Microsoft
`Broadcast Technologies White Paper
`
`
`
`Broadcast-Enabled Computer Hardware
`Requirements
`
`This paper describes the hardware requirements of a broadcast-enabled computer.
`
`
`
`
`
`Contents
`Hardware Requirements ........................................................................................................................................... 3
`Minimum Hardware Configuration .................................................................................................................... 3
`Recommended Hardware Configuration ............................................................................................................ 3
`Windows 95 Requirements ................................................................................................................................ 4
`Manufacturing Hardware ................................................................................................................................... 4
`Broadcast Network Receiver Card ........................................................................................................................... 4
`Functionality ...................................................................................................................................................... 4
`Requirements ..................................................................................................................................................... 6
`Other Networks .................................................................................................................................................. 7
`MPEG Decoding and Display .................................................................................................................................. 7
`Functionality ...................................................................................................................................................... 7
`Requirements ..................................................................................................................................................... 8
`Recommended Configuration ............................................................................................................................ 9
`Interface to the Computer .................................................................................................................................. 9
`Analog Audio and Video Interconnections ........................................................................................................ 9
`Integration Possibilities .................................................................................................................................... 10
`Sound Card ............................................................................................................................................................ 10
`Functionality .................................................................................................................................................... 10
`Requirements ................................................................................................................................................... 11
`Recommended Features ................................................................................................................................... 11
`Large-Screen Monitors .......................................................................................................................................... 11
`Functionality .................................................................................................................................................... 11
`Requirements ................................................................................................................................................... 12
`Recommended Features ................................................................................................................................... 12
`Input Devices ......................................................................................................................................................... 12
`Overview of Remote Input Devices ................................................................................................................. 12
`New Keys ......................................................................................................................................................... 14
`Modem ................................................................................................................................................................... 15
`Functionality .................................................................................................................................................... 15
`Requirements ................................................................................................................................................... 15
`Recommendations ............................................................................................................................................ 15
`Details .............................................................................................................................................................. 16
`Related Hardware Design Information .................................................................................................................. 16
`Video Display Adapter Recommendations ...................................................................................................... 16
`Plug and Play Specifications ............................................................................................................................ 18
`
`
`© 1997 Microsoft Corporation. All rights reserved.
`
`SAMSUNG 1020
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`
` Broadcast-Enabled Computer Hardware Requirements — 2
`
`
`
`This document is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS OR
`IMPLIED, IN THIS DOCUMENT.
`Microsoft Corporation may have patents or pending patent applications, trademarks, copyrights, or other
`intellectual property rights covering subject matter in this document. The furnishing of this document does not
`give you any license to the patents, trademarks, copyrights, or other intellectual property rights except as
`expressly provided in any written license agreement from Microsoft Corporation.
`Microsoft does not make any representation or warranty regarding specifications in this document or any product
`or item developed based on these specifications. Microsoft disclaims all express and implied warranties,
`including but not limited to the implied warranties or merchantability, fitness for a particular purpose and
`freedom from infringement. Without limiting the generality of the foregoing, Microsoft does not make any
`warranty of any kind that any item developed based on these specifications, or any portion of a specification, will
`not infringe any copyright, patent, trade secret or other intellectual property right of any person or entity in any
`country. It is your responsibility to seek licenses for such intellectual property rights where appropriate.
`Microsoft shall not be liable for any damages arising out of or in connection with the use of these specifications,
`including liability for lost profit, business interruption, or any other damages whatsoever. Some states do not
`allow the exclusion or limitation of liability or consequential or incidental damages; the above limitation may not
`apply to you.
`ActiveMovie, ActiveX, BackOffice, Developer Studio, Direct3D, DirectDraw, DirectInput, DirectPlay,
`DirectSound, DirectVideo, DirectX, Microsoft, NetMeeting, NetShow, Visual Basic, Win32, Windows, and
`Windows NT are trademarks or registered trademarks of Microsoft Corporation in the United States and/or other
`countries. Other product and company names mentioned herein may be the trademarks of their respective owners.
`© 1997 Microsoft Corporation. All rights reserved.
`
`© 1997 Microsoft Corporation. All rights reserved.
`
`2
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`

`
` Broadcast-Enabled Computer Hardware Requirements — 3
`
`Hardware Requirements
`This section explains the minimum and recommended hardware and operating system requirements
`for the platform, and states the Microsoft hardware manufacturing policy.
`
`Minimum Hardware Configuration
`
`The minimum requirements for a broadcast-enabled computer are:
`
`Intel Pentium-120 MHz processor or compatible
` High-speed buswith adequate slots to accommodate high-speed broadcast network and video card
` 16MB RAM
` 1 GB hard disk
` 27" SVGA display capable of 640x480 resolution with 60Hz non-interlaced refresh rate
` 3.5" 1.44 MB floppy disk drive
` Quad-speed CD-ROM drive
` 14,400-bps internal or external modem (TAPI compatible)
` Standard computer keyboard
` Pointing device with two buttons
`
`For details on the minimum requirements for the Video and Display subsystem, broadcast network
`receiver card, access card reader, and other components in the system, see the following sections for
`each component.
`
`
`
`Recommended Hardware Configuration
`
`The recommended configuration for a broadcast-enabled computer is:
`
`Intel Pentium 150 MHz processor
` PCI bus with at least four slots available
` Consumer-electronics-style case with low-noise fan or noiseless cooling system(OnNow-capable)
`
`Note: User should not perceive system noise from a distance of 6 feet in a quiet living room
`environment.
`
` Support for SIPC (Simply Interactive PC) initiatives such as OnNow, Drive Bay, 1394, and USB
`to provide a more consumer-friendly appearance
` 16 MB RAM or more
` 2 GB or larger hard disk with fast data transfer rate
` 3.5" 1.44MB floppy drive
` 6x-speed CD-ROM drive or DVD-ROM
` 31" display capable of 800x600 resolution with 60 Hz non-interlaced refresh rate
` 28,800 bps or higher internal fax modem (AT command set compatible).
`
`Note: Modem functionality can be incorporated on expansion cards for the broadcast-enabled
`computer and so may not be a separate peripheral.
`
` Wireless (RF or IR), battery-operated keyboard with built-in pointing device
`
`© 1997 Microsoft Corporation. All rights reserved.
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` Broadcast-Enabled Computer Hardware Requirements — 4
`
` Wireless TV-style remote control
` Battery-operated, combination remote control/wireless mouse with power/sleep button, TV
`buttons (channel up/down, volume up/down, mute, TV)
` Sound system expansion card with digital audio (wave) support, a MIDI port, a MIDI-controlled
`wave-table synthesizer, multiple analog and digital audio inputs, software-controllable low-noise
`audio mixer/preamplifier, and multiple audio outputs
`
`
`Note: Sound-card functionality can be incorporated on motherboard or expansion cards for the
`broadcast-enabled computer and so may not be a separate peripheral.
`
` A built-in microphone or a front-mounted microphone jack suitable for teleconferencing,
`education, karaoke, and other applications requiring sound input.
` AC-3 audio decoding for DVD compatibility
`
`IR blaster capable of controlling consumer electronic devices
`
`For details on the minimum requirements for the Video and Display subsystem, broadcast network
`receiver card, access card reader, and other components in the system, see the specific sections for
`each component.
`
`
`
`Windows 95 Requirements
`
`Because the Broadcast Architecture uses Microsoft ® Windows® 95 as its general purpose operating
`system, hardware designed for it must conform to the Plug and Play architecture. For detailed
`information on designing Plug and Play compliant hardware, refer to the documents listed at the end
`of this paper.
`
`Manufacturing Hardware
`
`Microsoft will not sell Broadcast Architecture platform components directly to the end user
`(exceptions may exist for keyboards or pointing devices). Rather, OEMs and hardware vendors will
`license the technology from a network provider (where applicable), and will license Microsoft
`Broadcast Data Network (MSBDN) designs and services from Microsoft. OEMs and hardware
`vendors may build, sell, install, and service their own products. By making hardware designs and
`software components available to numerous OEMs, Microsoft expects competition to drive the
`development of many feature enhancements, and create distinct price points from which the end user
`can choose.
`Initially, Microsoft will work with OEMs to develop the first Broadcast Architecture platform. From
`this work will come different kits, including Device Driver Kits (DDKs), and Software Development
`Kits (SDKs), that will be provided to OEMs who wish to become Broadcast Architecture licensees.
`
`Broadcast Network Receiver Card
`This section describes the functions of a broadcast network receiver card and the requirements it must
`meet to support a Broadcast Architecture platform.
`
`Functionality
`
`Because the Broadcast Architecture works with many different types of broadcast digital networks,
`the exact details of the broadcast receiver card are dependent on the broadcast network and network-
`specific access-control mechanisms. Broadcast Architecture software expects specific software drivers
`for each network card to be supplied by the card vendor or network provider.
`
`© 1997 Microsoft Corporation. All rights reserved.
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`
` Broadcast-Enabled Computer Hardware Requirements — 5
`
`Network Interface Connector or Antenna
`For a digital broadcast satellite network, the antenna is typically referred to as an Outdoor Unit
`(ODU). For a cable network interface, the connector is likely a typical F connector. For a
`Multichannel Multipoint Distributed System (MMDS) configuration for a wireless cable system, a
`microwave antenna is required.
`
`Signal Paths
`The broadcast receiver card must be able to receive both normal broadcast-network-related broadcast
`information and data stream information, as defined by the MSBDN/MPT IP data transmission
`format, as defined in the MSBDN Receiver Board Specification section. Because data streams are
`statistically likely to be on separate channels (cable and MMDS) or transponders (DBS) from the
`video and audio streams, the receiver card requires two paths and signal lines. In this specification, we
`refer to these paths as the “digital audio/video signal path” and the “digital data signal path.” These
`signal paths are described separately to clarify their differences.
`Microsoft anticipates that hardware vendors will eventually combine both signal paths (including two
`separate tuners) on the same PCI-bus card, to share control, interface, bus mastering, power, and
`antenna connector resources. However, it is expected that early versions of the broadcast receiver card
`will include only one tuner. Microsoft requires that one-tuner versions of the receiver receive both
`data and audio/video signals without user intervention (though not simultaneously, unless the signals
`are broadcast on the same channel or transponder). This functionality requires the receiver to include
`both network access control circuitry and MSBDN circuitry and a smart card as appropriate.
`
`Digital Audio/Video Signal Path
`The digital audio/video signal path contains the network-specific (and perhaps licensed) technology
`for tuning, demodulation, decoding, error-correcting, demultiplexing, decrypting, and controlling
`access to the digital audio and video signals.
`The digital audio/video signal path typically must be capable of receiving at least five substreams
`simultaneously (such as access control, video, audio, data, and program guide). The design of the
`receiver card must allow transfer of these streams to computer-memory with very low CPU utilization
`(less than 10 percent), so that the transfer doesn’t interfere with the performance of applications
`running on the computer. This requirement implies that the card will use bus mastering or other direct
`memory access techniques.
`Certain network designs mandate particular access control functionality (for interactions with the
`consumer) to be resident in hardware. In the broadcast computer system, the particular network
`“verifier software” is divided into a number of parts. Security functions typically run on a
`microprocessor on the receiver card. The user interface and any modem interface functions are
`implemented in the computer. The different portions communicate with each other through Broadcast
`Architecture driver interfaces that manage communication with the user and network authorization
`center.
`Digital audio/video data is tuned, demodulated, and error corrected (generally referred to as
`“transport”), then routed to circuitry that selects portions of the total stream (SCIDs or packet
`identifiers (PIDs)) of interest. Information of interest can be passed through MSBDN DES decryption
`circuitry, after which it is bus-mastered into CPU memory. Note that some data will not need to be
`decrypted, since it is sent in the clear. It is possible to take selected data directly from the error
`correction circuitry and bus-master it into memory.
`
`Digital Data Signal Path
`The signal path that receives digital data is similar to the existing audio/video path, but includes
`several extra requirements. First, the digital data signal path must demultiplex a packet stream from
`
`© 1997 Microsoft Corporation. All rights reserved.
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`
` Broadcast-Enabled Computer Hardware Requirements — 6
`
`one or more substreams and filter out unwanted packets based on a field in the packet header. Second,
`it must provide access control and decryption services.
`For a more complete description of the data receiver and required decryption functionality, refer to the
`MSBDN Receiver Board Specification paper.
`
`Requirements
`
`The receiver card’s interface with the computer should have the following features:
` Provide a mechanism for moving data into the computer and specify the destination for data in
`computer memory, preferably through bus mastering.
` Control the tuner and retrieve tuner information.
` Control decoding of video, audio, and other data information.
` Control the different Viterbi or other decoding rates used by the digital broadcast network.
` Control what SCIDs or PIDs are received and what data is routed to the conditional access
`subsystem.
` Provide a mechanism for the conditional access hardware on the receiver card to communicate
`with the driver for communication with the conditional access subsystem. All calls generated by
`the conditional access hardware on the receiver card will be handled by the conditional access
`software.
` Retrieve status information about errors and control error correction.
` Satisfy the requirements for receiving MSBDN packets, which can require additional hardware
`beyond that required for audio and video. Refer to the MSBDN Receiver Board Specification
`paper.
` A card reader that complies with the conditional access requirements of the network operator.
`There will be external access to these devices as they are designed for user replacement. This will
`be possible without opening the case or powering-down the device.
` Support of five or more PID/SCIDs simultaneously (eight recommended).
` Either
` Present an advancing 27 MHz register (LTIME), a register with the last received system clock
`reference or reference time stamp (LASTSCR), and a register containing the value of LTIME
`latched when the last SCR was received.
`or
` Generate an interrupt immediately upon receipt of each SCR and be able to have that SCR read
`through the PCI bus.
` Perform PCI bus mastering with support for scatter/gather memory access and unaligned, odd-
`byte memory transfers. This requirement includes time-critical, 127-byte and shorter MPEG
`packets.
`
`
`
`© 1997 Microsoft Corporation. All rights reserved.
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`
` Broadcast-Enabled Computer Hardware Requirements — 7
`
`Broadcast Network
`Receiver
`Smart Card
`
`9600bps
`
`CPU + RAM + ROM
`"Verifier"
`
`control
`
`keys
`
`Control
`
`Transport
`
`DES Decryptor
`
`TUNER
`QPSK
`DEMOD
`FEC
`
` 30.5Mbps
`
`SCID
`Selector
`&
`Router
`
`Multiple SCIDs up
`to 30.5 Mbps total
`
`PCI Bus
`
`Figure 1. Conceptual model of broadcast network receiver card
`
`
`
`Other Networks
`
`Microsoft expects cards that are very similar to the broadcast network receiver card to be built for the
`cable, DVD, ADSL, and MMDS environments. Because these network cards will receive broadcast
`data rather than individually-targeted data and have no back-channel requirement, they will require
`minimal support from a network head-end.
`
`MPEG Decoding and Display
`This section describes the functions of an MPEG decoder and display card and the requirements it
`must meet to support the Broadcast Architecture platform.
`
`Functionality
`
`The MPEG decoder is an MPEG-2 video and audio decoder capable of handling MPEG-2 Main
`Profile/Main Level data rates (15 Mbits/sec). It combines the MPEG video with the standard
`computer video for display on the SVGA monitor. It has 2MB RAM for SVGA (including frame
`buffer) and another 2MB for the MPEG decoder. The system should also offer a TV tuner and base-
`band and S-video inputs and outputs for routing NTSC/PAL signals to and from VCRs, LaserDisc
`players, and other video sources. The system must provide NTSC encoder/decoder circuitry to convert
`NTSC/PAL input signals into digital data in the video frame buffer and to convert decoded MPEG
`video in the video frame buffer to NTSC/PAL output signals.
`The system will provide separate audio and video outputs that contain only audio and video from the
`video sources (as opposed to computer-generated music and sound effects), so that video and its
`associated audio can be recorded without recording the computer-generated music and sound effects.
`Associated circuitry provides recording control features that can be activated and deactivated under
`software control. This includes Macrovision encoding of NTSC video generated directly from the
`MPEG decoder.
`The display adapter portion must meet the criteria of the Windows Plug and Play Framework
`architecture. The Plug and Play Framework architecture contains specific information regarding
`
`© 1997 Microsoft Corporation. All rights reserved.
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`
` Broadcast-Enabled Computer Hardware Requirements — 8
`
`extending the VGA register set and appearance of expanded display adapter resources on the system
`bus. A list of sources for further information is provided at the end of this paper.
`
`Comp/SVHS
`
`NTSC Video Decoder
`
`YUV Data
`
`Overlay MUX
`
`YUV Data
`
`SVGA Media DAC
`
`IIC Interface Bus
`
`SVGA / Media
`Overlay Chipset
`
`SVGA
`
`YUV Data
`
`Comp/SVHS
`
`NTSC Video Encoder
`
`YUV Data
`
`Video / Audio(L+R) Crossbar Multiplexor
`
`Left Audio In
`
`Composite In
`
`SVHS Chroma In
`
`SVHS Luma In
`
`Right Audio In
`
`Left Audio Out
`
`Comp/SVHS Out
`
`SVHS Chroma Out
`
`MPEG-2 Audio / Video
`Decoder Chip
`
`Audio/Video
`MPEG FIFO
`
`Register
`Interface
`
`SVHS Luma Out
`
`Left & Right
`
`PCM To Audio DAC
`
`PCM Audio
`
`Left & Right
`
`Comp/SVHS
`
`Right Audio Out
`
`Coax TV Cable
`
`Cable TV Tuner
`
`MPEG Decoder RAM
`3 I-Frames + MPEG Buffer
`2MB ( 4 * 256KB * 16Bits)
`
`SVGA / Overlay VRAM
` 2MB (4 * 256K * 16 Bits)
`Frame Buffer
`
`SVGA
`Monitor
`
`
`
`Figure 2. MPEG decoder and video adapter
`
`Requirements
`
`The video adapter will have the following features:
` Super VGA adapter capable of at least 800x600x8 bits per pixel (bpp), with a 60 Hz refresh rate
` High-speed 2D graphics acceleration support (preferably with 3D bitmap and MPEG textured
`polygons)
` MPEG-2 decoder chip set (15Mbits/sec–720x480xYUV4:2:2)
` Bus mastering data transfers from memory to the MPEG decoder (up to 2 MB/sec). Include
`support for unaligned, odd byte transfers and scatter/gather memory access
` Capture and display of each 720x240 video field stretched vertically to 720x480 without
`decimation
` Broadcast/Cable NTSC Cable TV tuner
` Composite/SVHS-type NTSC/PAL (to YUV) decoder chip with interface to the SVGA chip set
` Composite/SVHS type NTSC/PAL encoder chip with direct interface from the MPEG decoder
` Audio and video crossbar switching chips for interconnecting composite/SVHS inputs and
`outputs
` SVGA supports YUV frame buffer capture for prioritized overlay and scaling with horizontal and
`vertical interpolation
` Merging of YUV video frame and SVGA video frame in DAC using chroma and color keying
` Controllable Macrovision video encoding of all output composite video signals
`
`© 1997 Microsoft Corporation. All rights reserved.
`
`8
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`
` Broadcast-Enabled Computer Hardware Requirements — 9
`
` Decoding of NTSC VBI data (such as Close Captioning [CC]) from all composite inputs
` Encoding of NTSC VBI data (such as CC or time code) on all composite outputs
` Full driver support on Windows 95 (Display driver, MPEG Miniport)
` Support for output of audio from video sources to the line input of standard audio cards
`
`Recommended Configuration
`
`Those listed above, plus:
` Super VGA adapter capable of at least 800x600x24 bpp with a 60 Hz refresh rate
` Direct3D hardware acceleration
` Broadcast/Cable NTSC/PAL/SECAM Cable TV tuner (foreign and domestic stereo versions)
` Multiple composite and S-video jacks
` Optional: Decoding of arbitrary NTSC VBI data (such as Intercast) from all composite inputs
`
`
`
`
`
`Interface to the Computer
`
`The video adapter’s interface to the computer will have the following features:
` Conform to the Plug and Play specification as a PCI multiple-function device (separate spaces for
`SVGA, MPEG, and tuner functions)
` PCI bus mastering of audio and video MPEG data
` Support unaligned, odd byte transfers and scatter/gather memory access
` Data buffering control and status
` MPEG video decoding control and status
` MPEG audio decoding control and status
` Cable TV tuner control and status
` Base-band video encoding and decoding control and status
` Audio and video signal path control and status
` Closed Captioning input and output to audio and video signal paths
`
`Analog Audio and Video Interconnections
`
`If a video adapter supports analog connections, it should allocate connections of input sources to
`output sinks. The following tables show suggested allocations of input lines to output lines and match
`the video and audio input sources and output sinks with what their typical uses are. Actual devices
`will vary somewhat based on consumer equipment, but some of the connections of inputs to outputs
`are fixed, in that they interconnect specific devices, such as computer encoders to decoders. There are
`many possible input sources and output sinks such as a VCR for playing, a VCR for recording, a
`Laser Disc player, a camcorder, a game console box, a cable box, a cassette tape deck, and an FM
`audio tuner.
`
`
`
`© 1997 Microsoft Corporation. All rights reserved.
`
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`
` Broadcast-Enabled Computer Hardware Requirements — 10
`
`Video input
`(8 sources)
`Comp 1
`S-video Y 1
`S-video C 1
`Comp 2
`S-video Y 2
`S-video C 2
`Comp 3
`Comp 4
`
`Audio input
`(5 stereo sources)
`Left 1 and Right 1
`
`Left 2 and Right 2
`Left 3 and Right 3
`
`Left 4 and Right 4
`Left 5 and Right 5
`
`Typical Input
`
`PC MPEG NTSC
`TV encoder
`
`SVHS VCR
`
`PC TV tuner
`Camcorder
`
`Typical Input
`
`PC MPEG/AC-3
`PCM D to A
`SVHS VCR
`PC TV tuner
`
`Camcorder
`PC CD-ROM
`audio wire
`
`Video output
`(6 sinks)
`Comp 1
`S-video Y 1
`S-video C 1
`Comp 2
`S-video Y 2
`S-video C 2
`
`
`
`Audio output
`(4 stereo sinks)
`Left 1 and Right 1
`
`Left 2 and Right 2
`Left 3 and Right 3
`
`Left 4 and Right 4
`Left 5 and Right 5
`
`Typical Output
`
`PC NTSC decoder
`
`SVHS VCR
`
`
`
`
`Typical Output
`
`PC SB CD-ROM
`audio in
`SVHS VCR
`Surround sound
`audio processor
`Headphones
`
`
`Integration Possibilities
`
`The following list describes some of the possible audio/video card configurations.
` SVGA PCI bus mastering adapter with integrated MPEG-2 audio/video decoder and audio/video
`switching, SoundBlaster-compatible ISA audio adapter.
` SVGA PCI bus mastering adapter with integrated MPEG-2 audio/video decoder, SoundBlaster
`chip set and audio/video switching.
`
`
`Note: Any of these configurations will work, but they have significant tradeoff issues in terms of the
`number of boards and use of standardized adapters. In general, it is better to have both fewer boards
`and to use more standard adapters.
`
`
`Sound Card
`This section describes the functions of a sound card and the requirements it must meet to support a
`Broadcast Architecture platform.
`
`
`
`
`
`
`
`Functionality
`
`Sound components can be laid out on a separate sound card or integrated elsewhere. If laid out on
`separate cards, the TV and MPEG sound from the video card must be connected to the sound card’s
`line-in port and controlled with the standard Windows mixer interface. The video card selects the TV-
`related sound that is heard by users, and the mixer controls the TV volume.
`For game support on a broadcast-enabled computer, SoundBlaster-compatible sound components with
`wave table synthesis are recommended. The sound components must be capable of 90 dB signal-to-
`noise ratio (to maintain the audio quality of the digital broadcast network). It must be possible to use
`
`© 1997 Microsoft Corporation. All rights reserved.
`
`10
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`

`
` Broadcast-Enabled Computer Hardware Requirements — 11
`
`the sound-card circuitry independent of the digital broadcast audio output—for example, when the
`user tape-records a program while playing a video game.
`While sound and video display components can be laid out on separate cards, achieving the highest
`possible sound quality normally requires a digital connection between the video display card and the
`sound card.
`For compatibility with DVD audio, an AC-3 audio decoder is recommended.
`
`Requirements
`
` Stereo
` SoundBlaster compatibility
` 90 dB S/N
` Satisfy sound requirements of broadcast network (DBS)
` Be able to mix audio from the computer, the current video source, and reference CDs.
`
`Recommended Features
`
`Those listed above, plus:
` Wave-table synthesis
` Separate mixer volume controls for tuner and MPEG audio output
` AC-3 audio support
`
`
`
`
`
`Large-Screen Monitors
`This section describes the attributes a monitor must possess and the requirements it must meet to
`support the Broadcast Architecture platform.
`
`Functionality
`
`Large-screen monitors for a broadcast-enabled computer should have some of the following key
`attributes:
` Minimum resolution is currently 640 by 480. Typical satellite digital broadcasters are transmitting
`main level/main profile MPEG-2—the middle level of the five possible levels of MPEG-2-
`encoded video data. That translates into 720 by 480 by 60 fields per second (fps) for NTSC. For
`PAL, this would translate into 720 by 576 by 25 fps.
`
`
`Note: As a result, display decimation will occur at 640x480 display resolution, which is why
`800x600 is strongly recommended.
`
` Support color gamut suitable for display of television and computer data. Diverting an MPEG
`stream to a computer monitor can cause color problems. The MPEG stream is encoded into an
`abstract color space, then decoded and sent to a computer monitor with a different (and possibly
`greater) color gamut than an NTSC display device.
` A picture tube that is ideal for both computers and televisions (high luminance, analog SVGA
`inputs, medium phosphor persistence, and 60 Hz progressive scan).
` Good corner convergence.
` For an optimal viewing experience, it is recommended that OEMs build large-screen monitors for
`the Broadcast Architecture platform (31 or 33 inches, measured on the diagonal). However, the
`
`© 1997 Microsoft Corporation. All rights reserved.
`
`11
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`

`
` Broadcast-Enabled Computer Hardware Requirements — 12
`
`broadcast functionality works on any size computer display, leaving the ultimate configuration up
`to the OEMs.
` Refresh rate of 60 Hz, or an integral multiple of 60 Hz, for any mode in which video is displayed.
`As most source video content (such as NTSC or MPEG-2 video and film) is created or adjusted
`through temporal rescaling or pulldown (at a 3:2 ratio) expressly for 60Hz television monitors,
`further pulldown to other refresh rates (such as 72 Hz) will introduce unacceptable motion
`artifacts (such as non-linear screen motion). By using a refresh rate of 60 Hz, the monitor can be
`balanced with the monitor phosphor. For a flicker-free viewing experience, a medium persistence
`phosphor will be used instead of a short persistence phosphor. If the refresh rate is fixed at 120
`Hz, the standard computer-monitor phosphors can be used.
`
`Requirements
`
` Physical 27" analog Super