OpenShot Library | libopenshot  0.3.3
ChunkReader.cpp
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1 
9 // Copyright (c) 2008-2019 OpenShot Studios, LLC
10 //
11 // SPDX-License-Identifier: LGPL-3.0-or-later
12 
13 #include <fstream>
14 
15 #include "ChunkReader.h"
16 #include "Exceptions.h"
17 #include "FFmpegReader.h"
18 
19 #include <QDir>
20 
21 using namespace openshot;
22 
23 ChunkReader::ChunkReader(std::string path, ChunkVersion chunk_version)
24  : path(path), chunk_size(24 * 3), is_open(false), version(chunk_version), local_reader(NULL)
25 {
26  // Check if folder exists?
27  if (!does_folder_exist(path))
28  // Raise exception
29  throw InvalidFile("Chunk folder could not be opened.", path);
30 
31  // Init previous location
32  previous_location.number = 0;
33  previous_location.frame = 0;
34 
35  // Open and Close the reader, to populate its attributes (such as height, width, etc...)
36  Open();
37  Close();
38 }
39 
40 // Check if folder path existing
41 bool ChunkReader::does_folder_exist(std::string path)
42 {
43  QDir dir(path.c_str());
44  return dir.exists();
45 }
46 
47 // Load JSON meta data about this chunk folder
48 void ChunkReader::load_json()
49 {
50  // Load path of chunk folder
51  std::string json_path = QDir::cleanPath(QString(path.c_str()) + QDir::separator() + "info.json").toStdString();
52  std::stringstream json_string;
53 
54  // Read the JSON file
55  std::ifstream myfile (json_path.c_str());
56  std::string line = "";
57  if (myfile.is_open())
58  {
59  while (myfile.good())
60  {
61  getline (myfile, line);
62  json_string << line;
63  }
64  myfile.close();
65  }
66 
67  // Parse JSON string into JSON objects
68  Json::Value root;
69  Json::CharReaderBuilder rbuilder;
70 
71  std::string errors;
72  bool success = Json::parseFromStream(rbuilder, json_string, &root, &errors);
73  if (!success)
74  // Raise exception
75  throw InvalidJSON("Chunk folder could not be opened.", path);
76 
77 
78  // Set info from the JSON objects
79  try
80  {
81  info.has_video = root["has_video"].asBool();
82  info.has_audio = root["has_audio"].asBool();
83  info.duration = root["duration"].asDouble();
84  info.file_size = std::stoll(root["file_size"].asString());
85  info.height = root["height"].asInt();
86  info.width = root["width"].asInt();
87  info.pixel_format = root["pixel_format"].asInt();
88  info.fps.num = root["fps"]["num"].asInt();
89  info.fps.den = root["fps"]["den"].asInt();
90  info.video_bit_rate = root["video_bit_rate"].asUInt();
91  info.pixel_ratio.num = root["pixel_ratio"]["num"].asInt();
92  info.pixel_ratio.den = root["pixel_ratio"]["den"].asInt();
93  info.display_ratio.num = root["display_ratio"]["num"].asInt();
94  info.display_ratio.den = root["display_ratio"]["den"].asInt();
95  info.vcodec = root["vcodec"].asString();
96  info.video_length = std::stoll(root["video_length"].asString());
97  info.video_stream_index = root["video_stream_index"].asInt();
98  info.video_timebase.num = root["video_timebase"]["num"].asInt();
99  info.video_timebase.den = root["video_timebase"]["den"].asInt();
100  info.interlaced_frame = root["interlaced_frame"].asBool();
101  info.top_field_first = root["top_field_first"].asBool();
102  info.acodec = root["acodec"].asString();
103  info.audio_bit_rate = root["audio_bit_rate"].asUInt();
104  info.sample_rate = root["sample_rate"].asUInt();
105  info.channels = root["channels"].asInt();
106  info.audio_stream_index = root["audio_stream_index"].asInt();
107  info.audio_timebase.num = root["audio_timebase"]["num"].asInt();
108  info.audio_timebase.den = root["audio_timebase"]["den"].asInt();
109 
110  }
111  catch (const std::exception& e)
112  {
113  // Error parsing JSON (or missing keys)
114  throw InvalidJSON("JSON could not be parsed (or is invalid).", path);
115  }
116 }
117 
118 // Find the location of a frame in a chunk
119 ChunkLocation ChunkReader::find_chunk_frame(int64_t requested_frame)
120 {
121  // Determine which chunk contains this frame.
122  int64_t chunk_number = (requested_frame / chunk_size) + 1;
123 
124  // Determine which frame in this chunk
125  int64_t start_frame_of_chunk = (chunk_number - 1) * chunk_size;
126  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.
127 
128  // Prepare chunk location struct
129  ChunkLocation location = {chunk_number, chunk_frame_number};
130 
131  return location;
132 }
133 
134 // Open chunk folder or file
136 {
137  // Open reader if not already open
138  if (!is_open)
139  {
140  // parse JSON and load info.json file
141  load_json();
142 
143  // Mark as "open"
144  is_open = true;
145  }
146 }
147 
148 // Close image file
150 {
151  // Close all objects, if reader is 'open'
152  if (is_open)
153  {
154  // Mark as "closed"
155  is_open = false;
156  }
157 }
158 
159 // get a formatted path of a specific chunk
160 std::string ChunkReader::get_chunk_path(int64_t chunk_number, std::string folder, std::string extension)
161 {
162  // Create path of new chunk video
163  std::stringstream chunk_count_string;
164  chunk_count_string << chunk_number;
165  QString padded_count = "%1"; //chunk_count_string.str().c_str();
166  padded_count = padded_count.arg(chunk_count_string.str().c_str(), 6, '0');
167  if (folder.length() != 0 && extension.length() != 0)
168  // Return path with FOLDER and EXTENSION name
169  return QDir::cleanPath(QString(path.c_str()) + QDir::separator() + folder.c_str() + QDir::separator() + padded_count + extension.c_str()).toStdString();
170 
171  else if (folder.length() == 0 && extension.length() != 0)
172  // Return path with NO FOLDER and EXTENSION name
173  return QDir::cleanPath(QString(path.c_str()) + QDir::separator() + padded_count + extension.c_str()).toStdString();
174 
175  else if (folder.length() != 0 && extension.length() == 0)
176  // Return path with FOLDER and NO EXTENSION
177  return QDir::cleanPath(QString(path.c_str()) + QDir::separator() + folder.c_str()).toStdString();
178  else
179  return "";
180 }
181 
182 // Get an openshot::Frame object for a specific frame number of this reader.
183 std::shared_ptr<Frame> ChunkReader::GetFrame(int64_t requested_frame)
184 {
185  // Determine what chunk contains this frame
186  ChunkLocation location = find_chunk_frame(requested_frame);
187 
188  // New Chunk (Close the old reader, and open the new one)
189  if (previous_location.number != location.number)
190  {
191  // Determine version of chunk
192  std::string folder_name = "";
193  switch (version)
194  {
195  case THUMBNAIL:
196  folder_name = "thumb";
197  break;
198  case PREVIEW:
199  folder_name = "preview";
200  break;
201  case FINAL:
202  folder_name = "final";
203  break;
204  }
205 
206  // Load path of chunk video
207  std::string chunk_video_path = get_chunk_path(location.number, folder_name, ".webm");
208 
209  // Close existing reader (if needed)
210  if (local_reader)
211  {
212  // Close and delete old reader
213  local_reader->Close();
214  delete local_reader;
215  }
216 
217  try
218  {
219  // Load new FFmpegReader
220  local_reader = new FFmpegReader(chunk_video_path);
221  local_reader->Open(); // open reader
222 
223  } catch (const InvalidFile& e)
224  {
225  // Invalid Chunk (possibly it is not found)
226  throw ChunkNotFound(path, requested_frame, location.number, location.frame);
227  }
228 
229  // Set the new location
230  previous_location = location;
231  }
232 
233  // Get the frame (from the current reader)
234  last_frame = local_reader->GetFrame(location.frame);
235 
236  // Update the frame number property
237  last_frame->number = requested_frame;
238 
239  // Return the frame
240  return last_frame;
241 }
242 
243 // Generate JSON string of this object
244 std::string ChunkReader::Json() const {
245 
246  // Return formatted string
247  return JsonValue().toStyledString();
248 }
249 
250 // Generate Json::Value for this object
251 Json::Value ChunkReader::JsonValue() const {
252 
253  // Create root json object
254  Json::Value root = ReaderBase::JsonValue(); // get parent properties
255  root["type"] = "ChunkReader";
256  root["path"] = path;
257  std::stringstream chunk_size_stream;
258  chunk_size_stream << chunk_size;
259  root["chunk_size"] = chunk_size_stream.str();
260  root["chunk_version"] = version;
261 
262  // return JsonValue
263  return root;
264 }
265 
266 // Load JSON string into this object
267 void ChunkReader::SetJson(const std::string value) {
268 
269  try
270  {
271  const Json::Value root = openshot::stringToJson(value);
272  // Set all values that match
273  SetJsonValue(root);
274  }
275  catch (const std::exception& e)
276  {
277  // Error parsing JSON (or missing keys)
278  throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
279  }
280 }
281 
282 // Load Json::Value into this object
283 void ChunkReader::SetJsonValue(const Json::Value root) {
284 
285  // Set parent data
287 
288  // Set data from Json (if key is found)
289  if (!root["path"].isNull())
290  path = root["path"].asString();
291  if (!root["chunk_size"].isNull())
292  chunk_size = std::stoll(root["chunk_size"].asString());
293  if (!root["chunk_version"].isNull())
294  version = (ChunkVersion) root["chunk_version"].asInt();
295 
296  // Re-Open path, and re-init everything (if needed)
297  if (is_open)
298  {
299  Close();
300  Open();
301  }
302 }
openshot::stringToJson
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:16
openshot::ChunkReader::SetJson
void SetJson(const std::string value) override
Load JSON string into this object.
Definition: ChunkReader.cpp:267
openshot::ReaderInfo::sample_rate
int sample_rate
The number of audio samples per second (44100 is a common sample rate)
Definition: ReaderBase.h:60
openshot::ChunkReader::GetFrame
std::shared_ptr< openshot::Frame > GetFrame(int64_t requested_frame) override
Get an openshot::Frame object for a specific frame number of this reader.
Definition: ChunkReader.cpp:183
openshot::ReaderBase::JsonValue
virtual Json::Value JsonValue() const =0
Generate Json::Value for this object.
Definition: ReaderBase.cpp:107
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:162
openshot
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:28
openshot::ReaderBase::info
openshot::ReaderInfo info
Information about the current media file.
Definition: ReaderBase.h:88
openshot::ReaderInfo::interlaced_frame
bool interlaced_frame
Definition: ReaderBase.h:56
openshot::ReaderInfo::audio_bit_rate
int audio_bit_rate
The bit rate of the audio stream (in bytes)
Definition: ReaderBase.h:59
openshot::ReaderInfo::duration
float duration
Length of time (in seconds)
Definition: ReaderBase.h:43
openshot::ChunkLocation
This struct holds the location of a frame within a chunk.
Definition: ChunkReader.h:33
openshot::ReaderInfo::has_video
bool has_video
Determines if this file has a video stream.
Definition: ReaderBase.h:40
openshot::ChunkReader::SetJsonValue
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Definition: ChunkReader.cpp:283
openshot::ReaderInfo::width
int width
The width of the video (in pixesl)
Definition: ReaderBase.h:46
openshot::ReaderInfo::video_length
int64_t video_length
The number of frames in the video stream.
Definition: ReaderBase.h:53
openshot::ReaderInfo::height
int height
The height of the video (in pixels)
Definition: ReaderBase.h:45
openshot::Fraction::num
int num
Numerator for the fraction.
Definition: Fraction.h:32
openshot::ChunkNotFound
Exception when a required chunk is missing.
Definition: Exceptions.h:78
openshot::Fraction::den
int den
Denominator for the fraction.
Definition: Fraction.h:33
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:41
openshot::InvalidJSON
Exception for invalid JSON.
Definition: Exceptions.h:217
openshot::ReaderInfo::file_size
int64_t file_size
Size of file (in bytes)
Definition: ReaderBase.h:44
openshot::ReaderInfo::video_timebase
openshot::Fraction video_timebase
The video timebase determines how long each frame stays on the screen.
Definition: ReaderBase.h:55
openshot::FFmpegReader
This class uses the FFmpeg libraries, to open video files and audio files, and return openshot::Frame...
Definition: FFmpegReader.h:101
path
path
Definition: FFmpegWriter.cpp:1479
ChunkReader.h
Header file for ChunkReader class.
openshot::InvalidFile
Exception for files that can not be found or opened.
Definition: Exceptions.h:187
openshot::ReaderInfo::audio_stream_index
int audio_stream_index
The index of the audio stream.
Definition: ReaderBase.h:63
openshot::ReaderInfo::audio_timebase
openshot::Fraction audio_timebase
The audio timebase determines how long each audio packet should be played.
Definition: ReaderBase.h:64
openshot::ChunkLocation::number
int64_t number
The chunk number.
Definition: ChunkReader.h:35
openshot::ReaderInfo::pixel_format
int pixel_format
The pixel format (i.e. YUV420P, RGB24, etc...)
Definition: ReaderBase.h:47
openshot::ReaderInfo::vcodec
std::string vcodec
The name of the video codec used to encode / decode the video stream.
Definition: ReaderBase.h:52
openshot::ChunkReader::Json
std::string Json() const override
Generate JSON string of this object.
Definition: ChunkReader.cpp:244
openshot::ChunkReader::Close
void Close() override
Close the reader.
Definition: ChunkReader.cpp:149
openshot::ReaderInfo::fps
openshot::Fraction fps
Frames per second, as a fraction (i.e. 24/1 = 24 fps)
Definition: ReaderBase.h:48
openshot::ReaderInfo::video_bit_rate
int video_bit_rate
The bit rate of the video stream (in bytes)
Definition: ReaderBase.h:49
openshot::ReaderInfo::top_field_first
bool top_field_first
Definition: ReaderBase.h:57
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:50
openshot::ChunkLocation::frame
int64_t frame
The frame number.
Definition: ChunkReader.h:36
openshot::ReaderInfo::video_stream_index
int video_stream_index
The index of the video stream.
Definition: ReaderBase.h:54
openshot::ChunkReader::Open
void Open() override
Open the reader. This is required before you can access frames or data from the reader.
Definition: ChunkReader.cpp:135
openshot::ReaderInfo::acodec
std::string acodec
The name of the audio codec used to encode / decode the video stream.
Definition: ReaderBase.h:58
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:51
openshot::ChunkVersion
ChunkVersion
This enumeration allows the user to choose which version of the chunk they would like (low,...
Definition: ChunkReader.h:49
openshot::ReaderInfo::channels
int channels
The number of audio channels used in the audio stream.
Definition: ReaderBase.h:61
openshot::THUMBNAIL
@ THUMBNAIL
The lowest quality stream contained in this chunk file.
Definition: ChunkReader.h:51
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:23
Exceptions.h
Header file for all Exception classes.
openshot::ChunkReader::JsonValue
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition: ChunkReader.cpp:251
FFmpegReader.h
Header file for FFmpegReader class.
openshot::FINAL
@ FINAL
The highest quality stream contained in this chunk file.
Definition: ChunkReader.h:53
openshot::PREVIEW
@ PREVIEW
The medium quality stream contained in this chunk file.
Definition: ChunkReader.h:52