For audio conversion of some album kinds (operas, symphonies, live concerts, musicals, shows, etc.), seamless/gapless transients between neighbor tracks are required.

True Gapless Conversion (TGC) is seamless album conversion. It allows to avoid of conversion artifacts on the borders between adjacent tracks. Keep reading...

June 18, 2023 updated | since February 18, 2015

Author: Yuri Korzunov,
Audiophile Inventory's developer with 25+ year experience in digital signal processing,
author of the articles that make audio easy for beginners



What is True Gapless Conversion

There are albums like operas, live concerts, etc., where no pauses between neighboring tracks. Also, non-zero levels at track borders of the albums may be there.

Some ISO (1-bit audio) has a level bias (DC-bias, direct current bias) throughout a full album. At the beginning and end of tracks, DC bias (non-zero level) is present. It can be heard as a click.

Level bias (DC-bias) throughout the full album

ISO DC bias (1-bit HD audio)

In conversion may be applied audio processing:

  1. Resampling (sample rate altering)
  2. Altering 1-bit audio stuff (DSF, DFF, ISO).
AuI ConverteR - True Gapless Conversion

In conversion without the processing, there are no artifacts at output-track borders.

But, if each album track (file) is processed separately, a non-zero level at the input file's border generates the artifact at border of output file. Because the processing is re-initialized for each track.

For seamless audio processing of the album, all its audio files are processed as a continuous audio stream without re-initializing of processing for each track (file).

Audiophile Inventory's trueG is a seamless conversion algorithm that allows seamless processing of adjacent tracks of album.

True gapless mode is switched in AuI ConverteR's main window > Parameters tab (upper left).  Turn ON (checked state) / OFF (unchecked state) for "True Gapless Mode" switch.

Management of True Gapless Conversion mode

True gapless conversion management

Here merged converted neighbor album tracks are shown

True gapless conversion spectrum


If True Gapless Conversion is turned OFF, we see the noise splash on the border of merged resampled tracks after the conversion. The splash at the spectrum shows short level increase, which is absent in source files.

The noise splash is an additional ringing artifact rising due to a rather significant non-zero level at the beginning or end of file. It happens when resampling filter gets a sharp level transient.

If True Gapless Conversion is turned ON, we see seamless transient between resampled converted tracks. Like input source files.

In this case, resampling filter gets a continuous input stream and has no additional ringing at the output.

AuI ConverteR 48x44 provides True Gapless Conversion for the following conditions:

  1. All input (source) tracks (files) must have the same sample rate and bit depth.
  2. Input tracks must be sorted in album order.



  1. True gapless mode can't use multi-CPU capability. Because files (album tracks) should be processed sequentially. To convert the next audio file, converter state at end of the previous track is needed.
  2. Audio player (software or hardware), that playback processed files, should support gapless (seamless, without re-initialization on each file) playback. All files should be played back as a continuous stream.





AuI ConverteR has several price/functionality options that allow saving your budget for the required functionality. You can expand Modula-R abilities later by purchasing new modules. Unlimited-time license, major updates (... 10.x > 11.x > 12.x > ... versions) are paid.

WARNING: Modula-R modules (parts of AuI ConverteR’s functionality) are NOT compatible with Free version.
ADD-ON modules work with certain CORE modules only (see details).
The module is license key received in order email. To activate module functionality, enter its key in Modula-R executable.
All "Modula-R" modules together have "PROduce-RD"'s abilities.
Full-featured "PROduce-RD" version is like a discount on price of full module kit of "Modula-R" version.

To expand functionality, module(s) (compatible with purchased major version number) may be ordered separately.
Modula-R license cannot be replaced with PROduce-RD.

* All prices on this page are in U.S. dollars without V.A.T. and other applicable taxes and fees. The prices are recommended. Information on this page is not a public offer.


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