OpenShot Library | libopenshot 0.3.3
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Compressor.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 "Compressor.h"
14#include "Exceptions.h"
15#include "Frame.h"
16
17using namespace openshot;
18
19Compressor::Compressor() : Compressor::Compressor(-10, 1, 1, 1, 1, false) {}
20
22 Keyframe release, Keyframe makeup_gain,
23 Keyframe bypass):
24 threshold(threshold), ratio(ratio), attack(attack),
25 release(release), makeup_gain(makeup_gain), bypass(bypass),
26 input_level(0.0), yl_prev(0.0)
27{
28 // Init effect properties
29 init_effect_details();
30}
31
32// Init effect settings
33void Compressor::init_effect_details()
34{
37
39 info.class_name = "Compressor";
40 info.name = "Compressor";
41 info.description = "Reduce the volume of loud sounds or amplify quiet sounds.";
42 info.has_audio = true;
43 info.has_video = false;
44}
45
46// This method is required for all derived classes of EffectBase, and returns a
47// modified openshot::Frame object
48std::shared_ptr<openshot::Frame> Compressor::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
49{
50 // Adding Compressor
51 const int num_input_channels = frame->audio->getNumChannels();
52 const int num_output_channels = frame->audio->getNumChannels();
53 const int num_samples = frame->audio->getNumSamples();
54
55 mixed_down_input.setSize(1, num_samples);
56 inverse_sample_rate = 1.0f / frame->SampleRate();
57 inverseE = 1.0f / M_E;
58
59 if ((bool)bypass.GetValue(frame_number))
60 return frame;
61
62 mixed_down_input.clear();
63
64 for (int channel = 0; channel < num_input_channels; ++channel)
65 mixed_down_input.addFrom(0, 0, *frame->audio, channel, 0, num_samples, 1.0f / num_input_channels);
66
67 for (int sample = 0; sample < num_samples; ++sample) {
68 float T = threshold.GetValue(frame_number);
69 float R = ratio.GetValue(frame_number);
70 float alphaA = calculateAttackOrRelease(attack.GetValue(frame_number));
71 float alphaR = calculateAttackOrRelease(release.GetValue(frame_number));
72 float gain = makeup_gain.GetValue(frame_number);
73 float input_squared = powf(mixed_down_input.getSample(0, sample), 2.0f);
74
75 input_level = input_squared;
76
77 xg = (input_level <= 1e-6f) ? -60.0f : 10.0f * log10f(input_level);
78
79 if (xg < T)
80 yg = xg;
81 else
82 yg = T + (xg - T) / R;
83
84 xl = xg - yg;
85
86 if (xl > yl_prev)
87 yl = alphaA * yl_prev + (1.0f - alphaA) * xl;
88 else
89 yl = alphaR * yl_prev + (1.0f - alphaR) * xl;
90
91 control = powf (10.0f, (gain - yl) * 0.05f);
92 yl_prev = yl;
93
94 for (int channel = 0; channel < num_input_channels; ++channel) {
95 float new_value = frame->audio->getSample(channel, sample)*control;
96 frame->audio->setSample(channel, sample, new_value);
97 }
98 }
99
100 for (int channel = num_input_channels; channel < num_output_channels; ++channel)
101 frame->audio->clear(channel, 0, num_samples);
102
103 // return the modified frame
104 return frame;
105}
106
108{
109 if (value == 0.0f)
110 return 0.0f;
111 else
112 return pow (inverseE, inverse_sample_rate / value);
113}
114
115// Generate JSON string of this object
116std::string Compressor::Json() const {
117
118 // Return formatted string
119 return JsonValue().toStyledString();
120}
121
122// Generate Json::Value for this object
123Json::Value Compressor::JsonValue() const {
124
125 // Create root json object
126 Json::Value root = EffectBase::JsonValue(); // get parent properties
127 root["type"] = info.class_name;
128 root["threshold"] = threshold.JsonValue();
129 root["ratio"] = ratio.JsonValue();
130 root["attack"] = attack.JsonValue();
131 root["release"] = release.JsonValue();
132 root["makeup_gain"] = makeup_gain.JsonValue();
133 root["bypass"] = bypass.JsonValue();
134
135 // return JsonValue
136 return root;
137}
138
139// Load JSON string into this object
140void Compressor::SetJson(const std::string value) {
141
142 // Parse JSON string into JSON objects
143 try
144 {
145 const Json::Value root = openshot::stringToJson(value);
146 // Set all values that match
147 SetJsonValue(root);
148 }
149 catch (const std::exception& e)
150 {
151 // Error parsing JSON (or missing keys)
152 throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
153 }
154}
155
156// Load Json::Value into this object
157void Compressor::SetJsonValue(const Json::Value root) {
158
159 // Set parent data
161
162 // Set data from Json (if key is found)
163 if (!root["threshold"].isNull())
164 threshold.SetJsonValue(root["threshold"]);
165
166 if (!root["ratio"].isNull())
167 ratio.SetJsonValue(root["ratio"]);
168
169 if (!root["attack"].isNull())
170 attack.SetJsonValue(root["attack"]);
171
172 if (!root["release"].isNull())
173 release.SetJsonValue(root["release"]);
174
175 if (!root["makeup_gain"].isNull())
176 makeup_gain.SetJsonValue(root["makeup_gain"]);
177
178 if (!root["bypass"].isNull())
179 bypass.SetJsonValue(root["bypass"]);
180}
181
182// Get all properties for a specific frame
183std::string Compressor::PropertiesJSON(int64_t requested_frame) const {
184
185 // Generate JSON properties list
186 Json::Value root = BasePropertiesJSON(requested_frame);
187
188 // Keyframes
189 root["threshold"] = add_property_json("Threshold (dB)", threshold.GetValue(requested_frame), "float", "", &threshold, -60, 0, false, requested_frame);
190 root["ratio"] = add_property_json("Ratio", ratio.GetValue(requested_frame), "float", "", &ratio, 1, 100, false, requested_frame);
191 root["attack"] = add_property_json("Attack (ms)", attack.GetValue(requested_frame), "float", "", &attack, 0.1, 100, false, requested_frame);
192 root["release"] = add_property_json("Release (ms)", release.GetValue(requested_frame), "float", "", &release, 10, 1000, false, requested_frame);
193 root["makeup_gain"] = add_property_json("Makeup gain (dB)", makeup_gain.GetValue(requested_frame), "float", "", &makeup_gain, -12, 12, false, requested_frame);
194 root["bypass"] = add_property_json("Bypass", bypass.GetValue(requested_frame), "bool", "", &bypass, 0, 1, false, requested_frame);
195
196 // Return formatted string
197 return root.toStyledString();
198}
Header file for Compressor audio effect class.
Header file for all Exception classes.
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
This class adds a compressor into the audio.
Definition Compressor.h:36
std::string PropertiesJSON(int64_t requested_frame) const override
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 Compressor.h:72
Compressor()
Default constructor.
Json::Value JsonValue() const override
Generate Json::Value for this object.
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
juce::AudioBuffer< float > mixed_down_input
Definition Compressor.h:50
void SetJson(const std::string value) override
Load JSON string into this object.
std::string Json() const override
Generate JSON string of this object.
float calculateAttackOrRelease(float value)
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
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