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Distortion.cpp
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// Copyright (c) 2008-2019 OpenShot Studios, LLC
//
// SPDX-License-Identifier: LGPL-3.0-or-later
#include "Distortion.h"
#include "Exceptions.h"
using namespace openshot;
Distortion::Distortion(): Distortion::Distortion(HARD_CLIPPING, 10, -10, 5) { }
Distortion::Distortion(openshot::DistortionType distortion_type,
Keyframe input_gain, Keyframe output_gain,
Keyframe tone):
distortion_type(distortion_type), input_gain(input_gain),
output_gain(output_gain), tone(tone)
{
// Init effect properties
init_effect_details();
}
// Init effect settings
void Distortion::init_effect_details()
{
InitEffectInfo();
info.class_name = "Distortion";
info.name = "Distortion";
info.description = "Alter the audio by clipping the signal.";
info.has_audio = true;
info.has_video = false;
}
// This method is required for all derived classes of EffectBase, and returns a
// modified openshot::Frame object
std::shared_ptr<openshot::Frame> Distortion::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
{
filters.clear();
for (int i = 0; i < frame->audio->getNumChannels(); ++i) {
Filter* filter;
filters.add (filter = new Filter());
}
updateFilters(frame_number);
// Add distortion
for (int channel = 0; channel < frame->audio->getNumChannels(); channel++)
{
auto *channel_data = frame->audio->getWritePointer(channel);
float out;
for (auto sample = 0; sample < frame->audio->getNumSamples(); ++sample)
{
const int input_gain_value = (int)input_gain.GetValue(frame_number);
const int output_gain_value = (int)output_gain.GetValue(frame_number);
const float in = channel_data[sample]*powf(10.0f, input_gain_value * 0.05f);
// Use the current distortion type
switch (distortion_type) {
case HARD_CLIPPING: {
float threshold = 0.5f;
if (in > threshold)
out = threshold;
else if (in < -threshold)
out = -threshold;
else
out = in;
break;
}
case SOFT_CLIPPING: {
float threshold1 = 1.0f / 3.0f;
float threshold2 = 2.0f / 3.0f;
if (in > threshold2)
out = 1.0f;
else if (in > threshold1)
out = 1.0f - powf (2.0f - 3.0f * in, 2.0f) / 3.0f;
else if (in < -threshold2)
out = -1.0f;
else if (in < -threshold1)
out = -1.0f + powf (2.0f + 3.0f * in, 2.0f) / 3.0f;
else
out = 2.0f * in;
out *= 0.5f;
break;
}
case EXPONENTIAL: {
if (in > 0.0f)
out = 1.0f - expf (-in);
else
out = -1.0f + expf (in);
break;
}
case FULL_WAVE_RECTIFIER: {
out = fabsf (in);
break;
}
case HALF_WAVE_RECTIFIER: {
if (in > 0.0f)
out = in;
else
out = 0.0f;
break;
}
}
float filtered = filters[channel]->processSingleSampleRaw(out);
channel_data[sample] = filtered*powf(10.0f, output_gain_value * 0.05f);
}
}
// return the modified frame
return frame;
}
void Distortion::updateFilters(int64_t frame_number)
{
double discrete_frequency = M_PI * 0.01;
double gain = pow(10.0, (float)tone.GetValue(frame_number) * 0.05);
for (int i = 0; i < filters.size(); ++i)
filters[i]->updateCoefficients(discrete_frequency, gain);
}
// Generate JSON string of this object
std::string Distortion::Json() const {
// Return formatted string
return JsonValue().toStyledString();
}
void Distortion::Filter::updateCoefficients(const double discrete_frequency, const double gain)
{
double tan_half_wc = tan(discrete_frequency / 2.0);
double sqrt_gain = sqrt(gain);
coefficients = juce::IIRCoefficients(/* b0 */ sqrt_gain * tan_half_wc + gain,
/* b1 */ sqrt_gain * tan_half_wc - gain,
/* b2 */ 0.0,
/* a0 */ sqrt_gain * tan_half_wc + 1.0,
/* a1 */ sqrt_gain * tan_half_wc - 1.0,
/* a2 */ 0.0);
setCoefficients(coefficients);
}
// Generate Json::Value for this object
Json::Value Distortion::JsonValue() const {
// Create root json object
Json::Value root = EffectBase::JsonValue(); // get parent properties
root["type"] = info.class_name;
root["distortion_type"] = distortion_type;
root["input_gain"] = input_gain.JsonValue();
root["output_gain"] = output_gain.JsonValue();
root["tone"] = tone.JsonValue();
// return JsonValue
return root;
}
// Load JSON string into this object
void Distortion::SetJson(const std::string value) {
// Parse JSON string into JSON objects
try
{
const Json::Value root = openshot::stringToJson(value);
// Set all values that match
SetJsonValue(root);
}
catch (const std::exception& e)
{
// Error parsing JSON (or missing keys)
throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
}
}
// Load Json::Value into this object
void Distortion::SetJsonValue(const Json::Value root) {
// Set parent data
EffectBase::SetJsonValue(root);
// Set data from Json (if key is found)
if (!root["distortion_type"].isNull())
distortion_type = (DistortionType)root["distortion_type"].asInt();
if (!root["input_gain"].isNull())
input_gain.SetJsonValue(root["input_gain"]);
if (!root["output_gain"].isNull())
output_gain.SetJsonValue(root["output_gain"]);
if (!root["tone"].isNull())
tone.SetJsonValue(root["tone"]);
}
// Get all properties for a specific frame
std::string Distortion::PropertiesJSON(int64_t requested_frame) const {
// Generate JSON properties list
Json::Value root = BasePropertiesJSON(requested_frame);
// Keyframes
root["distortion_type"] = add_property_json("Distortion Type", distortion_type, "int", "", NULL, 0, 3, false, requested_frame);
root["input_gain"] = add_property_json("Input Gain (dB)", input_gain.GetValue(requested_frame), "int", "", &input_gain, -24, 24, false, requested_frame);
root["output_gain"] = add_property_json("Output Gain (dB)", output_gain.GetValue(requested_frame), "int", "", &output_gain, -24, 24, false, requested_frame);
root["tone"] = add_property_json("Tone (dB)", tone.GetValue(requested_frame), "int", "", &tone, -24, 24, false, requested_frame);
// Add distortion_type choices (dropdown style)
root["distortion_type"]["choices"].append(add_property_choice_json("Hard Clipping", HARD_CLIPPING, distortion_type));
root["distortion_type"]["choices"].append(add_property_choice_json("Soft Clipping", SOFT_CLIPPING, distortion_type));
root["distortion_type"]["choices"].append(add_property_choice_json("Exponential", EXPONENTIAL, distortion_type));
root["distortion_type"]["choices"].append(add_property_choice_json("Full Wave Rectifier", FULL_WAVE_RECTIFIER, distortion_type));
root["distortion_type"]["choices"].append(add_property_choice_json("Half Wave Rectifier", HALF_WAVE_RECTIFIER, distortion_type));
// Return formatted string
return root.toStyledString();
}
Distortion.h
Header file for Distortion audio effect class.
Exceptions.h
Header file for all Exception classes.
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::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::Distortion::Filter
Definition Distortion.h:71
openshot::Distortion::Filter::updateCoefficients
void updateCoefficients(const double discrete_frequency, const double gain)
Definition Distortion.cpp:149
openshot::Distortion
This class adds a distortion into the audio.
Definition Distortion.h:38
openshot::Distortion::distortion_type
openshot::DistortionType distortion_type
Definition Distortion.h:44
openshot::Distortion::PropertiesJSON
std::string PropertiesJSON(int64_t requested_frame) const override
Definition Distortion.cpp:216
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::filters
juce::OwnedArray< Filter > filters
Definition Distortion.h:76
openshot::Distortion::input_gain
Keyframe input_gain
Definition Distortion.h:45
openshot::Distortion::output_gain
Keyframe output_gain
Definition Distortion.h:46
openshot::Distortion::updateFilters
void updateFilters(int64_t frame_number)
Definition Distortion.cpp:133
openshot::Distortion::tone
Keyframe tone
Definition Distortion.h:47
openshot::Distortion::JsonValue
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition Distortion.cpp:164
openshot::Distortion::SetJson
void SetJson(const std::string value) override
Load JSON string into this object.
Definition Distortion.cpp:179
openshot::Distortion::SetJsonValue
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Definition Distortion.cpp:196
openshot::Distortion::Distortion
Distortion()
Default constructor.
Definition Distortion.cpp:18
openshot::Distortion::Json
std::string Json() const override
Generate JSON string of this object.
Definition Distortion.cpp:143
openshot::EffectBase::JsonValue
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
Definition EffectBase.cpp:79
openshot::EffectBase::InitEffectInfo
void InitEffectInfo()
Definition EffectBase.cpp:24
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::EffectBase::SetJsonValue
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition EffectBase.cpp:115
openshot::EffectBase::info
EffectInfoStruct info
Information about the current effect.
Definition EffectBase.h:69
openshot::InvalidJSON
Exception for invalid JSON.
Definition Exceptions.h:218
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::Keyframe::SetJsonValue
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition KeyFrame.cpp:372
openshot::Keyframe::GetValue
double GetValue(int64_t index) const
Get the value at a specific index.
Definition KeyFrame.cpp:258
openshot::Keyframe::JsonValue
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition KeyFrame.cpp:339
openshot
This namespace is the default namespace for all code in the openshot library.
Definition Compressor.h:29
openshot::DistortionType
DistortionType
This enumeration determines the distortion type of Distortion Effect.
Definition Enums.h:70
openshot::HALF_WAVE_RECTIFIER
@ HALF_WAVE_RECTIFIER
Definition Enums.h:75
openshot::FULL_WAVE_RECTIFIER
@ FULL_WAVE_RECTIFIER
Definition Enums.h:74
openshot::EXPONENTIAL
@ EXPONENTIAL
Definition Enums.h:73
openshot::SOFT_CLIPPING
@ SOFT_CLIPPING
Definition Enums.h:72
openshot::HARD_CLIPPING
@ HARD_CLIPPING
Definition Enums.h:71
openshot::stringToJson
const Json::Value stringToJson(const std::string value)
Definition Json.cpp:16
openshot::EffectInfoStruct::has_video
bool has_video
Determines if this effect manipulates the image of a frame.
Definition EffectBase.h:40
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::name
std::string name
The name of the effect.
Definition EffectBase.h:37
openshot::EffectInfoStruct::description
std::string description
The description of this effect and what it does.
Definition EffectBase.h:38