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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/jpegli/bitstream.h"
#include <cmath>
#include "lib/jpegli/bit_writer.h"
#include "lib/jpegli/error.h"
#include "lib/jpegli/memory_manager.h"
namespace jpegli {
void WriteOutput(j_compress_ptr cinfo, const uint8_t* buf, size_t bufsize) {
size_t pos = 0;
while (pos < bufsize) {
if (cinfo->dest->free_in_buffer == 0 &&
!(*cinfo->dest->empty_output_buffer)(cinfo)) {
JPEGLI_ERROR("Destination suspension is not supported in markers.");
}
size_t len = std::min<size_t>(cinfo->dest->free_in_buffer, bufsize - pos);
memcpy(cinfo->dest->next_output_byte, buf + pos, len);
pos += len;
cinfo->dest->free_in_buffer -= len;
cinfo->dest->next_output_byte += len;
}
}
void WriteOutput(j_compress_ptr cinfo, const std::vector<uint8_t>& bytes) {
WriteOutput(cinfo, bytes.data(), bytes.size());
}
void WriteOutput(j_compress_ptr cinfo, std::initializer_list<uint8_t> bytes) {
WriteOutput(cinfo, bytes.begin(), bytes.size());
}
void EncodeAPP0(j_compress_ptr cinfo) {
WriteOutput(cinfo,
{0xff, 0xe0, 0, 16, 'J', 'F', 'I', 'F', '\0',
cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
cinfo->density_unit, static_cast<uint8_t>(cinfo->X_density >> 8),
static_cast<uint8_t>(cinfo->X_density & 0xff),
static_cast<uint8_t>(cinfo->Y_density >> 8),
static_cast<uint8_t>(cinfo->Y_density & 0xff), 0, 0});
}
void EncodeAPP14(j_compress_ptr cinfo) {
uint8_t color_transform = cinfo->jpeg_color_space == JCS_YCbCr ? 1
: cinfo->jpeg_color_space == JCS_YCCK ? 2
: 0;
WriteOutput(cinfo, {0xff, 0xee, 0, 14, 'A', 'd', 'o', 'b', 'e', 0, 100, 0, 0,
0, 0, color_transform});
}
void WriteFileHeader(j_compress_ptr cinfo) {
WriteOutput(cinfo, {0xFF, 0xD8}); // SOI
if (cinfo->write_JFIF_header) {
EncodeAPP0(cinfo);
}
if (cinfo->write_Adobe_marker) {
EncodeAPP14(cinfo);
}
}
bool EncodeDQT(j_compress_ptr cinfo, bool write_all_tables) {
uint8_t data[4 + NUM_QUANT_TBLS * (1 + 2 * DCTSIZE2)]; // 520 bytes
size_t pos = 0;
data[pos++] = 0xFF;
data[pos++] = 0xDB;
pos += 2; // Length will be filled in later.
int send_table[NUM_QUANT_TBLS] = {};
if (write_all_tables) {
for (int i = 0; i < NUM_QUANT_TBLS; ++i) {
if (cinfo->quant_tbl_ptrs[i]) send_table[i] = 1;
}
} else {
for (int c = 0; c < cinfo->num_components; ++c) {
send_table[cinfo->comp_info[c].quant_tbl_no] = 1;
}
}
bool is_baseline = true;
for (int i = 0; i < NUM_QUANT_TBLS; ++i) {
if (!send_table[i]) continue;
JQUANT_TBL* quant_table = cinfo->quant_tbl_ptrs[i];
if (quant_table == nullptr) {
JPEGLI_ERROR("Missing quant table %d", i);
}
int precision = 0;
for (UINT16 q : quant_table->quantval) {
if (q > 255) {
precision = 1;
is_baseline = false;
}
}
if (quant_table->sent_table) {
continue;
}
data[pos++] = (precision << 4) + i;
for (size_t j = 0; j < DCTSIZE2; ++j) {
int val_idx = kJPEGNaturalOrder[j];
int val = quant_table->quantval[val_idx];
if (val == 0) {
JPEGLI_ERROR("Invalid quantval 0.");
}
if (precision) {
data[pos++] = val >> 8;
}
data[pos++] = val & 0xFFu;
}
quant_table->sent_table = TRUE;
}
if (pos > 4) {
data[2] = (pos - 2) >> 8u;
data[3] = (pos - 2) & 0xFFu;
WriteOutput(cinfo, data, pos);
}
return is_baseline;
}
void EncodeSOF(j_compress_ptr cinfo, bool is_baseline) {
if (cinfo->data_precision != kJpegPrecision) {
JPEGLI_ERROR("Unsupported data precision %d", cinfo->data_precision);
}
const uint8_t marker = cinfo->progressive_mode ? 0xc2
: is_baseline ? 0xc0
: 0xc1;
const size_t n_comps = cinfo->num_components;
const size_t marker_len = 8 + 3 * n_comps;
std::vector<uint8_t> data(marker_len + 2);
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++] = cinfo->image_height >> 8u;
data[pos++] = cinfo->image_height & 0xFFu;
data[pos++] = cinfo->image_width >> 8u;
data[pos++] = cinfo->image_width & 0xFFu;
data[pos++] = n_comps;
for (size_t i = 0; i < n_comps; ++i) {
jpeg_component_info* comp = &cinfo->comp_info[i];
data[pos++] = comp->component_id;
data[pos++] = ((comp->h_samp_factor << 4u) | (comp->v_samp_factor));
const uint32_t quant_idx = comp->quant_tbl_no;
if (cinfo->quant_tbl_ptrs[quant_idx] == nullptr) {
JPEGLI_ERROR("Invalid component quant table index %u.", quant_idx);
}
data[pos++] = quant_idx;
}
WriteOutput(cinfo, data);
}
void WriteFrameHeader(j_compress_ptr cinfo) {
jpeg_comp_master* m = cinfo->master;
bool is_baseline = EncodeDQT(cinfo, /*write_all_tables=*/false);
if (cinfo->progressive_mode || cinfo->arith_code ||
cinfo->data_precision != 8) {
is_baseline = false;
}
for (size_t i = 0; i < m->num_huffman_tables; ++i) {
int slot_id = m->slot_id_map[i];
if (slot_id > 0x11 || (slot_id > 0x01 && slot_id < 0x10)) {
is_baseline = false;
}
}
EncodeSOF(cinfo, is_baseline);
}
void EncodeDRI(j_compress_ptr cinfo) {
WriteOutput(cinfo, {0xFF, 0xDD, 0, 4,
static_cast<uint8_t>(cinfo->restart_interval >> 8),
static_cast<uint8_t>(cinfo->restart_interval & 0xFF)});
}
void EncodeDHT(j_compress_ptr cinfo, size_t offset, size_t num) {
jpeg_comp_master* m = cinfo->master;
size_t marker_len = 2;
for (size_t i = 0; i < num; ++i) {
const JHUFF_TBL& table = m->huffman_tables[offset + i];
if (table.sent_table) continue;
marker_len += kJpegHuffmanMaxBitLength + 1;
for (size_t j = 0; j <= kJpegHuffmanMaxBitLength; ++j) {
marker_len += table.bits[j];
}
}
std::vector<uint8_t> data(marker_len + 2);
size_t pos = 0;
data[pos++] = 0xFF;
data[pos++] = 0xC4;
data[pos++] = marker_len >> 8u;
data[pos++] = marker_len & 0xFFu;
for (size_t i = 0; i < num; ++i) {
const JHUFF_TBL& table = m->huffman_tables[offset + i];
if (table.sent_table) continue;
size_t total_count = 0;
for (size_t i = 0; i <= kJpegHuffmanMaxBitLength; ++i) {
total_count += table.bits[i];
}
data[pos++] = m->slot_id_map[offset + i];
for (size_t i = 1; i <= kJpegHuffmanMaxBitLength; ++i) {
data[pos++] = table.bits[i];
}
for (size_t i = 0; i < total_count; ++i) {
data[pos++] = table.huffval[i];
}
}
if (marker_len > 2) {
WriteOutput(cinfo, data);
}
}
void EncodeSOS(j_compress_ptr cinfo, int scan_index) {
jpeg_comp_master* m = cinfo->master;
const jpeg_scan_info* scan_info = &cinfo->scan_info[scan_index];
const size_t marker_len = 6 + 2 * scan_info->comps_in_scan;
std::vector<uint8_t> data(marker_len + 2);
size_t pos = 0;
data[pos++] = 0xFF;
data[pos++] = 0xDA;
data[pos++] = marker_len >> 8u;
data[pos++] = marker_len & 0xFFu;
data[pos++] = scan_info->comps_in_scan;
for (int i = 0; i < scan_info->comps_in_scan; ++i) {
int comp_idx = scan_info->component_index[i];
data[pos++] = cinfo->comp_info[comp_idx].component_id;
int dc_slot_id = m->slot_id_map[m->context_map[comp_idx]];
int ac_context = m->ac_ctx_offset[scan_index] + i;
int ac_slot_id = m->slot_id_map[m->context_map[ac_context]];
data[pos++] = (dc_slot_id << 4u) + (ac_slot_id - 16);
}
data[pos++] = scan_info->Ss;
data[pos++] = scan_info->Se;
data[pos++] = ((scan_info->Ah << 4u) | (scan_info->Al));
WriteOutput(cinfo, data);
}
void WriteScanHeader(j_compress_ptr cinfo, int scan_index) {
jpeg_comp_master* m = cinfo->master;
const jpeg_scan_info* scan_info = &cinfo->scan_info[scan_index];
cinfo->restart_interval = m->scan_token_info[scan_index].restart_interval;
if (cinfo->restart_interval != m->last_restart_interval) {
EncodeDRI(cinfo);
m->last_restart_interval = cinfo->restart_interval;
}
size_t num_dht = 0;
if (scan_index == 0) {
// For the first scan we emit all DC and at most 4 AC Huffman codes.
for (size_t i = 0, num_ac = 0; i < m->num_huffman_tables; ++i) {
if (m->slot_id_map[i] >= 16 && num_ac++ >= 4) break;
++num_dht;
}
} else if (scan_info->Ss > 0) {
// For multi-scan sequential and progressive DC scans we have already
// emitted all Huffman codes that we need before the first scan. For
// progressive AC scans we only need at most one new Huffman code.
if (m->context_map[m->ac_ctx_offset[scan_index]] == m->next_dht_index) {
num_dht = 1;
}
}
if (num_dht > 0) {
EncodeDHT(cinfo, m->next_dht_index, num_dht);
m->next_dht_index += num_dht;
}
EncodeSOS(cinfo, scan_index);
}
void WriteBlock(const int32_t* JXL_RESTRICT symbols,
const int32_t* JXL_RESTRICT extra_bits, const int num_nonzeros,
const bool emit_eob,
const HuffmanCodeTable* JXL_RESTRICT dc_code,
const HuffmanCodeTable* JXL_RESTRICT ac_code,
JpegBitWriter* JXL_RESTRICT bw) {
int symbol = symbols[0];
WriteBits(bw, dc_code->depth[symbol], dc_code->code[symbol] | extra_bits[0]);
for (int i = 1; i < num_nonzeros; ++i) {
symbol = symbols[i];
if (symbol > 255) {
WriteBits(bw, ac_code->depth[0xf0], ac_code->code[0xf0]);
symbol -= 256;
if (symbol > 255) {
WriteBits(bw, ac_code->depth[0xf0], ac_code->code[0xf0]);
symbol -= 256;
if (symbol > 255) {
WriteBits(bw, ac_code->depth[0xf0], ac_code->code[0xf0]);
symbol -= 256;
}
}
}
WriteBits(bw, ac_code->depth[symbol],
ac_code->code[symbol] | extra_bits[i]);
}
if (emit_eob) {
WriteBits(bw, ac_code->depth[0], ac_code->code[0]);
}
}
namespace {
JXL_INLINE void EmitMarker(JpegBitWriter* bw, int marker) {
bw->data[bw->pos++] = 0xFF;
bw->data[bw->pos++] = marker;
}
void WriteTokens(j_compress_ptr cinfo, int scan_index, JpegBitWriter* bw) {
jpeg_comp_master* m = cinfo->master;
HuffmanCodeTable* coding_tables = &m->coding_tables[0];
int next_restart_marker = 0;
const ScanTokenInfo& sti = m->scan_token_info[scan_index];
size_t num_token_arrays = m->cur_token_array + 1;
size_t total_tokens = 0;
size_t restart_idx = 0;
size_t next_restart = sti.restarts[restart_idx];
uint8_t* context_map = m->context_map;
for (size_t i = 0; i < num_token_arrays; ++i) {
Token* tokens = m->token_arrays[i].tokens;
size_t num_tokens = m->token_arrays[i].num_tokens;
if (sti.token_offset < total_tokens + num_tokens &&
total_tokens < sti.token_offset + sti.num_tokens) {
size_t start_ix =
total_tokens < sti.token_offset ? sti.token_offset - total_tokens : 0;
size_t end_ix = std::min(sti.token_offset + sti.num_tokens - total_tokens,
num_tokens);
size_t cycle_len = bw->len / 8;
size_t next_cycle = cycle_len;
for (size_t i = start_ix; i < end_ix; ++i) {
if (total_tokens + i == next_restart) {
JumpToByteBoundary(bw);
EmitMarker(bw, 0xD0 + next_restart_marker);
next_restart_marker += 1;
next_restart_marker &= 0x7;
next_restart = sti.restarts[++restart_idx];
}
Token t = tokens[i];
const HuffmanCodeTable* code = &coding_tables[context_map[t.context]];
WriteBits(bw, code->depth[t.symbol], code->code[t.symbol] | t.bits);
if (--next_cycle == 0) {
if (!EmptyBitWriterBuffer(bw)) {
JPEGLI_ERROR(
"Output suspension is not supported in "
"finish_compress");
}
next_cycle = cycle_len;
}
}
}
total_tokens += num_tokens;
}
}
void WriteACRefinementTokens(j_compress_ptr cinfo, int scan_index,
JpegBitWriter* bw) {
jpeg_comp_master* m = cinfo->master;
const ScanTokenInfo& sti = m->scan_token_info[scan_index];
const uint8_t context = m->ac_ctx_offset[scan_index];
const HuffmanCodeTable* code = &m->coding_tables[m->context_map[context]];
size_t cycle_len = bw->len / 64;
size_t next_cycle = cycle_len;
size_t refbit_idx = 0;
size_t eobrun_idx = 0;
size_t restart_idx = 0;
size_t next_restart = sti.restarts[restart_idx];
int next_restart_marker = 0;
for (size_t i = 0; i < sti.num_tokens; ++i) {
if (i == next_restart) {
JumpToByteBoundary(bw);
EmitMarker(bw, 0xD0 + next_restart_marker);
next_restart_marker += 1;
next_restart_marker &= 0x7;
next_restart = sti.restarts[++restart_idx];
}
RefToken t = sti.tokens[i];
int symbol = t.symbol & 253;
uint16_t bits = 0;
if ((symbol & 1) == 0) {
int r = symbol >> 4;
if (r > 0 && r < 15) {
bits = sti.eobruns[eobrun_idx++];
}
} else {
bits = (t.symbol >> 1) & 1;
}
WriteBits(bw, code->depth[symbol], code->code[symbol] | bits);
for (int j = 0; j < t.refbits; ++j) {
WriteBits(bw, 1, sti.refbits[refbit_idx++]);
}
if (--next_cycle == 0) {
if (!EmptyBitWriterBuffer(bw)) {
JPEGLI_ERROR("Output suspension is not supported in finish_compress");
}
next_cycle = cycle_len;
}
}
}
void WriteDCRefinementBits(j_compress_ptr cinfo, int scan_index,
JpegBitWriter* bw) {
jpeg_comp_master* m = cinfo->master;
const ScanTokenInfo& sti = m->scan_token_info[scan_index];
size_t restart_idx = 0;
size_t next_restart = sti.restarts[restart_idx];
int next_restart_marker = 0;
size_t cycle_len = bw->len * 4;
size_t next_cycle = cycle_len;
size_t refbit_idx = 0;
for (size_t i = 0; i < sti.num_tokens; ++i) {
if (i == next_restart) {
JumpToByteBoundary(bw);
EmitMarker(bw, 0xD0 + next_restart_marker);
next_restart_marker += 1;
next_restart_marker &= 0x7;
next_restart = sti.restarts[++restart_idx];
}
WriteBits(bw, 1, sti.refbits[refbit_idx++]);
if (--next_cycle == 0) {
if (!EmptyBitWriterBuffer(bw)) {
JPEGLI_ERROR(
"Output suspension is not supported in "
"finish_compress");
}
next_cycle = cycle_len;
}
}
}
} // namespace
void WriteScanData(j_compress_ptr cinfo, int scan_index) {
const jpeg_scan_info* scan_info = &cinfo->scan_info[scan_index];
JpegBitWriter* bw = &cinfo->master->bw;
if (scan_info->Ah == 0) {
WriteTokens(cinfo, scan_index, bw);
} else if (scan_info->Ss > 0) {
WriteACRefinementTokens(cinfo, scan_index, bw);
} else {
WriteDCRefinementBits(cinfo, scan_index, bw);
}
if (!bw->healthy) {
JPEGLI_ERROR("Unknown Huffman coded symbol found in scan %d", scan_index);
}
JumpToByteBoundary(bw);
if (!EmptyBitWriterBuffer(bw)) {
JPEGLI_ERROR("Output suspension is not supported in finish_compress");
}
}
} // namespace jpegli