Classes¶

class CMacroBlock
A macro block is a decoding unit of fixed size (uncoded)

Public Member Functions¶

CDecoder (CPGFStream *stream, PGFPreHeader &preHeader, PGFHeader &header, PGFPostHeader &postHeader, UINT32 *&levelLength, UINT64 &userDataPos, bool useOMP, UINT32 userDataPolicy)
~CDecoder ()
Destructor. void Partition (CSubband *band, int quantParam, int width, int height, int startPos, int pitch)
void DecodeInterleaved (CWaveletTransform *wtChannel, int level, int quantParam)
UINT32 GetEncodedHeaderLength () const
void SetStreamPosToStart ()
Resets stream position to beginning of PGF pre-header. void SetStreamPosToData ()
Resets stream position to beginning of data block. void Skip (UINT64 offset)
void DequantizeValue (CSubband *band, UINT32 bandPos, int quantParam)
UINT32 ReadEncodedData (UINT8 *target, UINT32 len) const
void DecodeBuffer ()
CPGFStream * GetStream ()
void GetNextMacroBlock ()

Private Member Functions¶

void ReadMacroBlock (CMacroBlock *block)
throws IOException

Private Attributes¶

CPGFStream * m_stream
input PGF stream UINT64 m_startPos
stream position at the beginning of the PGF pre-header UINT64 m_streamSizeEstimation
estimation of stream size UINT32 m_encodedHeaderLength
stream offset from startPos to the beginning of the data part (highest level) CMacroBlock ** m_macroBlocks
array of macroblocks int m_currentBlockIndex
index of current macro block int m_macroBlockLen
array length int m_macroBlocksAvailable
number of decoded macro blocks (including currently used macro block) CMacroBlock * m_currentBlock
current macro block (used by main thread)

CDecoder::CDecoder (CPGFStream * stream, PGFPreHeader & preHeader, PGFHeader & header, PGFPostHeader & postHeader, UINT32 *& levelLength, UINT64 & userDataPos, bool useOMP, UINT32 userDataPolicy)¶

Constructor: Read pre-header, header, and levelLength at current stream position. It might throw an IOException.

Parameters

Constructor Read pre-header, header, and levelLength It might throw an IOException.

Parameters

Definition at line 73 of file Decoder.cpp.

76 : m_stream(stream)
77 , m_startPos(0)
78 , m_streamSizeEstimation(0)
79 , m_encodedHeaderLength(0)
80 , m_currentBlockIndex(0)
81 , m_macroBlocksAvailable(0)
82 #ifdef __PGFROISUPPORT__
83 , m_roi(false)
84 #endif
85 {
86         ASSERT(m_stream);
87 
88         int count, expected;
89 
90         // store current stream position
91         m_startPos = m_stream->GetPos();
92 
93         // read magic and version
94         count = expected = MagicVersionSize;
95         m_stream->Read(&count, &preHeader);
96         if (count != expected) ReturnWithError(MissingData);
97 
98         // read header size
99         if (preHeader.version & Version6) {
100                 // 32 bit header size since version 6
101                 count = expected = 4;
102         } else {
103                 count = expected = 2;
104         }
105         m_stream->Read(&count, ((UINT8*)&preHeader) + MagicVersionSize);
106         if (count != expected) ReturnWithError(MissingData);
107 
108         // make sure the values are correct read
109         preHeader.hSize = __VAL(preHeader.hSize);
110 
111         // check magic number
112         if (memcmp(preHeader.magic, PGFMagic, 3) != 0) {
113                 // error condition: wrong Magic number
114                 ReturnWithError(FormatCannotRead);
115         }
116 
117         // read file header
118         count = expected = (preHeader.hSize < HeaderSize) ? preHeader.hSize : HeaderSize;
119         m_stream->Read(&count, &header);
120         if (count != expected) ReturnWithError(MissingData);
121 
122         // make sure the values are correct read
123         header.height = __VAL(UINT32(header.height));
124         header.width = __VAL(UINT32(header.width));
125 
126         // be ready to read all versions including version 0
127         if (preHeader.version > 0) {
128 #ifndef __PGFROISUPPORT__
129                 // check ROI usage
130                 if (preHeader.version & PGFROI) ReturnWithError(FormatCannotRead);
131 #endif
132 
133                 UINT32 size = preHeader.hSize;
134 
135                 if (size > HeaderSize) {
136                         size -= HeaderSize;
137                         count = 0;
138 
139                         // read post-header
140                         if (header.mode == ImageModeIndexedColor) {
141                                 if (size < ColorTableSize) ReturnWithError(FormatCannotRead);
142                                 // read color table
143                                 count = expected = ColorTableSize;
144                                 m_stream->Read(&count, postHeader.clut);
145                                 if (count != expected) ReturnWithError(MissingData);
146                         }
147 
148                         if (size > (UINT32)count) {
149                                 size -= count;
150 
151                                 // read/skip user data
152                                 UserdataPolicy policy = (UserdataPolicy)((userDataPolicy <= MaxUserDataSize) ? UP_CachePrefix : 0xFFFFFFFF - userDataPolicy);
153                                 userDataPos = m_stream->GetPos();
154                                 postHeader.userDataLen = size;
155 
156                                 if (policy == UP_Skip) {
157                                         postHeader.cachedUserDataLen = 0;
158                                         postHeader.userData = nullptr;
159                                         Skip(size);
160                                 } else {
161                                         postHeader.cachedUserDataLen = (policy == UP_CachePrefix) ? __min(size, userDataPolicy) : size;
162 
163                                         // create user data memory block
164                                         postHeader.userData = new(std::nothrow) UINT8[postHeader.cachedUserDataLen];
165                                         if (!postHeader.userData) ReturnWithError(InsufficientMemory);
166 
167                                         // read user data
168                                         count = expected = postHeader.cachedUserDataLen;
169                                         m_stream->Read(&count, postHeader.userData);
170                                         if (count != expected) ReturnWithError(MissingData);
171 
172                                         // skip remaining user data
173                                         if (postHeader.cachedUserDataLen < size) Skip(size - postHeader.cachedUserDataLen);
174                                 }
175                         }
176                 }
177 
178                 // create levelLength
179                 levelLength = new(std::nothrow) UINT32[header.nLevels];
180                 if (!levelLength) ReturnWithError(InsufficientMemory);
181 
182                 // read levelLength
183                 count = expected = header.nLevels*WordBytes;
184                 m_stream->Read(&count, levelLength);
185                 if (count != expected) ReturnWithError(MissingData);
186 
187 #ifdef PGF_USE_BIG_ENDIAN 
188                 // make sure the values are correct read
189                 for (int i=0; i < header.nLevels; i++) {
190                         levelLength[i] = __VAL(levelLength[i]);
191                 }
192 #endif
193 
194                 // compute the total size in bytes; keep attention: level length information is optional
195                 for (int i=0; i < header.nLevels; i++) {
196                         m_streamSizeEstimation += levelLength[i];
197                 }
198                 
199         }
200 
201         // store current stream position
202         m_encodedHeaderLength = UINT32(m_stream->GetPos() - m_startPos);
203 
204         // set number of threads
205 #ifdef LIBPGF_USE_OPENMP 
206         m_macroBlockLen = omp_get_num_procs();
207 #else
208         m_macroBlockLen = 1;
209 #endif
210 
211         if (useOMP && m_macroBlockLen > 1) {
212 #ifdef LIBPGF_USE_OPENMP
213                 omp_set_num_threads(m_macroBlockLen);
214 #endif
215 
216                 // create macro block array
217                 m_macroBlocks = new(std::nothrow) CMacroBlock*[m_macroBlockLen];
218                 if (!m_macroBlocks) ReturnWithError(InsufficientMemory);
219                 for (int i = 0; i < m_macroBlockLen; i++) m_macroBlocks[i] = new CMacroBlock();
220                 m_currentBlock = m_macroBlocks[m_currentBlockIndex];
221         } else {
222                 m_macroBlocks = 0;
223                 m_macroBlockLen = 1; // there is only one macro block
224                 m_currentBlock = new(std::nothrow) CMacroBlock();
225                 if (!m_currentBlock) ReturnWithError(InsufficientMemory);
226         }
227 }

CDecoder::~CDecoder ()¶

Destructor.

Definition at line 231 of file Decoder.cpp.

231                     {
232         if (m_macroBlocks) {
233                 for (int i=0; i < m_macroBlockLen; i++) delete m_macroBlocks[i];
234                 delete[] m_macroBlocks;
235         } else {
236                 delete m_currentBlock;
237         }
238 }

void CDecoder::DecodeBuffer ()¶

Reads next block(s) from stream and decodes them It might throw an IOException.

Definition at line 494 of file Decoder.cpp.

494                             {
495         ASSERT(m_macroBlocksAvailable <= 0);
496 
497         // macro block management
498         if (m_macroBlockLen == 1) {
499                 ASSERT(m_currentBlock);
500                 ReadMacroBlock(m_currentBlock);
501                 m_currentBlock->BitplaneDecode();
502                 m_macroBlocksAvailable = 1;
503         } else {
504                 m_macroBlocksAvailable = 0;
505                 for (int i=0; i < m_macroBlockLen; i++) {
506                         // read sequentially several blocks
507                         try {
508                                 ReadMacroBlock(m_macroBlocks[i]);
509                                 m_macroBlocksAvailable++;
510                         } catch(IOException& ex) {
511                                 if (ex.error == MissingData || ex.error == FormatCannotRead) {
512                                         break; // no further data available or the data isn't valid PGF data (might occur in streaming or PPPExt)
513                                 } else {
514                                         throw;
515                                 }
516                         }
517                 }
518 #ifdef LIBPGF_USE_OPENMP
519                 // decode in parallel
520                 #pragma omp parallel for default(shared) //no declared exceptions in next block
521 #endif
522                 for (int i=0; i < m_macroBlocksAvailable; i++) {
523                         m_macroBlocks[i]->BitplaneDecode();
524                 }
525                 
526                 // prepare current macro block
527                 m_currentBlockIndex = 0;
528                 m_currentBlock = m_macroBlocks[m_currentBlockIndex];
529         }
530 }

void CDecoder::DecodeInterleaved (CWaveletTransform * wtChannel, int level, int quantParam)¶

Deccoding and dequantization of HL and LH subband (interleaved) using partitioning scheme. Partitioning scheme: The plane is partitioned in squares of side length InterBlockSize. It might throw an IOException.

Parameters

Definition at line 333 of file Decoder.cpp.

333                                                                                         {
334         CSubband* hlBand = wtChannel->GetSubband(level, HL);
335         CSubband* lhBand = wtChannel->GetSubband(level, LH);
336         const div_t lhH = div(lhBand->GetHeight(), InterBlockSize);
337         const div_t hlW = div(hlBand->GetWidth(), InterBlockSize);
338         const int hlws = hlBand->GetWidth() - InterBlockSize;
339         const int hlwr = hlBand->GetWidth() - hlW.rem;
340         const int lhws = lhBand->GetWidth() - InterBlockSize;
341         const int lhwr = lhBand->GetWidth() - hlW.rem;
342         int hlPos, lhPos;
343         int hlBase = 0, lhBase = 0, hlBase2, lhBase2;
344 
345         ASSERT(lhBand->GetWidth() >= hlBand->GetWidth());
346         ASSERT(hlBand->GetHeight() >= lhBand->GetHeight());
347 
348         if (!hlBand->AllocMemory()) ReturnWithError(InsufficientMemory);
349         if (!lhBand->AllocMemory()) ReturnWithError(InsufficientMemory);
350 
351         // correct quantParam with normalization factor
352         quantParam -= level;
353         if (quantParam < 0) quantParam = 0;
354 
355         // main height
356         for (int i=0; i < lhH.quot; i++) {
357                 // main width
358                 hlBase2 = hlBase;
359                 lhBase2 = lhBase;
360                 for (int j=0; j < hlW.quot; j++) {
361                         hlPos = hlBase2;
362                         lhPos = lhBase2;
363                         for (int y=0; y < InterBlockSize; y++) {
364                                 for (int x=0; x < InterBlockSize; x++) {
365                                         DequantizeValue(hlBand, hlPos, quantParam);
366                                         DequantizeValue(lhBand, lhPos, quantParam);
367                                         hlPos++;
368                                         lhPos++;
369                                 }
370                                 hlPos += hlws;
371                                 lhPos += lhws;
372                         }
373                         hlBase2 += InterBlockSize;
374                         lhBase2 += InterBlockSize;
375                 }
376                 // rest of width
377                 hlPos = hlBase2;
378                 lhPos = lhBase2;
379                 for (int y=0; y < InterBlockSize; y++) {
380                         for (int x=0; x < hlW.rem; x++) {
381                                 DequantizeValue(hlBand, hlPos, quantParam);
382                                 DequantizeValue(lhBand, lhPos, quantParam);
383                                 hlPos++;
384                                 lhPos++;
385                         }
386                         // width difference between HL and LH
387                         if (lhBand->GetWidth() > hlBand->GetWidth()) {
388                                 DequantizeValue(lhBand, lhPos, quantParam);
389                         }
390                         hlPos += hlwr;
391                         lhPos += lhwr;
392                         hlBase += hlBand->GetWidth();
393                         lhBase += lhBand->GetWidth();
394                 }
395         }
396         // main width 
397         hlBase2 = hlBase;
398         lhBase2 = lhBase;
399         for (int j=0; j < hlW.quot; j++) {
400                 // rest of height
401                 hlPos = hlBase2;
402                 lhPos = lhBase2;
403                 for (int y=0; y < lhH.rem; y++) {
404                         for (int x=0; x < InterBlockSize; x++) {
405                                 DequantizeValue(hlBand, hlPos, quantParam);
406                                 DequantizeValue(lhBand, lhPos, quantParam);
407                                 hlPos++;
408                                 lhPos++;
409                         }
410                         hlPos += hlws;
411                         lhPos += lhws;
412                 }
413                 hlBase2 += InterBlockSize;
414                 lhBase2 += InterBlockSize;
415         }
416         // rest of height
417         hlPos = hlBase2;
418         lhPos = lhBase2;
419         for (int y=0; y < lhH.rem; y++) {
420                 // rest of width
421                 for (int x=0; x < hlW.rem; x++) {
422                         DequantizeValue(hlBand, hlPos, quantParam);
423                         DequantizeValue(lhBand, lhPos, quantParam);
424                         hlPos++;
425                         lhPos++;
426                 }
427                 // width difference between HL and LH
428                 if (lhBand->GetWidth() > hlBand->GetWidth()) {
429                         DequantizeValue(lhBand, lhPos, quantParam);
430                 }
431                 hlPos += hlwr;
432                 lhPos += lhwr;
433                 hlBase += hlBand->GetWidth();
434         }
435         // height difference between HL and LH
436         if (hlBand->GetHeight() > lhBand->GetHeight()) {
437                 // total width
438                 hlPos = hlBase;
439                 for (int j=0; j < hlBand->GetWidth(); j++) {
440                         DequantizeValue(hlBand, hlPos, quantParam);
441                         hlPos++;
442                 }
443         }
444 }

void CDecoder::DequantizeValue (CSubband * band, UINT32 bandPos, int quantParam)¶

Dequantization of a single value at given position in subband. It might throw an IOException.

Parameters

Dequantization of a single value at given position in subband. If encoded data is available, then stores dequantized band value into buffer m_value at position m_valuePos. Otherwise reads encoded data block and decodes it. It might throw an IOException.

Parameters

Definition at line 462 of file Decoder.cpp.

462                                                                              {
463         ASSERT(m_currentBlock);
464 
465         if (m_currentBlock->IsCompletelyRead()) {
466                 // all data of current macro block has been read --> prepare next macro block
467                 GetNextMacroBlock();
468         }
469         
470         band->SetData(bandPos, m_currentBlock->m_value[m_currentBlock->m_valuePos] << quantParam);
471         m_currentBlock->m_valuePos++;
472 }

UINT32 CDecoder::GetEncodedHeaderLength () const [inline]¶

Returns the length of all encoded headers in bytes.

Returns

Definition at line 136 of file Decoder.h.

136 { return m_encodedHeaderLength; }

void CDecoder::GetNextMacroBlock ()¶

Gets next macro block It might throw an IOException.

Definition at line 477 of file Decoder.cpp.

477                                  {
478         // current block has been read --> prepare next current block
479         m_macroBlocksAvailable--;
480 
481         if (m_macroBlocksAvailable > 0) {
482                 m_currentBlock = m_macroBlocks[++m_currentBlockIndex];
483         } else {
484                 DecodeBuffer();
485         }
486         ASSERT(m_currentBlock);
487 }

CPGFStream * CDecoder::GetStream () [inline]¶

Returns

Definition at line 174 of file Decoder.h.

174 { return m_stream; }

void CDecoder::Partition (CSubband * band, int quantParam, int width, int height, int startPos, int pitch)¶

Unpartitions a rectangular region of a given subband. Partitioning scheme: The plane is partitioned in squares of side length LinBlockSize. Read wavelet coefficients from the output buffer of a macro block. It might throw an IOException.

Parameters

Definition at line 266 of file Decoder.cpp.

266                                                                                                        {
267         ASSERT(band);
268 
269         const div_t ww = div(width, LinBlockSize);
270         const div_t hh = div(height, LinBlockSize);
271         const int ws = pitch - LinBlockSize;
272         const int wr = pitch - ww.rem;
273         int pos, base = startPos, base2;
274 
275         // main height
276         for (int i=0; i < hh.quot; i++) {
277                 // main width
278                 base2 = base;
279                 for (int j=0; j < ww.quot; j++) {
280                         pos = base2;
281                         for (int y=0; y < LinBlockSize; y++) {
282                                 for (int x=0; x < LinBlockSize; x++) {
283                                         DequantizeValue(band, pos, quantParam);
284                                         pos++;
285                                 }
286                                 pos += ws;
287                         }
288                         base2 += LinBlockSize;
289                 }
290                 // rest of width
291                 pos = base2;
292                 for (int y=0; y < LinBlockSize; y++) {
293                         for (int x=0; x < ww.rem; x++) {
294                                 DequantizeValue(band, pos, quantParam);
295                                 pos++;
296                         }
297                         pos += wr;
298                         base += pitch;
299                 }
300         }
301         // main width 
302         base2 = base;
303         for (int j=0; j < ww.quot; j++) {
304                 // rest of height
305                 pos = base2;
306                 for (int y=0; y < hh.rem; y++) {
307                         for (int x=0; x < LinBlockSize; x++) {
308                                 DequantizeValue(band, pos, quantParam);
309                                 pos++;
310                         }
311                         pos += ws;
312                 }
313                 base2 += LinBlockSize;
314         }
315         // rest of height
316         pos = base2;
317         for (int y=0; y < hh.rem; y++) {
318                 // rest of width
319                 for (int x=0; x < ww.rem; x++) {
320                         DequantizeValue(band, pos, quantParam);
321                         pos++;
322                 }
323                 pos += wr;
324         }
325 }

UINT32 CDecoder::ReadEncodedData (UINT8 * target, UINT32 len) const¶

Copies data from the open stream to a target buffer. It might throw an IOException.

Parameters

Returns

Definition at line 246 of file Decoder.cpp.

246                                                                 {
247         ASSERT(m_stream);
248 
249         int count = len;
250         m_stream->Read(&count, target);
251 
252         return count;
253 }

void CDecoder::ReadMacroBlock (CMacroBlock * block) [private]¶

throws IOException

Definition at line 535 of file Decoder.cpp.

535                                                 {
536         ASSERT(block);
537 
538         UINT16 wordLen;
539         ROIBlockHeader h(BufferSize);
540         int count, expected;
541 
542 #ifdef TRACE
543         //UINT32 filePos = (UINT32)m_stream->GetPos();
544         //printf("DecodeBuffer: %d\n", filePos);
545 #endif
546 
547         // read wordLen
548         count = expected = sizeof(UINT16);
549         m_stream->Read(&count, &wordLen); 
550         if (count != expected) ReturnWithError(MissingData);
551         wordLen = __VAL(wordLen); // convert wordLen
552         if (wordLen > BufferSize) ReturnWithError(FormatCannotRead);
553 
554 #ifdef __PGFROISUPPORT__
555         // read ROIBlockHeader
556         if (m_roi) {
557                 count = expected = sizeof(ROIBlockHeader);
558                 m_stream->Read(&count, &h.val);
559                 if (count != expected) ReturnWithError(MissingData);
560                 h.val = __VAL(h.val); // convert ROIBlockHeader
561         }
562 #endif
563         // save header
564         block->m_header = h;
565 
566         // read data
567         count = expected = wordLen*WordBytes;
568         m_stream->Read(&count, block->m_codeBuffer);
569         if (count != expected) ReturnWithError(MissingData);
570 
571 #ifdef PGF_USE_BIG_ENDIAN 
572         // convert data
573         count /= WordBytes;
574         for (int i=0; i < count; i++) {
575                 block->m_codeBuffer[i] = __VAL(block->m_codeBuffer[i]);
576         }
577 #endif
578 
579 #ifdef __PGFROISUPPORT__
580         ASSERT(m_roi && h.rbh.bufferSize <= BufferSize || h.rbh.bufferSize == BufferSize);
581 #else
582         ASSERT(h.rbh.bufferSize == BufferSize);
583 #endif
584 }

void CDecoder::SetStreamPosToData () [inline]¶

Resets stream position to beginning of data block.

Definition at line 144 of file Decoder.h.

144 { ASSERT(m_stream); m_stream->SetPos(FSFromStart, m_startPos + m_encodedHeaderLength); }

void CDecoder::SetStreamPosToStart () [inline]¶

Resets stream position to beginning of PGF pre-header.

Definition at line 140 of file Decoder.h.

140 { ASSERT(m_stream); m_stream->SetPos(FSFromStart, m_startPos); }

void CDecoder::Skip (UINT64 offset)¶

Skips a given number of bytes in the open stream. It might throw an IOException.

Definition at line 449 of file Decoder.cpp.

449                                  {
450         m_stream->SetPos(FSFromCurrent, offset);
451 }

CMacroBlock* CDecoder::m_currentBlock [private]¶

current macro block (used by main thread)

Definition at line 209 of file Decoder.h.

int CDecoder::m_currentBlockIndex [private]¶

index of current macro block

Definition at line 206 of file Decoder.h.

UINT32 CDecoder::m_encodedHeaderLength [private]¶

stream offset from startPos to the beginning of the data part (highest level)

Definition at line 203 of file Decoder.h.

int CDecoder::m_macroBlockLen [private]¶

array length

Definition at line 207 of file Decoder.h.

CMacroBlock** CDecoder::m_macroBlocks [private]¶

array of macroblocks

Definition at line 205 of file Decoder.h.

int CDecoder::m_macroBlocksAvailable [private]¶

number of decoded macro blocks (including currently used macro block)

Definition at line 208 of file Decoder.h.

UINT64 CDecoder::m_startPos [private]¶

stream position at the beginning of the PGF pre-header

Definition at line 201 of file Decoder.h.

CPGFStream* CDecoder::m_stream [private]¶

input PGF stream

Definition at line 200 of file Decoder.h.

UINT64 CDecoder::m_streamSizeEstimation [private]¶

estimation of stream size

Definition at line 202 of file Decoder.h.