Tag Parser  10.0.1
C++ library for reading and writing MP4 (iTunes), ID3, Vorbis, Opus, FLAC and Matroska tags
id3v1tag.cpp
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1 #include "./id3v1tag.h"
2 #include "./id3genres.h"
3 
4 #include "../diagnostics.h"
5 #include "../exceptions.h"
6 
7 #include <c++utilities/conversion/conversionexception.h>
8 #include <c++utilities/conversion/stringbuilder.h>
9 
10 #include <cstring>
11 #include <initializer_list>
12 
13 using namespace std;
14 using namespace CppUtilities;
15 
16 namespace TagParser {
17 
26 Id3v1Tag::Id3v1Tag()
27 {
28 }
29 
30 TagType Id3v1Tag::type() const
31 {
32  return TagType::Id3v1Tag;
33 }
34 
35 std::string_view Id3v1Tag::typeName() const
36 {
37  return tagName;
38 }
39 
48 bool Id3v1Tag::canEncodingBeUsed(TagTextEncoding encoding) const
49 {
50  return encoding == TagTextEncoding::Latin1;
51 }
52 
59 void Id3v1Tag::parse(std::istream &stream, Diagnostics &diag)
60 {
61  CPP_UTILITIES_UNUSED(diag)
62  char buffer[128];
63  stream.read(buffer, 128);
64  if (buffer[0] != 0x54 || buffer[1] != 0x41 || buffer[2] != 0x47) {
65  throw NoDataFoundException();
66  }
67  m_size = 128;
68  readValue(m_title, 30, buffer + 3);
69  readValue(m_artist, 30, buffer + 33);
70  readValue(m_album, 30, buffer + 63);
71  readValue(m_year, 4, buffer + 93);
72  const auto is11 = buffer[125] == 0;
73  if (is11) {
74  readValue(m_comment, 28, buffer + 97);
75  m_version = "1.1";
76  } else {
77  readValue(m_comment, 30, buffer + 97);
78  m_version = "1.0";
79  }
80  readValue(m_comment, is11 ? 28 : 30, buffer + 97);
81  if (is11) {
82  m_trackPos.assignPosition(PositionInSet(*reinterpret_cast<char *>(buffer + 126), 0));
83  }
84  m_genre.assignStandardGenreIndex(*reinterpret_cast<unsigned char *>(buffer + 127));
85 }
86 
94 void Id3v1Tag::make(ostream &stream, Diagnostics &diag)
95 {
96  static const string context("making ID3v1 tag");
97  char buffer[30];
98  buffer[0] = 0x54;
99  buffer[1] = 0x41;
100  buffer[2] = 0x47;
101  stream.write(buffer, 3);
102 
103  // write text fields
104  writeValue(m_title, 30, buffer, stream, diag);
105  writeValue(m_artist, 30, buffer, stream, diag);
106  writeValue(m_album, 30, buffer, stream, diag);
107  writeValue(m_year, 4, buffer, stream, diag);
108  writeValue(m_comment, 28, buffer, stream, diag);
109 
110  // set "default" values for numeric fields
111  buffer[0] = 0x0; // empty byte
112  buffer[1] = 0x0; // track number
113  buffer[2] = 0x0; // genre
114 
115  // write track
116  if (!m_trackPos.isEmpty()) {
117  try {
118  const auto position(m_trackPos.toPositionInSet().position());
119  if (position < 0x00 || position > 0xFF) {
120  throw ConversionException();
121  }
122  buffer[1] = static_cast<char>(position);
123  } catch (const ConversionException &) {
124  diag.emplace_back(
125  DiagLevel::Warning, "Track position field can not be set because given value can not be converted appropriately.", context);
126  }
127  }
128 
129  // write genre
130  try {
131  const auto genreIndex(m_genre.toStandardGenreIndex());
132  if (genreIndex < 0x00 || genreIndex > 0xFF) {
133  throw ConversionException();
134  }
135  buffer[2] = static_cast<char>(genreIndex);
136  } catch (const ConversionException &) {
137  diag.emplace_back(DiagLevel::Warning,
138  "Genre field can not be set because given value can not be converted to a standard genre number supported by ID3v1.", context);
139  }
140 
141  stream.write(buffer, 3);
142  stream.flush();
143 }
144 
145 const TagValue &Id3v1Tag::value(KnownField field) const
146 {
147  switch (field) {
148  case KnownField::Title:
149  return m_title;
150  case KnownField::Artist:
151  return m_artist;
152  case KnownField::Album:
153  return m_album;
154  case KnownField::RecordDate:
155  return m_year;
156  case KnownField::Comment:
157  return m_comment;
159  return m_trackPos;
160  case KnownField::Genre:
161  return m_genre;
162  default:
163  return TagValue::empty();
164  }
165 }
166 
167 bool Id3v1Tag::setValue(KnownField field, const TagValue &value)
168 {
169  switch (field) {
170  case KnownField::Title:
171  m_title = value;
172  break;
173  case KnownField::Artist:
174  m_artist = value;
175  break;
176  case KnownField::Album:
177  m_album = value;
178  break;
179  case KnownField::RecordDate:
180  m_year = value;
181  break;
182  case KnownField::Comment:
183  m_comment = value;
184  break;
186  m_trackPos = value;
187  break;
188  case KnownField::Genre:
189  m_genre = value;
190  break;
191  default:
192  return false;
193  }
194  return true;
195 }
196 
197 bool Id3v1Tag::setValueConsideringTypeInfo(KnownField field, const TagValue &value, const string &)
198 {
199  return setValue(field, value);
200 }
201 
202 bool Id3v1Tag::hasField(KnownField field) const
203 {
204  switch (field) {
205  case KnownField::Title:
206  return !m_title.isEmpty();
207  case KnownField::Artist:
208  return !m_artist.isEmpty();
209  case KnownField::Album:
210  return !m_album.isEmpty();
211  return !m_year.isEmpty();
212  case KnownField::Comment:
213  return !m_comment.isEmpty();
215  return !m_trackPos.isEmpty();
216  case KnownField::Genre:
217  return !m_genre.isEmpty();
218  default:
219  return false;
220  }
221 }
222 
223 void Id3v1Tag::removeAllFields()
224 {
225  m_title.clearDataAndMetadata();
226  m_artist.clearDataAndMetadata();
227  m_album.clearDataAndMetadata();
228  m_year.clearDataAndMetadata();
229  m_comment.clearDataAndMetadata();
230  m_trackPos.clearDataAndMetadata();
231  m_genre.clearDataAndMetadata();
232 }
233 
234 std::size_t Id3v1Tag::fieldCount() const
235 {
236  auto count = std::size_t(0);
237  for (const auto &value : std::initializer_list<const TagValue *>{ &m_title, &m_artist, &m_album, &m_year, &m_comment, &m_trackPos, &m_genre }) {
238  if (!value->isEmpty()) {
239  ++count;
240  }
241  }
242  return count;
243 }
244 
245 bool Id3v1Tag::supportsField(KnownField field) const
246 {
247  switch (field) {
248  case KnownField::Title:
249  case KnownField::Artist:
250  case KnownField::Album:
251  case KnownField::RecordDate:
252  case KnownField::Comment:
254  case KnownField::Genre:
255  return true;
256  default:
257  return false;
258  }
259 }
260 
261 void Id3v1Tag::ensureTextValuesAreProperlyEncoded()
262 {
263  for (auto *value : initializer_list<TagValue *>{ &m_title, &m_artist, &m_album, &m_year, &m_comment, &m_trackPos, &m_genre }) {
264  // convert UTF-16 to UTF-8
265  switch (value->dataEncoding()) {
266  case TagTextEncoding::Latin1:
268  case TagTextEncoding::Unspecified:
269  break;
270  default:
271  value->convertDataEncoding(TagTextEncoding::Utf8);
272  }
273  }
274 }
275 
279 void Id3v1Tag::readValue(TagValue &value, size_t maxLength, const char *buffer)
280 {
281  const char *end = buffer + maxLength - 1;
282  while ((*end == 0x0 || *end == ' ') && end >= buffer) {
283  --end;
284  --maxLength;
285  }
286  if (buffer == end) {
287  return;
288  }
289  if (maxLength >= 3 && BE::toUInt24(buffer) == 0x00EFBBBF) {
290  value.assignData(buffer + 3, maxLength - 3, TagDataType::Text, TagTextEncoding::Utf8);
291  } else {
292  value.assignData(buffer, maxLength, TagDataType::Text, TagTextEncoding::Latin1);
293  }
294 }
295 
299 void Id3v1Tag::writeValue(const TagValue &value, size_t length, char *buffer, ostream &targetStream, Diagnostics &diag)
300 {
301  // initialize buffer with zeroes
302  memset(buffer, 0, length);
303 
304  // stringify value
305  string valueAsString;
306  try {
307  valueAsString = value.toString();
308  } catch (const ConversionException &) {
309  diag.emplace_back(
310  DiagLevel::Warning, "Field can not be set because given value can not be converted appropriately.", "making ID3v1 tag field");
311  }
312 
313  // handle encoding
314  auto *valueStart = buffer;
315  auto valueLength = length;
316  switch (value.dataEncoding()) {
317  case TagTextEncoding::Latin1:
318  case TagTextEncoding::Unspecified:
319  break;
321  // write
322  for (const auto c : valueAsString) {
323  if ((c & 0x80) == 0) {
324  continue;
325  }
326  buffer[0] = static_cast<char>(0xEF);
327  buffer[1] = static_cast<char>(0xBB);
328  buffer[2] = static_cast<char>(0xBF);
329  valueStart += 3;
330  valueLength -= 3;
331  break;
332  }
333  [[fallthrough]];
334  default:
335  diag.emplace_back(DiagLevel::Warning, "The used encoding is unlikely to be supported by other software.", "making ID3v1 tag field");
336  }
337 
338  // copy the string
339  if (valueAsString.size() > length) {
340  diag.emplace_back(
341  DiagLevel::Warning, argsToString("Value has been truncated. Max. ", length, " characters supported."), "making ID3v1 tag field");
342  }
343  valueAsString.copy(valueStart, valueLength);
344 
345  targetStream.write(buffer, static_cast<streamsize>(length));
346 }
347 
348 } // namespace TagParser
The Diagnostics class is a container for DiagMessage.
Definition: diagnostics.h:156
The exception that is thrown when the data to be parsed holds no parsable information (e....
Definition: exceptions.h:18
The PositionInSet class describes the position of an element in a set which consists of a certain num...
Definition: positioninset.h:21
The TagValue class wraps values of different types.
Definition: tagvalue.h:95
void assignData(const char *data, std::size_t length, TagDataType type=TagDataType::Binary, TagTextEncoding encoding=TagTextEncoding::Latin1)
Contains all classes and functions of the TagInfo library.
Definition: aaccodebook.h:10
KnownField
Specifies the field.
Definition: tag.h:42
TagTextEncoding
Specifies the text encoding.
Definition: tagvalue.h:28
TagType
Specifies the tag type.
Definition: tag.h:20