1/*
2 This file is part of the KDE project
3 SPDX-FileCopyrightText: 2003 Dominik Seichter <domseichter@web.de>
4 SPDX-FileCopyrightText: 2004 Ignacio Castaño <castano@ludicon.com>
5 SPDX-FileCopyrightText: 2010 Troy Unrau <troy@kde.org>
6 SPDX-FileCopyrightText: 2023 Mirco Miranda <mircomir@outlook.com>
7
8 SPDX-License-Identifier: LGPL-2.0-or-later
9*/
10
11#include "ras_p.h"
12#include "util_p.h"
13
14#include <QDataStream>
15#include <QDebug>
16#include <QImage>
17
18namespace // Private.
19{
20// format info from http://www.fileformat.info/format/sunraster/egff.htm
21
22// Header format of saved files.
23quint32 rasMagicBigEndian = 0x59a66a95;
24// quint32 rasMagicLittleEndian = 0x956aa659; # used to support wrong encoded files
25
26enum RASType {
27 RAS_TYPE_OLD = 0x0,
28 RAS_TYPE_STANDARD = 0x1,
29 RAS_TYPE_BYTE_ENCODED = 0x2,
30 RAS_TYPE_RGB_FORMAT = 0x3,
31 RAS_TYPE_TIFF_FORMAT = 0x4,
32 RAS_TYPE_IFF_FORMAT = 0x5,
33 RAS_TYPE_EXPERIMENTAL = 0xFFFF,
34};
35
36enum RASColorMapType {
37 RAS_COLOR_MAP_TYPE_NONE = 0x0,
38 RAS_COLOR_MAP_TYPE_RGB = 0x1,
39 RAS_COLOR_MAP_TYPE_RAW = 0x2,
40};
41
42struct RasHeader {
43 quint32 MagicNumber = 0;
44 quint32 Width = 0;
45 quint32 Height = 0;
46 quint32 Depth = 0;
47 quint32 Length = 0;
48 quint32 Type = 0;
49 quint32 ColorMapType = 0;
50 quint32 ColorMapLength = 0;
51 enum {
52 SIZE = 32,
53 }; // 8 fields of four bytes each
54};
55
56static QDataStream &operator>>(QDataStream &s, RasHeader &head)
57{
58 s >> head.MagicNumber;
59 s >> head.Width;
60 s >> head.Height;
61 s >> head.Depth;
62 s >> head.Length;
63 s >> head.Type;
64 s >> head.ColorMapType;
65 s >> head.ColorMapLength;
66 /*qDebug() << "MagicNumber: " << head.MagicNumber
67 << "Width: " << head.Width
68 << "Height: " << head.Height
69 << "Depth: " << head.Depth
70 << "Length: " << head.Length
71 << "Type: " << head.Type
72 << "ColorMapType: " << head.ColorMapType
73 << "ColorMapLength: " << head.ColorMapLength;*/
74 return s;
75}
76
77static bool IsSupported(const RasHeader &head)
78{
79 // check magic number
80 if (head.MagicNumber != rasMagicBigEndian) {
81 return false;
82 }
83 // check for an appropriate depth
84 if (head.Depth != 1 && head.Depth != 8 && head.Depth != 24 && head.Depth != 32) {
85 return false;
86 }
87 if (head.Width == 0 || head.Height == 0) {
88 return false;
89 }
90 // the Type field adds support for RLE(BGR), RGB and other encodings
91 // we support Type 1: Normal(BGR), Type 2: RLE(BGR) and Type 3: Normal(RGB) ONLY!
92 // TODO: add support for Type 4,5: TIFF/IFF
93 if (!(head.Type == RAS_TYPE_STANDARD || head.Type == RAS_TYPE_RGB_FORMAT || head.Type == RAS_TYPE_BYTE_ENCODED)) {
94 return false;
95 }
96 return true;
97}
98
99static QImage::Format imageFormat(const RasHeader &header)
100{
101 if (header.ColorMapType == RAS_COLOR_MAP_TYPE_RGB) {
102 return QImage::Format_Indexed8;
103 }
104 if (header.Depth == 8 && header.ColorMapType == RAS_COLOR_MAP_TYPE_NONE) {
105 return QImage::Format_Grayscale8;
106 }
107 if (header.Depth == 1) {
108 return QImage::Format_Mono;
109 }
110 return QImage::Format_RGB32;
111}
112
113class LineDecoder
114{
115public:
116 LineDecoder(QIODevice *d, const RasHeader &ras)
117 : device(d)
118 , header(ras)
119 {
120 }
121
122 QByteArray readLine(qint64 size)
123 {
124 /* *** uncompressed
125 */
126 if (header.Type != RAS_TYPE_BYTE_ENCODED) {
127 return device->read(maxlen: size);
128 }
129
130 /* *** rle compressed
131 * The Run-length encoding (RLE) scheme optionally used in Sun Raster
132 * files (Type = 0002h) is used to encode bytes of image data
133 * separately. RLE encoding may be found in any Sun Raster file
134 * regardless of the type of image data it contains.
135 *
136 * The RLE packets are typically three bytes in size:
137 * - The first byte is a Flag Value indicating the type of RLE packet.
138 * - The second byte is the Run Count.
139 * - The third byte is the Run Value.
140 *
141 * A Flag Value of 80h is followed by a Run Count in the range of 01h
142 * to FFh. The Run Value follows the Run count and is in the range of
143 * 00h to FFh. The pixel run is the Run Value repeated Run Count times.
144 * There are two exceptions to this algorithm. First, if the Run Count
145 * following the Flag Value is 00h, this is an indication that the run
146 * is a single byte in length and has a value of 80h. And second, if
147 * the Flag Value is not 80h, then it is assumed that the data is
148 * unencoded pixel data and is written directly to the output stream.
149 *
150 * source: http://www.fileformat.info/format/sunraster/egff.htm
151 */
152 for (qsizetype psz = 0, ptr = 0; uncBuffer.size() < size;) {
153 rleBuffer.append(a: device->read(maxlen: std::min(a: qint64(32768), b: size)));
154 qsizetype sz = rleBuffer.size();
155 if (psz == sz) {
156 break; // avoid infinite loop (data corrupted?!)
157 }
158 auto data = reinterpret_cast<uchar *>(rleBuffer.data());
159 for (; ptr < sz;) {
160 auto flag = data[ptr++];
161 if (flag == 0x80) {
162 if (ptr >= sz) {
163 ptr -= 1;
164 break;
165 }
166 auto cnt = data[ptr++];
167 if (cnt == 0) {
168 uncBuffer.append(c: char(0x80));
169 continue;
170 } else if (ptr >= sz) {
171 ptr -= 2;
172 break;
173 }
174 auto val = data[ptr++];
175 uncBuffer.append(a: QByteArray(1 + cnt, char(val)));
176 } else {
177 uncBuffer.append(c: char(flag));
178 }
179 }
180 if (ptr) { // remove consumed data
181 rleBuffer.remove(index: 0, len: ptr);
182 ptr = 0;
183 }
184 psz = rleBuffer.size();
185 }
186 if (uncBuffer.size() < size) {
187 return QByteArray(); // something wrong
188 }
189 auto line = uncBuffer.mid(index: 0, len: size);
190 uncBuffer.remove(index: 0, len: line.size()); // remove consumed data
191 return line;
192 }
193
194private:
195 QIODevice *device;
196 RasHeader header;
197
198 // RLE decoding buffers
199 QByteArray rleBuffer;
200 QByteArray uncBuffer;
201};
202
203static bool LoadRAS(QDataStream &s, const RasHeader &ras, QImage &img)
204{
205 s.device()->seek(pos: RasHeader::SIZE);
206
207 // The width of a scan line is always a multiple of 16 bits, padded when necessary.
208 auto rasLineSize = (qint64(ras.Width) * ras.Depth + 7) / 8;
209 if (rasLineSize & 1)
210 ++rasLineSize;
211 if (rasLineSize > kMaxQVectorSize) {
212 qWarning() << "LoadRAS() unsupported line size" << rasLineSize;
213 return false;
214 }
215
216 // Allocate image
217 img = imageAlloc(width: ras.Width, height: ras.Height, format: imageFormat(header: ras));
218 if (img.isNull()) {
219 return false;
220 }
221
222 // Read palette if needed.
223 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_RGB) {
224 QList<quint8> palette(ras.ColorMapLength);
225 for (quint32 i = 0; i < ras.ColorMapLength; ++i) {
226 s >> palette[i];
227 }
228 QList<QRgb> colorTable;
229 for (quint32 i = 0, n = ras.ColorMapLength / 3; i < n; ++i) {
230 colorTable << qRgb(r: palette.at(i), g: palette.at(i: i + n), b: palette.at(i: i + 2 * n));
231 }
232 for (; colorTable.size() < 256;) {
233 colorTable << qRgb(r: 255, g: 255, b: 255);
234 }
235 img.setColorTable(colorTable);
236 if (s.status() != QDataStream::Ok) {
237 return false;
238 }
239 }
240
241 LineDecoder dec(s.device(), ras);
242 auto bytesPerLine = std::min(a: img.bytesPerLine(), b: qsizetype(rasLineSize));
243 for (quint32 y = 0; y < ras.Height; ++y) {
244 auto rasLine = dec.readLine(size: rasLineSize);
245 if (rasLine.size() != rasLineSize) {
246 qWarning() << "LoadRAS() unable to read line" << y << ": the seems corrupted!";
247 return false;
248 }
249
250 // Grayscale 1-bit / Grayscale 8-bit (never seen)
251 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && (ras.Depth == 1 || ras.Depth == 8)) {
252 for (auto &&b : rasLine) {
253 b = ~b;
254 }
255 std::memcpy(dest: img.scanLine(y), src: rasLine.constData(), n: bytesPerLine);
256 continue;
257 }
258
259 // Image with palette
260 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_RGB && (ras.Depth == 1 || ras.Depth == 8)) {
261 std::memcpy(dest: img.scanLine(y), src: rasLine.constData(), n: bytesPerLine);
262 continue;
263 }
264
265 // BGR 24-bit
266 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && ras.Depth == 24 && (ras.Type == RAS_TYPE_STANDARD || ras.Type == RAS_TYPE_BYTE_ENCODED)) {
267 quint8 red;
268 quint8 green;
269 quint8 blue;
270 auto scanLine = reinterpret_cast<QRgb *>(img.scanLine(y));
271 for (quint32 x = 0; x < ras.Width; x++) {
272 red = rasLine.at(i: x * 3 + 2);
273 green = rasLine.at(i: x * 3 + 1);
274 blue = rasLine.at(i: x * 3);
275 *(scanLine + x) = qRgb(r: red, g: green, b: blue);
276 }
277 continue;
278 }
279
280 // RGB 24-bit
281 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && ras.Depth == 24 && ras.Type == RAS_TYPE_RGB_FORMAT) {
282 quint8 red;
283 quint8 green;
284 quint8 blue;
285 auto scanLine = reinterpret_cast<QRgb *>(img.scanLine(y));
286 for (quint32 x = 0; x < ras.Width; x++) {
287 red = rasLine.at(i: x * 3);
288 green = rasLine.at(i: x * 3 + 1);
289 blue = rasLine.at(i: x * 3 + 2);
290 *(scanLine + x) = qRgb(r: red, g: green, b: blue);
291 }
292 continue;
293 }
294
295 // BGR 32-bit (not tested: test case missing)
296 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && ras.Depth == 32 && (ras.Type == RAS_TYPE_STANDARD || ras.Type == RAS_TYPE_BYTE_ENCODED)) {
297 quint8 red;
298 quint8 green;
299 quint8 blue;
300 auto scanLine = reinterpret_cast<QRgb *>(img.scanLine(y));
301 for (quint32 x = 0; x < ras.Width; x++) {
302 red = rasLine.at(i: x * 4 + 3);
303 green = rasLine.at(i: x * 4 + 2);
304 blue = rasLine.at(i: x * 4 + 1);
305 *(scanLine + x) = qRgb(r: red, g: green, b: blue);
306 }
307
308 continue;
309 }
310
311 // RGB 32-bit (tested: test case missing due to image too large)
312 if (ras.ColorMapType == RAS_COLOR_MAP_TYPE_NONE && ras.Depth == 32 && ras.Type == RAS_TYPE_RGB_FORMAT) {
313 quint8 red;
314 quint8 green;
315 quint8 blue;
316 auto scanLine = reinterpret_cast<QRgb *>(img.scanLine(y));
317 for (quint32 x = 0; x < ras.Width; x++) {
318 red = rasLine.at(i: x * 4 + 1);
319 green = rasLine.at(i: x * 4 + 2);
320 blue = rasLine.at(i: x * 4 + 3);
321 *(scanLine + x) = qRgb(r: red, g: green, b: blue);
322 }
323 continue;
324 }
325
326 qWarning() << "LoadRAS() unsupported format!"
327 << "ColorMapType:" << ras.ColorMapType << "Type:" << ras.Type << "Depth:" << ras.Depth;
328 return false;
329 }
330
331 return true;
332}
333} // namespace
334
335RASHandler::RASHandler()
336{
337}
338
339bool RASHandler::canRead() const
340{
341 if (canRead(device: device())) {
342 setFormat("ras");
343 return true;
344 }
345 return false;
346}
347
348bool RASHandler::canRead(QIODevice *device)
349{
350 if (!device) {
351 qWarning(msg: "RASHandler::canRead() called with no device");
352 return false;
353 }
354
355 if (device->isSequential()) {
356 // qWarning("Reading ras files from sequential devices not supported");
357 return false;
358 }
359
360 qint64 oldPos = device->pos();
361 QByteArray head = device->read(maxlen: RasHeader::SIZE); // header is exactly 32 bytes, always FIXME
362 int readBytes = head.size(); // this should always be 32 bytes
363
364 device->seek(pos: oldPos);
365
366 if (readBytes < RasHeader::SIZE) {
367 return false;
368 }
369
370 QDataStream stream(head);
371 stream.setByteOrder(QDataStream::BigEndian);
372 RasHeader ras;
373 stream >> ras;
374 return IsSupported(head: ras);
375}
376
377bool RASHandler::read(QImage *outImage)
378{
379 QDataStream s(device());
380 s.setByteOrder(QDataStream::BigEndian);
381
382 // Read image header.
383 RasHeader ras;
384 s >> ras;
385
386 if (ras.ColorMapLength > kMaxQVectorSize) {
387 qWarning() << "LoadRAS() unsupported image color map length in file header" << ras.ColorMapLength;
388 return false;
389 }
390
391 // Check supported file types.
392 if (!IsSupported(head: ras)) {
393 // qDebug() << "This RAS file is not supported.";
394 return false;
395 }
396
397 QImage img;
398 bool result = LoadRAS(s, ras, img);
399
400 if (result == false) {
401 // qDebug() << "Error loading RAS file.";
402 return false;
403 }
404
405 *outImage = img;
406 return true;
407}
408
409bool RASHandler::supportsOption(ImageOption option) const
410{
411 if (option == QImageIOHandler::Size) {
412 return true;
413 }
414 if (option == QImageIOHandler::ImageFormat) {
415 return true;
416 }
417 return false;
418}
419
420QVariant RASHandler::option(ImageOption option) const
421{
422 QVariant v;
423
424 if (option == QImageIOHandler::Size) {
425 if (auto d = device()) {
426 // transactions works on both random and sequential devices
427 d->startTransaction();
428 auto ba = d->read(maxlen: RasHeader::SIZE);
429 d->rollbackTransaction();
430
431 QDataStream s(ba);
432 s.setByteOrder(QDataStream::BigEndian);
433
434 RasHeader header;
435 s >> header;
436
437 if (s.status() == QDataStream::Ok && IsSupported(head: header)) {
438 v = QVariant::fromValue(value: QSize(header.Width, header.Height));
439 }
440 }
441 }
442
443 if (option == QImageIOHandler::ImageFormat) {
444 if (auto d = device()) {
445 // transactions works on both random and sequential devices
446 d->startTransaction();
447 auto ba = d->read(maxlen: RasHeader::SIZE);
448 d->rollbackTransaction();
449
450 QDataStream s(ba);
451 s.setByteOrder(QDataStream::BigEndian);
452
453 RasHeader header;
454 s >> header;
455
456 if (s.status() == QDataStream::Ok && IsSupported(head: header)) {
457 v = QVariant::fromValue(value: imageFormat(header));
458 }
459 }
460 }
461
462 return v;
463}
464
465QImageIOPlugin::Capabilities RASPlugin::capabilities(QIODevice *device, const QByteArray &format) const
466{
467 if (format == "im1" || format == "im8" || format == "im24" || format == "im32" || format == "ras" || format == "sun") {
468 return Capabilities(CanRead);
469 }
470 if (!format.isEmpty()) {
471 return {};
472 }
473 if (!device->isOpen()) {
474 return {};
475 }
476
477 Capabilities cap;
478 if (device->isReadable() && RASHandler::canRead(device)) {
479 cap |= CanRead;
480 }
481 return cap;
482}
483
484QImageIOHandler *RASPlugin::create(QIODevice *device, const QByteArray &format) const
485{
486 QImageIOHandler *handler = new RASHandler;
487 handler->setDevice(device);
488 handler->setFormat(format);
489 return handler;
490}
491
492#include "moc_ras_p.cpp"
493

source code of kimageformats/src/imageformats/ras.cpp