OpenShot Library | libopenshot 0.2.7
Compressor.cpp
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1/**
2 * @file
3 * @brief Source file for Compressor audio effect class
4 * @author
5 *
6 * @ref License
7 */
8
9/* LICENSE
10 *
11 * Copyright (c) 2008-2019 OpenShot Studios, LLC
12 * <http://www.openshotstudios.com/>. This file is part of
13 * OpenShot Library (libopenshot), an open-source project dedicated to
14 * delivering high quality video editing and animation solutions to the
15 * world. For more information visit <http://www.openshot.org/>.
16 *
17 * OpenShot Library (libopenshot) is free software: you can redistribute it
18 * and/or modify it under the terms of the GNU Lesser General Public License
19 * as published by the Free Software Foundation, either version 3 of the
20 * License, or (at your option) any later version.
21 *
22 * OpenShot Library (libopenshot) is distributed in the hope that it will be
23 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU Lesser General Public License for more details.
26 *
27 * You should have received a copy of the GNU Lesser General Public License
28 * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
29 */
30
31#include "Compressor.h"
32#include "Exceptions.h"
33
34using namespace openshot;
35
36/// Blank constructor, useful when using Json to load the effect properties
37Compressor::Compressor() : threshold(-10), ratio(1), attack(1), release(1), makeup_gain(1), bypass(false) {
38 // Init effect properties
39 init_effect_details();
40}
41
42// Default constructor
43Compressor::Compressor(Keyframe new_threshold, Keyframe new_ratio, Keyframe new_attack, Keyframe new_release, Keyframe new_makeup_gain, Keyframe new_bypass) :
44 threshold(new_threshold), ratio(new_ratio), attack(new_attack), release(new_release), makeup_gain(new_makeup_gain), bypass(new_bypass)
45{
46 // Init effect properties
47 init_effect_details();
48}
49
50// Init effect settings
51void Compressor::init_effect_details()
52{
53 /// Initialize the values of the EffectInfo struct.
55
56 /// Set the effect info
57 info.class_name = "Compressor";
58 info.name = "Compressor";
59 info.description = "Reduce the volume of loud sounds or amplify quiet sounds.";
60 info.has_audio = true;
61 info.has_video = false;
62
63 input_level = 0.0f;
64 yl_prev = 0.0f;
65}
66
67// This method is required for all derived classes of EffectBase, and returns a
68// modified openshot::Frame object
69std::shared_ptr<openshot::Frame> Compressor::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
70{
71 // Adding Compressor
72 const int num_input_channels = frame->audio->getNumChannels();
73 const int num_output_channels = frame->audio->getNumChannels();
74 const int num_samples = frame->audio->getNumSamples();
75
76 mixed_down_input.setSize(1, num_samples);
77 inverse_sample_rate = 1.0f / frame->SampleRate();
78 inverseE = 1.0f / M_E;
79
80 if ((bool)bypass.GetValue(frame_number))
81 return frame;
82
83 mixed_down_input.clear();
84
85 for (int channel = 0; channel < num_input_channels; ++channel)
86 mixed_down_input.addFrom(0, 0, *frame->audio, channel, 0, num_samples, 1.0f / num_input_channels);
87
88 for (int sample = 0; sample < num_samples; ++sample) {
89 float T = threshold.GetValue(frame_number);
90 float R = ratio.GetValue(frame_number);
91 float alphaA = calculateAttackOrRelease(attack.GetValue(frame_number));
92 float alphaR = calculateAttackOrRelease(release.GetValue(frame_number));
93 float gain = makeup_gain.GetValue(frame_number);
94 float input_squared = powf(mixed_down_input.getSample(0, sample), 2.0f);
95
96 input_level = input_squared;
97
98 xg = (input_level <= 1e-6f) ? -60.0f : 10.0f * log10f(input_level);
99
100 if (xg < T)
101 yg = xg;
102 else
103 yg = T + (xg - T) / R;
104
105 xl = xg - yg;
106
107 if (xl > yl_prev)
108 yl = alphaA * yl_prev + (1.0f - alphaA) * xl;
109 else
110 yl = alphaR * yl_prev + (1.0f - alphaR) * xl;
111
112 control = powf (10.0f, (gain - yl) * 0.05f);
113 yl_prev = yl;
114
115 for (int channel = 0; channel < num_input_channels; ++channel) {
116 float new_value = frame->audio->getSample(channel, sample)*control;
117 frame->audio->setSample(channel, sample, new_value);
118 }
119 }
120
121 for (int channel = num_input_channels; channel < num_output_channels; ++channel)
122 frame->audio->clear(channel, 0, num_samples);
123
124 // return the modified frame
125 return frame;
126}
127
129{
130 if (value == 0.0f)
131 return 0.0f;
132 else
133 return pow (inverseE, inverse_sample_rate / value);
134}
135
136// Generate JSON string of this object
137std::string Compressor::Json() const {
138
139 // Return formatted string
140 return JsonValue().toStyledString();
141}
142
143// Generate Json::Value for this object
144Json::Value Compressor::JsonValue() const {
145
146 // Create root json object
147 Json::Value root = EffectBase::JsonValue(); // get parent properties
148 root["type"] = info.class_name;
149 root["threshold"] = threshold.JsonValue();
150 root["ratio"] = ratio.JsonValue();
151 root["attack"] = attack.JsonValue();
152 root["release"] = release.JsonValue();
153 root["makeup_gain"] = makeup_gain.JsonValue();
154 root["bypass"] = bypass.JsonValue();
155
156 // return JsonValue
157 return root;
158}
159
160// Load JSON string into this object
161void Compressor::SetJson(const std::string value) {
162
163 // Parse JSON string into JSON objects
164 try
165 {
166 const Json::Value root = openshot::stringToJson(value);
167 // Set all values that match
168 SetJsonValue(root);
169 }
170 catch (const std::exception& e)
171 {
172 // Error parsing JSON (or missing keys)
173 throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
174 }
175}
176
177// Load Json::Value into this object
178void Compressor::SetJsonValue(const Json::Value root) {
179
180 // Set parent data
182
183 // Set data from Json (if key is found)
184 if (!root["threshold"].isNull())
185 threshold.SetJsonValue(root["threshold"]);
186
187 if (!root["ratio"].isNull())
188 ratio.SetJsonValue(root["ratio"]);
189
190 if (!root["attack"].isNull())
191 attack.SetJsonValue(root["attack"]);
192
193 if (!root["release"].isNull())
194 release.SetJsonValue(root["release"]);
195
196 if (!root["makeup_gain"].isNull())
197 makeup_gain.SetJsonValue(root["makeup_gain"]);
198
199 if (!root["bypass"].isNull())
200 bypass.SetJsonValue(root["bypass"]);
201}
202
203// Get all properties for a specific frame
204std::string Compressor::PropertiesJSON(int64_t requested_frame) const {
205
206 // Generate JSON properties list
207 Json::Value root;
208 root["id"] = add_property_json("ID", 0.0, "string", Id(), NULL, -1, -1, true, requested_frame);
209 root["layer"] = add_property_json("Track", Layer(), "int", "", NULL, 0, 20, false, requested_frame);
210 root["start"] = add_property_json("Start", Start(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
211 root["end"] = add_property_json("End", End(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
212 root["duration"] = add_property_json("Duration", Duration(), "float", "", NULL, 0, 1000 * 60 * 30, true, requested_frame);
213
214 // Keyframes
215 root["threshold"] = add_property_json("Threshold (dB)", threshold.GetValue(requested_frame), "float", "", &threshold, -60, 0, false, requested_frame);
216 root["ratio"] = add_property_json("Ratio", ratio.GetValue(requested_frame), "float", "", &ratio, 1, 100, false, requested_frame);
217 root["attack"] = add_property_json("Attack (ms)", attack.GetValue(requested_frame), "float", "", &attack, 0.1, 100, false, requested_frame);
218 root["release"] = add_property_json("Release (ms)", release.GetValue(requested_frame), "float", "", &release, 10, 1000, false, requested_frame);
219 root["makeup_gain"] = add_property_json("Makeup gain (dB)", makeup_gain.GetValue(requested_frame), "float", "", &makeup_gain, -12, 12, false, requested_frame);
220 root["bypass"] = add_property_json("Bypass", bypass.GetValue(requested_frame), "bool", "", &bypass, 0, 1, false, requested_frame);
221
222 // Return formatted string
223 return root.toStyledString();
224}
Header file for Compressor audio effect class.
Header file for all Exception classes.
float End() const
Get end position (in seconds) of clip (trim end of video)
Definition: ClipBase.h:111
float Start() const
Get start position (in seconds) of clip (trim start of video)
Definition: ClipBase.h:110
float Duration() const
Get the length of this clip (in seconds)
Definition: ClipBase.h:112
std::string Id() const
Get the Id of this clip object.
Definition: ClipBase.h:107
int Layer() const
Get layer of clip on timeline (lower number is covered by higher numbers)
Definition: ClipBase.h:109
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:68
std::string PropertiesJSON(int64_t requested_frame) const override
Definition: Compressor.cpp:204
Keyframe makeup_gain
Definition: Compressor.h:65
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:97
Compressor()
Blank constructor, useful when using Json to load the effect properties.
Definition: Compressor.cpp:37
juce::AudioSampleBuffer mixed_down_input
Definition: Compressor.h:68
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition: Compressor.cpp:144
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Definition: Compressor.cpp:178
void SetJson(const std::string value) override
Load JSON string into this object.
Definition: Compressor.cpp:161
std::string Json() const override
Generate JSON string of this object.
Definition: Compressor.cpp:137
float calculateAttackOrRelease(float value)
Definition: Compressor.cpp:128
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: EffectBase.cpp:92
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: EffectBase.cpp:127
EffectInfoStruct info
Information about the current effect.
Definition: EffectBase.h:87
Exception for invalid JSON.
Definition: Exceptions.h:206
A Keyframe is a collection of Point instances, which is used to vary a number or property over time.
Definition: KeyFrame.h:72
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: KeyFrame.cpp:368
double GetValue(int64_t index) const
Get the value at a specific index.
Definition: KeyFrame.cpp:268
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: KeyFrame.cpp:335
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:47
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:34
bool has_video
Determines if this effect manipulates the image of a frame.
Definition: EffectBase.h:58
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition: EffectBase.h:59
std::string class_name
The class name of the effect.
Definition: EffectBase.h:54
std::string name
The name of the effect.
Definition: EffectBase.h:55
std::string description
The description of this effect and what it does.
Definition: EffectBase.h:56