Intel High Definition Audio

Intel High Definition Audio (HD Audio, and IHD or Azalia ) is a specification for audio chips, which was introduced in 2004 to replace the old standard AC97. Sound chips that meet this new standard must be able to deliver stereo signals at 192 kHz in a 32- bit quality and up to eight channels of 96 kHz in 32- bit; which corresponds to 7.1 surround sound. Whether the computer is actually outputting a usable 7.1 signal depends on the specifications of the motherboard.

Details

The standard says nothing about the other capabilities of the chip, but only sets the minimum requirement which digital signals are converted to analog. It is in the specification is neither a codec ( such as MP3 ), nor to a specific chip in the computer. For comparison, a standard CD player converts the data stored on a compact disc digital information into an analog signal that is output through the headphone jack or an amplifier. On a CD with the information in 44.1 kHz 16- bit are stored. If the CD player on the new standard ( as there are some DVD players ), he could also play higher data rates or better sampled music - he is not, he remains silent because he can not process the digital information.

Support

For Windows XP with Service Pack 2, the high-definition audio patch ( KB888111 ) is required. In Service Pack 3, this patch and thus the support for HD audio is already integrated.

Under Linux the ALSA kernel module ' snd- hda -intel " takes care of the control of the HD audio sound chips. Because of the wide variety of HD audio sound chips and a mostly missing or incomplete documentation of the manufacturer as to their form, the creation of open drivers is difficult.