TABLE OF CONTENTS An audio signal chain is only as good as its weakest link. Different parts of the audio subsystem are tested at different times in the development process. Testing might be to standards created by the OEM developing the system or to standards created by an external entity such as the Microsoft WHQL program or Dolby separate implementation and system-level testing. To make matters worse, you must test a wide degree of variability and functionality, with ever increasing combinations and permutations of options.
The options available on modern systems require a wide range of test coverage to ensure a quality product. This matrix has about ten dimensions, and that number appears to be increasing. Here are some of the dimensions:
64-bit OS versus 32-bit OS
Choice of CPU Vendor
Choice of Dual-core CPU versus Single-core CPU
Choice of Intel HD Audio controller vendor
Choice of Intel HD Audio codec vendor
Windows Vista versus Windows XP versus earlier operating systems
Mobility versus Portability versus Desktop
The number of inputs and outputs
Multi-streaming versus single-streaming
Class Driver versus codec-vendor-supplied audio function driver
Localization, usually required for 10 to 30 languages
The test manager must choose the proper set of target test systems to properly exercise the variables in this matrix. As a practical matter, it is close to impossible to provide complete coverage for all of these variables, but you can develop a strategy that covers the most likely failures. For instance, driver bugs...
