1/*
2Copyright 2018 Google Inc. All Rights Reserved.
3
4Licensed under the Apache License, Version 2.0 (the "License");
5you may not use this file except in compliance with the License.
6You may obtain a copy of the License at
7
8 http://www.apache.org/licenses/LICENSE-2.0
9
10Unless required by applicable law or agreed to in writing, software
11distributed under the License is distributed on an "AS-IS" BASIS,
12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13See the License for the specific language governing permissions and
14limitations under the License.
15*/
16
17#include "graph/ambisonic_mixing_encoder_node.h"
18
19#include "ambisonics/utils.h"
20#include "base/constants_and_types.h"
21#include "base/logging.h"
22
23
24namespace vraudio {
25
26AmbisonicMixingEncoderNode::AmbisonicMixingEncoderNode(
27 const SystemSettings& system_settings,
28 const AmbisonicLookupTable& lookup_table, int ambisonic_order)
29 : system_settings_(system_settings),
30 lookup_table_(lookup_table),
31 ambisonic_order_(ambisonic_order),
32 gain_mixer_(GetNumPeriphonicComponents(ambisonic_order: ambisonic_order_),
33 system_settings_.GetFramesPerBuffer()),
34 coefficients_(GetNumPeriphonicComponents(ambisonic_order: ambisonic_order_)) {}
35
36const AudioBuffer* AmbisonicMixingEncoderNode::AudioProcess(
37 const NodeInput& input) {
38
39
40 const WorldPosition& listener_position = system_settings_.GetHeadPosition();
41 const WorldRotation& listener_rotation = system_settings_.GetHeadRotation();
42
43 gain_mixer_.Reset();
44 for (auto& input_buffer : input.GetInputBuffers()) {
45 const int source_id = input_buffer->source_id();
46 const auto source_parameters =
47 system_settings_.GetSourceParameters(source_id);
48 DCHECK_NE(source_id, kInvalidSourceId);
49 DCHECK_EQ(input_buffer->num_channels(), 1U);
50
51 // Compute the relative source direction in spherical angles.
52 const ObjectTransform& source_transform =
53 source_parameters->object_transform;
54 WorldPosition relative_direction;
55 GetRelativeDirection(from_position: listener_position, from_rotation: listener_rotation,
56 to_position: source_transform.position, relative_direction: &relative_direction);
57 const SphericalAngle source_direction =
58 SphericalAngle::FromWorldPosition(world_position: relative_direction);
59
60 lookup_table_.GetEncodingCoeffs(ambisonic_order: ambisonic_order_, source_direction,
61 source_spread_deg: source_parameters->spread_deg,
62 encoding_coeffs: &coefficients_);
63
64 gain_mixer_.AddInputChannel(input: (*input_buffer)[0], source_id, gains: coefficients_);
65 }
66 return gain_mixer_.GetOutput();
67}
68
69} // namespace vraudio
70

source code of qtmultimedia/src/3rdparty/resonance-audio/resonance_audio/graph/ambisonic_mixing_encoder_node.cc