OpenShot Library | libopenshot 0.2.7
DummyReader.h
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1/**
2 * @file
3 * @brief Header file for DummyReader class
4 * @author Jonathan Thomas <jonathan@openshot.org>
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#ifndef OPENSHOT_DUMMY_READER_H
32#define OPENSHOT_DUMMY_READER_H
33
34#include "ReaderBase.h"
35
36#include <cmath>
37#include <ctime>
38#include <iostream>
39#include <omp.h>
40#include <stdio.h>
41#include <memory>
42#include "CacheMemory.h"
43#include "Fraction.h"
44
45namespace openshot
46{
47 /**
48 * @brief This class is used as a simple, dummy reader, which can be very useful when writing
49 * unit tests. It can return a single blank frame or it can return custom frame objects
50 * which were passed into the constructor with a Cache object.
51 *
52 * A dummy reader can be created with any framerate or samplerate. This is useful in unit
53 * tests that need to test different framerates or samplerates.
54 *
55 * @note Timeline does buffering by requesting more frames than it
56 * strictly needs. Thus if you use this DummyReader with a custom
57 * cache in a Timeline, make sure it has enough
58 * frames. Specifically you need some frames after the last frame
59 * you plan to access through the Timeline.
60 *
61 * @code
62 * // Create cache object to store fake Frame objects
63 * CacheMemory cache;
64 *
65 * // Now let's create some test frames
66 * for (int64_t frame_number = 1; frame_number <= 30; frame_number++)
67 * {
68 * // Create blank frame (with specific frame #, samples, and channels)
69 * // Sample count should be 44100 / 30 fps = 1470 samples per frame
70 * int sample_count = 1470;
71 * auto f = std::make_shared<openshot::Frame>(frame_number, sample_count, 2);
72 *
73 * // Create test samples with incrementing value
74 * float *audio_buffer = new float[sample_count];
75 * for (int64_t sample_number = 0; sample_number < sample_count; sample_number++)
76 * {
77 * // Generate an incrementing audio sample value (just as an example)
78 * audio_buffer[sample_number] = float(frame_number) + (float(sample_number) / float(sample_count));
79 * }
80 *
81 * // Add custom audio samples to Frame (bool replaceSamples, int destChannel, int destStartSample, const float* source,
82 * // int numSamples, float gainToApplyToSource = 1.0f)
83 * f->AddAudio(true, 0, 0, audio_buffer, sample_count, 1.0); // add channel 1
84 * f->AddAudio(true, 1, 0, audio_buffer, sample_count, 1.0); // add channel 2
85 *
86 * // Add test frame to cache
87 * cache.Add(f);
88 * }
89 *
90 * // Create a reader (Fraction fps, int width, int height, int sample_rate, int channels, float duration, CacheBase* cache)
91 * openshot::DummyReader r(openshot::Fraction(30, 1), 1920, 1080, 44100, 2, 30.0, &cache);
92 * r.Open(); // Open the reader
93 *
94 * // Now let's verify our DummyReader works
95 * std::shared_ptr<openshot::Frame> f = r.GetFrame(1);
96 * // r.GetFrame(1)->GetAudioSamples(0)[1] should equal 1.00068033 based on our above calculations
97 *
98 * // Clean up
99 * r.Close();
100 * cache.Clear()
101 * @endcode
102 */
103 class DummyReader : public ReaderBase
104 {
105 private:
106 CacheBase* dummy_cache;
107 std::shared_ptr<openshot::Frame> image_frame;
108 bool is_open;
109
110 /// Initialize variables used by constructor
111 void init(Fraction fps, int width, int height, int sample_rate, int channels, float duration);
112
113 public:
114
115 /// Blank constructor for DummyReader, with default settings.
116 DummyReader();
117
118 /// Constructor for DummyReader.
119 DummyReader(openshot::Fraction fps, int width, int height, int sample_rate, int channels, float duration);
120
121 /// Constructor for DummyReader which takes a frame cache object.
122 DummyReader(openshot::Fraction fps, int width, int height, int sample_rate, int channels, float duration, CacheBase* cache);
123
124 virtual ~DummyReader();
125
126 /// Close File
127 void Close() override;
128
129 /// Get the cache object used by this reader (always returns NULL for this reader)
130 CacheMemory* GetCache() override { return NULL; };
131
132 /// Get an openshot::Frame object for a specific frame number of this reader. All numbers
133 /// return the same Frame, since they all share the same image data.
134 ///
135 /// @returns The requested frame (containing the image)
136 /// @param requested_frame The frame number that is requested.
137 std::shared_ptr<openshot::Frame> GetFrame(int64_t requested_frame) override;
138
139 /// Determine if reader is open or closed
140 bool IsOpen() override { return is_open; };
141
142 /// Return the type name of the class
143 std::string Name() override { return "DummyReader"; };
144
145 // Get and Set JSON methods
146 std::string Json() const override; ///< Generate JSON string of this object
147 void SetJson(const std::string value) override; ///< Load JSON string into this object
148 Json::Value JsonValue() const override; ///< Generate Json::Value for this object
149 void SetJsonValue(const Json::Value root) override; ///< Load Json::Value into this object
150
151 /// Open File - which is called by the constructor automatically
152 void Open() override;
153 };
154
155}
156
157#endif
Header file for CacheMemory class.
Header file for Fraction class.
Header file for ReaderBase class.
All cache managers in libopenshot are based on this CacheBase class.
Definition: CacheBase.h:49
This class is a memory-based cache manager for Frame objects.
Definition: CacheMemory.h:50
This class is used as a simple, dummy reader, which can be very useful when writing unit tests....
Definition: DummyReader.h:104
bool IsOpen() override
Determine if reader is open or closed.
Definition: DummyReader.h:140
DummyReader()
Blank constructor for DummyReader, with default settings.
Definition: DummyReader.cpp:67
std::shared_ptr< openshot::Frame > GetFrame(int64_t requested_frame) override
void SetJson(const std::string value) override
Load JSON string into this object.
Json::Value JsonValue() const override
Generate Json::Value for this object.
std::string Json() const override
Generate JSON string of this object.
void Open() override
Open File - which is called by the constructor automatically.
Definition: DummyReader.cpp:94
CacheMemory * GetCache() override
Get the cache object used by this reader (always returns NULL for this reader)
Definition: DummyReader.h:130
void Close() override
Close File.
std::string Name() override
Return the type name of the class.
Definition: DummyReader.h:143
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
This class represents a fraction.
Definition: Fraction.h:48
This abstract class is the base class, used by all readers in libopenshot.
Definition: ReaderBase.h:98
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:47