OpenShot Library | libopenshot  0.2.7
Distortion.cpp
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1 /**
2  * @file
3  * @brief Source file for Distortion 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 "Distortion.h"
32 #include "Exceptions.h"
33 
34 using namespace openshot;
35 
36 /// Blank constructor, useful when using Json to load the effect properties
37 Distortion::Distortion() : distortion_type(HARD_CLIPPING), input_gain(10), output_gain(-10), tone(5) {
38  // Init effect properties
39  init_effect_details();
40 }
41 
42 // Default constructor
43 Distortion::Distortion(openshot::DistortionType new_distortion_type, Keyframe new_input_gain, Keyframe new_output_gain, Keyframe new_tone) :
44  distortion_type(new_distortion_type), input_gain(new_input_gain), output_gain(new_output_gain), tone(new_tone)
45 {
46  // Init effect properties
47  init_effect_details();
48 }
49 
50 // Init effect settings
51 void Distortion::init_effect_details()
52 {
53  /// Initialize the values of the EffectInfo struct.
55 
56  /// Set the effect info
57  info.class_name = "Distortion";
58  info.name = "Distortion";
59  info.description = "Alter the audio by clipping the signal.";
60  info.has_audio = true;
61  info.has_video = false;
62 }
63 
64 
65 // This method is required for all derived classes of EffectBase, and returns a
66 // modified openshot::Frame object
67 std::shared_ptr<openshot::Frame> Distortion::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
68 {
69  filters.clear();
70 
71  for (int i = 0; i < frame->audio->getNumChannels(); ++i) {
72  Filter* filter;
73  filters.add (filter = new Filter());
74  }
75 
76  updateFilters(frame_number);
77 
78  // Add distortion
79  for (int channel = 0; channel < frame->audio->getNumChannels(); channel++)
80  {
81  auto *channel_data = frame->audio->getWritePointer(channel);
82  float out;
83 
84  for (auto sample = 0; sample < frame->audio->getNumSamples(); ++sample)
85  {
86 
87  const int input_gain_value = (int)input_gain.GetValue(frame_number);
88  const int output_gain_value = (int)output_gain.GetValue(frame_number);
89  const float in = channel_data[sample]*powf(10.0f, input_gain_value * 0.05f);
90 
91  // Use the current distortion type
92  switch (distortion_type) {
93 
94  case HARD_CLIPPING: {
95  float threshold = 0.5f;
96  if (in > threshold)
97  out = threshold;
98  else if (in < -threshold)
99  out = -threshold;
100  else
101  out = in;
102  break;
103  }
104 
105  case SOFT_CLIPPING: {
106  float threshold1 = 1.0f / 3.0f;
107  float threshold2 = 2.0f / 3.0f;
108  if (in > threshold2)
109  out = 1.0f;
110  else if (in > threshold1)
111  out = 1.0f - powf (2.0f - 3.0f * in, 2.0f) / 3.0f;
112  else if (in < -threshold2)
113  out = -1.0f;
114  else if (in < -threshold1)
115  out = -1.0f + powf (2.0f + 3.0f * in, 2.0f) / 3.0f;
116  else
117  out = 2.0f * in;
118  out *= 0.5f;
119  break;
120  }
121 
122  case EXPONENTIAL: {
123  if (in > 0.0f)
124  out = 1.0f - expf (-in);
125  else
126  out = -1.0f + expf (in);
127  break;
128  }
129 
130  case FULL_WAVE_RECTIFIER: {
131  out = fabsf (in);
132  break;
133  }
134 
135  case HALF_WAVE_RECTIFIER: {
136  if (in > 0.0f)
137  out = in;
138  else
139  out = 0.0f;
140  break;
141  }
142  }
143 
144  float filtered = filters[channel]->processSingleSampleRaw(out);
145  channel_data[sample] = filtered*powf(10.0f, output_gain_value * 0.05f);
146  }
147  }
148 
149  // return the modified frame
150  return frame;
151 }
152 
153 void Distortion::updateFilters(int64_t frame_number)
154 {
155  double discrete_frequency = M_PI * 0.01;
156  double gain = pow(10.0, (float)tone.GetValue(frame_number) * 0.05);
157 
158  for (int i = 0; i < filters.size(); ++i)
159  filters[i]->updateCoefficients(discrete_frequency, gain);
160 }
161 
162 // Generate JSON string of this object
163 std::string Distortion::Json() const {
164 
165  // Return formatted string
166  return JsonValue().toStyledString();
167 }
168 
169 void Distortion::Filter::updateCoefficients(const double discrete_frequency, const double gain)
170 {
171  double tan_half_wc = tan(discrete_frequency / 2.0);
172  double sqrt_gain = sqrt(gain);
173 
174  coefficients = juce::IIRCoefficients(/* b0 */ sqrt_gain * tan_half_wc + gain,
175  /* b1 */ sqrt_gain * tan_half_wc - gain,
176  /* b2 */ 0.0,
177  /* a0 */ sqrt_gain * tan_half_wc + 1.0,
178  /* a1 */ sqrt_gain * tan_half_wc - 1.0,
179  /* a2 */ 0.0);
180  setCoefficients(coefficients);
181 }
182 
183 // Generate Json::Value for this object
184 Json::Value Distortion::JsonValue() const {
185 
186  // Create root json object
187  Json::Value root = EffectBase::JsonValue(); // get parent properties
188  root["type"] = info.class_name;
189  root["distortion_type"] = distortion_type;
190  root["input_gain"] = input_gain.JsonValue();
191  root["output_gain"] = output_gain.JsonValue();
192  root["tone"] = tone.JsonValue();
193 
194  // return JsonValue
195  return root;
196 }
197 
198 // Load JSON string into this object
199 void Distortion::SetJson(const std::string value) {
200 
201  // Parse JSON string into JSON objects
202  try
203  {
204  const Json::Value root = openshot::stringToJson(value);
205  // Set all values that match
206  SetJsonValue(root);
207  }
208  catch (const std::exception& e)
209  {
210  // Error parsing JSON (or missing keys)
211  throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
212  }
213 }
214 
215 // Load Json::Value into this object
216 void Distortion::SetJsonValue(const Json::Value root) {
217 
218  // Set parent data
220 
221  // Set data from Json (if key is found)
222  if (!root["distortion_type"].isNull())
223  distortion_type = (DistortionType)root["distortion_type"].asInt();
224 
225  if (!root["input_gain"].isNull())
226  input_gain.SetJsonValue(root["input_gain"]);
227 
228  if (!root["output_gain"].isNull())
229  output_gain.SetJsonValue(root["output_gain"]);
230 
231  if (!root["tone"].isNull())
232  tone.SetJsonValue(root["tone"]);
233 }
234 
235 // Get all properties for a specific frame
236 std::string Distortion::PropertiesJSON(int64_t requested_frame) const {
237 
238  // Generate JSON properties list
239  Json::Value root;
240  root["id"] = add_property_json("ID", 0.0, "string", Id(), NULL, -1, -1, true, requested_frame);
241  root["layer"] = add_property_json("Track", Layer(), "int", "", NULL, 0, 20, false, requested_frame);
242  root["start"] = add_property_json("Start", Start(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
243  root["end"] = add_property_json("End", End(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
244  root["duration"] = add_property_json("Duration", Duration(), "float", "", NULL, 0, 1000 * 60 * 30, true, requested_frame);
245 
246  // Keyframes
247  root["distortion_type"] = add_property_json("Distortion Type", distortion_type, "int", "", NULL, 0, 3, false, requested_frame);
248  root["input_gain"] = add_property_json("Input Gain (dB)", input_gain.GetValue(requested_frame), "int", "", &input_gain, -24, 24, false, requested_frame);
249  root["output_gain"] = add_property_json("Output Gain (dB)", output_gain.GetValue(requested_frame), "int", "", &output_gain, -24, 24, false, requested_frame);
250  root["tone"] = add_property_json("Tone (dB)", tone.GetValue(requested_frame), "int", "", &tone, -24, 24, false, requested_frame);
251 
252  // Add distortion_type choices (dropdown style)
253  root["distortion_type"]["choices"].append(add_property_choice_json("Hard Clipping", HARD_CLIPPING, distortion_type));
254  root["distortion_type"]["choices"].append(add_property_choice_json("Soft Clipping", SOFT_CLIPPING, distortion_type));
255  root["distortion_type"]["choices"].append(add_property_choice_json("Exponential", EXPONENTIAL, distortion_type));
256  root["distortion_type"]["choices"].append(add_property_choice_json("Full Wave Rectifier", FULL_WAVE_RECTIFIER, distortion_type));
257  root["distortion_type"]["choices"].append(add_property_choice_json("Half Wave Rectifier", HALF_WAVE_RECTIFIER, distortion_type));
258 
259  // Return formatted string
260  return root.toStyledString();
261 }
openshot::DistortionType distortion_type
Definition: Distortion.h:62
juce::OwnedArray< Filter > filters
Definition: Distortion.h:112
std::string Id() const
Get the Id of this clip object.
Definition: ClipBase.h:107
float Start() const
Get start position (in seconds) of clip (trim start of video)
Definition: ClipBase.h:110
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: EffectBase.cpp:127
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:34
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: EffectBase.cpp:92
std::string Json() const override
Generate JSON string of this object.
Definition: Distortion.cpp:163
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition: EffectBase.h:59
Header file for all Exception classes.
void updateFilters(int64_t frame_number)
Definition: Distortion.cpp:153
Json::Value add_property_choice_json(std::string name, int value, int selected_value) const
Generate JSON choice for a property (dropdown properties)
Definition: ClipBase.cpp:104
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Definition: Distortion.cpp:216
Keyframe output_gain
Definition: Distortion.h:64
void SetJson(const std::string value) override
Load JSON string into this object.
Definition: Distortion.cpp:199
Header file for Distortion audio effect class.
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
DistortionType
This enumeration determines the distortion type of Distortion Effect.
Definition: Enums.h:86
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: Distortion.h:81
float Duration() const
Get the length of this clip (in seconds)
Definition: ClipBase.h:112
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: KeyFrame.cpp:368
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:46
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: KeyFrame.cpp:335
std::string description
The description of this effect and what it does.
Definition: EffectBase.h:56
bool has_video
Determines if this effect manipulates the image of a frame.
Definition: EffectBase.h:58
Exception for invalid JSON.
Definition: Exceptions.h:205
double GetValue(int64_t index) const
Get the value at a specific index.
Definition: KeyFrame.cpp:268
Distortion()
Blank constructor, useful when using Json to load the effect properties.
Definition: Distortion.cpp:37
void updateCoefficients(const double discrete_frequency, const double gain)
Definition: Distortion.cpp:169
float End() const
Get end position (in seconds) of clip (trim end of video)
Definition: ClipBase.h:111
std::string PropertiesJSON(int64_t requested_frame) const override
Definition: Distortion.cpp:236
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition: Distortion.cpp:184
A Keyframe is a collection of Point instances, which is used to vary a number or property over time...
Definition: KeyFrame.h:72
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
int Layer() const
Get layer of clip on timeline (lower number is covered by higher numbers)
Definition: ClipBase.h:109
EffectInfoStruct info
Information about the current effect.
Definition: EffectBase.h:87