Intelligent Audio Crossfade Using Instrument Track Separation

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Solution Overview

Problem

Existing audio mixing techniques, such as crossfading, face challenges when transitioning between songs of different genres, tempos, or instrumentation, as they often result in audible errors due to partial separation of instrument tracks, especially when using methods like MPEG Spatial Audio Object Coding (SAOC) or blind source separation (BSS), which can affect the quality of the audio.

Innovation Solution

The method involves separating audio files into individual instrument tracks, identifying a dominant instrument and similar tracks, fading out non-dominant tracks from the first file while matching the tempo of the dominant instrument tracks to those in the second file, and then crossfading between the dominant and similar tracks, ensuring a seamless transition by selecting appropriate manipulation algorithms based on the type of instrument.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If simple crossfading is used between different songs, then the mixing process is simple and fast, but audible errors occur when songs of different genres, tempos, or instrumentation are crossfaded

Engineering Contradiction:
Improvecrossfading speedVSAvoidaudio quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The audio files are separated into multiple instrument tracks (e.g., vocals, drums, bass, other instruments) using blind source separation or MPEG SAOC. This segmentation allows selective crossfading of specific tracks rather than the entire audio file, enabling intelligent mixing that maintains audio quality while achieving smooth transitions.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If manual crossfading by DJs is performed, then intelligence is improved in handling different song types, but the process becomes more complex and time-consuming

Engineering Contradiction:
Improvehandling different song typesVSAvoidmixing process complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system automatically performs blind source separation, identifies dominant instruments, selects appropriate manipulation algorithms, and executes crossfading without human intervention. This automation maintains the intelligence needed for handling different song types while eliminating the complexity and time consumption of manual DJ mixing.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system dynamically adjusts parameters such as tempo, pitch, and volume for specific instrument tracks during crossfading. By changing these parameters automatically based on the detected dominant instruments and song characteristics, the system adapts to different song types without requiring complex manual intervention.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If MPEG SAOC or blind source separation is used to separate instrument tracks, then partial separation is achieved, but audio quality is affected by the separation process

Engineering Contradiction:
Improveinstrument track separationVSAvoidaudio quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system extracts only the dominant instrument tracks that are relevant for crossfading, rather than attempting to perfectly separate all instruments. By focusing on the most prominent instruments (e.g., drums, bass, vocals) and using them for the crossfade operation, the system achieves effective track separation while minimizing the quality degradation associated with full blind source separation.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS10235981B2Intelligent crossfade with separated instrument tracks
Publication Date: 2019.03.19 NOKIA TECHNOLOGIES OY
  • US10235981B2 patent drawing
  • US10235981B2 patent drawing
  • US10235981B2 patent drawing

AI summary

A method is provided including separating a first file into a first plurality of instrument tracks and a second file into a second plurality of instrument tracks, wherein each instrument track of each of the first plurality and second plurality corresponds to a type of instrument; selecting a first instrument track from the first plurality of instrument tracks and a second instrument track from the second plurality of instrument tracks based at least on the type of instrument corresponding to the first instrument track and the second instrument track; fading out other instrument tracks from the first plurality of instrument tracks; performing a crossfade between the first instrument track and the second instrument track; and fading in other instrument tracks from the second plurality of instrument tracks.