blob: a3e28cc7c3d17a17c98b0bbe334b266b35afd87e [file] [log] [blame]
// Copyright 2014 The PDFium Authors
// 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/flate/flatemodule.h"
#include <stdint.h>
#include <string.h>
#include <algorithm>
#include <limits>
#include <memory>
#include <utility>
#include <vector>
#include "core/fxcodec/scanlinedecoder.h"
#include "core/fxcrt/data_vector.h"
#include "core/fxcrt/fixed_zeroed_data_vector.h"
#include "core/fxcrt/fx_extension.h"
#include "core/fxcrt/fx_memory_wrappers.h"
#include "core/fxcrt/fx_safe_types.h"
#include "core/fxcrt/span_util.h"
#include "core/fxge/calculate_pitch.h"
#include "third_party/base/check.h"
#include "third_party/base/containers/span.h"
#include "third_party/base/notreached.h"
#include "third_party/base/numerics/safe_conversions.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 fxcodec {
namespace {
static constexpr uint32_t kMaxTotalOutSize = 1024 * 1024 * 1024; // 1 GiB
uint32_t FlateGetPossiblyTruncatedTotalOut(z_stream* context) {
return std::min(pdfium::base::saturated_cast<uint32_t>(context->total_out),
kMaxTotalOutSize);
}
uint32_t FlateGetPossiblyTruncatedTotalIn(z_stream* context) {
return pdfium::base::saturated_cast<uint32_t>(context->total_in);
}
bool FlateCompress(unsigned char* dest_buf,
unsigned long* dest_size,
const unsigned char* src_buf,
unsigned long src_size) {
return compress(dest_buf, dest_size, src_buf, src_size) == Z_OK;
}
z_stream* FlateInit() {
z_stream* p = FX_Alloc(z_stream, 1);
p->zalloc = my_alloc_func;
p->zfree = my_free_func;
inflateInit(p);
return p;
}
void FlateInput(z_stream* context, pdfium::span<const uint8_t> src_buf) {
context->next_in = const_cast<unsigned char*>(src_buf.data());
context->avail_in = static_cast<uint32_t>(src_buf.size());
}
uint32_t FlateOutput(z_stream* context,
unsigned char* dest_buf,
uint32_t dest_size) {
context->next_out = dest_buf;
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);
DCHECK(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(z_stream* context) {
return context->avail_out;
}
void FlateEnd(z_stream* context) {
inflateEnd(context);
FX_Free(context);
}
// For use with std::unique_ptr<z_stream>.
struct FlateDeleter {
inline void operator()(z_stream* context) { FlateEnd(context); }
};
class CLZWDecoder {
public:
CLZWDecoder(pdfium::span<const uint8_t> src_span, bool early_change);
bool Decode();
uint32_t GetSrcSize() const { return (src_bit_pos_ + 7) / 8; }
uint32_t GetDestSize() const { return dest_byte_pos_; }
std::unique_ptr<uint8_t, FxFreeDeleter> TakeDestBuf() {
return std::move(dest_buf_);
}
private:
void AddCode(uint32_t prefix_code, uint8_t append_char);
void DecodeString(uint32_t code);
void ExpandDestBuf(uint32_t additional_size);
pdfium::span<const uint8_t> const src_span_;
std::unique_ptr<uint8_t, FxFreeDeleter> dest_buf_;
uint32_t src_bit_pos_ = 0;
uint32_t dest_buf_size_ = 0; // Actual allocated size.
uint32_t dest_byte_pos_ = 0; // Size used.
uint32_t stack_len_ = 0;
FixedZeroedDataVector<uint8_t> decode_stack_;
const uint8_t early_change_;
uint8_t code_len_ = 9;
uint32_t current_code_ = 0;
FixedZeroedDataVector<uint32_t> codes_;
};
CLZWDecoder::CLZWDecoder(pdfium::span<const uint8_t> src_span,
bool early_change)
: src_span_(src_span),
decode_stack_(4000),
early_change_(early_change ? 1 : 0),
codes_(5021) {}
void CLZWDecoder::AddCode(uint32_t prefix_code, uint8_t append_char) {
if (current_code_ + early_change_ == 4094)
return;
pdfium::span<uint32_t> codes_span = codes_.writable_span();
codes_span[current_code_++] = (prefix_code << 16) | append_char;
if (current_code_ + early_change_ == 512 - 258)
code_len_ = 10;
else if (current_code_ + early_change_ == 1024 - 258)
code_len_ = 11;
else if (current_code_ + early_change_ == 2048 - 258)
code_len_ = 12;
}
void CLZWDecoder::DecodeString(uint32_t code) {
pdfium::span<uint8_t> decode_span = decode_stack_.writable_span();
pdfium::span<const uint32_t> codes_span = codes_.span();
while (true) {
int index = code - 258;
if (index < 0 || static_cast<uint32_t>(index) >= current_code_)
break;
uint32_t data = codes_span[index];
if (stack_len_ >= decode_span.size())
return;
decode_span[stack_len_++] = static_cast<uint8_t>(data);
code = data >> 16;
}
if (stack_len_ >= decode_span.size())
return;
decode_span[stack_len_++] = static_cast<uint8_t>(code);
}
void CLZWDecoder::ExpandDestBuf(uint32_t additional_size) {
FX_SAFE_UINT32 new_size = std::max(dest_buf_size_ / 2, additional_size);
new_size += dest_buf_size_;
if (!new_size.IsValid()) {
dest_buf_.reset();
return;
}
dest_buf_size_ = new_size.ValueOrDie();
dest_buf_.reset(FX_Realloc(uint8_t, dest_buf_.release(), dest_buf_size_));
}
bool CLZWDecoder::Decode() {
pdfium::span<uint8_t> decode_span = decode_stack_.writable_span();
uint32_t old_code = 0xFFFFFFFF;
uint8_t last_char = 0;
// In one PDF test set, 40% of Decode() calls did not need to realloc with
// this size.
dest_buf_size_ = 512;
dest_buf_.reset(FX_Alloc(uint8_t, dest_buf_size_));
while (true) {
if (src_bit_pos_ + code_len_ > src_span_.size() * 8)
break;
int byte_pos = src_bit_pos_ / 8;
int bit_pos = src_bit_pos_ % 8;
uint8_t bit_left = code_len_;
uint32_t code = 0;
if (bit_pos) {
bit_left -= 8 - bit_pos;
code = (src_span_[byte_pos++] & ((1 << (8 - bit_pos)) - 1)) << bit_left;
}
if (bit_left < 8) {
code |= src_span_[byte_pos] >> (8 - bit_left);
} else {
bit_left -= 8;
code |= src_span_[byte_pos++] << bit_left;
if (bit_left)
code |= src_span_[byte_pos] >> (8 - bit_left);
}
src_bit_pos_ += code_len_;
if (code < 256) {
if (dest_byte_pos_ >= dest_buf_size_) {
ExpandDestBuf(dest_byte_pos_ - dest_buf_size_ + 1);
if (!dest_buf_)
return false;
}
dest_buf_.get()[dest_byte_pos_] = (uint8_t)code;
dest_byte_pos_++;
last_char = (uint8_t)code;
if (old_code != 0xFFFFFFFF)
AddCode(old_code, last_char);
old_code = code;
continue;
}
if (code == 256) {
code_len_ = 9;
current_code_ = 0;
old_code = 0xFFFFFFFF;
continue;
}
if (code == 257)
break;
// Case where |code| is 258 or greater.
if (old_code == 0xFFFFFFFF)
return false;
DCHECK(old_code < 256 || old_code >= 258);
stack_len_ = 0;
if (code - 258 >= current_code_) {
if (stack_len_ < decode_stack_.size())
decode_span[stack_len_++] = last_char;
DecodeString(old_code);
} else {
DecodeString(code);
}
FX_SAFE_UINT32 safe_required_size = dest_byte_pos_;
safe_required_size += stack_len_;
if (!safe_required_size.IsValid())
return false;
uint32_t required_size = safe_required_size.ValueOrDie();
if (required_size > dest_buf_size_) {
ExpandDestBuf(required_size - dest_buf_size_);
if (!dest_buf_)
return false;
}
for (uint32_t i = 0; i < stack_len_; i++)
dest_buf_.get()[dest_byte_pos_ + i] = decode_span[stack_len_ - i - 1];
dest_byte_pos_ += stack_len_;
last_char = decode_span[stack_len_ - 1];
if (old_code >= 258 && old_code - 258 >= current_code_)
break;
AddCode(old_code, last_char);
old_code = code;
}
return dest_byte_pos_ != 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_PredictLine(pdfium::span<uint8_t> dest_span,
pdfium::span<const uint8_t> src_span,
pdfium::span<const uint8_t> last_span,
int bpc,
int nColors,
int nPixels) {
uint8_t* pDestData = dest_span.data();
const uint8_t* pSrcData = src_span.data();
const uint8_t* pLastLine = last_span.data();
const uint32_t row_size = fxge::CalculatePitch8OrDie(bpc, nColors, nPixels);
const uint32_t BytesPerPixel = (bpc * nColors + 7) / 8;
uint8_t tag = pSrcData[0];
if (tag == 0) {
memmove(pDestData, pSrcData + 1, row_size);
return;
}
for (uint32_t 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(int Colors,
int BitsPerComponent,
int Columns,
std::unique_ptr<uint8_t, FxFreeDeleter>* data_buf,
uint32_t* data_size) {
const uint32_t row_size =
fxge::CalculatePitch8(BitsPerComponent, Colors, Columns).value_or(0);
if (row_size == 0) {
return false;
}
const uint32_t src_row_size = row_size + 1;
if (src_row_size == 0) {
// Avoid divide by 0.
return false;
}
const uint32_t row_count = (*data_size + row_size) / src_row_size;
if (row_count == 0) {
return false;
}
const uint32_t last_row_size = *data_size % src_row_size;
std::unique_ptr<uint8_t, FxFreeDeleter> dest_buf(
FX_Alloc2D(uint8_t, row_size, row_count));
uint32_t byte_cnt = 0;
const uint8_t* pSrcData = data_buf->get();
uint8_t* pDestData = dest_buf.get();
const uint8_t* pPrevDestData = nullptr;
for (uint32_t row = 0; row < row_count; row++) {
uint8_t tag = pSrcData[0];
byte_cnt++;
if (tag == 0) {
uint32_t move_size = row_size;
if ((row + 1) * (move_size + 1) > *data_size) {
move_size = last_row_size - 1;
}
memcpy(pDestData, pSrcData + 1, move_size);
pSrcData += move_size + 1;
pPrevDestData = pDestData;
pDestData += move_size;
byte_cnt += move_size;
continue;
}
const uint32_t BytesPerPixel = (Colors * BitsPerComponent + 7) / 8;
for (uint32_t byte = 0; byte < row_size && byte_cnt < *data_size;
++byte, ++byte_cnt) {
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 (pPrevDestData) {
up = pPrevDestData[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 (pPrevDestData) {
up = pPrevDestData[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 (pPrevDestData) {
up = pPrevDestData[byte];
}
uint8_t upper_left = 0;
if (pPrevDestData && byte >= BytesPerPixel) {
upper_left = pPrevDestData[byte - BytesPerPixel];
}
pDestData[byte] = raw_byte + PathPredictor(left, up, upper_left);
break;
}
default:
pDestData[byte] = raw_byte;
break;
}
}
pSrcData += src_row_size;
pPrevDestData = pDestData;
pDestData += row_size;
}
*data_buf = std::move(dest_buf);
*data_size = row_size * row_count -
(last_row_size > 0 ? (src_row_size - 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(int Colors,
int BitsPerComponent,
int Columns,
std::unique_ptr<uint8_t, FxFreeDeleter>* data_buf,
uint32_t* data_size) {
uint32_t row_size =
fxge::CalculatePitch8(BitsPerComponent, Colors, Columns).value_or(0);
if (row_size == 0)
return false;
const uint32_t row_count = (*data_size + row_size - 1) / row_size;
const uint32_t last_row_size = *data_size % row_size;
for (uint32_t row = 0; row < row_count; row++) {
uint8_t* scan_line = data_buf->get() + row * row_size;
if ((row + 1) * row_size > *data_size) {
row_size = last_row_size;
}
TIFF_PredictLine(scan_line, row_size, BitsPerComponent, Colors, Columns);
}
return true;
}
void FlateUncompress(pdfium::span<const uint8_t> src_buf,
uint32_t orig_size,
std::unique_ptr<uint8_t, FxFreeDeleter>* dest_buf,
uint32_t* dest_size,
uint32_t* offset) {
dest_buf->reset();
*dest_size = 0;
std::unique_ptr<z_stream, FlateDeleter> context(FlateInit());
if (!context)
return;
FlateInput(context.get(), src_buf);
const uint32_t kMaxInitialAllocSize = 10000000;
uint32_t guess_size =
orig_size ? orig_size
: pdfium::base::checked_cast<uint32_t>(src_buf.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<std::unique_ptr<uint8_t, FxFreeDeleter>> result_tmp_bufs;
{
std::unique_ptr<uint8_t, FxFreeDeleter> cur_buf = std::move(guess_buf);
while (true) {
uint32_t ret = FlateOutput(context.get(), cur_buf.get(), buf_size);
uint32_t avail_buf_size = FlateGetAvailOut(context.get());
if (ret != Z_OK || avail_buf_size != 0) {
last_buf_size = buf_size - avail_buf_size;
result_tmp_bufs.push_back(std::move(cur_buf));
break;
}
result_tmp_bufs.push_back(std::move(cur_buf));
cur_buf.reset(FX_Alloc(uint8_t, buf_size + 1));
cur_buf.get()[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.get());
*offset = FlateGetPossiblyTruncatedTotalIn(context.get());
if (result_tmp_bufs.size() == 1) {
*dest_buf = std::move(result_tmp_bufs[0]);
return;
}
std::unique_ptr<uint8_t, FxFreeDeleter> 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++) {
std::unique_ptr<uint8_t, FxFreeDeleter> tmp_buf =
std::move(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.get() + result_pos, tmp_buf.get(), cp_size);
result_pos += cp_size;
remaining -= cp_size;
}
*dest_buf = std::move(result_buf);
}
enum class PredictorType : uint8_t { kNone, kFlate, kPng };
static PredictorType GetPredictor(int predictor) {
if (predictor >= 10)
return PredictorType::kPng;
if (predictor == 2)
return PredictorType::kFlate;
return PredictorType::kNone;
}
class FlateScanlineDecoder : public ScanlineDecoder {
public:
FlateScanlineDecoder(pdfium::span<const uint8_t> src_span,
int width,
int height,
int nComps,
int bpc);
~FlateScanlineDecoder() override;
// ScanlineDecoder:
bool Rewind() override;
pdfium::span<uint8_t> GetNextLine() override;
uint32_t GetSrcOffset() override;
protected:
std::unique_ptr<z_stream, FlateDeleter> m_pFlate;
const pdfium::span<const uint8_t> m_SrcBuf;
DataVector<uint8_t> m_Scanline;
};
FlateScanlineDecoder::FlateScanlineDecoder(pdfium::span<const uint8_t> src_span,
int width,
int height,
int nComps,
int bpc)
: ScanlineDecoder(width,
height,
width,
height,
nComps,
bpc,
fxge::CalculatePitch8OrDie(bpc, nComps, width)),
m_SrcBuf(src_span),
m_Scanline(m_Pitch) {}
FlateScanlineDecoder::~FlateScanlineDecoder() {
// Span in superclass can't outlive our buffer.
m_pLastScanline = pdfium::span<uint8_t>();
}
bool FlateScanlineDecoder::Rewind() {
m_pFlate.reset(FlateInit());
if (!m_pFlate)
return false;
FlateInput(m_pFlate.get(), m_SrcBuf);
return true;
}
pdfium::span<uint8_t> FlateScanlineDecoder::GetNextLine() {
FlateOutput(m_pFlate.get(), m_Scanline.data(), m_Pitch);
return m_Scanline;
}
uint32_t FlateScanlineDecoder::GetSrcOffset() {
return FlateGetPossiblyTruncatedTotalIn(m_pFlate.get());
}
class FlatePredictorScanlineDecoder final : public FlateScanlineDecoder {
public:
FlatePredictorScanlineDecoder(pdfium::span<const uint8_t> src_span,
int width,
int height,
int comps,
int bpc,
PredictorType predictor,
int Colors,
int BitsPerComponent,
int Columns);
~FlatePredictorScanlineDecoder() override;
// ScanlineDecoder:
bool Rewind() override;
pdfium::span<uint8_t> GetNextLine() override;
private:
void GetNextLineWithPredictedPitch();
void GetNextLineWithoutPredictedPitch();
const PredictorType m_Predictor;
int m_Colors = 0;
int m_BitsPerComponent = 0;
int m_Columns = 0;
uint32_t m_PredictPitch = 0;
size_t m_LeftOver = 0;
DataVector<uint8_t> m_LastLine;
DataVector<uint8_t> m_PredictBuffer;
DataVector<uint8_t> m_PredictRaw;
};
FlatePredictorScanlineDecoder::FlatePredictorScanlineDecoder(
pdfium::span<const uint8_t> src_span,
int width,
int height,
int comps,
int bpc,
PredictorType predictor,
int Colors,
int BitsPerComponent,
int Columns)
: FlateScanlineDecoder(src_span, width, height, comps, bpc),
m_Predictor(predictor) {
DCHECK(m_Predictor != PredictorType::kNone);
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 =
fxge::CalculatePitch8OrDie(m_BitsPerComponent, m_Colors, m_Columns);
m_LastLine.resize(m_PredictPitch);
m_PredictBuffer.resize(m_PredictPitch);
m_PredictRaw.resize(m_PredictPitch + 1);
}
FlatePredictorScanlineDecoder::~FlatePredictorScanlineDecoder() {
// Span in superclass can't outlive our buffer.
m_pLastScanline = pdfium::span<uint8_t>();
}
bool FlatePredictorScanlineDecoder::Rewind() {
if (!FlateScanlineDecoder::Rewind())
return false;
m_LeftOver = 0;
return true;
}
pdfium::span<uint8_t> FlatePredictorScanlineDecoder::GetNextLine() {
if (m_Pitch == m_PredictPitch)
GetNextLineWithPredictedPitch();
else
GetNextLineWithoutPredictedPitch();
return m_Scanline;
}
void FlatePredictorScanlineDecoder::GetNextLineWithPredictedPitch() {
switch (m_Predictor) {
case PredictorType::kPng:
FlateOutput(m_pFlate.get(), m_PredictRaw.data(), m_PredictPitch + 1);
PNG_PredictLine(m_Scanline, m_PredictRaw, m_LastLine, m_BitsPerComponent,
m_Colors, m_Columns);
memcpy(m_LastLine.data(), m_Scanline.data(), m_PredictPitch);
break;
case PredictorType::kFlate:
FlateOutput(m_pFlate.get(), m_Scanline.data(), m_Pitch);
TIFF_PredictLine(m_Scanline.data(), m_PredictPitch, m_bpc, m_nComps,
m_OutputWidth);
break;
case PredictorType::kNone:
NOTREACHED_NORETURN();
}
}
void FlatePredictorScanlineDecoder::GetNextLineWithoutPredictedPitch() {
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_Scanline.data(), &m_PredictBuffer[m_PredictPitch - m_LeftOver],
read_leftover);
m_LeftOver -= read_leftover;
bytes_to_go -= read_leftover;
}
while (bytes_to_go) {
switch (m_Predictor) {
case PredictorType::kPng:
FlateOutput(m_pFlate.get(), m_PredictRaw.data(), m_PredictPitch + 1);
PNG_PredictLine(m_PredictBuffer, m_PredictRaw, m_LastLine,
m_BitsPerComponent, m_Colors, m_Columns);
memcpy(m_LastLine.data(), m_PredictBuffer.data(), m_PredictPitch);
break;
case PredictorType::kFlate:
FlateOutput(m_pFlate.get(), m_PredictBuffer.data(), m_PredictPitch);
TIFF_PredictLine(m_PredictBuffer.data(), m_PredictPitch,
m_BitsPerComponent, m_Colors, m_Columns);
break;
case PredictorType::kNone:
NOTREACHED_NORETURN();
}
size_t read_bytes =
m_PredictPitch > bytes_to_go ? bytes_to_go : m_PredictPitch;
fxcrt::spancpy(pdfium::make_span(m_Scanline).subspan(m_Pitch - bytes_to_go),
pdfium::make_span(m_PredictBuffer).first(read_bytes));
m_LeftOver += m_PredictPitch - read_bytes;
bytes_to_go -= read_bytes;
}
}
} // namespace
// static
std::unique_ptr<ScanlineDecoder> FlateModule::CreateDecoder(
pdfium::span<const uint8_t> src_span,
int width,
int height,
int nComps,
int bpc,
int predictor,
int Colors,
int BitsPerComponent,
int Columns) {
PredictorType predictor_type = GetPredictor(predictor);
if (predictor_type == PredictorType::kNone) {
return std::make_unique<FlateScanlineDecoder>(src_span, width, height,
nComps, bpc);
}
return std::make_unique<FlatePredictorScanlineDecoder>(
src_span, width, height, nComps, bpc, predictor_type, Colors,
BitsPerComponent, Columns);
}
// static
uint32_t FlateModule::FlateOrLZWDecode(
bool bLZW,
pdfium::span<const uint8_t> src_span,
bool bEarlyChange,
int predictor,
int Colors,
int BitsPerComponent,
int Columns,
uint32_t estimated_size,
std::unique_ptr<uint8_t, FxFreeDeleter>* dest_buf,
uint32_t* dest_size) {
dest_buf->reset();
uint32_t offset = 0;
PredictorType predictor_type = GetPredictor(predictor);
if (bLZW) {
auto decoder = std::make_unique<CLZWDecoder>(src_span, bEarlyChange);
if (!decoder->Decode())
return FX_INVALID_OFFSET;
offset = decoder->GetSrcSize();
*dest_size = decoder->GetDestSize();
*dest_buf = decoder->TakeDestBuf();
} else {
FlateUncompress(src_span, estimated_size, dest_buf, dest_size, &offset);
}
bool ret = false;
switch (predictor_type) {
case PredictorType::kNone:
return offset;
case PredictorType::kPng:
ret =
PNG_Predictor(Colors, BitsPerComponent, Columns, dest_buf, dest_size);
break;
case PredictorType::kFlate:
ret = TIFF_Predictor(Colors, BitsPerComponent, Columns, dest_buf,
dest_size);
break;
}
return ret ? offset : FX_INVALID_OFFSET;
}
// static
DataVector<uint8_t> FlateModule::Encode(pdfium::span<const uint8_t> src_span) {
const unsigned long src_size =
pdfium::base::checked_cast<unsigned long>(src_span.size());
pdfium::base::CheckedNumeric<unsigned long> safe_dest_size = src_size;
safe_dest_size += src_size / 1000;
safe_dest_size += 12;
unsigned long dest_size = safe_dest_size.ValueOrDie();
DataVector<uint8_t> dest_buf(dest_size);
if (!FlateCompress(dest_buf.data(), &dest_size, src_span.data(), src_size))
return {};
dest_buf.resize(pdfium::base::checked_cast<size_t>(dest_size));
return dest_buf;
}
} // namespace fxcodec