From d6bb375789821f4e4e175465f50e77e8a6b1aaf7 Mon Sep 17 00:00:00 2001
From: Alexander Nguyen <alexander.nguyen@stud.hfm-karlsruhe.de>
Date: Sun, 09 Mar 2025 18:42:11 +0100
Subject: [PATCH] feat: implemented encoding up to 7th order
---
sources/classes/sox-hoaencode.lisp | 164 ++++++++++++++++++++++++++++++++++++++----------------
1 files changed, 115 insertions(+), 49 deletions(-)
diff --git a/sources/classes/sox-hoaencode.lisp b/sources/classes/sox-hoaencode.lisp
index e7d1bf7..def1f08 100644
--- a/sources/classes/sox-hoaencode.lisp
+++ b/sources/classes/sox-hoaencode.lisp
@@ -1,11 +1,13 @@
-;Authors: A. Nguyen, 2025.
+;Authors:
+; A. Nguyen, 2025
+; M. Schumacher, 2025
; Design limitations:
; 1) Sounds must have identical sample rate; otherwise, SoX fails silently, literally.
; Questions:
-; 1) Is there a built-in (flatten lst)-function?
-; 2) Implement up to which order? <=> CLI issues to be expected (e.g., maximum command character length)?
+; 1) Is there a built-in (flatten lst)-function? Yes, om:flat
+; 2) Implement up to which order? <=> CLI issues to be expected (e.g., maximum command character length)? max character length for CLI should be changeable
(in-package :om)
@@ -34,29 +36,74 @@
)
)
-; Ambisonics
+; ### Ambisonics ###
+
(defun sox-hoaencode-sn3d-factor (order degree)
+"This is a placeholder for documentation"
(ecase order
(0 1)
(1 1)
(2
(ecase (abs degree)
- (2 (/ (sqrt 3) 6))
- (1 (/ (sqrt 3) 3))
(0 1)
+ (1 (/ (sqrt 3) 3))
+ (2 (/ (sqrt 3) 6))
))
(3
(ecase (abs degree)
- (3 (/ (sqrt 10) 60))
- (2 (/ (sqrt 15) 30))
- (1 (/ (sqrt 6) 6))
(0 1)
+ (1 (/ (sqrt 6) 6))
+ (2 (/ (sqrt 15) 30))
+ (3 (/ (sqrt 10) 60))
+ )
+ )
+ (4
+ (ecase (abs degree)
+ (0 1)
+ (1 (/ (sqrt 10) 10))
+ (2 (/ (sqrt 5) 30))
+ (3 (/ (sqrt 70) 420))
+ (4 (/ (sqrt 35) 840))
+ )
+ )
+ (5
+ (ecase (abs degree)
+ (0 1)
+ (1 (/ (sqrt 15) 15))
+ (2 (/ (sqrt 105) 210))
+ (3 (/ (sqrt 70) 840))
+ (4 (/ (sqrt 35) 2520))
+ (5 (/ (sqrt 14) 5040))
+ )
+ )
+ (6
+ (ecase (abs degree)
+ (0 1)
+ (1 (/ (sqrt 21) 21))
+ (2 (/ (sqrt 210) 420))
+ (3 (/ (sqrt 210) 2520))
+ (4 (/ (sqrt 7) 2520))
+ (5 (/ (sqrt 154) 55440))
+ (6 (/ (sqrt 462) 332640))
+ )
+ )
+ (7
+ (ecase (abs degree)
+ (0 1)
+ (1 (/ (sqrt 7) 14))
+ (2 (/ (sqrt 42) 252))
+ (3 (/ (sqrt 21) 1260))
+ (4 (/ (sqrt 231) 27720))
+ (5 (/ (sqrt 231) 166320))
+ (6 (/ (sqrt 6006) 4324320))
+ (7 (/ (sqrt 429) 4324320))
)
)
)
)
(defun sox-hoaencode-azimuth-factor (degree theta_deg)
+"This is a placeholder for documentation"
(let*
(
(theta (sox-hoaencode-deg-to-rad theta_deg))
@@ -69,6 +116,7 @@
)
(defun sox-hoaencode-elevation-factor (order degree phi_deg)
+"This is a placeholder for documentation"
(let*
(
(phi (sox-hoaencode-deg-to-rad phi_deg))
@@ -83,7 +131,7 @@
(2
(ecase (abs degree)
(0 (- (/ (* 3 (expt (sin phi) 2)) 2) (/ 1 2)))
- (1 (/ (* 3 (expt (sin phi) 2)) 2))
+ (1 (/ (* 3 (* (sin phi) 2)) 2))
(2 (* 3 (expt (cos phi) 2)))
))
(3
@@ -93,45 +141,54 @@
(2 (* -15 (sin phi) (- (expt (sin phi) 2) 1)))
(3 (* 15 (expt (cos phi) 3)))
))
+ (4
+ (ecase (abs degree)
+ (0 (+ (/ (* 35 (expt (cos phi) 4)) 8) (- (* 5 (expt (cos phi) 2))) 1))
+ (1 (- (/ (* (sin (* 2 phi)) (- (/ (* 35 (expt (cos phi) 2)) 2) 10)) 2)))
+ (2 (- (/ (* (* 15 (expt (cos phi) 2)) (- (* 7 (expt (cos phi) 2)) 6)) 2)))
+ (3 (* 105 (expt (cos phi) 3) (sin phi) ))
+ (4 (* 105 (expt (cos phi) 4)))
+ ))
+ (5
+ (ecase (abs degree)
+ (0 (/ (* (sin phi) (+ (- (* 63 (expt (sin phi) 4)) (* 70 (expt (sin phi) 2))) 15)) 8))
+ (1 (/ (* 15 (sin phi) (+ (- (* 21 (expt (cos phi) 4)) (* 28 (expt (cos phi) 2))) 8)) 8))
+ (2 (- (/ (* 105 (sin phi) (+ (- (* 3 (expt (sin phi) 4)) (* 4 (expt (sin phi) 2))) 1)) 2)))
+ (3 (- (/ (* 105 (expt (cos phi) 3) (- (* 9 (expt (cos phi) 2)) 8)) 2)))
+ (4 (* 945 (sin phi) (expt (- (expt (sin phi) 2) 1) 2)))
+ (5 (* 945 (expt (cos phi) 5)))
+ ))
+ (6
+ (ecase (abs degree)
+ (0 (+ (- (/ (* 231 (expt (cos phi) 6)) 16)) (/ (* 189 (expt (cos phi) 4)) 8) (- (/ (* 21 (expt (cos phi) 2)) 2)) 1))
+ (1 (/ (* 21 (sin (* 2 phi)) (+ (* 33 (expt (sin phi) 4)) (- (* 30 (expt (sin phi) 2))) 5)) 16))
+ (2 (/ (* 105 (expt (cos phi) 2) (+ (* 33 (expt (cos phi) 4)) (- (* 48 (expt (cos phi) 2))) 16)) 8))
+ (3 (- (/ (* 315 (expt (cos phi) 3) (sin phi)) (- (* 11 (expt (cos phi) 2)) 8)) 2))
+ (4 (- (/ (* 945 (expt (cos phi) 4) (- (* 11 (expt (cos phi) 2)) 10)) 2)))
+ (5 (* 10395 (expt (cos phi) 5) (sin phi)))
+ (6 (* 10395 (expt (cos phi) 6)))
+ ))
+ (7
+ (ecase (abs degree)
+ (0 (/ (* (sin phi) (+ (* 429 (expt (sin phi) 6)) (- (* 693 (expt (sin phi) 4))) (* 315 (expt (sin phi) 2)) (- 35))) 16))
+ (1 (- (/ (* (* 7 (cos phi)) (+ (* 429 (expt (cos phi) 6)) (- (* 792 (expt (cos phi) 4))) (* 432 (expt (cos phi) 2)) (- 64))) 16)))
+ (2 (- (/ (* 63 (sin phi) (- (expt (sin phi) 2) 1) (+ (* 143 (expt (sin phi) 4)) (- (* 110 (expt (sin phi) 2))) 15)) 8)))
+ (3 (/ (* (* 315 (expt (cos phi) 3)) (+ (* 143 (expt (cos phi) 4)) (- (* 220 (expt (cos phi) 2))) 80)) 8))
+ (4 (/ (* 3465 (sin phi) (- (* 13 (expt (sin phi) 2)) 3) (expt (- (expt (sin phi) 2) 1) 2)) 2))
+ (5 (- (/ (* 10395 (expt (cos phi) 5) (- (* 13 (expt (cos phi) 2)) 12)) 2)))
+ (6 (* -135135 (sin phi) (expt (- (expt (sin phi) 2) 1) 3)))
+ (7 (* 135135 (expt (cos phi) 7)))
+ ))
)
))
-; Convenience functions
-; Ensures that positions are given as '((azimuth elevation) ...) (in degrees), i.e.
-; 1) if list of list of three values, input is assumed to be '(x y z) coordinates and will be transformed to '(azimuth elevation) coordinates (in the navigational spherical coordinate system).
-; 2) if list of list of two values, input is assumed to be '(azimuth elevation) coordinates and won't be transformed any further.
-; 3) if 3dc, input is transformed to '(azimuth elevation) coordinates.
-(defun sox-hoaencode-auto-convert-positions (positions)
- (cond
- ((subtypep (type-of positions) '3dc)
- (progn ; convert xyz->aed, keep azimuth and elevation only.
- (mat-trans
- (butlast
- (mat-trans
- (mapcar
- (lambda (xyz) (multiple-value-list (om:xyz->aed (first xyz) (second xyz) (third xyz))))
- (mat-trans (list (x-points positions) (y-points positions) (z-points positions)))
- ))))))
- ((subtypep (type-of positions) 'list)
- (cond
- ((= 2 (length (first positions)))
- positions)
- ((= 3 (length (first positions)))
- (mat-trans
- (butlast
- (mat-trans
- (mapcar
- (lambda (xyz) (multiple-value-list (om:xyz->aed (first xyz) (second xyz) (third xyz))))
- positions
- )))))
- (t (error "Input must contain lists of length 2 (ae) or 3 (xyz)."))
- ))
- (t (error "Input must be 3dc or list."))))
-; High-level API
-; Returns the gain value (linear, -1 to 1) for a single ACN-channel
+; ####### High-level API ##########
+
+
(defun sox-hoaencode-gain-single-component (order degree azimuth_deg elevation_deg)
+ "Returns the gain value (linear, -1 to 1) for a single ACN-channel"
(let
(
; It is assumed that azimuth_deg follows the implementation details of SpatDIF,
@@ -146,13 +203,18 @@
(sox-hoaencode-elevation-factor order degree elevation_deg)))
)
-; Returns the gain values for all components at a specific order
+; (sox-hoaencode-gain-single-component 1 1 45 0)
+; @AN: what is the difference between "order" and "degree"?
+
+
(defun sox-hoaencode-gains-by-order (order azimuth_deg elevation_deg)
+ "Returns the gain values for all components at a specific order"
(loop for degree from (* -1 order) to order collect
(sox-hoaencode-gain-single-component order degree azimuth_deg elevation_deg)))
-; Returns the gain values for all components up to a specific order
+
(defun sox-hoaencode-gains-up-to-order (order azimuth_deg elevation_deg)
+ "Returns the gain values for all components up to a specific order"
(sox-hoaencode-double-to-float
(flatten
(loop for ord from 0 to order collect
@@ -161,11 +223,13 @@
(defclass! sox-hoaencode (sox-input)
(
- (positions :accessor positions :initarg :positions :initform nil :documentation *sox-hoaencode-positions-doc*)
- (order :accessor order :initarg :order :initform nil :documentation *sox-hoaencode-order-doc*)
+ (gains :accessor gains :initarg :gains :initform nil :documentation *sox-gain-doc*)
+ (azimuth :accessor azimuth :initarg :azimuth :initform 0 :documentation "azimuth angle in degrees")
+ (elevation :accessor elevation :initarg :elevation :initform 0 :documentation "elevation angle in degrees")
+ (order :accessor order :initarg :order :initform 3 :documentation *sox-hoaencode-order-doc*)
)
(:icon 100)
- (:documentation "Sox-hoaencode transforms <sound> into a <order>-th ambisonic (HOA) signal at <positions>.
+ (:documentation "Sox-hoaencode encodes <sound> into a <order>-th ambisonic (HOA) signal at <positions>.
The signal follows the ambiX convention, i.e. it uses SN3D normalization and ACN channel ordering. The resulting file has (<order>+1)^2 channels (order 0: 1 channel, order 1: 4 channels, order 2: 9 channels, order 3: 16 channels, ...).")
)
@@ -173,6 +237,8 @@
(defmethod initialize-instance :after ((self sox-hoaencode) &rest l)
(declare (ignore l))
(when (sound self)
- (sox-init-sound self 'list)
+ (sox-init-sound self 'atom)
)
)
+
+
--
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