OpenShot Library | libopenshot 0.3.1
Echo.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 "Echo.h"
14#include "Exceptions.h"
15#include "Frame.h"
16
17using namespace openshot;
18
19Echo::Echo() : Echo::Echo(0.1, 0.5, 0.5) { }
20
21Echo::Echo(Keyframe echo_time, Keyframe feedback, Keyframe mix) :
22 echo_time(echo_time), feedback(feedback), mix(mix)
23{
24 // Init effect properties
25 init_effect_details();
26}
27
28// Init effect settings
29void Echo::init_effect_details()
30{
33
35 info.class_name = "Echo";
36 info.name = "Echo";
37 info.description = "Reflection of sound with a delay after the direct sound.";
38 info.has_audio = true;
39 info.has_video = false;
40 initialized = false;
41}
42
43void Echo::setup(std::shared_ptr<openshot::Frame> frame)
44{
45 if (!initialized)
46 {
47 const float max_echo_time = 5;
48 echo_buffer_samples = (int)(max_echo_time * (float)frame->SampleRate()) + 1;
49
50 if (echo_buffer_samples < 1)
52
53 echo_buffer_channels = frame->audio->getNumChannels();
55 echo_buffer.clear();
57 initialized = true;
58 }
59}
60
61// This method is required for all derived classes of EffectBase, and returns a
62// modified openshot::Frame object
63std::shared_ptr<openshot::Frame> Echo::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
64{
65 const float echo_time_value = (float)echo_time.GetValue(frame_number)*(float)frame->SampleRate();
66 const float feedback_value = feedback.GetValue(frame_number);
67 const float mix_value = mix.GetValue(frame_number);
68 int local_write_position;
69
70 setup(frame);
71
72 for (int channel = 0; channel < frame->audio->getNumChannels(); channel++)
73 {
74 float *channel_data = frame->audio->getWritePointer(channel);
75 float *echo_data = echo_buffer.getWritePointer(channel);
76 local_write_position = echo_write_position;
77
78 for (auto sample = 0; sample < frame->audio->getNumSamples(); ++sample)
79 {
80 const float in = (float)(channel_data[sample]);
81 float out = 0.0f;
82
83 float read_position = fmodf((float)local_write_position - echo_time_value + (float)echo_buffer_samples, echo_buffer_samples);
84 int local_read_position = floorf(read_position);
85
86 if (local_read_position != local_write_position)
87 {
88 float fraction = read_position - (float)local_read_position;
89 float echoed1 = echo_data[(local_read_position + 0)];
90 float echoed2 = echo_data[(local_read_position + 1) % echo_buffer_samples];
91 out = (float)(echoed1 + fraction * (echoed2 - echoed1));
92 channel_data[sample] = in + mix_value*(out - in);
93 echo_data[local_write_position] = in + out*feedback_value;
94 }
95
96 if (++local_write_position >= echo_buffer_samples)
97 local_write_position -= echo_buffer_samples;
98 }
99 }
100
101 echo_write_position = local_write_position;
102
103 // return the modified frame
104 return frame;
105}
106
107// Generate JSON string of this object
108std::string Echo::Json() const {
109
110 // Return formatted string
111 return JsonValue().toStyledString();
112}
113
114// Generate Json::Value for this object
115Json::Value Echo::JsonValue() const {
116
117 // Create root json object
118 Json::Value root = EffectBase::JsonValue(); // get parent properties
119 root["type"] = info.class_name;
120 root["echo_time"] = echo_time.JsonValue();
121 root["feedback"] = feedback.JsonValue();
122 root["mix"] = mix.JsonValue();
123
124 // return JsonValue
125 return root;
126}
127
128// Load JSON string into this object
129void Echo::SetJson(const std::string value) {
130
131 // Parse JSON string into JSON objects
132 try
133 {
134 const Json::Value root = openshot::stringToJson(value);
135 // Set all values that match
136 SetJsonValue(root);
137 }
138 catch (const std::exception& e)
139 {
140 // Error parsing JSON (or missing keys)
141 throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
142 }
143}
144
145// Load Json::Value into this object
146void Echo::SetJsonValue(const Json::Value root) {
147
148 // Set parent data
150
151 // Set data from Json (if key is found)
152 if (!root["echo_time"].isNull())
153 echo_time.SetJsonValue(root["echo_time"]);
154 if (!root["feedback"].isNull())
155 feedback.SetJsonValue(root["feedback"]);
156 if (!root["mix"].isNull())
157 mix.SetJsonValue(root["mix"]);
158}
159
160// Get all properties for a specific frame
161std::string Echo::PropertiesJSON(int64_t requested_frame) const {
162
163 // Generate JSON properties list
164 Json::Value root;
165 root["id"] = add_property_json("ID", 0.0, "string", Id(), NULL, -1, -1, true, requested_frame);
166 root["layer"] = add_property_json("Track", Layer(), "int", "", NULL, 0, 20, false, requested_frame);
167 root["start"] = add_property_json("Start", Start(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
168 root["end"] = add_property_json("End", End(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
169 root["duration"] = add_property_json("Duration", Duration(), "float", "", NULL, 0, 1000 * 60 * 30, true, requested_frame);
170
171 // Keyframes
172 root["echo_time"] = add_property_json("Time", echo_time.GetValue(requested_frame), "float", "", &echo_time, 0, 5, false, requested_frame);
173 root["feedback"] = add_property_json("Feedback", feedback.GetValue(requested_frame), "float", "", &feedback, 0, 1, false, requested_frame);
174 root["mix"] = add_property_json("Mix", mix.GetValue(requested_frame), "float", "", &mix, 0, 1, false, requested_frame);
175
176 // Return formatted string
177 return root.toStyledString();
178}
Header file for Echo audio effect class.
Header file for all Exception classes.
Header file for Frame class.
float Start() const
Get start position (in seconds) of clip (trim start of video)
Definition: ClipBase.h:88
float Duration() const
Get the length of this clip (in seconds)
Definition: ClipBase.h:90
virtual float End() const
Get end position (in seconds) of clip (trim end of video)
Definition: ClipBase.h:89
std::string Id() const
Get the Id of this clip object.
Definition: ClipBase.h:85
int Layer() const
Get layer of clip on timeline (lower number is covered by higher numbers)
Definition: ClipBase.h:87
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
This class adds a echo into the audio.
Definition: Echo.h:36
Keyframe mix
Definition: Echo.h:44
void SetJson(const std::string value) override
Load JSON string into this object.
Definition: Echo.cpp:129
int echo_buffer_channels
Definition: Echo.h:48
Keyframe echo_time
Definition: Echo.h:42
std::string Json() const override
Generate JSON string of this object.
Definition: Echo.cpp:108
int echo_write_position
Definition: Echo.h:49
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Definition: Echo.cpp:146
juce::AudioBuffer< float > echo_buffer
Definition: Echo.h:46
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: Echo.h:58
bool initialized
Definition: Echo.h:50
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition: Echo.cpp:115
Echo()
Default constructor.
Definition: Echo.cpp:19
int echo_buffer_samples
Definition: Echo.h:47
std::string PropertiesJSON(int64_t requested_frame) const override
Definition: Echo.cpp:161
void setup(std::shared_ptr< openshot::Frame > frame)
Definition: Echo.cpp:43
Keyframe feedback
Definition: Echo.h:43
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: EffectBase.cpp:77
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: EffectBase.cpp:112
EffectInfoStruct info
Information about the current effect.
Definition: EffectBase.h:69
Exception for invalid JSON.
Definition: Exceptions.h:218
A Keyframe is a collection of Point instances, which is used to vary a number or property over time.
Definition: KeyFrame.h:53
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: KeyFrame.cpp:372
double GetValue(int64_t index) const
Get the value at a specific index.
Definition: KeyFrame.cpp:258
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: KeyFrame.cpp:339
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:29
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:16
bool has_video
Determines if this effect manipulates the image of a frame.
Definition: EffectBase.h:40
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition: EffectBase.h:41
std::string class_name
The class name of the effect.
Definition: EffectBase.h:36
std::string name
The name of the effect.
Definition: EffectBase.h:37
std::string description
The description of this effect and what it does.
Definition: EffectBase.h:38