OpenShot Library | libopenshot  0.2.5
ChunkReader.cpp
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1 /**
2  * @file
3  * @brief Source file for ChunkReader 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 #include "../include/ChunkReader.h"
32 #include "../include/FFmpegReader.h"
33 
34 using namespace openshot;
35 
36 ChunkReader::ChunkReader(std::string path, ChunkVersion chunk_version)
37  : path(path), chunk_size(24 * 3), is_open(false), version(chunk_version), local_reader(NULL)
38 {
39  // Check if folder exists?
40  if (!does_folder_exist(path))
41  // Raise exception
42  throw InvalidFile("Chunk folder could not be opened.", path);
43 
44  // Init previous location
45  previous_location.number = 0;
46  previous_location.frame = 0;
47 
48  // Open and Close the reader, to populate its attributes (such as height, width, etc...)
49  Open();
50  Close();
51 }
52 
53 // Check if folder path existing
54 bool ChunkReader::does_folder_exist(std::string path)
55 {
56  QDir dir(path.c_str());
57  return dir.exists();
58 }
59 
60 // Load JSON meta data about this chunk folder
61 void ChunkReader::load_json()
62 {
63  // Load path of chunk folder
64  std::string json_path = QDir::cleanPath(QString(path.c_str()) + QDir::separator() + "info.json").toStdString();
65  std::stringstream json_string;
66 
67  // Read the JSON file
68  std::ifstream myfile (json_path.c_str());
69  std::string line = "";
70  if (myfile.is_open())
71  {
72  while (myfile.good())
73  {
74  getline (myfile, line);
75  json_string << line;
76  }
77  myfile.close();
78  }
79 
80  // Parse JSON string into JSON objects
81  Json::Value root;
82  Json::CharReaderBuilder rbuilder;
83 
84  std::string errors;
85  bool success = Json::parseFromStream(rbuilder, json_string, &root, &errors);
86  if (!success)
87  // Raise exception
88  throw InvalidJSON("Chunk folder could not be opened.", path);
89 
90 
91  // Set info from the JSON objects
92  try
93  {
94  info.has_video = root["has_video"].asBool();
95  info.has_audio = root["has_audio"].asBool();
96  info.duration = root["duration"].asDouble();
97  info.file_size = std::stoll(root["file_size"].asString());
98  info.height = root["height"].asInt();
99  info.width = root["width"].asInt();
100  info.pixel_format = root["pixel_format"].asInt();
101  info.fps.num = root["fps"]["num"].asInt();
102  info.fps.den = root["fps"]["den"].asInt();
103  info.video_bit_rate = root["video_bit_rate"].asUInt();
104  info.pixel_ratio.num = root["pixel_ratio"]["num"].asInt();
105  info.pixel_ratio.den = root["pixel_ratio"]["den"].asInt();
106  info.display_ratio.num = root["display_ratio"]["num"].asInt();
107  info.display_ratio.den = root["display_ratio"]["den"].asInt();
108  info.vcodec = root["vcodec"].asString();
109  info.video_length = std::stoll(root["video_length"].asString());
110  info.video_stream_index = root["video_stream_index"].asInt();
111  info.video_timebase.num = root["video_timebase"]["num"].asInt();
112  info.video_timebase.den = root["video_timebase"]["den"].asInt();
113  info.interlaced_frame = root["interlaced_frame"].asBool();
114  info.top_field_first = root["top_field_first"].asBool();
115  info.acodec = root["acodec"].asString();
116  info.audio_bit_rate = root["audio_bit_rate"].asUInt();
117  info.sample_rate = root["sample_rate"].asUInt();
118  info.channels = root["channels"].asInt();
119  info.audio_stream_index = root["audio_stream_index"].asInt();
120  info.audio_timebase.num = root["audio_timebase"]["num"].asInt();
121  info.audio_timebase.den = root["audio_timebase"]["den"].asInt();
122 
123  }
124  catch (const std::exception& e)
125  {
126  // Error parsing JSON (or missing keys)
127  throw InvalidJSON("JSON could not be parsed (or is invalid).", path);
128  }
129 }
130 
131 // Find the location of a frame in a chunk
132 ChunkLocation ChunkReader::find_chunk_frame(int64_t requested_frame)
133 {
134  // Determine which chunk contains this frame.
135  int64_t chunk_number = (requested_frame / chunk_size) + 1;
136 
137  // Determine which frame in this chunk
138  int64_t start_frame_of_chunk = (chunk_number - 1) * chunk_size;
139  int64_t chunk_frame_number = (requested_frame - start_frame_of_chunk) + 1; // Add 1 to adjust for the 1st frame of every chunk is just there to "stoke" the audio samples from the previous chunk.
140 
141  // Prepare chunk location struct
142  ChunkLocation location = {chunk_number, chunk_frame_number};
143 
144  return location;
145 }
146 
147 // Open chunk folder or file
149 {
150  // Open reader if not already open
151  if (!is_open)
152  {
153  // parse JSON and load info.json file
154  load_json();
155 
156  // Mark as "open"
157  is_open = true;
158  }
159 }
160 
161 // Close image file
163 {
164  // Close all objects, if reader is 'open'
165  if (is_open)
166  {
167  // Mark as "closed"
168  is_open = false;
169  }
170 }
171 
172 // get a formatted path of a specific chunk
173 std::string ChunkReader::get_chunk_path(int64_t chunk_number, std::string folder, std::string extension)
174 {
175  // Create path of new chunk video
176  std::stringstream chunk_count_string;
177  chunk_count_string << chunk_number;
178  QString padded_count = "%1"; //chunk_count_string.str().c_str();
179  padded_count = padded_count.arg(chunk_count_string.str().c_str(), 6, '0');
180  if (folder.length() != 0 && extension.length() != 0)
181  // Return path with FOLDER and EXTENSION name
182  return QDir::cleanPath(QString(path.c_str()) + QDir::separator() + folder.c_str() + QDir::separator() + padded_count + extension.c_str()).toStdString();
183 
184  else if (folder.length() == 0 && extension.length() != 0)
185  // Return path with NO FOLDER and EXTENSION name
186  return QDir::cleanPath(QString(path.c_str()) + QDir::separator() + padded_count + extension.c_str()).toStdString();
187 
188  else if (folder.length() != 0 && extension.length() == 0)
189  // Return path with FOLDER and NO EXTENSION
190  return QDir::cleanPath(QString(path.c_str()) + QDir::separator() + folder.c_str()).toStdString();
191  else
192  return "";
193 }
194 
195 // Get an openshot::Frame object for a specific frame number of this reader.
196 std::shared_ptr<Frame> ChunkReader::GetFrame(int64_t requested_frame)
197 {
198  // Determine what chunk contains this frame
199  ChunkLocation location = find_chunk_frame(requested_frame);
200 
201  // New Chunk (Close the old reader, and open the new one)
202  if (previous_location.number != location.number)
203  {
204  // Determine version of chunk
205  std::string folder_name = "";
206  switch (version)
207  {
208  case THUMBNAIL:
209  folder_name = "thumb";
210  break;
211  case PREVIEW:
212  folder_name = "preview";
213  break;
214  case FINAL:
215  folder_name = "final";
216  break;
217  }
218 
219  // Load path of chunk video
220  std::string chunk_video_path = get_chunk_path(location.number, folder_name, ".webm");
221 
222  // Close existing reader (if needed)
223  if (local_reader)
224  {
225  std::cout << "Close READER" << std::endl;
226  // Close and delete old reader
227  local_reader->Close();
228  delete local_reader;
229  }
230 
231  try
232  {
233  std::cout << "Load READER: " << chunk_video_path << std::endl;
234  // Load new FFmpegReader
235  local_reader = new FFmpegReader(chunk_video_path);
236  local_reader->Open(); // open reader
237 
238  } catch (const InvalidFile& e)
239  {
240  // Invalid Chunk (possibly it is not found)
241  throw ChunkNotFound(path, requested_frame, location.number, location.frame);
242  }
243 
244  // Set the new location
245  previous_location = location;
246  }
247 
248  // Get the frame (from the current reader)
249  last_frame = local_reader->GetFrame(location.frame);
250 
251  // Update the frame number property
252  last_frame->number = requested_frame;
253 
254  // Return the frame
255  return last_frame;
256 }
257 
258 // Generate JSON string of this object
259 std::string ChunkReader::Json() const {
260 
261  // Return formatted string
262  return JsonValue().toStyledString();
263 }
264 
265 // Generate Json::Value for this object
266 Json::Value ChunkReader::JsonValue() const {
267 
268  // Create root json object
269  Json::Value root = ReaderBase::JsonValue(); // get parent properties
270  root["type"] = "ChunkReader";
271  root["path"] = path;
272  std::stringstream chunk_size_stream;
273  chunk_size_stream << chunk_size;
274  root["chunk_size"] = chunk_size_stream.str();
275  root["chunk_version"] = version;
276 
277  // return JsonValue
278  return root;
279 }
280 
281 // Load JSON string into this object
282 void ChunkReader::SetJson(const std::string value) {
283 
284  try
285  {
286  const Json::Value root = openshot::stringToJson(value);
287  // Set all values that match
288  SetJsonValue(root);
289  }
290  catch (const std::exception& e)
291  {
292  // Error parsing JSON (or missing keys)
293  throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
294  }
295 }
296 
297 // Load Json::Value into this object
298 void ChunkReader::SetJsonValue(const Json::Value root) {
299 
300  // Set parent data
302 
303  // Set data from Json (if key is found)
304  if (!root["path"].isNull())
305  path = root["path"].asString();
306  if (!root["chunk_size"].isNull())
307  chunk_size = std::stoll(root["chunk_size"].asString());
308  if (!root["chunk_version"].isNull())
309  version = (ChunkVersion) root["chunk_version"].asInt();
310 
311  // Re-Open path, and re-init everything (if needed)
312  if (is_open)
313  {
314  Close();
315  Open();
316  }
317 }
openshot::stringToJson
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:33
openshot::ReaderInfo::sample_rate
int sample_rate
The number of audio samples per second (44100 is a common sample rate)
Definition: ReaderBase.h:82
openshot::ReaderBase::JsonValue
virtual Json::Value JsonValue() const =0
Generate Json::Value for this object.
Definition: ReaderBase.cpp:116
openshot::ReaderBase::GetFrame
virtual std::shared_ptr< openshot::Frame > GetFrame(int64_t number)=0
openshot::ReaderBase::SetJsonValue
virtual void SetJsonValue(const Json::Value root)=0
Load Json::Value into this object.
Definition: ReaderBase.cpp:171
openshot
This namespace is the default namespace for all code in the openshot library.
Definition: AudioBufferSource.h:39
openshot::ReaderBase::info
openshot::ReaderInfo info
Information about the current media file.
Definition: ReaderBase.h:111
openshot::ReaderInfo::interlaced_frame
bool interlaced_frame
Definition: ReaderBase.h:78
openshot::ReaderInfo::audio_bit_rate
int audio_bit_rate
The bit rate of the audio stream (in bytes)
Definition: ReaderBase.h:81
openshot::ReaderInfo::duration
float duration
Length of time (in seconds)
Definition: ReaderBase.h:65
openshot::ChunkLocation
This struct holds the location of a frame within a chunk.
Definition: ChunkReader.h:59
openshot::ChunkReader::SetJsonValue
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: ChunkReader.cpp:298
openshot::ReaderInfo::has_video
bool has_video
Determines if this file has a video stream.
Definition: ReaderBase.h:62
openshot::ReaderInfo::width
int width
The width of the video (in pixesl)
Definition: ReaderBase.h:68
openshot::ChunkReader::GetFrame
std::shared_ptr< openshot::Frame > GetFrame(int64_t requested_frame)
Get an openshot::Frame object for a specific frame number of this reader.
Definition: ChunkReader.cpp:196
openshot::ReaderInfo::video_length
int64_t video_length
The number of frames in the video stream.
Definition: ReaderBase.h:75
openshot::ReaderInfo::height
int height
The height of the video (in pixels)
Definition: ReaderBase.h:67
openshot::Fraction::num
int num
Numerator for the fraction.
Definition: Fraction.h:47
openshot::ChunkNotFound
Exception when a required chunk is missing.
Definition: Exceptions.h:59
openshot::Fraction::den
int den
Denominator for the fraction.
Definition: Fraction.h:48
openshot::ReaderBase::Open
virtual void Open()=0
Open the reader (and start consuming resources, such as images or video files)
openshot::ReaderInfo::has_audio
bool has_audio
Determines if this file has an audio stream.
Definition: ReaderBase.h:63
openshot::InvalidJSON
Exception for invalid JSON.
Definition: Exceptions.h:206
openshot::ReaderInfo::file_size
int64_t file_size
Size of file (in bytes)
Definition: ReaderBase.h:66
openshot::ChunkReader::SetJson
void SetJson(const std::string value)
Load JSON string into this object.
Definition: ChunkReader.cpp:282
openshot::ReaderInfo::video_timebase
openshot::Fraction video_timebase
The video timebase determines how long each frame stays on the screen.
Definition: ReaderBase.h:77
openshot::ChunkReader::Open
void Open()
Open the reader. This is required before you can access frames or data from the reader.
Definition: ChunkReader.cpp:148
openshot::FFmpegReader
This class uses the FFmpeg libraries, to open video files and audio files, and return openshot::Frame...
Definition: FFmpegReader.h:94
path
path
Definition: FFmpegWriter.cpp:1410
openshot::InvalidFile
Exception for files that can not be found or opened.
Definition: Exceptions.h:174
openshot::ReaderInfo::audio_stream_index
int audio_stream_index
The index of the audio stream.
Definition: ReaderBase.h:85
openshot::ReaderInfo::audio_timebase
openshot::Fraction audio_timebase
The audio timebase determines how long each audio packet should be played.
Definition: ReaderBase.h:86
openshot::ChunkLocation::number
int64_t number
The chunk number.
Definition: ChunkReader.h:60
openshot::ReaderInfo::pixel_format
int pixel_format
The pixel format (i.e. YUV420P, RGB24, etc...)
Definition: ReaderBase.h:69
openshot::ReaderInfo::vcodec
std::string vcodec
The name of the video codec used to encode / decode the video stream.
Definition: ReaderBase.h:74
openshot::ChunkReader::Json
std::string Json() const override
Get and Set JSON methods.
Definition: ChunkReader.cpp:259
openshot::ChunkReader::Close
void Close()
Close the reader.
Definition: ChunkReader.cpp:162
openshot::ReaderInfo::fps
openshot::Fraction fps
Frames per second, as a fraction (i.e. 24/1 = 24 fps)
Definition: ReaderBase.h:70
openshot::ReaderInfo::video_bit_rate
int video_bit_rate
The bit rate of the video stream (in bytes)
Definition: ReaderBase.h:71
openshot::ReaderInfo::top_field_first
bool top_field_first
Definition: ReaderBase.h:79
openshot::ReaderBase::Close
virtual void Close()=0
Close the reader (and any resources it was consuming)
openshot::ReaderInfo::pixel_ratio
openshot::Fraction pixel_ratio
The pixel ratio of the video stream as a fraction (i.e. some pixels are not square)
Definition: ReaderBase.h:72
openshot::ChunkLocation::frame
int64_t frame
The frame number.
Definition: ChunkReader.h:61
openshot::ReaderInfo::video_stream_index
int video_stream_index
The index of the video stream.
Definition: ReaderBase.h:76
openshot::ReaderInfo::acodec
std::string acodec
The name of the audio codec used to encode / decode the video stream.
Definition: ReaderBase.h:80
openshot::ReaderInfo::display_ratio
openshot::Fraction display_ratio
The ratio of width to height of the video stream (i.e. 640x480 has a ratio of 4/3)
Definition: ReaderBase.h:73
openshot::ChunkVersion
ChunkVersion
This enumeration allows the user to choose which version of the chunk they would like (low,...
Definition: ChunkReader.h:75
openshot::ReaderInfo::channels
int channels
The number of audio channels used in the audio stream.
Definition: ReaderBase.h:83
openshot::THUMBNAIL
@ THUMBNAIL
The lowest quality stream contained in this chunk file.
Definition: ChunkReader.h:76
openshot::ChunkReader::ChunkReader
ChunkReader(std::string path, ChunkVersion chunk_version)
Constructor for ChunkReader. This automatically opens the chunk file or folder and loads frame 1,...
Definition: ChunkReader.cpp:36
openshot::ChunkReader::JsonValue
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition: ChunkReader.cpp:266
openshot::FINAL
@ FINAL
The highest quality stream contained in this chunk file.
Definition: ChunkReader.h:78
openshot::PREVIEW
@ PREVIEW
The medium quality stream contained in this chunk file.
Definition: ChunkReader.h:77