality images and sound; monitors, such as speakers and a video display, to check the quality of the playback; a capture card that accurately transfers or converts the source signals to the computer; a computer capable of reliably moving data from the card to a storage device; and a storage device that can quickly and reliably read, write, and store large amounts of data. If they do need editing or sound design services, Contoso can employ a third-party service.

Because Contoso Movies Online will most often work with digital video, they can expect a higher-quality capture of the video to their workstation computers. When transferring audio and video from analog sources (such as S-VHS tape) to digital format, quality is degraded in the conversion process. High-quality conversion of analog sources requires careful adjustment of audio and video parameters. For example, when converting an analog video to a file, you must adjust the color and brightness or video level of the picture, and the audio level. High-quality conversion also requires capture cards that are capable of accurately processing and sampling the analog signal.

With digital video, you do not have to convert an analog signal into digital samples; you merely play back the data on the VCR and copy it to the computer. It is very similar to copying a file, except that the source is a digital videotape. The only way the quality can be degraded is by capturing with a computer system that cannot handle the high volume of real-time digital media data. In Contoso’s case, however, the workstations can handle the data transfer and storage at the speeds required. During the capture, the only conversions that take place are restructuring the data to a format such as AVI or Windows Media Format, and to a different pixel format. However, these modifications to the data do not require any adjustments by the Contoso staff; the format conversions are handled quickly and automatically. (For more information about pixel formats, see chapter 1.)

Thinking about the types of processing and configurations you will make is important in the early stages of planning a workstation, because you not only need to determine hardware and software requirements, you also need to know how much space the system will require and where you can locate it. For example, Contoso Movies Online will need to check the quality of the captured audio, so the space in which they locate the workstations should enable them to play the audio clearly and should block outside noises from sources such as air conditioners and elevators.

Workstation Placement

Contoso is located in a large loft environment with broad open spaces and cubicles. To avoid polluting the workspace with unwanted sound, the workstations will be located in an area with walls and a ceiling. Because the conversions will not require processing or editing, the sound level can be kept low; headphones can be used to spot-check the recording.

The small room must house at least two workstations, so the size of each system must be kept to a minimum. Therefore, the systems will use small audio speakers and small, accurate video displays. By accurate, we mean displays that correctly reproduce images. To help contain the sound, Contoso will also pad the walls.

Later in this book, we will describe how to build a compression suite in which a company can do some sound design and video editing. For more details, see chapter 15.

In addition to the two workstations, the room will house two or more encoding computers. These computers will do nothing more than encode Windows Media files from uncompressed AVI files. Because all of their work will be handled by software, these computers do not require audio and video capture cards or high-quality video displays. The computer CPUs, memory, bus speeds, and disk input/output speeds do not need to be as fast as those of the capturing computers because the process does not have to take place in real time.

When encoding from a file, you will get the same quality from a dual-processor, 1-GHz system as from a single 200-MHz CPU. The only difference is that a slower CPU will take much longer. However, once the encoding process has started, it does not require operator attention, so several computers can be configured to encode files while the operator monitors a capture on one of the workstations. On faster computers, the time it takes to encode a file can actually be less than real time. File-to-file encoding can be a good way to give old computers a second life.

Hardware Specifications

The following list describes the hardware that Contoso Movies Online will use in a production workstation:

• Digital Betacam VCR. They do not need a VCR that records and edits, so Contoso can save money by purchasing one that plays back videotape only. The deck needs to have a composite video output (so the encoding staff can view the tape with a video monitor) and an SDI video output. The SDI output provides standard, broadcast-quality digital video and connects directly to the video capture card. Figure 10.1 shows an illustration of a Digital Betacam deck.

  Figure 10.1: A typical Digital Betacam deck.

• Alternate video sources. A number of other video playback devices can be purchased and shared between the workstations, such as S-VHS, DVD, laser disc, and MiniDV devices. Movies and other material will be requested from the studios in the Digital Betacam format. However, other video sources may need to be used.

• Waveform monitor and vectorscope. These electronic instruments display a video signal in ways that enable you to check or adjust video levels and color according to television standards. A waveform monitor displays the video signal as a complex wave. A vectorscope displays the color components of the signal. Often, both instruments are combined in one device. Figure 10.2 shows a waveform monitor/vectorscope unit.

  Figure 10.2: A typical waveform monitor/vectorscope.

  Most tapes that Contoso Movies Online receives from studios will be digital, so they can bypass the setup process by using the SDI output. In those cases, they will not need a waveform monitor/vectorscope because the data is transferred directly without conversion or processing. However, Contoso will include a waveform/vectorscope in the workstation because it will enable them to properly configure the Digital Betacam when capturing from an analog tape.

  The monitor/scope can be used to display the video signal from the alternate sources, such as the S-VHS and DVD decks. However, most consumer decks do not provide a way to adjust the video. The monitor/scope must have two inputs so Contoso can use it for both Digital Betacams. We will describe how to set up video later in this chapter.

• Video monitor. You can view the video output of the VCRs on the computer video display. However, a small video monitor with two inputs is useful when the computer is busy with another task and you need to view a tape.

• Audio mixer and monitors. To conserve space, Contoso will use a pair of small, professional-quality monitor speakers. Good-quality computer speakers are available from a variety of companies. For more critical listening, they can use a pair of good-quality headphones. Contoso will also use a small audio mixer to monitor multiple computers from one set of speakers.

• Video capture card. There are several good-quality video capture cards that are recommended for use with Windows Media Encoder 9 Series. Contoso will use a capture card that provides an SDI input so that they can capture the digital video signal directly from the Digital Betacam VCRs.

• Workstation computer. Contoso decided to use computers with dual 700 MHz processors or higher, 256 MB of RAM or more, and a fast PCI bus. Check the Microsoft Web site (http://www.microsoft.com/windowsmedia) for the latest requirements.

  In the two-step process that Contoso will use, they will capture movies to an uncompressed AVI file first, and then encode a Windows Media file from the AVI file. The computer to be used for capturing will also be capable of encoding directly, using the one-step process. The PCI bus speed and the read/write speed of the hard drive are critical for capturing uncompressed audio and video. A fast CPU is required for capturing directly with the encoder because encoding includes compression, which uses a great deal of processor time.

• Raid array or fast hard drive. When choosing a storage system, Contoso considered not only the amount of storage, but the read/write speed of the drives as well. An uncompressed movie requires a continuous read/write speed of at least 27 megabytes per second, and can require 80 to 120 GB of storage. After the movie has been encoded, the AVI file can be deleted.

• Network interface card (NIC). The card must be capable of a speed of 100 mbps.

• Sound card for output. Used to monitor the audio.

The following list describes the hardware that Contoso Movies Online will be using for their encode-only computers:

• Encode-only computer. The minimum requirements for a computer to encode from file to file are a 500 MHz CPU and 32 MB of RAM. However, a 500-MHz CPU with 128 MB of RAM is recommended to run the encoder on Windows XP Professional. Again, the faster the CPU, the shorter the encode time. The computer will also require access to 80 to 120 GB of storage, which can be an internal hard drive or network share.

• NIC. Same as the workstation computer.

Software Specifications

The following list describes the software required for a production workstation:

• Capture utility. The video capture card you choose often comes with a utility that enables you to do simple captures to AVI files, such as the Microsoft software Amcap, Windows Media 9 Capture, and Vidcap32. The Windows Media 9 Capture utility is pre-configured for capturing at standard video frame rates, which we will require for optimum quality.

• Capture card driver. Make sure the latest drivers and utilities have been installed for the video capture card.

• Windows Media Encoder 9 Series and utilities. When you install Windows Media Encoder, a set of utilities is also installed. These enable you to perform tasks such as simple editing of a Windows Media file and editing encoding profiles.

• Windows Media Player 9 Series. The Player can be installed from the Microsoft Windows Media Web site. You will need it to test playback of the files you create.

• Windows XP Professional. Windows XP Home Edition and Windows 2000 are also supported by Windows Media 9 Series. However, Contoso Movies Online will use Windows XP Professional because it supports computers with multiple processors. The hard disk must be formatted as an NTFS volume so files larger than 4 GB can be recorded.