SYSTEM AND METHOD FOR FORMING AND RENDERING 3D MIDI MESSAGES

• US 20110252950A1
• Filed: 03/09/2011
• Published: 10/20/2011
• Est. Priority Date: 12/01/2004
• Status: Active Grant

• Current Assignee: Creative Technology Ltd.
• Original Assignee: Creative Technology Ltd.
• Inventors: JOT, Jean-Marc, SAVELL, Thomas C., TRIVI, Jean-Michel, GUZEWICZ, Michael
• Granted Patent: US 9,924,289 B2
• Time in Patent Office: Days
• US Class Current: 84/645
• CPC Class Codes: G10H 1/0066 using a MIDI interface
• CPC Class Codes: H04S 2400/01 Multi-channel, i.e. more than two input channels, sound reproduction with two speakers wherein the multi-channel information is substantially preserved
• CPC Class Codes: H04S 2420/01 Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD]
• CPC Class Codes: H04S 7/30 Control circuits for electronic adaptation of the sound field

Abstract

MIDI-generated audio streams or other input streams of audio events are perceptually associated with specific locations in 3D space with respect to the listener. A conventional pan parameter is redefined so that it no longer specifies the relative balance between the audio being fed to two fixed speaker locations. Instead, the new MIDI pan parameter extension specifies a virtual position of an audio stream in 3D space. Preferably, the relative position of a single audio stream is set along a predefined arc in 3D space.

Claims

1. A method of upmixing an input signal having audio control data, the method comprising:

receiving the input signal having a first set of parameters identified from the control data;

deriving a second set of parameters from the input signal audio control data; and

generating an output signal having the second set of parameters associated with it, wherein at least one of the second set of parameters in the output signal is modified as a function of at least one of the first set of parameters provided by the input signal.

2. The method as recited in claim 1 wherein the input signal is a MIDI signal and the first set of parameters comprises at least one of the following MIDI parameters:

Modulation, Breath, Volume, Balance, Pan, Expression, and Pitch Bend.

3. The method as recited in claim 1 wherein the output signal is a 3D MIDI signal and the second set of parameters comprises at least one of the following 3D MIDI parameters:

Azimuth, Elevation, Gain, Distance Ratio, Maximum Distance, Gain At Maximum Distance, Reference Distance, Pan Spread, and Roll.

4. A method of positioning audio events in a presentation space the method comprising:

receiving an input audio stream comprising at least one channel of audio, wherein the input audio stream defines sounds positioned in a stereo field;

processing the at least one channel of audio to derive a secondary audio stream comprising three or more secondary channels of audio wherein at least one secondary channel of audio is assigned a position parameter that describes a position in the stereo field;

combining the position parameter with a spread parameter controlling the angular size of the stereo field to determine an output position in the presentation space;

and assigning the output position to the at least one secondary channels.

5. The method as recited in claim 4 wherein the input audio stream is derived from a MIDI signal.

6. The method as recited in claim 4 including the reproduction of the at least one secondary audio channel at the output position in the listening space.

7. The method as recited in claim 8 where reproduction of the at least one secondary audio channel comprises generating an audio signal to feed headphones or loudspeakers.

8. The method as recited in claim 4 wherein the spread parameter is used to affect a wrap-around effect of the audio events in the presentation space.

9. The method as recited in claim 4 wherein the spread parameter is controlled by the user on a user interface device.

10. A method of positioning events in a presentation space, the method comprising:

receiving an input stream of events with at least one event having virtual location information defining a position of a predefined arc within the presentation space, the at least one event having separate pan information defining a virtual source position along the predefined arc; and

assigning an output position in the presentation space for the at least one event based on a combination of the position of the predefined arc and the pan information and a separate second parameter.

11. The method of claim 10, wherein the at least one event has a separate pan spread parameter defining the distance between the endpoint positions of the predefined arc and wherein the separate second parameter is the separate pan spread parameter.