OpenShot Library | libopenshot  0.2.7
ParametricEQ.cpp
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1 /**
2  * @file
3  * @brief Source file for ParametricEQ 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 "ParametricEQ.h"
32 #include "Exceptions.h"
33 
34 using namespace openshot;
35 
36 /// Blank constructor, useful when using Json to load the effect properties
37 ParametricEQ::ParametricEQ() : filter_type(LOW_PASS), frequency(500), gain(0), q_factor(0) {
38  // Init effect properties
39  init_effect_details();
40 }
41 
42 
43 // Default constructor
44 ParametricEQ::ParametricEQ(openshot::FilterType new_filter_type, Keyframe new_frequency, Keyframe new_gain, Keyframe new_q_factor) :
45  filter_type(new_filter_type), frequency(new_frequency), gain(new_gain), q_factor(new_q_factor)
46 {
47  // Init effect properties
48  init_effect_details();
49 }
50 
51 // Init effect settings
52 void ParametricEQ::init_effect_details()
53 {
54  /// Initialize the values of the EffectInfo struct.
56 
57  /// Set the effect info
58  info.class_name = "ParametricEQ";
59  info.name = "Parametric EQ";
60  info.description = "Filter that allows you to adjust the volume level of a frequency in the audio track.";
61  info.has_audio = true;
62  info.has_video = false;
63  initialized = false;
64 }
65 
66 // This method is required for all derived classes of EffectBase, and returns a
67 // modified openshot::Frame object
68 std::shared_ptr<openshot::Frame> ParametricEQ::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
69 {
70  if (!initialized)
71  {
72  filters.clear();
73 
74  for (int i = 0; i < frame->audio->getNumChannels(); ++i) {
75  Filter *filter;
76  filters.add(filter = new Filter());
77  }
78 
79  initialized = true;
80  }
81 
82  const int num_input_channels = frame->audio->getNumChannels();
83  const int num_output_channels = frame->audio->getNumChannels();
84  const int num_samples = frame->audio->getNumSamples();
85  updateFilters(frame_number, num_samples);
86 
87  for (int channel = 0; channel < frame->audio->getNumChannels(); channel++)
88  {
89  auto *channel_data = frame->audio->getWritePointer(channel);
90  filters[channel]->processSamples(channel_data, num_samples);
91  }
92 
93  for (int channel = num_input_channels; channel < num_output_channels; ++channel)
94  {
95  frame->audio->clear(channel, 0, num_samples);
96  }
97 
98  // return the modified frame
99  return frame;
100 }
101 
103  const double discrete_frequency,
104  const double q_factor,
105  const double gain,
106  const int filter_type)
107 {
108  double bandwidth = jmin (discrete_frequency / q_factor, M_PI * 0.99);
109  double two_cos_wc = -2.0 * cos (discrete_frequency);
110  double tan_half_bw = tan (bandwidth / 2.0);
111  double tan_half_wc = tan (discrete_frequency / 2.0);
112  double sqrt_gain = sqrt (gain);
113 
114  switch (filter_type) {
115  case 0 /* LOW_PASS */: {
116  coefficients = IIRCoefficients (/* b0 */ tan_half_wc,
117  /* b1 */ tan_half_wc,
118  /* b2 */ 0.0,
119  /* a0 */ tan_half_wc + 1.0,
120  /* a1 */ tan_half_wc - 1.0,
121  /* a2 */ 0.0);
122  break;
123  }
124  case 1 /* HIGH_PASS */: {
125  coefficients = IIRCoefficients (/* b0 */ 1.0,
126  /* b1 */ -1.0,
127  /* b2 */ 0.0,
128  /* a0 */ tan_half_wc + 1.0,
129  /* a1 */ tan_half_wc - 1.0,
130  /* a2 */ 0.0);
131  break;
132  }
133  case 2 /* LOW_SHELF */: {
134  coefficients = IIRCoefficients (/* b0 */ gain * tan_half_wc + sqrt_gain,
135  /* b1 */ gain * tan_half_wc - sqrt_gain,
136  /* b2 */ 0.0,
137  /* a0 */ tan_half_wc + sqrt_gain,
138  /* a1 */ tan_half_wc - sqrt_gain,
139  /* a2 */ 0.0);
140  break;
141  }
142  case 3 /* HIGH_SHELF */: {
143  coefficients = IIRCoefficients (/* b0 */ sqrt_gain * tan_half_wc + gain,
144  /* b1 */ sqrt_gain * tan_half_wc - gain,
145  /* b2 */ 0.0,
146  /* a0 */ sqrt_gain * tan_half_wc + 1.0,
147  /* a1 */ sqrt_gain * tan_half_wc - 1.0,
148  /* a2 */ 0.0);
149  break;
150  }
151  case 4 /* BAND_PASS */: {
152  coefficients = IIRCoefficients (/* b0 */ tan_half_bw,
153  /* b1 */ 0.0,
154  /* b2 */ -tan_half_bw,
155  /* a0 */ 1.0 + tan_half_bw,
156  /* a1 */ two_cos_wc,
157  /* a2 */ 1.0 - tan_half_bw);
158  break;
159  }
160  case 5 /* BAND_STOP */: {
161  coefficients = IIRCoefficients (/* b0 */ 1.0,
162  /* b1 */ two_cos_wc,
163  /* b2 */ 1.0,
164  /* a0 */ 1.0 + tan_half_bw,
165  /* a1 */ two_cos_wc,
166  /* a2 */ 1.0 - tan_half_bw);
167  break;
168  }
169  case 6 /* PEAKING_NOTCH */: {
170  coefficients = IIRCoefficients (/* b0 */ sqrt_gain + gain * tan_half_bw,
171  /* b1 */ sqrt_gain * two_cos_wc,
172  /* b2 */ sqrt_gain - gain * tan_half_bw,
173  /* a0 */ sqrt_gain + tan_half_bw,
174  /* a1 */ sqrt_gain * two_cos_wc,
175  /* a2 */ sqrt_gain - tan_half_bw);
176  break;
177  }
178  }
179 
180  setCoefficients(coefficients);
181 }
182 
183 void ParametricEQ::updateFilters(int64_t frame_number, double sample_rate)
184 {
185  double discrete_frequency = 2.0 * M_PI * (double)frequency.GetValue(frame_number) / sample_rate;
186  double q_value = (double)q_factor.GetValue(frame_number);
187  double gain_value = pow(10.0, (double)gain.GetValue(frame_number) * 0.05);
188  int filter_type_value = (int)filter_type;
189 
190  for (int i = 0; i < filters.size(); ++i)
191  filters[i]->updateCoefficients(discrete_frequency, q_value, gain_value, filter_type_value);
192 }
193 
194 // Generate JSON string of this object
195 std::string ParametricEQ::Json() const {
196 
197  // Return formatted string
198  return JsonValue().toStyledString();
199 }
200 
201 // Generate Json::Value for this object
202 Json::Value ParametricEQ::JsonValue() const {
203 
204  // Create root json object
205  Json::Value root = EffectBase::JsonValue(); // get parent properties
206  root["type"] = info.class_name;
207  root["filter_type"] = filter_type;
208  root["frequency"] = frequency.JsonValue();;
209  root["q_factor"] = q_factor.JsonValue();
210  root["gain"] = gain.JsonValue();
211 
212  // return JsonValue
213  return root;
214 }
215 
216 // Load JSON string into this object
217 void ParametricEQ::SetJson(const std::string value) {
218 
219  // Parse JSON string into JSON objects
220  try
221  {
222  const Json::Value root = openshot::stringToJson(value);
223  // Set all values that match
224  SetJsonValue(root);
225  }
226  catch (const std::exception& e)
227  {
228  // Error parsing JSON (or missing keys)
229  throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
230  }
231 }
232 
233 // Load Json::Value into this object
234 void ParametricEQ::SetJsonValue(const Json::Value root) {
235 
236  // Set parent data
238 
239  // Set data from Json (if key is found)
240  if (!root["filter_type"].isNull())
241  filter_type = (FilterType)root["filter_type"].asInt();
242 
243  if (!root["frequency"].isNull())
244  frequency.SetJsonValue(root["frequency"]);
245 
246  if (!root["gain"].isNull())
247  gain.SetJsonValue(root["gain"]);
248 
249  if (!root["q_factor"].isNull())
250  q_factor.SetJsonValue(root["q_factor"]);
251 }
252 
253 // Get all properties for a specific frame
254 std::string ParametricEQ::PropertiesJSON(int64_t requested_frame) const {
255 
256  // Generate JSON properties list
257  Json::Value root;
258  root["id"] = add_property_json("ID", 0.0, "string", Id(), NULL, -1, -1, true, requested_frame);
259  root["layer"] = add_property_json("Track", Layer(), "int", "", NULL, 0, 20, false, requested_frame);
260  root["start"] = add_property_json("Start", Start(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
261  root["end"] = add_property_json("End", End(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
262  root["duration"] = add_property_json("Duration", Duration(), "float", "", NULL, 0, 1000 * 60 * 30, true, requested_frame);
263 
264  // Keyframes
265  root["filter_type"] = add_property_json("Filter Type", filter_type, "int", "", NULL, 0, 3, false, requested_frame);
266  root["frequency"] = add_property_json("Frequency (Hz)", frequency.GetValue(requested_frame), "int", "", &frequency, 20, 20000, false, requested_frame);
267  root["gain"] = add_property_json("Gain (dB)", gain.GetValue(requested_frame), "int", "", &gain, -24, 24, false, requested_frame);
268  root["q_factor"] = add_property_json("Q Factor", q_factor.GetValue(requested_frame), "float", "", &q_factor, 0, 20, false, requested_frame);
269 
270  // Add filter_type choices (dropdown style)
271  root["filter_type"]["choices"].append(add_property_choice_json("Low Pass", LOW_PASS, filter_type));
272  root["filter_type"]["choices"].append(add_property_choice_json("High Pass", HIGH_PASS, filter_type));
273  root["filter_type"]["choices"].append(add_property_choice_json("Low Shelf", LOW_SHELF, filter_type));
274  root["filter_type"]["choices"].append(add_property_choice_json("High Shelf", HIGH_SHELF, filter_type));
275  root["filter_type"]["choices"].append(add_property_choice_json("Band Pass", BAND_PASS, filter_type));
276  root["filter_type"]["choices"].append(add_property_choice_json("Band Stop", BAND_STOP, filter_type));
277  root["filter_type"]["choices"].append(add_property_choice_json("Peaking Notch", PEAKING_NOTCH, filter_type));
278 
279  // Return formatted string
280  return root.toStyledString();
281 }
Header file for all Exception classes.
Header file for Parametric EQ audio effect class.
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
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
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
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
void updateCoefficients(const double discrete_frequency, const double q_factor, const double gain, const int filter_type)
std::string PropertiesJSON(int64_t requested_frame) const override
void SetJson(const std::string value) override
Load JSON string into this object.
ParametricEQ()
Blank constructor, useful when using Json to load the effect properties.
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: ParametricEQ.h:82
std::string Json() const override
Generate JSON string of this object.
void updateFilters(int64_t frame_number, double sample_rate)
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Json::Value JsonValue() const override
Generate Json::Value for this object.
openshot::FilterType filter_type
Definition: ParametricEQ.h:62
juce::OwnedArray< Filter > filters
Definition: ParametricEQ.h:116
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:47
FilterType
This enumeration determines the filter type of ParametricEQ Effect.
Definition: Enums.h:97
@ LOW_SHELF
Definition: Enums.h:100
@ HIGH_SHELF
Definition: Enums.h:101
@ BAND_PASS
Definition: Enums.h:102
@ BAND_STOP
Definition: Enums.h:103
@ LOW_PASS
Definition: Enums.h:98
@ HIGH_PASS
Definition: Enums.h:99
@ PEAKING_NOTCH
Definition: Enums.h:104
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