OpenShot Library | libopenshot 0.3.3
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Expander.cpp
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1
9// Copyright (c) 2008-2019 OpenShot Studios, LLC
10//
11// SPDX-License-Identifier: LGPL-3.0-or-later
12
13#include "Expander.h"
14#include "Exceptions.h"
15#include "Frame.h"
16
17using namespace openshot;
18
19Expander::Expander(): Expander::Expander(-10, 1, 1, 1, 1, false) { }
20
21// Default constructor
23 Keyframe release, Keyframe makeup_gain, Keyframe bypass) :
24 threshold(threshold), ratio(ratio), attack(attack),
25 release(release), makeup_gain(makeup_gain), bypass(bypass)
26{
27 // Init effect properties
28 init_effect_details();
29}
30
31// Init effect settings
32void Expander::init_effect_details()
33{
36
38 info.class_name = "Expander";
39 info.name = "Expander";
40 info.description = "Louder parts of audio becomes relatively louder and quieter parts becomes quieter.";
41 info.has_audio = true;
42 info.has_video = false;
43
44 input_level = 0.0f;
45 yl_prev = 0.0f;
46
47
48}
49
50// This method is required for all derived classes of EffectBase, and returns a
51// modified openshot::Frame object
52std::shared_ptr<openshot::Frame> Expander::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
53{
54 // Adding Expander
55 const int num_input_channels = frame->audio->getNumChannels();
56 const int num_output_channels = frame->audio->getNumChannels();
57 const int num_samples = frame->audio->getNumSamples();
58
59 mixed_down_input.setSize(1, num_samples);
60 inverse_sample_rate = 1.0f / frame->SampleRate();
61 inverseE = 1.0f / M_E;
62
63 if ((bool)bypass.GetValue(frame_number))
64 return frame;
65
66 mixed_down_input.clear();
67
68 for (int channel = 0; channel < num_input_channels; ++channel)
69 mixed_down_input.addFrom(0, 0, *frame->audio, channel, 0, num_samples, 1.0f / num_input_channels);
70
71 for (int sample = 0; sample < num_samples; ++sample) {
72 float T = threshold.GetValue(frame_number);
73 float R = ratio.GetValue(frame_number);
74 float alphaA = calculateAttackOrRelease(attack.GetValue(frame_number));
75 float alphaR = calculateAttackOrRelease(release.GetValue(frame_number));
76 float gain = makeup_gain.GetValue(frame_number);
77 float input_squared = powf(mixed_down_input.getSample(0, sample), 2.0f);
78
79 const float average_factor = 0.9999f;
80 input_level = average_factor * input_level + (1.0f - average_factor) * input_squared;
81
82 xg = (input_level <= 1e-6f) ? -60.0f : 10.0f * log10f(input_level);
83
84 if (xg > T)
85 yg = xg;
86 else
87 yg = T + (xg - T) * R;
88
89 xl = xg - yg;
90
91 if (xl < yl_prev)
92 yl = alphaA * yl_prev + (1.0f - alphaA) * xl;
93 else
94 yl = alphaR * yl_prev + (1.0f - alphaR) * xl;
95
96
97 control = powf (10.0f, (gain - yl) * 0.05f);
98 yl_prev = yl;
99
100 for (int channel = 0; channel < num_input_channels; ++channel) {
101 float new_value = frame->audio->getSample(channel, sample)*control;
102 frame->audio->setSample(channel, sample, new_value);
103 }
104 }
105
106 for (int channel = num_input_channels; channel < num_output_channels; ++channel)
107 frame->audio->clear(channel, 0, num_samples);
108
109 // return the modified frame
110 return frame;
111}
112
114{
115 if (value == 0.0f)
116 return 0.0f;
117 else
118 return pow (inverseE, inverse_sample_rate / value);
119}
120
121// Generate JSON string of this object
122std::string Expander::Json() const {
123
124 // Return formatted string
125 return JsonValue().toStyledString();
126}
127
128// Generate Json::Value for this object
129Json::Value Expander::JsonValue() const {
130
131 // Create root json object
132 Json::Value root = EffectBase::JsonValue(); // get parent properties
133 root["type"] = info.class_name;
134 root["threshold"] = threshold.JsonValue();
135 root["ratio"] = ratio.JsonValue();
136 root["attack"] = attack.JsonValue();
137 root["release"] = release.JsonValue();
138 root["makeup_gain"] = makeup_gain.JsonValue();
139 root["bypass"] = bypass.JsonValue();
140
141 // return JsonValue
142 return root;
143}
144
145// Load JSON string into this object
146void Expander::SetJson(const std::string value) {
147
148 // Parse JSON string into JSON objects
149 try
150 {
151 const Json::Value root = openshot::stringToJson(value);
152 // Set all values that match
153 SetJsonValue(root);
154 }
155 catch (const std::exception& e)
156 {
157 // Error parsing JSON (or missing keys)
158 throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
159 }
160}
161
162// Load Json::Value into this object
163void Expander::SetJsonValue(const Json::Value root) {
164
165 // Set parent data
167
168 // Set data from Json (if key is found)
169 if (!root["threshold"].isNull())
170 threshold.SetJsonValue(root["threshold"]);
171
172 if (!root["ratio"].isNull())
173 ratio.SetJsonValue(root["ratio"]);
174
175 if (!root["attack"].isNull())
176 attack.SetJsonValue(root["attack"]);
177
178 if (!root["release"].isNull())
179 release.SetJsonValue(root["release"]);
180
181 if (!root["makeup_gain"].isNull())
182 makeup_gain.SetJsonValue(root["makeup_gain"]);
183
184 if (!root["bypass"].isNull())
185 bypass.SetJsonValue(root["bypass"]);
186}
187
188// Get all properties for a specific frame
189std::string Expander::PropertiesJSON(int64_t requested_frame) const {
190
191 // Generate JSON properties list
192 Json::Value root = BasePropertiesJSON(requested_frame);
193
194 // Keyframes
195 root["threshold"] = add_property_json("Threshold (dB)", threshold.GetValue(requested_frame), "float", "", &threshold, -60, 0, false, requested_frame);
196 root["ratio"] = add_property_json("Ratio", ratio.GetValue(requested_frame), "float", "", &ratio, 1, 100, false, requested_frame);
197 root["attack"] = add_property_json("Attack (ms)", attack.GetValue(requested_frame), "float", "", &attack, 0.1, 100, false, requested_frame);
198 root["release"] = add_property_json("Release (ms)", release.GetValue(requested_frame), "float", "", &release, 10, 1000, false, requested_frame);
199 root["makeup_gain"] = add_property_json("Makeup gain (dB)", makeup_gain.GetValue(requested_frame), "float", "", &makeup_gain, -12, 12, false, requested_frame);
200 root["bypass"] = add_property_json("Bypass", bypass.GetValue(requested_frame), "bool", "", &bypass, 0, 1, false, requested_frame);
201
202 // Return formatted string
203 return root.toStyledString();
204}
Header file for all Exception classes.
Header file for Expander audio effect class.
Header file for Frame class.
Json::Value add_property_json(std::string name, float value, std::string type, std::string memo, const Keyframe *keyframe, float min_value, float max_value, bool readonly, int64_t requested_frame) const
Generate JSON for a property.
Definition ClipBase.cpp:96
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
Json::Value BasePropertiesJSON(int64_t requested_frame) const
Generate JSON object of base properties (recommended to be used by all effects)
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
EffectInfoStruct info
Information about the current effect.
Definition EffectBase.h:69
This class adds a expander (or noise gate) into the audio.
Definition Expander.h:37
Expander()
Default constructor.
Definition Expander.cpp:19
float inverse_sample_rate
Definition Expander.h:61
std::string PropertiesJSON(int64_t requested_frame) const override
Definition Expander.cpp:189
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Definition Expander.cpp:163
Keyframe makeup_gain
Definition Expander.h:48
Keyframe release
Definition Expander.h:47
float calculateAttackOrRelease(float value)
Definition Expander.cpp:113
void SetJson(const std::string value) override
Load JSON string into this object.
Definition Expander.cpp:146
Keyframe threshold
Definition Expander.h:44
Keyframe bypass
Definition Expander.h:49
Keyframe attack
Definition Expander.h:46
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition Expander.cpp:129
juce::AudioBuffer< float > mixed_down_input
Definition Expander.h:51
std::string Json() const override
Generate JSON string of this object.
Definition Expander.cpp:122
std::shared_ptr< openshot::Frame > GetFrame(int64_t frame_number) override
This method is required for all derived classes of ClipBase, and returns a new openshot::Frame object...
Definition Expander.h:73
Exception for invalid JSON.
Definition Exceptions.h:218
A Keyframe is a collection of Point instances, which is used to vary a number or property over time.
Definition KeyFrame.h:53
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition KeyFrame.cpp:372
double GetValue(int64_t index) const
Get the value at a specific index.
Definition KeyFrame.cpp:258
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition KeyFrame.cpp:339
This namespace is the default namespace for all code in the openshot library.
Definition Compressor.h:29
const Json::Value stringToJson(const std::string value)
Definition Json.cpp:16
bool has_video
Determines if this effect manipulates the image of a frame.
Definition EffectBase.h:40
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition EffectBase.h:41
std::string class_name
The class name of the effect.
Definition EffectBase.h:36
std::string name
The name of the effect.
Definition EffectBase.h:37
std::string description
The description of this effect and what it does.
Definition EffectBase.h:38