  This paper addresses the challenges associated with both the conversion
between different spatial audio formats and the decoding of a spatial audio
format to a specific loudspeaker layout. Existing approaches often rely on
layout remapping tools, which may not guarantee optimal conversion from a
psychoacoustic perspective. To overcome these challenges, we present the
Universal Spatial Audio Transcoder (USAT) method and its corresponding open
source implementation. USAT generates an optimal decoder or transcoder for any
input spatial audio format, adapting it to any output format or 2D/3D
loudspeaker configuration. Drawing upon optimization techniques based on
psychoacoustic principles, the algorithm maximizes the preservation of spatial
information. We present examples of the decoding and transcoding of several
audio formats, and show that USAT approach is advantageous compared to the most
common methods in the field.
