User manual

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1. Introduction

HQPlayer is a high quality audio player for Windows Vista, Windows 7, Linux and Mac

OS X. HQPlayer also features several user selectable high quality resamplers as well

as user selectable dither/noise shaping algorithms.

Some of the more affordable sound cards and D/A converters have suboptimal digital

and analog filters, while still having support for higher sampling rates. Effect of this can

reduced by applying high quality upsampling in software before feeding the signal to

the audio hardware at higher rate. This moves some of the artifacts of the suboptimal

hardware to higher frequencies, away from the audible band. Many of the home-

theater amplifiers also re-sample internally to 48, 96 or 192 kHz, with the HQPlayer,

these can be fed at the native rate.

Most modern D/A converters are delta-sigma type. Built-in delta-sigma modulator of

HQPlayer allows using DSD-capable converters with this native data format, in many

cases bypassing lot of DSP processing in these converters and allowing more direct

data path to the conversion stage.

Resampling also allows playback for high resolution audio files on hardware capable

of only lower sampling rates or bit depths. For lower bit depth playback, high quality

dither or noise shaping can be employed.

HQPlayer also includes a convolution engine for applying digital room correction filters

or other kinds of equalization.

These features ensure the best possible audio quality with the available audio

hardware.

1.1. DSDIFF and DSF playback

Playback of DSDIFF and DSF files is supported. In case hardware and drivers support

ASIO DSD -mode, or one of the “PCM packed” modes, these files can be played back

in native format.

For devices capable of only PCM input, PDM (pulse density modulation) content of

these files is converted to 176.4 (64fs), 352.8 (128fs) or 705.6 kHz (256fs) PCM (pulse

code modulation) format for playback through PCM audio hardware.The playback rate

of DSDIFF and DSF files can be further altered by using resampling to chosen rate.

Thus, playback rates from 32 to 1536 kHz are possible. Used bit depth is always

maximum supported by the playback hardware.

Also multichannel loudspeaker delay- and level-processing is supported in both

converted and native modes.