System Requirements for Video and Broadcast Components

This section summarizes the PC 98 requirements for video and broadcast components.

1. System meets PC 98 requirements for DVD-Video and MPEG-2 playback
Consumer PC 98 Office PC 98 Entertainment PC 98
Required Required with DVD-Video Required

Under Windows and Windows NT, operating-system playback support for MPEG-1 is provided through DirectShow. This requirement refers to built-in system support for DVD-Video playback or any other MPEG-2 playback capabilities, whether provided as a hardware decoder, a software decoder, or a combination of the two. This requirement does not apply for Office PC 98 systems that provide DVD-ROM drives for storage purposes only.

Related requirements are defined in the “MPEG-2 Playback Requirements” and “DVD-Video Playback Requirements” sections later in this chapter.

2. System supports PC 98 analog video input and capture capabilities
Consumer PC 98 Office PC 98 Entertainment PC 98
Recommended Recommended Required

Analog video capture capability is recommended for Consumer PC 98 and Office PC 98 and is required for Entertainment PC 98.

Video input and capture functionality can be implemented as an add-on device or as a direct interface on the system board. If video capture capability is implemented in a PC 98 system, it must meet the requirements defined in the “Video Input and Capture Requirements” section later in this chapter.

For PC 98, all video input sources and capture devices must implement driver support as defined for WDM Stream class in the Windows NT 5.0 DDK.

3. System includes analog television tuner
Consumer PC 98 Office PC 98 Entertainment PC 98
Recommended Recommended Required

An analog television tuner is required for any Entertainment PC 98 system. This can be implemented as a cable tuner or broadcast tuner. For information about the supporting tuner device, see the “Television Tuner and VBI Capture Requirements” section later in this chapter

4. System includes digital broadcast or satellite subsystem
Consumer PC 98 Office PC 98 Entertainment PC 98
Recommended Recommended Recommended

If this capability is included in a PC 98 system, the implementation must include a digital broadcast or satellite network adapter, a smart card, and drivers that meet PC 98 requirements as defined in the “Digital Broadcast Television Requirements” section later in this chapter.

5. System includes DTV support
Consumer PC 98 Office PC 98 Entertainment PC 98
Recommended Recommended Required (U.S. only)

This recommendation represents an effort to realize the full potential of digital television (DTV) based on technical standards defined by the Advanced Television Systems Committee (ATSC) across a range of PCs, hybrid PC/TVs, and DTV appliances. ATSC DTV offers the richness of high-resolution video and high-fidelity audio joined with the interactive content of the PC and the Internet.

It is anticipated that within the 1998–99 time frame, Entertainment PC 98 systems will include support for ATSC DTV. This is consistent with current projections for when DTV broadcasts will begin in major U.S. markets. As with all PC 98 components, compliance testing will begin when all related components are generally available.

Specifications and technical information are available at http://www.atsc.org. Support for ATSC DTV includes meeting hardware and software requirements for a tuner/demodulator, MPEG-2 decode capabilities, and graphics adapters as defined in the “Digital Broadcast Television Requirements” section later in this chapter.

6. Video input, capture, and broadcast device support is based on DirectX foundation class and WDM Stream class
Consumer PC 98 Office PC 98 Entertainment PC 98
Required Required Required

The driver for any video or tuner device must use the DirectX foundation class to control all video data. The WDM Stream class must be used to support any data streaming. For information, see the DirectX 5.0 DDK and the Windows NT 5.0 DDK. See also the PC 98 requirements defined in the “Device Drivers and Installation for Video and Broadcast Components” section later in this chapter.

7. Hardware MPEG-2 decoder uses video port for video data
Consumer PC 98 Office PC 98 Entertainment PC 98
Required Required Required

For any PC 98 system that includes an MPEG-2 hardware decoder that is not integrated in the graphics accelerator, the decoder must use a video port for piping video data to the graphics adapter’s frame buffer. Systems with MPEG-2 decoders that use the video port of the graphics accelerator must provide a method to disable output. A separate external multiplexor (MUX) meets this requirement.

Systems with multiple video sources that use the video port on the graphics accelerator—including television tuner and capture on the system board or multiple Zoomed Video (ZV) ports—should offer a way to control the flow of video from multiple video sources into a single video port.

For mobile PCs, the ZV standard is available for CardBus peripherals. ZV support must be implemented as defined in PC Card Standard Guidelines, Volume 10 (PC Card standard). For more information, see the “PC Card” chapter in Part 3 of this guide.

For tri-stated video sources, each source should have a method for arbitrating among multiple devices.

Driver support for any video port implementation must be based on DirectDraw Video Port Extensions (VPE) as defined in the DirectX 5.0 DDK. For more information, see the related “Video port meets PC 98 specifications” requirement in the “Graphics Adapters” chapter in Part 4 of this guide. See also the white paper on DirectDraw VPE and kernel-mode video transport at http://www.microsoft.com/hwdev/devdes/.

8. PCI-based tuners and decoders support bus mastering with scatter/gather DMA
Required

PCI-based hardware must support byte-aligned, multisegment bus master DMA transfers. Devices that are sources (or sinks) for data must be capable of transferring data to or from multiple, non-contiguous host memory buffers that are byte-aligned and odd-sized. The device must support such byte-aligned, odd-sized, non-contiguous buffers using host memory-based buffer transfer descriptors.

This requirement applies for PCI-based MPEG-2 decoders and digital broadcast or satellite television devices. This is required in order to minimize the CPU bandwidth needed to move data from an input source, such as a DVD drive or digital tuner card, to an MPEG decoder.

Because some MPEG-2 packets are 127 bytes long and MPEG-2 streams often contain data bursts and times when data rates are low, bus mastering operations must be able to operate on non-aligned, odd-length data.

Specifically, this means that each stream (with a minimum of eight streams) must have a set of logical buffers (digital broadcast satellite and DVD require a minimum of 16 buffers) composed of physical data segments (with a minimum of 16 + 1 of up to 64K each). Each logical buffer can begin or end on any byte position in physical memory. Thus, the first and last physical data segment can be smaller than a physical memory page (4K), but the intervening segments will be contiguous multiples of the 4K physical-memory page size.

As defined in the “Storage and Related Components” chapter in Part 4 of this guide, DVD drives and other IDE storage controllers and devices must support DMA.

9. Background tasks do not interfere with MPEG-2 playback
Consumer PC 98 Office PC 98 Entertainment PC 98
Required Recommended Required

This requirement applies to background tasks initiated by applications included with the PC. Video performance should be such that non-foreground tasks—such as downloading a web page or using answering-machine software—should occur without disrupting video playback, including DVD and television. When the user runs an application in the foreground that requires significant system resources, such as a game or video answering machine, the system should degrade gracefully.

For Consumer PC 98, this requirement applies only to applications that are started automatically by the OEM software pre-configuration, such as programs in the Windows/Start Menu/Programs/Startup folder. This guarantees that the video experience “out of the box” is as good or better than consumer television and other A/V components.

For Entertainment PC 98, this requirement applies to all applications included with the system, whether run automatically by the OEM software pre-configuration or run only by the user. This is a critical requirement for Entertainment PC 98 systems, whose users will rely on the PC to perform normal day-to-day operations simultaneously with DVD-Video playback and television.

Specific examples of operations that must not interfere with MPEG-2 playback include the following:

  • Answering the telephone to receive voice mail or fax. This applies only to telephony software included with the PC, not third-party software installed by the user. Notice that telephone answering must not be automatically disabled during MPEG-2 playback unless explicitly configured by the user.

  • Running scheduled communications tasks such as automatic connection using the modem or ISDN to transfer e-mail and faxes, download cached Internet content, and so on.

Note: Programs that make intensive use of system resources or that are designed for interactive foreground operation are excluded from this requirement. This includes games, video and audio playback, speakerphone, and disk utilities such as error checking, defragmentation, and virus protection.

Notice also that for software decoder implementations, compliance testing for the Entertainment PC 98 requirement will begin in a reasonable time frame after enhanced kernel-mode support is provided for MPEG-2 video playback in the Windows operating system.

10. All components meet PC 98 general device requirements

Required

This includes the basic requirements for a Plug and Play device ID, automated software-only settings for device configuration, device drivers and Windows-based installation, and icons for external connectors. For more information, see the “Basic PC 98” chapter in Part 2 of this guide.

Note: To ensure proper connection by the user between the video graphics array (VGA) monitor, S-Video, and composite cables and connectors, an icon must be added to any external connector using vendor designs or any of the appropriate designs provided in the “Icons” appendix in the References part of this guide.