OpenShot Library | libopenshot  0.3.3
Distortion.cpp
Go to the documentation of this file.
1 
9 // Copyright (c) 2008-2019 OpenShot Studios, LLC
10 //
11 // SPDX-License-Identifier: LGPL-3.0-or-later
12 
13 #include "Distortion.h"
14 #include "Exceptions.h"
15 
16 using namespace openshot;
17 
19 
21  Keyframe input_gain, Keyframe output_gain,
22  Keyframe tone):
23  distortion_type(distortion_type), input_gain(input_gain),
24  output_gain(output_gain), tone(tone)
25 {
26  // Init effect properties
27  init_effect_details();
28 }
29 
30 // Init effect settings
31 void Distortion::init_effect_details()
32 {
35 
37  info.class_name = "Distortion";
38  info.name = "Distortion";
39  info.description = "Alter the audio by clipping the signal.";
40  info.has_audio = true;
41  info.has_video = false;
42 }
43 
44 
45 // This method is required for all derived classes of EffectBase, and returns a
46 // modified openshot::Frame object
47 std::shared_ptr<openshot::Frame> Distortion::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
48 {
49  filters.clear();
50 
51  for (int i = 0; i < frame->audio->getNumChannels(); ++i) {
52  Filter* filter;
53  filters.add (filter = new Filter());
54  }
55 
56  updateFilters(frame_number);
57 
58  // Add distortion
59  for (int channel = 0; channel < frame->audio->getNumChannels(); channel++)
60  {
61  auto *channel_data = frame->audio->getWritePointer(channel);
62  float out;
63 
64  for (auto sample = 0; sample < frame->audio->getNumSamples(); ++sample)
65  {
66 
67  const int input_gain_value = (int)input_gain.GetValue(frame_number);
68  const int output_gain_value = (int)output_gain.GetValue(frame_number);
69  const float in = channel_data[sample]*powf(10.0f, input_gain_value * 0.05f);
70 
71  // Use the current distortion type
72  switch (distortion_type) {
73 
74  case HARD_CLIPPING: {
75  float threshold = 0.5f;
76  if (in > threshold)
77  out = threshold;
78  else if (in < -threshold)
79  out = -threshold;
80  else
81  out = in;
82  break;
83  }
84 
85  case SOFT_CLIPPING: {
86  float threshold1 = 1.0f / 3.0f;
87  float threshold2 = 2.0f / 3.0f;
88  if (in > threshold2)
89  out = 1.0f;
90  else if (in > threshold1)
91  out = 1.0f - powf (2.0f - 3.0f * in, 2.0f) / 3.0f;
92  else if (in < -threshold2)
93  out = -1.0f;
94  else if (in < -threshold1)
95  out = -1.0f + powf (2.0f + 3.0f * in, 2.0f) / 3.0f;
96  else
97  out = 2.0f * in;
98  out *= 0.5f;
99  break;
100  }
101 
102  case EXPONENTIAL: {
103  if (in > 0.0f)
104  out = 1.0f - expf (-in);
105  else
106  out = -1.0f + expf (in);
107  break;
108  }
109 
110  case FULL_WAVE_RECTIFIER: {
111  out = fabsf (in);
112  break;
113  }
114 
115  case HALF_WAVE_RECTIFIER: {
116  if (in > 0.0f)
117  out = in;
118  else
119  out = 0.0f;
120  break;
121  }
122  }
123 
124  float filtered = filters[channel]->processSingleSampleRaw(out);
125  channel_data[sample] = filtered*powf(10.0f, output_gain_value * 0.05f);
126  }
127  }
128 
129  // return the modified frame
130  return frame;
131 }
132 
133 void Distortion::updateFilters(int64_t frame_number)
134 {
135  double discrete_frequency = M_PI * 0.01;
136  double gain = pow(10.0, (float)tone.GetValue(frame_number) * 0.05);
137 
138  for (int i = 0; i < filters.size(); ++i)
139  filters[i]->updateCoefficients(discrete_frequency, gain);
140 }
141 
142 // Generate JSON string of this object
143 std::string Distortion::Json() const {
144 
145  // Return formatted string
146  return JsonValue().toStyledString();
147 }
148 
149 void Distortion::Filter::updateCoefficients(const double discrete_frequency, const double gain)
150 {
151  double tan_half_wc = tan(discrete_frequency / 2.0);
152  double sqrt_gain = sqrt(gain);
153 
154  coefficients = juce::IIRCoefficients(/* b0 */ sqrt_gain * tan_half_wc + gain,
155  /* b1 */ sqrt_gain * tan_half_wc - gain,
156  /* b2 */ 0.0,
157  /* a0 */ sqrt_gain * tan_half_wc + 1.0,
158  /* a1 */ sqrt_gain * tan_half_wc - 1.0,
159  /* a2 */ 0.0);
160  setCoefficients(coefficients);
161 }
162 
163 // Generate Json::Value for this object
164 Json::Value Distortion::JsonValue() const {
165 
166  // Create root json object
167  Json::Value root = EffectBase::JsonValue(); // get parent properties
168  root["type"] = info.class_name;
169  root["distortion_type"] = distortion_type;
170  root["input_gain"] = input_gain.JsonValue();
171  root["output_gain"] = output_gain.JsonValue();
172  root["tone"] = tone.JsonValue();
173 
174  // return JsonValue
175  return root;
176 }
177 
178 // Load JSON string into this object
179 void Distortion::SetJson(const std::string value) {
180 
181  // Parse JSON string into JSON objects
182  try
183  {
184  const Json::Value root = openshot::stringToJson(value);
185  // Set all values that match
186  SetJsonValue(root);
187  }
188  catch (const std::exception& e)
189  {
190  // Error parsing JSON (or missing keys)
191  throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
192  }
193 }
194 
195 // Load Json::Value into this object
196 void Distortion::SetJsonValue(const Json::Value root) {
197 
198  // Set parent data
200 
201  // Set data from Json (if key is found)
202  if (!root["distortion_type"].isNull())
203  distortion_type = (DistortionType)root["distortion_type"].asInt();
204 
205  if (!root["input_gain"].isNull())
206  input_gain.SetJsonValue(root["input_gain"]);
207 
208  if (!root["output_gain"].isNull())
209  output_gain.SetJsonValue(root["output_gain"]);
210 
211  if (!root["tone"].isNull())
212  tone.SetJsonValue(root["tone"]);
213 }
214 
215 // Get all properties for a specific frame
216 std::string Distortion::PropertiesJSON(int64_t requested_frame) const {
217 
218  // Generate JSON properties list
219  Json::Value root = BasePropertiesJSON(requested_frame);
220 
221  // Keyframes
222  root["distortion_type"] = add_property_json("Distortion Type", distortion_type, "int", "", NULL, 0, 3, false, requested_frame);
223  root["input_gain"] = add_property_json("Input Gain (dB)", input_gain.GetValue(requested_frame), "int", "", &input_gain, -24, 24, false, requested_frame);
224  root["output_gain"] = add_property_json("Output Gain (dB)", output_gain.GetValue(requested_frame), "int", "", &output_gain, -24, 24, false, requested_frame);
225  root["tone"] = add_property_json("Tone (dB)", tone.GetValue(requested_frame), "int", "", &tone, -24, 24, false, requested_frame);
226 
227  // Add distortion_type choices (dropdown style)
228  root["distortion_type"]["choices"].append(add_property_choice_json("Hard Clipping", HARD_CLIPPING, distortion_type));
229  root["distortion_type"]["choices"].append(add_property_choice_json("Soft Clipping", SOFT_CLIPPING, distortion_type));
230  root["distortion_type"]["choices"].append(add_property_choice_json("Exponential", EXPONENTIAL, distortion_type));
231  root["distortion_type"]["choices"].append(add_property_choice_json("Full Wave Rectifier", FULL_WAVE_RECTIFIER, distortion_type));
232  root["distortion_type"]["choices"].append(add_property_choice_json("Half Wave Rectifier", HALF_WAVE_RECTIFIER, distortion_type));
233 
234  // Return formatted string
235  return root.toStyledString();
236 }
openshot::ClipBase::add_property_json
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
openshot::stringToJson
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:16
openshot::Distortion::SetJsonValue
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Definition: Distortion.cpp:196
openshot::EffectBase::info
EffectInfoStruct info
Information about the current effect.
Definition: EffectBase.h:69
openshot::Distortion::output_gain
Keyframe output_gain
Definition: Distortion.h:46
openshot::Distortion::updateFilters
void updateFilters(int64_t frame_number)
Definition: Distortion.cpp:133
Distortion.h
Header file for Distortion audio effect class.
openshot::Distortion::Filter
Definition: Distortion.h:70
openshot
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:28
openshot::Distortion::GetFrame
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:56
openshot::Distortion::SetJson
void SetJson(const std::string value) override
Load JSON string into this object.
Definition: Distortion.cpp:179
openshot::ClipBase::add_property_choice_json
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:132
openshot::EffectBase::JsonValue
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: EffectBase.cpp:79
openshot::Distortion::Distortion
Distortion()
Default constructor.
Definition: Distortion.cpp:18
openshot::Distortion
This class adds a distortion into the audio.
Definition: Distortion.h:37
openshot::Keyframe::SetJsonValue
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: KeyFrame.cpp:372
openshot::Distortion::JsonValue
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition: Distortion.cpp:164
openshot::Distortion::input_gain
Keyframe input_gain
Definition: Distortion.h:45
openshot::Distortion::PropertiesJSON
std::string PropertiesJSON(int64_t requested_frame) const override
Definition: Distortion.cpp:216
openshot::Keyframe::JsonValue
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: KeyFrame.cpp:339
openshot::EffectBase::BasePropertiesJSON
Json::Value BasePropertiesJSON(int64_t requested_frame) const
Generate JSON object of base properties (recommended to be used by all effects)
Definition: EffectBase.cpp:179
openshot::Distortion::distortion_type
openshot::DistortionType distortion_type
Definition: Distortion.h:44
openshot::Keyframe
A Keyframe is a collection of Point instances, which is used to vary a number or property over time.
Definition: KeyFrame.h:53
openshot::Distortion::filters
juce::OwnedArray< Filter > filters
Definition: Distortion.h:76
openshot::InvalidJSON
Exception for invalid JSON.
Definition: Exceptions.h:217
openshot::FULL_WAVE_RECTIFIER
@ FULL_WAVE_RECTIFIER
Definition: Enums.h:74
openshot::EffectBase::InitEffectInfo
void InitEffectInfo()
Definition: EffectBase.cpp:24
openshot::EffectInfoStruct::has_audio
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition: EffectBase.h:41
openshot::EffectInfoStruct::class_name
std::string class_name
The class name of the effect.
Definition: EffectBase.h:36
openshot::EffectInfoStruct::description
std::string description
The description of this effect and what it does.
Definition: EffectBase.h:38
openshot::EffectInfoStruct::has_video
bool has_video
Determines if this effect manipulates the image of a frame.
Definition: EffectBase.h:40
openshot::Distortion::tone
Keyframe tone
Definition: Distortion.h:47
openshot::SOFT_CLIPPING
@ SOFT_CLIPPING
Definition: Enums.h:72
openshot::EffectInfoStruct::name
std::string name
The name of the effect.
Definition: EffectBase.h:37
openshot::HALF_WAVE_RECTIFIER
@ HALF_WAVE_RECTIFIER
Definition: Enums.h:75
openshot::EXPONENTIAL
@ EXPONENTIAL
Definition: Enums.h:73
openshot::Distortion::Json
std::string Json() const override
Generate JSON string of this object.
Definition: Distortion.cpp:143
openshot::Distortion::Filter::updateCoefficients
void updateCoefficients(const double discrete_frequency, const double gain)
Definition: Distortion.cpp:149
openshot::DistortionType
DistortionType
This enumeration determines the distortion type of Distortion Effect.
Definition: Enums.h:69
Exceptions.h
Header file for all Exception classes.
openshot::HARD_CLIPPING
@ HARD_CLIPPING
Definition: Enums.h:71
openshot::EffectBase::SetJsonValue
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: EffectBase.cpp:115
openshot::Keyframe::GetValue
double GetValue(int64_t index) const
Get the value at a specific index.
Definition: KeyFrame.cpp:258