Upsampling and upmixing
Upsampling is the mathematical treatment that increases the resolution of the digital signal, e.g. from CD quality 16bit/44.1kHz to 24bit/96kHz (to be read as 96000 samples per seconds coded as 24 bits each). When an analog signal is digitized, periodical samples/snapshots of the signal are taken, analogous to the 30 frames per seconds of a movie. The more samples the better, as the image becomes less "jumpy" and the digital sound wave better approximates the analog wave. Likewise, more bits increases the precision of each sample. It has been argued that most people cannot hear above 20kHz. While this is true, the electronics is more succeptible to introduce detectable artifacts and distorsions at lower sampling rates as explained in the benefits of 96kHz sampling rate and why does high-resolution sound better.
The HD-audio product line includes a custom designed professional quality upsampling algorithm optimized to convert from 44.1kHz to 48/88.2/96/176.4/192kHz, and that uses state of the art theoretical concepts (FIR linear phase filters, multi-stages, cascaded).
Upmixing is another mathematical treatment that analyses the stereo signal to detect spatial information and deducts/produces additional surround channels to better render the original sound stage. It is implemented in the HD-Audio product line through a VST plug-in called V.I.
Universal DVD-Audio/DVD-Video disc
A good media combination is a disc that has both a DVD-Audio area (AUDIO_TS) and a DVD-Video area (VIDEO_TS). Such a disc is called universal because it is capable of playing in any DVD player and it combines the best features of both technologies. Cirlinca's products generate a universal disc by mirroring the DVD-Audio area to the DVD-Video area. Both areas can be encoded in uncompressed PCM, but a common setting is to encode the DVD-Audio area in high-resolution PCM and the DVD-Video area in compressed A/52 format. A/52 is the format commonly used to encode surround 5.1 tracks in DVD-Video. This combination offers the best playback quality with the DVD-Audio area and guaranteed playability with the DVD-Video area.
The more the sampling points, the closer the analog signal is approximated