% SUpDEq - Spatial Upsampling by Directional Equalization
function SOFAobj = supdeq_writeSOFAobj(HRIR_L, HRIR_R , samplingGrid, fs, earDistance, sourceDistance)
This function can be used to generate a SOFA object based on a
pre-defined spherical grid and the corresponding HRIRs.
Output:
SOFAobj according to the SOFA convention "SimpleFreeFieldHRIR".
Specific attributes and metadata can be added manually afterwards.
Use SOFAsave to save SOFA object with specific filename.
Input:
HRIR_L/R - 2D Array [N X M] with
N = Sample point on spherical grid, M = Samples per IR,
Example: HRIR_L/R with dimensions [2702x256]--> 2702
HRIRs (according to samplingGrid with 2702 points) with
256 samples per HRIR
samplingGrid - 2D Array [AZ x EL] with
AZ = Azimuth, EL = Elevation in degree [DEG]!
fs - Sampling rate
Default: 48000
earDistance - earDistance of the receiver, only needed for HRIRs/BRIRs
Two receivers (=ears) on a head with radius H (in meter): ReceiverPosition=[0 -H 0; 0 +H 0].
Default: 0.165
sourceDistance- Distance between receiver and source. Only important for
measurement-based SOFA files (HRIRs/BRIRs/Array-IRs).
Default: 3.00 m - In the far field...
Dependencies: SOFA API
SOFA conventions - https://www.sofaconventions.org/mediawiki/index.php/SOFA_conventions
Standardized SOFA conventions
Standardized SOFA conventions are those which have been standardized by the AES. As with AES69-2015, we have:
GeneralFIR: General convention with FIR as DataType (no restrictions but DataType)
GeneralTF: General convention with TF as DataType (no restrictions but DataType)
SimpleFreeFieldHRIR: Free-field HRTFs stored as impulse responses, measured with an omnidirectional source for a single listener.
Note: Any modification in one of these conventions changes its status to "stable", i.e., not standardized anymore, unless the modification will be approved the AES.
Stable SOFA conventions
Stable SOFA conventions are those for which SOFA files are publicly available and can be read/modified by at least one publicly available software package.
GeneralFIRE: General convention with FIRE as DataType (no restrictions but DataType).
SimpleHeadphoneIR: Conventions to store headphone IRs recorded for each emitter and each ear, single listener and no directionality of emitter/receiver considered.
SimpleFreeFieldTF: as SimpleFreeFieldHRIR, but uses TF as DataType covering special needs coming from HRTF simulations.
SimpleFreeFieldSOS: as SimpleFreeFieldHRIR, but uses SOS as DataType (second-order sections) covering special needs coming from HRTF rendering.
SingleRoomDRIR: directional room impulse responses (DRIRs) measured with an arbitrary number of receivers (such as a microphone array) and an omnidirectional source in a single room.
MultiSpeakerBRIR: binaural room impulse responses (BRIRs) measured with an arbitrary number of emitters (such as a loudspeaker array).
These conventions, when used often and widely, can be proposed for standardization to the AES.
Proposed SOFA conventions
SimpleBRIR: Binaural room impulse responses measured with an omnidirectional source in a single reverberant space. Somebody wanted to have this, but the work stopped at the moment.
(C) 2018 by JMA, Johannes M. Arend
TH Köln - University of Applied Sciences
Institute of Communications Engineering
Department of Acoustics and Audio Signal Processing0001 %% SUpDEq - Spatial Upsampling by Directional Equalization 0002 % 0003 % function SOFAobj = supdeq_writeSOFAobj(HRIR_L, HRIR_R , samplingGrid, fs, earDistance, sourceDistance) 0004 % 0005 % This function can be used to generate a SOFA object based on a 0006 % pre-defined spherical grid and the corresponding HRIRs. 0007 % 0008 % Output: 0009 % SOFAobj according to the SOFA convention "SimpleFreeFieldHRIR". 0010 % Specific attributes and metadata can be added manually afterwards. 0011 % Use SOFAsave to save SOFA object with specific filename. 0012 % 0013 % Input: 0014 % HRIR_L/R - 2D Array [N X M] with 0015 % N = Sample point on spherical grid, M = Samples per IR, 0016 % Example: HRIR_L/R with dimensions [2702x256]--> 2702 0017 % HRIRs (according to samplingGrid with 2702 points) with 0018 % 256 samples per HRIR 0019 % samplingGrid - 2D Array [AZ x EL] with 0020 % AZ = Azimuth, EL = Elevation in degree [DEG]! 0021 % fs - Sampling rate 0022 % Default: 48000 0023 % earDistance - earDistance of the receiver, only needed for HRIRs/BRIRs 0024 % Two receivers (=ears) on a head with radius H (in meter): ReceiverPosition=[0 -H 0; 0 +H 0]. 0025 % Default: 0.165 0026 % sourceDistance- Distance between receiver and source. Only important for 0027 % measurement-based SOFA files (HRIRs/BRIRs/Array-IRs). 0028 % Default: 3.00 m - In the far field... 0029 % 0030 % Dependencies: SOFA API 0031 % 0032 % SOFA conventions - https://www.sofaconventions.org/mediawiki/index.php/SOFA_conventions 0033 % 0034 % Standardized SOFA conventions 0035 % Standardized SOFA conventions are those which have been standardized by the AES. As with AES69-2015, we have: 0036 % GeneralFIR: General convention with FIR as DataType (no restrictions but DataType) 0037 % GeneralTF: General convention with TF as DataType (no restrictions but DataType) 0038 % SimpleFreeFieldHRIR: Free-field HRTFs stored as impulse responses, measured with an omnidirectional source for a single listener. 0039 % Note: Any modification in one of these conventions changes its status to "stable", i.e., not standardized anymore, unless the modification will be approved the AES. 0040 % 0041 % Stable SOFA conventions 0042 % Stable SOFA conventions are those for which SOFA files are publicly available and can be read/modified by at least one publicly available software package. 0043 % GeneralFIRE: General convention with FIRE as DataType (no restrictions but DataType). 0044 % SimpleHeadphoneIR: Conventions to store headphone IRs recorded for each emitter and each ear, single listener and no directionality of emitter/receiver considered. 0045 % SimpleFreeFieldTF: as SimpleFreeFieldHRIR, but uses TF as DataType covering special needs coming from HRTF simulations. 0046 % SimpleFreeFieldSOS: as SimpleFreeFieldHRIR, but uses SOS as DataType (second-order sections) covering special needs coming from HRTF rendering. 0047 % SingleRoomDRIR: directional room impulse responses (DRIRs) measured with an arbitrary number of receivers (such as a microphone array) and an omnidirectional source in a single room. 0048 % MultiSpeakerBRIR: binaural room impulse responses (BRIRs) measured with an arbitrary number of emitters (such as a loudspeaker array). 0049 % These conventions, when used often and widely, can be proposed for standardization to the AES. 0050 % 0051 % Proposed SOFA conventions 0052 % SimpleBRIR: Binaural room impulse responses measured with an omnidirectional source in a single reverberant space. Somebody wanted to have this, but the work stopped at the moment. 0053 % 0054 % (C) 2018 by JMA, Johannes M. Arend 0055 % TH Köln - University of Applied Sciences 0056 % Institute of Communications Engineering 0057 % Department of Acoustics and Audio Signal Processing 0058 0059 function SOFAobj = supdeq_writeSOFAobj(HRIR_L, HRIR_R, samplingGrid, fs, earDistance, sourceDistance) 0060 0061 if nargin < 4 || isempty(fs) 0062 fs = 48000; 0063 end 0064 0065 if nargin < 5 || isempty(earDistance) 0066 earDistance = 0.165; 0067 end 0068 0069 if nargin < 6 || isempty(sourceDistance) 0070 sourceDistance = 3.00; 0071 end 0072 0073 %Write IRs 3D Array 0074 IRs = cat(3,HRIR_L',HRIR_R'); 0075 0076 if size(IRs,2) ~= size(samplingGrid,1) 0077 error('Number of IRs must match number to number of sampling grid points!'); 0078 end 0079 0080 0081 %% 0082 %Write SOFA file 0083 disp('Writing "SimpleFreeFieldHRIR" SOFA object'); 0084 0085 %Get empty SOFA object 0086 SOFAobj = SOFAgetConventions('SimpleFreeFieldHRIR'); 0087 0088 %Get number of grid points 0089 nPoints = size(samplingGrid,1); 0090 0091 %Transform grid to SOFA format 0092 samplingGrid(:,2) = 90-samplingGrid(:,2); 0093 0094 %Fill obj with data 0095 SOFAobj.Data.IR = IRs(:,:,1); %Channel1 - Left 0096 SOFAobj.Data.IR(:,:,2) = IRs(:,:,2); %Channel2 - Right 0097 SOFAobj.Data.IR = shiftdim(SOFAobj.Data.IR,1); % convert from [N M R] to [M R N] 0098 SOFAobj.Data.SamplingRate = fs; 0099 %Fill the mandatory variables (0 -radius 0; 0 radius 0) 0100 SOFAobj.ReceiverPosition = [0 earDistance/2 0; 0 -earDistance/2 0]; 0101 SOFAobj.ListenerPosition = [0 0 0]; 0102 SOFAobj.ListenerView = [1 0 0]; 0103 SOFAobj.ListenerUp = [0 0 1]; 0104 SOFAobj.SourcePosition = [... 0105 samplingGrid(:,1) ... % AZ in DEG 0106 samplingGrid(:,2) ... % EL in DEG 0107 sourceDistance*ones(nPoints,1)]; % nPoints source distance in m 0108 %Update dimensions 0109 SOFAobj=SOFAupdateDimensions(SOFAobj); 0110 0111 disp('Done...'); 0112 end 0113