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// Copyright 2014 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
#include "core/fxcodec/codec/codec_int.h"
#include <algorithm>
#include <memory>
#include <utility>
#include <vector>
#include "core/fxcodec/codec/ccodec_flatemodule.h"
#include "core/fxcodec/codec/ccodec_scanlinedecoder.h"
#include "core/fxcrt/fx_extension.h"
#include "third_party/base/numerics/safe_conversions.h"
#include "third_party/base/ptr_util.h"
#if defined(USE_SYSTEM_ZLIB)
#include <zlib.h>
#else
#include "third_party/zlib/zlib.h"
#endif
extern "C" {
static void* my_alloc_func(void* opaque,
unsigned int items,
unsigned int size) {
return FX_Alloc2D(uint8_t, items, size);
}
static void my_free_func(void* opaque, void* address) {
FX_Free(address);
}
} // extern "C"
namespace {
uint32_t FlateGetPossiblyTruncatedTotalOut(void* context) {
return pdfium::base::saturated_cast<uint32_t>(
static_cast<z_stream*>(context)->total_out);
}
uint32_t FlateGetPossiblyTruncatedTotalIn(void* context) {
return pdfium::base::saturated_cast<uint32_t>(
static_cast<z_stream*>(context)->total_in);
}
bool FlateCompress(unsigned char* dest_buf,
unsigned long* dest_size,
const unsigned char* src_buf,
uint32_t src_size) {
return compress(dest_buf, dest_size, src_buf, src_size) == Z_OK;
}
void* FlateInit() {
z_stream* p = FX_Alloc(z_stream, 1);
memset(p, 0, sizeof(z_stream));
p->zalloc = my_alloc_func;
p->zfree = my_free_func;
inflateInit(p);
return p;
}
void FlateInput(void* context,
const unsigned char* src_buf,
uint32_t src_size) {
static_cast<z_stream*>(context)->next_in =
const_cast<unsigned char*>(src_buf);
static_cast<z_stream*>(context)->avail_in = src_size;
}
uint32_t FlateOutput(void* context,
unsigned char* dest_buf,
uint32_t dest_size) {
static_cast<z_stream*>(context)->next_out = dest_buf;
static_cast<z_stream*>(context)->avail_out = dest_size;
uint32_t pre_pos = FlateGetPossiblyTruncatedTotalOut(context);
int ret = inflate(static_cast<z_stream*>(context), Z_SYNC_FLUSH);
uint32_t post_pos = FlateGetPossiblyTruncatedTotalOut(context);
ASSERT(post_pos >= pre_pos);
uint32_t written = post_pos - pre_pos;
if (written < dest_size)
memset(dest_buf + written, '\0', dest_size - written);
return ret;
}
uint32_t FlateGetAvailOut(void* context) {
return static_cast<z_stream*>(context)->avail_out;
}
void FlateEnd(void* context) {
inflateEnd(static_cast<z_stream*>(context));
static_cast<z_stream*>(context)->zfree(0, context);
}
class CLZWDecoder {
public:
int Decode(uint8_t* output,
uint32_t& outlen,
const uint8_t* input,
uint32_t& size,
bool bEarlyChange);
private:
void AddCode(uint32_t prefix_code, uint8_t append_char);
void DecodeString(uint32_t code);
uint32_t m_InPos;
uint32_t m_OutPos;
uint8_t* m_pOutput;
const uint8_t* m_pInput;
bool m_Early;
uint32_t m_CodeArray[5021];
uint32_t m_nCodes;
uint8_t m_DecodeStack[4000];
uint32_t m_StackLen;
int m_CodeLen;
};
void CLZWDecoder::AddCode(uint32_t prefix_code, uint8_t append_char) {
if (m_nCodes + m_Early == 4094) {
return;
}
m_CodeArray[m_nCodes++] = (prefix_code << 16) | append_char;
if (m_nCodes + m_Early == 512 - 258) {
m_CodeLen = 10;
} else if (m_nCodes + m_Early == 1024 - 258) {
m_CodeLen = 11;
} else if (m_nCodes + m_Early == 2048 - 258) {
m_CodeLen = 12;
}
}
void CLZWDecoder::DecodeString(uint32_t code) {
while (1) {
int index = code - 258;
if (index < 0 || index >= (int)m_nCodes) {
break;
}
uint32_t data = m_CodeArray[index];
if (m_StackLen >= sizeof(m_DecodeStack)) {
return;
}
m_DecodeStack[m_StackLen++] = (uint8_t)data;
code = data >> 16;
}
if (m_StackLen >= sizeof(m_DecodeStack)) {
return;
}
m_DecodeStack[m_StackLen++] = (uint8_t)code;
}
int CLZWDecoder::Decode(uint8_t* dest_buf,
uint32_t& dest_size,
const uint8_t* src_buf,
uint32_t& src_size,
bool bEarlyChange) {
m_CodeLen = 9;
m_InPos = 0;
m_OutPos = 0;
m_pInput = src_buf;
m_pOutput = dest_buf;
m_Early = bEarlyChange ? 1 : 0;
m_nCodes = 0;
uint32_t old_code = 0xFFFFFFFF;
uint8_t last_char = 0;
while (1) {
if (m_InPos + m_CodeLen > src_size * 8) {
break;
}
int byte_pos = m_InPos / 8;
int bit_pos = m_InPos % 8, bit_left = m_CodeLen;
uint32_t code = 0;
if (bit_pos) {
bit_left -= 8 - bit_pos;
code = (m_pInput[byte_pos++] & ((1 << (8 - bit_pos)) - 1)) << bit_left;
}
if (bit_left < 8) {
code |= m_pInput[byte_pos] >> (8 - bit_left);
} else {
bit_left -= 8;
code |= m_pInput[byte_pos++] << bit_left;
if (bit_left) {
code |= m_pInput[byte_pos] >> (8 - bit_left);
}
}
m_InPos += m_CodeLen;
if (code == 257)
break;
if (code < 256) {
if (m_OutPos == dest_size) {
return -5;
}
if (m_pOutput) {
m_pOutput[m_OutPos] = (uint8_t)code;
}
m_OutPos++;
last_char = (uint8_t)code;
if (old_code != 0xFFFFFFFF)
AddCode(old_code, last_char);
old_code = code;
} else if (code == 256) {
m_CodeLen = 9;
m_nCodes = 0;
old_code = 0xFFFFFFFF;
} else {
// Else 257 or greater.
if (old_code == 0xFFFFFFFF)
return 2;
m_StackLen = 0;
if (code >= m_nCodes + 258) {
if (m_StackLen < sizeof(m_DecodeStack)) {
m_DecodeStack[m_StackLen++] = last_char;
}
DecodeString(old_code);
} else {
DecodeString(code);
}
if (m_OutPos + m_StackLen > dest_size) {
return -5;
}
if (m_pOutput) {
for (uint32_t i = 0; i < m_StackLen; i++) {
m_pOutput[m_OutPos + i] = m_DecodeStack[m_StackLen - i - 1];
}
}
m_OutPos += m_StackLen;
last_char = m_DecodeStack[m_StackLen - 1];
if (old_code < 256) {
AddCode(old_code, last_char);
} else if (old_code - 258 >= m_nCodes) {
dest_size = m_OutPos;
src_size = (m_InPos + 7) / 8;
return 0;
} else {
AddCode(old_code, last_char);
}
old_code = code;
}
}
dest_size = m_OutPos;
src_size = (m_InPos + 7) / 8;
return 0;
}
uint8_t PathPredictor(int a, int b, int c) {
int p = a + b - c;
int pa = abs(p - a);
int pb = abs(p - b);
int pc = abs(p - c);
if (pa <= pb && pa <= pc)
return (uint8_t)a;
if (pb <= pc)
return (uint8_t)b;
return (uint8_t)c;
}
void PNG_PredictorEncode(uint8_t** data_buf, uint32_t* data_size) {
const int row_size = 7;
const int row_count = (*data_size + row_size - 1) / row_size;
const int last_row_size = *data_size % row_size;
uint8_t* dest_buf = FX_Alloc2D(uint8_t, row_size + 1, row_count);
int byte_cnt = 0;
uint8_t* pSrcData = *data_buf;
uint8_t* pDestData = dest_buf;
for (int row = 0; row < row_count; row++) {
for (int byte = 0; byte < row_size && byte_cnt < (int)*data_size; byte++) {
pDestData[0] = 2;
uint8_t up = 0;
if (row)
up = pSrcData[byte - row_size];
pDestData[byte + 1] = pSrcData[byte] - up;
++byte_cnt;
}
pDestData += (row_size + 1);
pSrcData += row_size;
}
FX_Free(*data_buf);
*data_buf = dest_buf;
*data_size = (row_size + 1) * row_count -
(last_row_size > 0 ? (row_size - last_row_size) : 0);
}
void PNG_PredictLine(uint8_t* pDestData,
const uint8_t* pSrcData,
const uint8_t* pLastLine,
int bpc,
int nColors,
int nPixels) {
int row_size = (nPixels * bpc * nColors + 7) / 8;
int BytesPerPixel = (bpc * nColors + 7) / 8;
uint8_t tag = pSrcData[0];
if (tag == 0) {
memmove(pDestData, pSrcData + 1, row_size);
return;
}
for (int byte = 0; byte < row_size; byte++) {
uint8_t raw_byte = pSrcData[byte + 1];
switch (tag) {
case 1: {
uint8_t left = 0;
if (byte >= BytesPerPixel) {
left = pDestData[byte - BytesPerPixel];
}
pDestData[byte] = raw_byte + left;
break;
}
case 2: {
uint8_t up = 0;
if (pLastLine) {
up = pLastLine[byte];
}
pDestData[byte] = raw_byte + up;
break;
}
case 3: {
uint8_t left = 0;
if (byte >= BytesPerPixel) {
left = pDestData[byte - BytesPerPixel];
}
uint8_t up = 0;
if (pLastLine) {
up = pLastLine[byte];
}
pDestData[byte] = raw_byte + (up + left) / 2;
break;
}
case 4: {
uint8_t left = 0;
if (byte >= BytesPerPixel) {
left = pDestData[byte - BytesPerPixel];
}
uint8_t up = 0;
if (pLastLine) {
up = pLastLine[byte];
}
uint8_t upper_left = 0;
if (byte >= BytesPerPixel && pLastLine) {
upper_left = pLastLine[byte - BytesPerPixel];
}
pDestData[byte] = raw_byte + PathPredictor(left, up, upper_left);
break;
}
default:
pDestData[byte] = raw_byte;
break;
}
}
}
bool PNG_Predictor(uint8_t*& data_buf,
uint32_t& data_size,
int Colors,
int BitsPerComponent,
int Columns) {
const int BytesPerPixel = (Colors * BitsPerComponent + 7) / 8;
const int row_size = (Colors * BitsPerComponent * Columns + 7) / 8;
if (row_size <= 0)
return false;
const int row_count = (data_size + row_size) / (row_size + 1);
if (row_count <= 0)
return false;
const int last_row_size = data_size % (row_size + 1);
uint8_t* dest_buf = FX_Alloc2D(uint8_t, row_size, row_count);
int byte_cnt = 0;
uint8_t* pSrcData = data_buf;
uint8_t* pDestData = dest_buf;
for (int row = 0; row < row_count; row++) {
uint8_t tag = pSrcData[0];
byte_cnt++;
if (tag == 0) {
int move_size = row_size;
if ((row + 1) * (move_size + 1) > (int)data_size) {
move_size = last_row_size - 1;
}
memmove(pDestData, pSrcData + 1, move_size);
pSrcData += move_size + 1;
pDestData += move_size;
byte_cnt += move_size;
continue;
}
for (int byte = 0; byte < row_size && byte_cnt < (int)data_size; byte++) {
uint8_t raw_byte = pSrcData[byte + 1];
switch (tag) {
case 1: {
uint8_t left = 0;
if (byte >= BytesPerPixel) {
left = pDestData[byte - BytesPerPixel];
}
pDestData[byte] = raw_byte + left;
break;
}
case 2: {
uint8_t up = 0;
if (row) {
up = pDestData[byte - row_size];
}
pDestData[byte] = raw_byte + up;
break;
}
case 3: {
uint8_t left = 0;
if (byte >= BytesPerPixel) {
left = pDestData[byte - BytesPerPixel];
}
uint8_t up = 0;
if (row) {
up = pDestData[byte - row_size];
}
pDestData[byte] = raw_byte + (up + left) / 2;
break;
}
case 4: {
uint8_t left = 0;
if (byte >= BytesPerPixel) {
left = pDestData[byte - BytesPerPixel];
}
uint8_t up = 0;
if (row) {
up = pDestData[byte - row_size];
}
uint8_t upper_left = 0;
if (byte >= BytesPerPixel && row) {
upper_left = pDestData[byte - row_size - BytesPerPixel];
}
pDestData[byte] = raw_byte + PathPredictor(left, up, upper_left);
break;
}
default:
pDestData[byte] = raw_byte;
break;
}
byte_cnt++;
}
pSrcData += row_size + 1;
pDestData += row_size;
}
FX_Free(data_buf);
data_buf = dest_buf;
data_size = row_size * row_count -
(last_row_size > 0 ? (row_size + 1 - last_row_size) : 0);
return true;
}
void TIFF_PredictLine(uint8_t* dest_buf,
uint32_t row_size,
int BitsPerComponent,
int Colors,
int Columns) {
if (BitsPerComponent == 1) {
int row_bits = std::min(BitsPerComponent * Colors * Columns,
pdfium::base::checked_cast<int>(row_size * 8));
int index_pre = 0;
int col_pre = 0;
for (int i = 1; i < row_bits; i++) {
int col = i % 8;
int index = i / 8;
if (((dest_buf[index] >> (7 - col)) & 1) ^
((dest_buf[index_pre] >> (7 - col_pre)) & 1)) {
dest_buf[index] |= 1 << (7 - col);
} else {
dest_buf[index] &= ~(1 << (7 - col));
}
index_pre = index;
col_pre = col;
}
return;
}
int BytesPerPixel = BitsPerComponent * Colors / 8;
if (BitsPerComponent == 16) {
for (uint32_t i = BytesPerPixel; i + 1 < row_size; i += 2) {
uint16_t pixel =
(dest_buf[i - BytesPerPixel] << 8) | dest_buf[i - BytesPerPixel + 1];
pixel += (dest_buf[i] << 8) | dest_buf[i + 1];
dest_buf[i] = pixel >> 8;
dest_buf[i + 1] = (uint8_t)pixel;
}
} else {
for (uint32_t i = BytesPerPixel; i < row_size; i++) {
dest_buf[i] += dest_buf[i - BytesPerPixel];
}
}
}
bool TIFF_Predictor(uint8_t*& data_buf,
uint32_t& data_size,
int Colors,
int BitsPerComponent,
int Columns) {
int row_size = (Colors * BitsPerComponent * Columns + 7) / 8;
if (row_size == 0)
return false;
const int row_count = (data_size + row_size - 1) / row_size;
const int last_row_size = data_size % row_size;
for (int row = 0; row < row_count; row++) {
uint8_t* scan_line = data_buf + row * row_size;
if ((row + 1) * row_size > (int)data_size) {
row_size = last_row_size;
}
TIFF_PredictLine(scan_line, row_size, BitsPerComponent, Colors, Columns);
}
return true;
}
void FlateUncompress(const uint8_t* src_buf,
uint32_t src_size,
uint32_t orig_size,
uint8_t*& dest_buf,
uint32_t& dest_size,
uint32_t& offset) {
dest_buf = nullptr;
dest_size = 0;
void* context = FlateInit();
if (!context)
return;
FlateInput(context, src_buf, src_size);
const uint32_t kMaxInitialAllocSize = 10000000;
uint32_t guess_size = orig_size ? orig_size : src_size * 2;
guess_size = std::min(guess_size, kMaxInitialAllocSize);
uint32_t buf_size = guess_size;
uint32_t last_buf_size = buf_size;
std::unique_ptr<uint8_t, FxFreeDeleter> guess_buf(
FX_Alloc(uint8_t, guess_size + 1));
guess_buf.get()[guess_size] = '\0';
std::vector<uint8_t*> result_tmp_bufs;
uint8_t* cur_buf = guess_buf.release();
while (1) {
uint32_t ret = FlateOutput(context, cur_buf, buf_size);
uint32_t avail_buf_size = FlateGetAvailOut(context);
if (ret != Z_OK || avail_buf_size != 0) {
last_buf_size = buf_size - avail_buf_size;
result_tmp_bufs.push_back(cur_buf);
break;
}
result_tmp_bufs.push_back(cur_buf);
cur_buf = FX_Alloc(uint8_t, buf_size + 1);
cur_buf[buf_size] = '\0';
}
// The TotalOut size returned from the library may not be big enough to
// handle the content the library returns. We can only handle items
// up to 4GB in size.
dest_size = FlateGetPossiblyTruncatedTotalOut(context);
offset = FlateGetPossiblyTruncatedTotalIn(context);
if (result_tmp_bufs.size() == 1) {
dest_buf = result_tmp_bufs[0];
} else {
uint8_t* result_buf = FX_Alloc(uint8_t, dest_size);
uint32_t result_pos = 0;
uint32_t remaining = dest_size;
for (size_t i = 0; i < result_tmp_bufs.size(); i++) {
uint8_t* tmp_buf = result_tmp_bufs[i];
uint32_t tmp_buf_size = buf_size;
if (i == result_tmp_bufs.size() - 1)
tmp_buf_size = last_buf_size;
uint32_t cp_size = std::min(tmp_buf_size, remaining);
memcpy(result_buf + result_pos, tmp_buf, cp_size);
result_pos += cp_size;
remaining -= cp_size;
FX_Free(result_tmp_bufs[i]);
}
dest_buf = result_buf;
}
FlateEnd(context);
}
} // namespace
class CCodec_FlateScanlineDecoder : public CCodec_ScanlineDecoder {
public:
CCodec_FlateScanlineDecoder();
~CCodec_FlateScanlineDecoder() override;
void Create(const uint8_t* src_buf,
uint32_t src_size,
int width,
int height,
int nComps,
int bpc,
int predictor,
int Colors,
int BitsPerComponent,
int Columns);
// CCodec_ScanlineDecoder
bool v_Rewind() override;
uint8_t* v_GetNextLine() override;
uint32_t GetSrcOffset() override;
void* m_pFlate;
const uint8_t* m_SrcBuf;
uint32_t m_SrcSize;
uint8_t* m_pScanline;
uint8_t* m_pLastLine;
uint8_t* m_pPredictBuffer;
uint8_t* m_pPredictRaw;
int m_Predictor;
int m_Colors;
int m_BitsPerComponent;
int m_Columns;
uint32_t m_PredictPitch;
size_t m_LeftOver;
};
CCodec_FlateScanlineDecoder::CCodec_FlateScanlineDecoder() {
m_pFlate = nullptr;
m_pScanline = nullptr;
m_pLastLine = nullptr;
m_pPredictBuffer = nullptr;
m_pPredictRaw = nullptr;
m_LeftOver = 0;
}
CCodec_FlateScanlineDecoder::~CCodec_FlateScanlineDecoder() {
FX_Free(m_pScanline);
FX_Free(m_pLastLine);
FX_Free(m_pPredictBuffer);
FX_Free(m_pPredictRaw);
if (m_pFlate)
FlateEnd(m_pFlate);
}
void CCodec_FlateScanlineDecoder::Create(const uint8_t* src_buf,
uint32_t src_size,
int width,
int height,
int nComps,
int bpc,
int predictor,
int Colors,
int BitsPerComponent,
int Columns) {
m_SrcBuf = src_buf;
m_SrcSize = src_size;
m_OutputWidth = m_OrigWidth = width;
m_OutputHeight = m_OrigHeight = height;
m_nComps = nComps;
m_bpc = bpc;
m_Pitch = (static_cast<uint32_t>(width) * nComps * bpc + 7) / 8;
m_pScanline = FX_Alloc(uint8_t, m_Pitch);
m_Predictor = 0;
if (predictor) {
if (predictor >= 10) {
m_Predictor = 2;
} else if (predictor == 2) {
m_Predictor = 1;
}
if (m_Predictor) {
if (BitsPerComponent * Colors * Columns == 0) {
BitsPerComponent = m_bpc;
Colors = m_nComps;
Columns = m_OrigWidth;
}
m_Colors = Colors;
m_BitsPerComponent = BitsPerComponent;
m_Columns = Columns;
m_PredictPitch =
(static_cast<uint32_t>(m_BitsPerComponent) * m_Colors * m_Columns +
7) /
8;
m_pLastLine = FX_Alloc(uint8_t, m_PredictPitch);
m_pPredictRaw = FX_Alloc(uint8_t, m_PredictPitch + 1);
m_pPredictBuffer = FX_Alloc(uint8_t, m_PredictPitch);
}
}
}
bool CCodec_FlateScanlineDecoder::v_Rewind() {
if (m_pFlate)
FlateEnd(m_pFlate);
m_pFlate = FlateInit();
if (!m_pFlate)
return false;
FlateInput(m_pFlate, m_SrcBuf, m_SrcSize);
m_LeftOver = 0;
return true;
}
uint8_t* CCodec_FlateScanlineDecoder::v_GetNextLine() {
if (m_Predictor) {
if (m_Pitch == m_PredictPitch) {
if (m_Predictor == 2) {
FlateOutput(m_pFlate, m_pPredictRaw, m_PredictPitch + 1);
PNG_PredictLine(m_pScanline, m_pPredictRaw, m_pLastLine,
m_BitsPerComponent, m_Colors, m_Columns);
memcpy(m_pLastLine, m_pScanline, m_PredictPitch);
} else {
FlateOutput(m_pFlate, m_pScanline, m_Pitch);
TIFF_PredictLine(m_pScanline, m_PredictPitch, m_bpc, m_nComps,
m_OutputWidth);
}
} else {
size_t bytes_to_go = m_Pitch;
size_t read_leftover =
m_LeftOver > bytes_to_go ? bytes_to_go : m_LeftOver;
if (read_leftover) {
memcpy(m_pScanline, m_pPredictBuffer + m_PredictPitch - m_LeftOver,
read_leftover);
m_LeftOver -= read_leftover;
bytes_to_go -= read_leftover;
}
while (bytes_to_go) {
if (m_Predictor == 2) {
FlateOutput(m_pFlate, m_pPredictRaw, m_PredictPitch + 1);
PNG_PredictLine(m_pPredictBuffer, m_pPredictRaw, m_pLastLine,
m_BitsPerComponent, m_Colors, m_Columns);
memcpy(m_pLastLine, m_pPredictBuffer, m_PredictPitch);
} else {
FlateOutput(m_pFlate, m_pPredictBuffer, m_PredictPitch);
TIFF_PredictLine(m_pPredictBuffer, m_PredictPitch, m_BitsPerComponent,
m_Colors, m_Columns);
}
size_t read_bytes =
m_PredictPitch > bytes_to_go ? bytes_to_go : m_PredictPitch;
memcpy(m_pScanline + m_Pitch - bytes_to_go, m_pPredictBuffer,
read_bytes);
m_LeftOver += m_PredictPitch - read_bytes;
bytes_to_go -= read_bytes;
}
}
} else {
FlateOutput(m_pFlate, m_pScanline, m_Pitch);
}
return m_pScanline;
}
uint32_t CCodec_FlateScanlineDecoder::GetSrcOffset() {
return FlateGetPossiblyTruncatedTotalIn(m_pFlate);
}
std::unique_ptr<CCodec_ScanlineDecoder> CCodec_FlateModule::CreateDecoder(
const uint8_t* src_buf,
uint32_t src_size,
int width,
int height,
int nComps,
int bpc,
int predictor,
int Colors,
int BitsPerComponent,
int Columns) {
auto pDecoder = pdfium::MakeUnique<CCodec_FlateScanlineDecoder>();
pDecoder->Create(src_buf, src_size, width, height, nComps, bpc, predictor,
Colors, BitsPerComponent, Columns);
return std::move(pDecoder);
}
uint32_t CCodec_FlateModule::FlateOrLZWDecode(bool bLZW,
const uint8_t* src_buf,
uint32_t src_size,
bool bEarlyChange,
int predictor,
int Colors,
int BitsPerComponent,
int Columns,
uint32_t estimated_size,
uint8_t** dest_buf,
uint32_t* dest_size) {
*dest_buf = nullptr;
uint32_t offset = 0;
int predictor_type = 0;
if (predictor) {
if (predictor >= 10)
predictor_type = 2;
else if (predictor == 2)
predictor_type = 1;
}
if (bLZW) {
auto decoder = pdfium::MakeUnique<CLZWDecoder>();
*dest_size = 0xFFFFFFFF;
offset = src_size;
int err =
decoder->Decode(nullptr, *dest_size, src_buf, offset, bEarlyChange);
if (err || *dest_size == 0 || *dest_size + 1 < *dest_size)
return FX_INVALID_OFFSET;
decoder = pdfium::MakeUnique<CLZWDecoder>();
*dest_buf = FX_Alloc(uint8_t, *dest_size + 1);
(*dest_buf)[*dest_size] = '\0';
decoder->Decode(*dest_buf, *dest_size, src_buf, offset, bEarlyChange);
} else {
FlateUncompress(src_buf, src_size, estimated_size, *dest_buf, *dest_size,
offset);
}
if (predictor_type == 0)
return offset;
bool ret = true;
if (predictor_type == 2) {
ret =
PNG_Predictor(*dest_buf, *dest_size, Colors, BitsPerComponent, Columns);
} else if (predictor_type == 1) {
ret = TIFF_Predictor(*dest_buf, *dest_size, Colors, BitsPerComponent,
Columns);
}
return ret ? offset : FX_INVALID_OFFSET;
}
bool CCodec_FlateModule::Encode(const uint8_t* src_buf,
uint32_t src_size,
uint8_t** dest_buf,
uint32_t* dest_size) {
*dest_size = src_size + src_size / 1000 + 12;
*dest_buf = FX_Alloc(uint8_t, *dest_size);
unsigned long temp_size = *dest_size;
if (!FlateCompress(*dest_buf, &temp_size, src_buf, src_size))
return false;
*dest_size = (uint32_t)temp_size;
return true;
}
bool CCodec_FlateModule::PngEncode(const uint8_t* src_buf,
uint32_t src_size,
uint8_t** dest_buf,
uint32_t* dest_size) {
uint8_t* pSrcBuf = FX_Alloc(uint8_t, src_size);
memcpy(pSrcBuf, src_buf, src_size);
PNG_PredictorEncode(&pSrcBuf, &src_size);
bool ret = Encode(pSrcBuf, src_size, dest_buf, dest_size);
FX_Free(pSrcBuf);
return ret;
}
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