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Microsoft Windows Logo Program System and Device Requirements  —  80

http://www.usb.org/developers/docs.html

B3.1.2.7 ACPI Specification

http://www.acpi.info/index.html

B3.1.3 General Audio - Quality

WHQL Test Specification References: Chapter 16: Audio Test Specification

B3.1.3.1 Pass WHQL tests - See B1.3.

See “Audio” in the HCT documentation.

B3.1.3.2 - See B1.3

B3.1.4 General Audio - Windows Experience

B3.1.4.1 DELETED
B3.1.4.2 Full Duplex
Audio subsystem supports basic data formats

Hardware sample rate conversion (SRC) is not required when the Microsoft software SRC is used. Windows provides software mixing and SRC, which eliminate the need for hardware to support any sampling rate other than 48 kHz.

48 kHz is required because it is the prevalent sampling rate for entertainment content, such as DVD movies. When 48 kHz content is present, the operating system switches the audio output to 48 kHz.

Support for other rates (8 kHz, 11.025 kHz, 16 kHz, 22.05 kHz, 32 kHz, or 44.1 kHz) in hardware is optional.

Audio subsystem supports full duplex operation

Full duplex audio is essential to support emerging communications applications such as Internet Protocol (IP) telephony, conferencing, and network gaming. These applications require the audio system to play back and record simultaneously. The following requirements ensure that full duplex operation is available and performance is consistent across implementations.

Full duplex operation is supported for all sampling rates supported by the hardware.

If the built-in or external audio device includes both input and output capabilities, full duplex operation must be supported for basic formats (16-bit, and 48 kHz), and for all other formats supported by the hardware, for example, at 8 kHz, 11.025 kHz, 16 kHz, 22.05 kHz, 32 kHz, or 44.1 kHz.

Independent selection of input and output sample rates.

If the built-in or external audio device includes both input and output capabilities, the audio device must support independent selection of input and output sample rates.

Sample rates are time-synchronized.

If the built-in or external audio device includes both input and output capabilities, the timing relationship between input and output sample rates must remain constant (i.e., no drift). For example,

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