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// Copyright (c) the JPEG XL Project Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "lib/jxl/jpeg/dec_jpeg_data_writer.h"
#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <cstdlib>
#include <cstring> /* for memset, memcpy */
#include <deque>
#include <utility>
#include <vector>
#include "lib/jxl/base/bits.h"
#include "lib/jxl/base/byte_order.h"
#include "lib/jxl/base/common.h"
#include "lib/jxl/base/status.h"
#include "lib/jxl/frame_dimensions.h"
#include "lib/jxl/jpeg/dec_jpeg_serialization_state.h"
#include "lib/jxl/jpeg/jpeg_data.h"
namespace jxl {
namespace jpeg {
namespace {
enum struct SerializationStatus {
NEEDS_MORE_INPUT,
NEEDS_MORE_OUTPUT,
ERROR,
DONE
};
const int kJpegPrecision = 8;
// JpegBitWriter: buffer size
const size_t kJpegBitWriterChunkSize = 16384;
// Returns non-zero if and only if x has a zero byte, i.e. one of
// x & 0xff, x & 0xff00, ..., x & 0xff00000000000000 is zero.
JXL_INLINE uint64_t HasZeroByte(uint64_t x) {
return (x - 0x0101010101010101ULL) & ~x & 0x8080808080808080ULL;
}
void JpegBitWriterInit(JpegBitWriter* bw,
std::deque<OutputChunk>* output_queue) {
bw->output = output_queue;
bw->chunk = OutputChunk(kJpegBitWriterChunkSize);
bw->pos = 0;
bw->put_buffer = 0;
bw->put_bits = 64;
bw->healthy = true;
bw->data = bw->chunk.buffer->data();
}
JXL_NOINLINE void SwapBuffer(JpegBitWriter* bw) {
bw->chunk.len = bw->pos;
bw->output->emplace_back(std::move(bw->chunk));
bw->chunk = OutputChunk(kJpegBitWriterChunkSize);
bw->data = bw->chunk.buffer->data();
bw->pos = 0;
}
JXL_INLINE void Reserve(JpegBitWriter* bw, size_t n_bytes) {
if (JXL_UNLIKELY((bw->pos + n_bytes) > kJpegBitWriterChunkSize)) {
SwapBuffer(bw);
}
}
/**
* Writes the given byte to the output, writes an extra zero if byte is 0xFF.
*
* This method is "careless" - caller must make sure that there is enough
* space in the output buffer. Emits up to 2 bytes to buffer.
*/
JXL_INLINE void EmitByte(JpegBitWriter* bw, int byte) {
bw->data[bw->pos] = byte;
bw->data[bw->pos + 1] = 0;
bw->pos += (byte != 0xFF ? 1 : 2);
}
JXL_INLINE void DischargeBitBuffer(JpegBitWriter* bw, int nbits,
uint64_t bits) {
// At this point we are ready to emit the put_buffer to the output.
// The JPEG format requires that after every 0xff byte in the entropy
// coded section, there is a zero byte, therefore we first check if any of
// the 8 bytes of put_buffer is 0xFF.
bw->put_buffer |= (bits >> -bw->put_bits);
if (JXL_UNLIKELY(HasZeroByte(~bw->put_buffer))) {
// We have a 0xFF byte somewhere, examine each byte and append a zero
// byte if necessary.
EmitByte(bw, (bw->put_buffer >> 56) & 0xFF);
EmitByte(bw, (bw->put_buffer >> 48) & 0xFF);
EmitByte(bw, (bw->put_buffer >> 40) & 0xFF);
EmitByte(bw, (bw->put_buffer >> 32) & 0xFF);
EmitByte(bw, (bw->put_buffer >> 24) & 0xFF);
EmitByte(bw, (bw->put_buffer >> 16) & 0xFF);
EmitByte(bw, (bw->put_buffer >> 8) & 0xFF);
EmitByte(bw, (bw->put_buffer) & 0xFF);
} else {
// We don't have any 0xFF bytes, output all 8 bytes without checking.
StoreBE64(bw->put_buffer, bw->data + bw->pos);
bw->pos += 8;
}
bw->put_bits += 64;
bw->put_buffer = bits << bw->put_bits;
}
JXL_INLINE void WriteBits(JpegBitWriter* bw, int nbits, uint64_t bits) {
JXL_DASSERT(nbits > 0);
bw->put_bits -= nbits;
if (JXL_UNLIKELY(bw->put_bits < 0)) {
if (JXL_UNLIKELY(nbits > 64)) {
bw->put_bits += nbits;
bw->healthy = false;
} else {
DischargeBitBuffer(bw, nbits, bits);
}
} else {
bw->put_buffer |= (bits << bw->put_bits);
}
}
void EmitMarker(JpegBitWriter* bw, int marker) {
Reserve(bw, 2);
JXL_DASSERT(marker != 0xFF);
bw->data[bw->pos++] = 0xFF;
bw->data[bw->pos++] = marker;
}
bool JumpToByteBoundary(JpegBitWriter* bw, const uint8_t** pad_bits,
const uint8_t* pad_bits_end) {
size_t n_bits = bw->put_bits & 7u;
uint8_t dangling_bits = 0;
uint8_t pad_pattern;
if (*pad_bits == nullptr) {
pad_pattern = (1u << n_bits) - 1;
} else {
pad_pattern = 0;
const uint8_t* src = *pad_bits;
// TODO(eustas): bitwise reading looks insanely ineffective!
while (n_bits--) {
pad_pattern <<= 1;
if (src >= pad_bits_end) return false;
uint8_t bit = *src;
src++;
dangling_bits |= bit;
pad_pattern |= bit;
}
*pad_bits = src;
}
if ((dangling_bits & ~1) != 0) return false;
Reserve(bw, 16);
while (bw->put_bits <= 56) {
int c = (bw->put_buffer >> 56) & 0xFF;
EmitByte(bw, c);
bw->put_buffer <<= 8;
bw->put_bits += 8;
}
if (bw->put_bits < 64) {
int pad_mask = 0xFFu >> (64 - bw->put_bits);
int c = ((bw->put_buffer >> 56) & ~pad_mask) | pad_pattern;
EmitByte(bw, c);
}
bw->put_buffer = 0;
bw->put_bits = 64;
return true;
}
void JpegBitWriterFinish(JpegBitWriter* bw) {
if (bw->pos == 0) return;
bw->chunk.len = bw->pos;
bw->output->emplace_back(std::move(bw->chunk));
bw->chunk = OutputChunk(nullptr, 0);
bw->data = nullptr;
bw->pos = 0;
}
void DCTCodingStateInit(DCTCodingState* s) {
s->eob_run_ = 0;
s->cur_ac_huff_ = nullptr;
s->refinement_bits_.clear();
s->refinement_bits_.reserve(64);
}
JXL_INLINE void WriteSymbol(int symbol, HuffmanCodeTable* table,
JpegBitWriter* bw) {
WriteBits(bw, table->depth[symbol], table->code[symbol]);
}
JXL_INLINE void WriteSymbolBits(int symbol, HuffmanCodeTable* table,
JpegBitWriter* bw, int nbits, uint64_t bits) {
WriteBits(bw, nbits + table->depth[symbol],
bits | (table->code[symbol] << nbits));
}
// Emit all buffered data to the bit stream using the given Huffman code and
// bit writer.
JXL_INLINE void Flush(DCTCodingState* s, JpegBitWriter* bw) {
if (s->eob_run_ > 0) {
Reserve(bw, 16);
int nbits = FloorLog2Nonzero<uint32_t>(s->eob_run_);
int symbol = nbits << 4u;
WriteSymbol(symbol, s->cur_ac_huff_, bw);
if (nbits > 0) {
WriteBits(bw, nbits, s->eob_run_ & ((1 << nbits) - 1));
}
s->eob_run_ = 0;
}
const size_t kStride = 124; // (515 - 16) / 2 / 2
size_t num_words = s->refinement_bits_count_ >> 4;
size_t i = 0;
while (i < num_words) {
size_t limit = std::min(i + kStride, num_words);
Reserve(bw, 512);
for (; i < limit; ++i) {
WriteBits(bw, 16, s->refinement_bits_[i]);
}
}
Reserve(bw, 16);
size_t tail = s->refinement_bits_count_ & 0xF;
if (tail) {
WriteBits(bw, tail, s->refinement_bits_.back());
}
s->refinement_bits_.clear();
s->refinement_bits_count_ = 0;
}
// Buffer some more data at the end-of-band (the last non-zero or newly
// non-zero coefficient within the [Ss, Se] spectral band).
JXL_INLINE void BufferEndOfBand(DCTCodingState* s, HuffmanCodeTable* ac_huff,
const int* new_bits_array,
size_t new_bits_count, JpegBitWriter* bw) {
if (s->eob_run_ == 0) {
s->cur_ac_huff_ = ac_huff;
}
++s->eob_run_;
if (new_bits_count) {
uint64_t new_bits = 0;
for (size_t i = 0; i < new_bits_count; ++i) {
new_bits = (new_bits << 1) | new_bits_array[i];
}
size_t tail = s->refinement_bits_count_ & 0xF;
if (tail) { // First stuff the tail item
size_t stuff_bits_count = std::min(16 - tail, new_bits_count);
uint16_t stuff_bits = new_bits >> (new_bits_count - stuff_bits_count);
stuff_bits &= ((1u << stuff_bits_count) - 1);
s->refinement_bits_.back() =
(s->refinement_bits_.back() << stuff_bits_count) | stuff_bits;
new_bits_count -= stuff_bits_count;
s->refinement_bits_count_ += stuff_bits_count;
}
while (new_bits_count >= 16) {
s->refinement_bits_.push_back(new_bits >> (new_bits_count - 16));
new_bits_count -= 16;
s->refinement_bits_count_ += 16;
}
if (new_bits_count) {
s->refinement_bits_.push_back(new_bits & ((1u << new_bits_count) - 1));
s->refinement_bits_count_ += new_bits_count;
}
}
if (s->eob_run_ == 0x7FFF) {
Flush(s, bw);
}
}
bool BuildHuffmanCodeTable(const JPEGHuffmanCode& huff,
HuffmanCodeTable* table) {
int huff_code[kJpegHuffmanAlphabetSize];
// +1 for a sentinel element.
uint32_t huff_size[kJpegHuffmanAlphabetSize + 1];
int p = 0;
for (size_t l = 1; l <= kJpegHuffmanMaxBitLength; ++l) {
int i = huff.counts[l];
if (p + i > kJpegHuffmanAlphabetSize + 1) {
return false;
}
while (i--) huff_size[p++] = l;
}
if (p == 0) {
return true;
}
// Reuse sentinel element.
int last_p = p - 1;
huff_size[last_p] = 0;
int code = 0;
uint32_t si = huff_size[0];
p = 0;
while (huff_size[p]) {
while ((huff_size[p]) == si) {
huff_code[p++] = code;
code++;
}
code <<= 1;
si++;
}
for (p = 0; p < last_p; p++) {
int i = huff.values[p];
table->depth[i] = huff_size[p];
table->code[i] = huff_code[p];
}
return true;
}
bool EncodeSOI(SerializationState* state) {
state->output_queue.push_back(OutputChunk({0xFF, 0xD8}));
return true;
}
bool EncodeEOI(const JPEGData& jpg, SerializationState* state) {
state->output_queue.push_back(OutputChunk({0xFF, 0xD9}));
state->output_queue.emplace_back(jpg.tail_data);
return true;
}
bool EncodeSOF(const JPEGData& jpg, uint8_t marker, SerializationState* state) {
if (marker <= 0xC2) state->is_progressive = (marker == 0xC2);
const size_t n_comps = jpg.components.size();
const size_t marker_len = 8 + 3 * n_comps;
state->output_queue.emplace_back(marker_len + 2);
uint8_t* data = state->output_queue.back().buffer->data();
size_t pos = 0;
data[pos++] = 0xFF;
data[pos++] = marker;
data[pos++] = marker_len >> 8u;
data[pos++] = marker_len & 0xFFu;
data[pos++] = kJpegPrecision;
data[pos++] = jpg.height >> 8u;
data[pos++] = jpg.height & 0xFFu;
data[pos++] = jpg.width >> 8u;
data[pos++] = jpg.width & 0xFFu;
data[pos++] = n_comps;
for (size_t i = 0; i < n_comps; ++i) {
data[pos++] = jpg.components[i].id;
data[pos++] = ((jpg.components[i].h_samp_factor << 4u) |
(jpg.components[i].v_samp_factor));
const size_t quant_idx = jpg.components[i].quant_idx;
if (quant_idx >= jpg.quant.size()) return false;
data[pos++] = jpg.quant[quant_idx].index;
}
return true;
}
bool EncodeSOS(const JPEGData& jpg, const JPEGScanInfo& scan_info,
SerializationState* state) {
const size_t n_scans = scan_info.num_components;
const size_t marker_len = 6 + 2 * n_scans;
state->output_queue.emplace_back(marker_len + 2);
uint8_t* data = state->output_queue.back().buffer->data();
size_t pos = 0;
data[pos++] = 0xFF;
data[pos++] = 0xDA;
data[pos++] = marker_len >> 8u;
data[pos++] = marker_len & 0xFFu;
data[pos++] = n_scans;
for (size_t i = 0; i < n_scans; ++i) {
const JPEGComponentScanInfo& si = scan_info.components[i];
if (si.comp_idx >= jpg.components.size()) return false;
data[pos++] = jpg.components[si.comp_idx].id;
data[pos++] = (si.dc_tbl_idx << 4u) + si.ac_tbl_idx;
}
data[pos++] = scan_info.Ss;
data[pos++] = scan_info.Se;
data[pos++] = ((scan_info.Ah << 4u) | (scan_info.Al));
return true;
}
bool EncodeDHT(const JPEGData& jpg, SerializationState* state) {
const std::vector<JPEGHuffmanCode>& huffman_code = jpg.huffman_code;
size_t marker_len = 2;
for (size_t i = state->dht_index; i < huffman_code.size(); ++i) {
const JPEGHuffmanCode& huff = huffman_code[i];
marker_len += kJpegHuffmanMaxBitLength;
for (uint32_t count : huff.counts) {
marker_len += count;
}
if (huff.is_last) break;
}
state->output_queue.emplace_back(marker_len + 2);
uint8_t* data = state->output_queue.back().buffer->data();
size_t pos = 0;
data[pos++] = 0xFF;
data[pos++] = 0xC4;
data[pos++] = marker_len >> 8u;
data[pos++] = marker_len & 0xFFu;
while (true) {
const size_t huffman_code_index = state->dht_index++;
if (huffman_code_index >= huffman_code.size()) {
return false;
}
const JPEGHuffmanCode& huff = huffman_code[huffman_code_index];
size_t index = huff.slot_id;
HuffmanCodeTable* huff_table;
if (index & 0x10) {
index -= 0x10;
huff_table = &state->ac_huff_table[index];
} else {
huff_table = &state->dc_huff_table[index];
}
// TODO(eustas): cache
huff_table->InitDepths(127);
if (!BuildHuffmanCodeTable(huff, huff_table)) {
return false;
}
huff_table->initialized = true;
size_t total_count = 0;
size_t max_length = 0;
for (size_t i = 0; i < huff.counts.size(); ++i) {
if (huff.counts[i] != 0) {
max_length = i;
}
total_count += huff.counts[i];
}
--total_count;
data[pos++] = huff.slot_id;
for (size_t i = 1; i <= kJpegHuffmanMaxBitLength; ++i) {
data[pos++] = (i == max_length ? huff.counts[i] - 1 : huff.counts[i]);
}
for (size_t i = 0; i < total_count; ++i) {
data[pos++] = huff.values[i];
}
if (huff.is_last) break;
}
return true;
}
bool EncodeDQT(const JPEGData& jpg, SerializationState* state) {
int marker_len = 2;
for (size_t i = state->dqt_index; i < jpg.quant.size(); ++i) {
const JPEGQuantTable& table = jpg.quant[i];
marker_len += 1 + (table.precision ? 2 : 1) * kDCTBlockSize;
if (table.is_last) break;
}
state->output_queue.emplace_back(marker_len + 2);
uint8_t* data = state->output_queue.back().buffer->data();
size_t pos = 0;
data[pos++] = 0xFF;
data[pos++] = 0xDB;
data[pos++] = marker_len >> 8u;
data[pos++] = marker_len & 0xFFu;
while (true) {
const size_t idx = state->dqt_index++;
if (idx >= jpg.quant.size()) {
return false; // corrupt input
}
const JPEGQuantTable& table = jpg.quant[idx];
data[pos++] = (table.precision << 4u) + table.index;
for (size_t i = 0; i < kDCTBlockSize; ++i) {
int val_idx = kJPEGNaturalOrder[i];
int val = table.values[val_idx];
if (table.precision) {
data[pos++] = val >> 8u;
}
data[pos++] = val & 0xFFu;
}
if (table.is_last) break;
}
return true;
}
bool EncodeDRI(const JPEGData& jpg, SerializationState* state) {
state->seen_dri_marker = true;
OutputChunk dri_marker = {0xFF,
0xDD,
0,
4,
static_cast<uint8_t>(jpg.restart_interval >> 8),
static_cast<uint8_t>(jpg.restart_interval & 0xFF)};
state->output_queue.push_back(std::move(dri_marker));
return true;
}
bool EncodeRestart(uint8_t marker, SerializationState* state) {
state->output_queue.push_back(OutputChunk({0xFF, marker}));
return true;
}
bool EncodeAPP(const JPEGData& jpg, uint8_t marker, SerializationState* state) {
// TODO(eustas): check that marker corresponds to payload?
(void)marker;
size_t app_index = state->app_index++;
if (app_index >= jpg.app_data.size()) return false;
state->output_queue.push_back(OutputChunk({0xFF}));
state->output_queue.emplace_back(jpg.app_data[app_index]);
return true;
}
bool EncodeCOM(const JPEGData& jpg, SerializationState* state) {
size_t com_index = state->com_index++;
if (com_index >= jpg.com_data.size()) return false;
state->output_queue.push_back(OutputChunk({0xFF}));
state->output_queue.emplace_back(jpg.com_data[com_index]);
return true;
}
bool EncodeInterMarkerData(const JPEGData& jpg, SerializationState* state) {
size_t index = state->data_index++;
if (index >= jpg.inter_marker_data.size()) return false;
state->output_queue.emplace_back(jpg.inter_marker_data[index]);
return true;
}
bool EncodeDCTBlockSequential(const coeff_t* coeffs, HuffmanCodeTable* dc_huff,
HuffmanCodeTable* ac_huff, int num_zero_runs,
coeff_t* last_dc_coeff, JpegBitWriter* bw) {
coeff_t temp2;
coeff_t temp;
coeff_t litmus = 0;
temp2 = coeffs[0];
temp = temp2 - *last_dc_coeff;
*last_dc_coeff = temp2;
temp2 = temp >> (8 * sizeof(coeff_t) - 1);
temp += temp2;
temp2 ^= temp;
int dc_nbits = (temp2 == 0) ? 0 : (FloorLog2Nonzero<uint32_t>(temp2) + 1);
WriteSymbol(dc_nbits, dc_huff, bw);
#if JXL_FALSE
// If the input is corrupt, this could be triggered. Checking is
// costly though, so it makes more sense to avoid this branch.
// (producing a corrupt JPEG when the input is corrupt, instead
// of catching it and returning error)
if (dc_nbits >= 12) return false;
#endif
if (dc_nbits) {
WriteBits(bw, dc_nbits, temp & ((1u << dc_nbits) - 1));
}
int16_t r = 0;
for (size_t i = 1; i < 64; i++) {
temp = coeffs[kJPEGNaturalOrder[i]];
if (temp == 0) {
r++;
} else {
temp2 = temp >> (8 * sizeof(coeff_t) - 1);
temp += temp2;
temp2 ^= temp;
if (JXL_UNLIKELY(r > 15)) {
WriteSymbol(0xf0, ac_huff, bw);
r -= 16;
if (r > 15) {
WriteSymbol(0xf0, ac_huff, bw);
r -= 16;
}
if (r > 15) {
WriteSymbol(0xf0, ac_huff, bw);
r -= 16;
}
}
litmus |= temp2;
int ac_nbits =
FloorLog2Nonzero<uint32_t>(static_cast<uint16_t>(temp2)) + 1;
int symbol = (r << 4u) + ac_nbits;
WriteSymbolBits(symbol, ac_huff, bw, ac_nbits,
temp & ((1 << ac_nbits) - 1));
r = 0;
}
}
for (int i = 0; i < num_zero_runs; ++i) {
WriteSymbol(0xf0, ac_huff, bw);
r -= 16;
}
if (r > 0) {
WriteSymbol(0, ac_huff, bw);
}
return (litmus >= 0);
}
bool EncodeDCTBlockProgressive(const coeff_t* coeffs, HuffmanCodeTable* dc_huff,
HuffmanCodeTable* ac_huff, int Ss, int Se,
int Al, int num_zero_runs,
DCTCodingState* coding_state,
coeff_t* last_dc_coeff, JpegBitWriter* bw) {
bool eob_run_allowed = Ss > 0;
coeff_t temp2;
coeff_t temp;
if (Ss == 0) {
temp2 = coeffs[0] >> Al;
temp = temp2 - *last_dc_coeff;
*last_dc_coeff = temp2;
temp2 = temp;
if (temp < 0) {
temp = -temp;
if (temp < 0) return false;
temp2--;
}
int nbits = (temp == 0) ? 0 : (FloorLog2Nonzero<uint32_t>(temp) + 1);
WriteSymbol(nbits, dc_huff, bw);
if (nbits) {
WriteBits(bw, nbits, temp2 & ((1 << nbits) - 1));
}
++Ss;
}
if (Ss > Se) {
return true;
}
int r = 0;
for (int k = Ss; k <= Se; ++k) {
temp = coeffs[kJPEGNaturalOrder[k]];
if (temp == 0) {
r++;
continue;
}
if (temp < 0) {
temp = -temp;
if (temp < 0) return false;
temp >>= Al;
temp2 = ~temp;
} else {
temp >>= Al;
temp2 = temp;
}
if (temp == 0) {
r++;
continue;
}
Flush(coding_state, bw);
while (r > 15) {
WriteSymbol(0xf0, ac_huff, bw);
r -= 16;
}
int nbits = FloorLog2Nonzero<uint32_t>(temp) + 1;
int symbol = (r << 4u) + nbits;
WriteSymbol(symbol, ac_huff, bw);
WriteBits(bw, nbits, temp2 & ((1 << nbits) - 1));
r = 0;
}
if (num_zero_runs > 0) {
Flush(coding_state, bw);
for (int i = 0; i < num_zero_runs; ++i) {
WriteSymbol(0xf0, ac_huff, bw);
r -= 16;
}
}
if (r > 0) {
BufferEndOfBand(coding_state, ac_huff, nullptr, 0, bw);
if (!eob_run_allowed) {
Flush(coding_state, bw);
}
}
return true;
}
bool EncodeRefinementBits(const coeff_t* coeffs, HuffmanCodeTable* ac_huff,
int Ss, int Se, int Al, DCTCodingState* coding_state,
JpegBitWriter* bw) {
bool eob_run_allowed = Ss > 0;
if (Ss == 0) {
// Emit next bit of DC component.
WriteBits(bw, 1, (coeffs[0] >> Al) & 1);
++Ss;
}
if (Ss > Se) {
return true;
}
int abs_values[kDCTBlockSize];
int eob = 0;
for (int k = Ss; k <= Se; k++) {
const coeff_t abs_val = std::abs(coeffs[kJPEGNaturalOrder[k]]);
abs_values[k] = abs_val >> Al;
if (abs_values[k] == 1) {
eob = k;
}
}
int r = 0;
int refinement_bits[kDCTBlockSize];
size_t refinement_bits_count = 0;
for (int k = Ss; k <= Se; k++) {
if (abs_values[k] == 0) {
r++;
continue;
}
while (r > 15 && k <= eob) {
Flush(coding_state, bw);
WriteSymbol(0xf0, ac_huff, bw);
r -= 16;
for (size_t i = 0; i < refinement_bits_count; ++i) {
WriteBits(bw, 1, refinement_bits[i]);
}
refinement_bits_count = 0;
}
if (abs_values[k] > 1) {
refinement_bits[refinement_bits_count++] = abs_values[k] & 1u;
continue;
}
Flush(coding_state, bw);
int symbol = (r << 4u) + 1;
int new_non_zero_bit = (coeffs[kJPEGNaturalOrder[k]] < 0) ? 0 : 1;
WriteSymbol(symbol, ac_huff, bw);
WriteBits(bw, 1, new_non_zero_bit);
for (size_t i = 0; i < refinement_bits_count; ++i) {
WriteBits(bw, 1, refinement_bits[i]);
}
refinement_bits_count = 0;
r = 0;
}
if (r > 0 || refinement_bits_count) {
BufferEndOfBand(coding_state, ac_huff, refinement_bits,
refinement_bits_count, bw);
if (!eob_run_allowed) {
Flush(coding_state, bw);
}
}
return true;
}
template <int kMode>
SerializationStatus JXL_NOINLINE DoEncodeScan(const JPEGData& jpg,
SerializationState* state) {
const JPEGScanInfo& scan_info = jpg.scan_info[state->scan_index];
EncodeScanState& ss = state->scan_state;
const int restart_interval =
state->seen_dri_marker ? jpg.restart_interval : 0;
const auto get_next_extra_zero_run_index = [&ss, &scan_info]() -> int {
if (ss.extra_zero_runs_pos < scan_info.extra_zero_runs.size()) {
return scan_info.extra_zero_runs[ss.extra_zero_runs_pos].block_idx;
} else {
return -1;
}
};
const auto get_next_reset_point = [&ss, &scan_info]() -> int {
if (ss.next_reset_point_pos < scan_info.reset_points.size()) {
return scan_info.reset_points[ss.next_reset_point_pos++];
} else {
return -1;
}
};
if (ss.stage == EncodeScanState::HEAD) {
if (!EncodeSOS(jpg, scan_info, state)) return SerializationStatus::ERROR;
JpegBitWriterInit(&ss.bw, &state->output_queue);
DCTCodingStateInit(&ss.coding_state);
ss.restarts_to_go = restart_interval;
ss.next_restart_marker = 0;
ss.block_scan_index = 0;
ss.extra_zero_runs_pos = 0;
ss.next_extra_zero_run_index = get_next_extra_zero_run_index();
ss.next_reset_point_pos = 0;
ss.next_reset_point = get_next_reset_point();
ss.mcu_y = 0;
memset(ss.last_dc_coeff, 0, sizeof(ss.last_dc_coeff));
ss.stage = EncodeScanState::BODY;
}
JpegBitWriter* bw = &ss.bw;
DCTCodingState* coding_state = &ss.coding_state;
if (ss.stage != EncodeScanState::BODY) return SerializationStatus::ERROR;
// "Non-interleaved" means color data comes in separate scans, in other words
// each scan can contain only one color component.
const bool is_interleaved = (scan_info.num_components > 1);
int MCUs_per_row = 0;
int MCU_rows = 0;
jpg.CalculateMcuSize(scan_info, &MCUs_per_row, &MCU_rows);
const bool is_progressive = state->is_progressive;
const int Al = is_progressive ? scan_info.Al : 0;
const int Ss = is_progressive ? scan_info.Ss : 0;
const int Se = is_progressive ? scan_info.Se : 63;
// DC-only is defined by [0..0] spectral range.
const bool want_ac = ((Ss != 0) || (Se != 0));
const bool want_dc = (Ss == 0);
// TODO(user): support streaming decoding again.
const bool complete_ac = true;
const bool has_ac = true;
if (want_ac && !has_ac) return SerializationStatus::NEEDS_MORE_INPUT;
// |has_ac| implies |complete_dc| but not vice versa; for the sake of
// simplicity we pretend they are equal, because they are separated by just a
// few bytes of input.
const bool complete_dc = has_ac;
const bool complete = want_ac ? complete_ac : complete_dc;
// When "incomplete" |ac_dc| tracks information about current ("incomplete")
// band parsing progress.
// FIXME: Is this always complete?
// const int last_mcu_y =
// complete ? MCU_rows : parsing_state.internal->ac_dc.next_mcu_y *
// v_group;
(void)complete;
const int last_mcu_y = complete ? MCU_rows : 0;
for (; ss.mcu_y < last_mcu_y; ++ss.mcu_y) {
for (int mcu_x = 0; mcu_x < MCUs_per_row; ++mcu_x) {
// Possibly emit a restart marker.
if (restart_interval > 0 && ss.restarts_to_go == 0) {
Flush(coding_state, bw);
if (!JumpToByteBoundary(bw, &state->pad_bits, state->pad_bits_end)) {
return SerializationStatus::ERROR;
}
EmitMarker(bw, 0xD0 + ss.next_restart_marker);
ss.next_restart_marker += 1;
ss.next_restart_marker &= 0x7;
ss.restarts_to_go = restart_interval;
memset(ss.last_dc_coeff, 0, sizeof(ss.last_dc_coeff));
}
// Encode one MCU
for (size_t i = 0; i < scan_info.num_components; ++i) {
const JPEGComponentScanInfo& si = scan_info.components[i];
const JPEGComponent& c = jpg.components[si.comp_idx];
size_t dc_tbl_idx = si.dc_tbl_idx;
size_t ac_tbl_idx = si.ac_tbl_idx;
HuffmanCodeTable* dc_huff = &state->dc_huff_table[dc_tbl_idx];
HuffmanCodeTable* ac_huff = &state->ac_huff_table[ac_tbl_idx];
if (want_dc && !dc_huff->initialized) {
return SerializationStatus::ERROR;
}
if (want_ac && !ac_huff->initialized) {
return SerializationStatus::ERROR;
}
int n_blocks_y = is_interleaved ? c.v_samp_factor : 1;
int n_blocks_x = is_interleaved ? c.h_samp_factor : 1;
for (int iy = 0; iy < n_blocks_y; ++iy) {
for (int ix = 0; ix < n_blocks_x; ++ix) {
int block_y = ss.mcu_y * n_blocks_y + iy;
int block_x = mcu_x * n_blocks_x + ix;
int block_idx = block_y * c.width_in_blocks + block_x;
if (ss.block_scan_index == ss.next_reset_point) {
Flush(coding_state, bw);
ss.next_reset_point = get_next_reset_point();
}
int num_zero_runs = 0;
if (ss.block_scan_index == ss.next_extra_zero_run_index) {
num_zero_runs = scan_info.extra_zero_runs[ss.extra_zero_runs_pos]
.num_extra_zero_runs;
++ss.extra_zero_runs_pos;
ss.next_extra_zero_run_index = get_next_extra_zero_run_index();
}
const coeff_t* coeffs = &c.coeffs[block_idx << 6];
bool ok;
// compressed size per block cannot be more than 512 bytes
Reserve(bw, 512);
if (kMode == 0) {
ok = EncodeDCTBlockSequential(coeffs, dc_huff, ac_huff,
num_zero_runs,
ss.last_dc_coeff + si.comp_idx, bw);
} else if (kMode == 1) {
ok = EncodeDCTBlockProgressive(
coeffs, dc_huff, ac_huff, Ss, Se, Al, num_zero_runs,
coding_state, ss.last_dc_coeff + si.comp_idx, bw);
} else {
ok = EncodeRefinementBits(coeffs, ac_huff, Ss, Se, Al,
coding_state, bw);
}
if (!ok) return SerializationStatus::ERROR;
++ss.block_scan_index;
}
}
}
--ss.restarts_to_go;
}
}
if (ss.mcu_y < MCU_rows) {
if (!bw->healthy) return SerializationStatus::ERROR;
return SerializationStatus::NEEDS_MORE_INPUT;
}
Flush(coding_state, bw);
if (!JumpToByteBoundary(bw, &state->pad_bits, state->pad_bits_end)) {
return SerializationStatus::ERROR;
}
JpegBitWriterFinish(bw);
ss.stage = EncodeScanState::HEAD;
state->scan_index++;
if (!bw->healthy) return SerializationStatus::ERROR;
return SerializationStatus::DONE;
}
SerializationStatus JXL_INLINE EncodeScan(const JPEGData& jpg,
SerializationState* state) {
const JPEGScanInfo& scan_info = jpg.scan_info[state->scan_index];
const bool is_progressive = state->is_progressive;
const int Al = is_progressive ? scan_info.Al : 0;
const int Ah = is_progressive ? scan_info.Ah : 0;
const int Ss = is_progressive ? scan_info.Ss : 0;
const int Se = is_progressive ? scan_info.Se : 63;
const bool need_sequential =
!is_progressive || (Ah == 0 && Al == 0 && Ss == 0 && Se == 63);
if (need_sequential) {
return DoEncodeScan<0>(jpg, state);
} else if (Ah == 0) {
return DoEncodeScan<1>(jpg, state);
} else {
return DoEncodeScan<2>(jpg, state);
}
}
SerializationStatus SerializeSection(uint8_t marker, SerializationState* state,
const JPEGData& jpg) {
const auto to_status = [](bool result) {
return result ? SerializationStatus::DONE : SerializationStatus::ERROR;
};
// TODO(eustas): add and use marker enum
switch (marker) {
case 0xC0:
case 0xC1:
case 0xC2:
case 0xC9:
case 0xCA:
return to_status(EncodeSOF(jpg, marker, state));
case 0xC4:
return to_status(EncodeDHT(jpg, state));
case 0xD0:
case 0xD1:
case 0xD2:
case 0xD3:
case 0xD4:
case 0xD5:
case 0xD6:
case 0xD7:
return to_status(EncodeRestart(marker, state));
case 0xD9:
return to_status(EncodeEOI(jpg, state));
case 0xDA:
return EncodeScan(jpg, state);
case 0xDB:
return to_status(EncodeDQT(jpg, state));
case 0xDD:
return to_status(EncodeDRI(jpg, state));
case 0xE0:
case 0xE1:
case 0xE2:
case 0xE3:
case 0xE4:
case 0xE5:
case 0xE6:
case 0xE7:
case 0xE8:
case 0xE9:
case 0xEA:
case 0xEB:
case 0xEC:
case 0xED:
case 0xEE:
case 0xEF:
return to_status(EncodeAPP(jpg, marker, state));
case 0xFE:
return to_status(EncodeCOM(jpg, state));
case 0xFF:
return to_status(EncodeInterMarkerData(jpg, state));
default:
return SerializationStatus::ERROR;
}
}
// TODO(veluca): add streaming support again.
Status WriteJpegInternal(const JPEGData& jpg, const JPEGOutput& out,
SerializationState* ss) {
const auto maybe_push_output = [&]() -> Status {
if (ss->stage != SerializationState::STAGE_ERROR) {
while (!ss->output_queue.empty()) {
auto& chunk = ss->output_queue.front();
size_t num_written = out(chunk.next, chunk.len);
if (num_written == 0 && chunk.len > 0) {
return StatusMessage(Status(StatusCode::kNotEnoughBytes),
"Failed to write output");
}
chunk.len -= num_written;
if (chunk.len == 0) {
ss->output_queue.pop_front();
}
}
}
return true;
};
while (true) {
switch (ss->stage) {
case SerializationState::STAGE_INIT: {
// Valid Brunsli requires, at least, 0xD9 marker.
// This might happen on corrupted stream, or on unconditioned JPEGData.
// TODO(eustas): check D9 in the only one and is the last one.
if (jpg.marker_order.empty()) {
ss->stage = SerializationState::STAGE_ERROR;
break;
}
ss->dc_huff_table.resize(kMaxHuffmanTables);
ss->ac_huff_table.resize(kMaxHuffmanTables);
if (jpg.has_zero_padding_bit) {
ss->pad_bits = jpg.padding_bits.data();
ss->pad_bits_end = ss->pad_bits + jpg.padding_bits.size();
}
EncodeSOI(ss);
JXL_QUIET_RETURN_IF_ERROR(maybe_push_output());
ss->stage = SerializationState::STAGE_SERIALIZE_SECTION;
break;
}
case SerializationState::STAGE_SERIALIZE_SECTION: {
if (ss->section_index >= jpg.marker_order.size()) {
ss->stage = SerializationState::STAGE_DONE;
break;
}
uint8_t marker = jpg.marker_order[ss->section_index];
SerializationStatus status = SerializeSection(marker, ss, jpg);
if (status == SerializationStatus::ERROR) {
JXL_WARNING("Failed to encode marker 0x%.2x", marker);
ss->stage = SerializationState::STAGE_ERROR;
break;
}
JXL_QUIET_RETURN_IF_ERROR(maybe_push_output());
if (status == SerializationStatus::NEEDS_MORE_INPUT) {
return JXL_FAILURE("Incomplete serialization data");
} else if (status != SerializationStatus::DONE) {
ss->stage = SerializationState::STAGE_ERROR;
return JXL_FAILURE("Internal logic error");
break;
}
++ss->section_index;
break;
}
case SerializationState::STAGE_DONE:
JXL_ENSURE(ss->output_queue.empty());
if (ss->pad_bits != nullptr && ss->pad_bits != ss->pad_bits_end) {
return JXL_FAILURE("Invalid number of padding bits.");
}
return true;
case SerializationState::STAGE_ERROR:
return JXL_FAILURE("JPEG serialization error");
}
}
}
} // namespace
Status WriteJpeg(const JPEGData& jpg, const JPEGOutput& out) {
auto ss = jxl::make_unique<SerializationState>();
return WriteJpegInternal(jpg, out, ss.get());
}
} // namespace jpeg
} // namespace jxl