diff options
Diffstat (limited to 'third_party/jpeg-xl/lib/jxl/jpeg/enc_jpeg_data_reader.cc')
| -rw-r--r-- | third_party/jpeg-xl/lib/jxl/jpeg/enc_jpeg_data_reader.cc | 1053 |
1 files changed, 1053 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/jpeg/enc_jpeg_data_reader.cc b/third_party/jpeg-xl/lib/jxl/jpeg/enc_jpeg_data_reader.cc new file mode 100644 index 0000000000..f569b73363 --- /dev/null +++ b/third_party/jpeg-xl/lib/jxl/jpeg/enc_jpeg_data_reader.cc @@ -0,0 +1,1053 @@ +// 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/enc_jpeg_data_reader.h" + +#include <inttypes.h> +#include <string.h> + +#include <algorithm> +#include <string> +#include <vector> + +#include "lib/jxl/base/printf_macros.h" +#include "lib/jxl/base/status.h" +#include "lib/jxl/common.h" +#include "lib/jxl/jpeg/enc_jpeg_huffman_decode.h" +#include "lib/jxl/jpeg/jpeg_data.h" + +namespace jxl { +namespace jpeg { + +namespace { +static const int kBrunsliMaxSampling = 15; + +// Macros for commonly used error conditions. + +#define JXL_JPEG_VERIFY_LEN(n) \ + if (*pos + (n) > len) { \ + return JXL_FAILURE("Unexpected end of input: pos=%" PRIuS \ + " need=%d len=%" PRIuS, \ + *pos, static_cast<int>(n), len); \ + } + +#define JXL_JPEG_VERIFY_INPUT(var, low, high, code) \ + if ((var) < (low) || (var) > (high)) { \ + return JXL_FAILURE("Invalid " #var ": %d", static_cast<int>(var)); \ + } + +#define JXL_JPEG_VERIFY_MARKER_END() \ + if (start_pos + marker_len != *pos) { \ + return JXL_FAILURE("Invalid marker length: declared=%" PRIuS \ + " actual=%" PRIuS, \ + marker_len, (*pos - start_pos)); \ + } + +#define JXL_JPEG_EXPECT_MARKER() \ + if (pos + 2 > len || data[pos] != 0xff) { \ + return JXL_FAILURE( \ + "Marker byte (0xff) expected, found: 0x%.2x pos=%" PRIuS \ + " len=%" PRIuS, \ + (pos < len ? data[pos] : 0), pos, len); \ + } + +inline int ReadUint8(const uint8_t* data, size_t* pos) { + return data[(*pos)++]; +} + +inline int ReadUint16(const uint8_t* data, size_t* pos) { + int v = (data[*pos] << 8) + data[*pos + 1]; + *pos += 2; + return v; +} + +// Reads the Start of Frame (SOF) marker segment and fills in *jpg with the +// parsed data. +bool ProcessSOF(const uint8_t* data, const size_t len, JpegReadMode mode, + size_t* pos, JPEGData* jpg) { + if (jpg->width != 0) { + return JXL_FAILURE("Duplicate SOF marker."); + } + const size_t start_pos = *pos; + JXL_JPEG_VERIFY_LEN(8); + size_t marker_len = ReadUint16(data, pos); + int precision = ReadUint8(data, pos); + int height = ReadUint16(data, pos); + int width = ReadUint16(data, pos); + int num_components = ReadUint8(data, pos); + // 'jbrd' is hardcoded for 8bits: + JXL_JPEG_VERIFY_INPUT(precision, 8, 8, PRECISION); + JXL_JPEG_VERIFY_INPUT(height, 1, kMaxDimPixels, HEIGHT); + JXL_JPEG_VERIFY_INPUT(width, 1, kMaxDimPixels, WIDTH); + JXL_JPEG_VERIFY_INPUT(num_components, 1, kMaxComponents, NUMCOMP); + JXL_JPEG_VERIFY_LEN(3 * num_components); + jpg->height = height; + jpg->width = width; + jpg->components.resize(num_components); + + // Read sampling factors and quant table index for each component. + std::vector<bool> ids_seen(256, false); + int max_h_samp_factor = 1; + int max_v_samp_factor = 1; + for (size_t i = 0; i < jpg->components.size(); ++i) { + const int id = ReadUint8(data, pos); + if (ids_seen[id]) { // (cf. section B.2.2, syntax of Ci) + return JXL_FAILURE("Duplicate ID %d in SOF.", id); + } + ids_seen[id] = true; + jpg->components[i].id = id; + int factor = ReadUint8(data, pos); + int h_samp_factor = factor >> 4; + int v_samp_factor = factor & 0xf; + JXL_JPEG_VERIFY_INPUT(h_samp_factor, 1, kBrunsliMaxSampling, SAMP_FACTOR); + JXL_JPEG_VERIFY_INPUT(v_samp_factor, 1, kBrunsliMaxSampling, SAMP_FACTOR); + jpg->components[i].h_samp_factor = h_samp_factor; + jpg->components[i].v_samp_factor = v_samp_factor; + jpg->components[i].quant_idx = ReadUint8(data, pos); + max_h_samp_factor = std::max(max_h_samp_factor, h_samp_factor); + max_v_samp_factor = std::max(max_v_samp_factor, v_samp_factor); + } + + // We have checked above that none of the sampling factors are 0, so the max + // sampling factors can not be 0. + int MCU_rows = DivCeil(jpg->height, max_v_samp_factor * 8); + int MCU_cols = DivCeil(jpg->width, max_h_samp_factor * 8); + // Compute the block dimensions for each component. + for (size_t i = 0; i < jpg->components.size(); ++i) { + JPEGComponent* c = &jpg->components[i]; + if (max_h_samp_factor % c->h_samp_factor != 0 || + max_v_samp_factor % c->v_samp_factor != 0) { + return JXL_FAILURE("Non-integral subsampling ratios."); + } + c->width_in_blocks = MCU_cols * c->h_samp_factor; + c->height_in_blocks = MCU_rows * c->v_samp_factor; + const uint64_t num_blocks = + static_cast<uint64_t>(c->width_in_blocks) * c->height_in_blocks; + if (mode == JpegReadMode::kReadAll) { + c->coeffs.resize(num_blocks * kDCTBlockSize); + } + } + JXL_JPEG_VERIFY_MARKER_END(); + return true; +} + +// Reads the Start of Scan (SOS) marker segment and fills in *scan_info with the +// parsed data. +bool ProcessSOS(const uint8_t* data, const size_t len, size_t* pos, + JPEGData* jpg) { + const size_t start_pos = *pos; + JXL_JPEG_VERIFY_LEN(3); + size_t marker_len = ReadUint16(data, pos); + size_t comps_in_scan = ReadUint8(data, pos); + JXL_JPEG_VERIFY_INPUT(comps_in_scan, 1, jpg->components.size(), + COMPS_IN_SCAN); + + JPEGScanInfo scan_info; + scan_info.num_components = comps_in_scan; + JXL_JPEG_VERIFY_LEN(2 * comps_in_scan); + std::vector<bool> ids_seen(256, false); + for (size_t i = 0; i < comps_in_scan; ++i) { + uint32_t id = ReadUint8(data, pos); + if (ids_seen[id]) { // (cf. section B.2.3, regarding CSj) + return JXL_FAILURE("Duplicate ID %d in SOS.", id); + } + ids_seen[id] = true; + bool found_index = false; + for (size_t j = 0; j < jpg->components.size(); ++j) { + if (jpg->components[j].id == id) { + scan_info.components[i].comp_idx = j; + found_index = true; + } + } + if (!found_index) { + return JXL_FAILURE("SOS marker: Could not find component with id %d", id); + } + int c = ReadUint8(data, pos); + int dc_tbl_idx = c >> 4; + int ac_tbl_idx = c & 0xf; + JXL_JPEG_VERIFY_INPUT(dc_tbl_idx, 0, 3, HUFFMAN_INDEX); + JXL_JPEG_VERIFY_INPUT(ac_tbl_idx, 0, 3, HUFFMAN_INDEX); + scan_info.components[i].dc_tbl_idx = dc_tbl_idx; + scan_info.components[i].ac_tbl_idx = ac_tbl_idx; + } + JXL_JPEG_VERIFY_LEN(3); + scan_info.Ss = ReadUint8(data, pos); + scan_info.Se = ReadUint8(data, pos); + JXL_JPEG_VERIFY_INPUT(static_cast<int>(scan_info.Ss), 0, 63, START_OF_SCAN); + JXL_JPEG_VERIFY_INPUT(scan_info.Se, scan_info.Ss, 63, END_OF_SCAN); + int c = ReadUint8(data, pos); + scan_info.Ah = c >> 4; + scan_info.Al = c & 0xf; + if (scan_info.Ah != 0 && scan_info.Al != scan_info.Ah - 1) { + // section G.1.1.1.2 : Successive approximation control only improves + // by one bit at a time. But it's not always respected, so we just issue + // a warning. + JXL_WARNING("Invalid progressive parameters: Al=%d Ah=%d", scan_info.Al, + scan_info.Ah); + } + // Check that all the Huffman tables needed for this scan are defined. + for (size_t i = 0; i < comps_in_scan; ++i) { + bool found_dc_table = false; + bool found_ac_table = false; + for (size_t j = 0; j < jpg->huffman_code.size(); ++j) { + uint32_t slot_id = jpg->huffman_code[j].slot_id; + if (slot_id == scan_info.components[i].dc_tbl_idx) { + found_dc_table = true; + } else if (slot_id == scan_info.components[i].ac_tbl_idx + 16) { + found_ac_table = true; + } + } + if (scan_info.Ss == 0 && !found_dc_table) { + return JXL_FAILURE( + "SOS marker: Could not find DC Huffman table with index %d", + scan_info.components[i].dc_tbl_idx); + } + if (scan_info.Se > 0 && !found_ac_table) { + return JXL_FAILURE( + "SOS marker: Could not find AC Huffman table with index %d", + scan_info.components[i].ac_tbl_idx); + } + } + jpg->scan_info.push_back(scan_info); + JXL_JPEG_VERIFY_MARKER_END(); + return true; +} + +// Reads the Define Huffman Table (DHT) marker segment and fills in *jpg with +// the parsed data. Builds the Huffman decoding table in either dc_huff_lut or +// ac_huff_lut, depending on the type and solt_id of Huffman code being read. +bool ProcessDHT(const uint8_t* data, const size_t len, JpegReadMode mode, + std::vector<HuffmanTableEntry>* dc_huff_lut, + std::vector<HuffmanTableEntry>* ac_huff_lut, size_t* pos, + JPEGData* jpg) { + const size_t start_pos = *pos; + JXL_JPEG_VERIFY_LEN(2); + size_t marker_len = ReadUint16(data, pos); + if (marker_len == 2) { + return JXL_FAILURE("DHT marker: no Huffman table found"); + } + while (*pos < start_pos + marker_len) { + JXL_JPEG_VERIFY_LEN(1 + kJpegHuffmanMaxBitLength); + JPEGHuffmanCode huff; + huff.slot_id = ReadUint8(data, pos); + int huffman_index = huff.slot_id; + int is_ac_table = (huff.slot_id & 0x10) != 0; + HuffmanTableEntry* huff_lut; + if (is_ac_table) { + huffman_index -= 0x10; + JXL_JPEG_VERIFY_INPUT(huffman_index, 0, 3, HUFFMAN_INDEX); + huff_lut = &(*ac_huff_lut)[huffman_index * kJpegHuffmanLutSize]; + } else { + JXL_JPEG_VERIFY_INPUT(huffman_index, 0, 3, HUFFMAN_INDEX); + huff_lut = &(*dc_huff_lut)[huffman_index * kJpegHuffmanLutSize]; + } + huff.counts[0] = 0; + int total_count = 0; + int space = 1 << kJpegHuffmanMaxBitLength; + int max_depth = 1; + for (size_t i = 1; i <= kJpegHuffmanMaxBitLength; ++i) { + int count = ReadUint8(data, pos); + if (count != 0) { + max_depth = i; + } + huff.counts[i] = count; + total_count += count; + space -= count * (1 << (kJpegHuffmanMaxBitLength - i)); + } + if (is_ac_table) { + JXL_JPEG_VERIFY_INPUT(total_count, 0, kJpegHuffmanAlphabetSize, + HUFFMAN_CODE); + } else { + JXL_JPEG_VERIFY_INPUT(total_count, 0, kJpegDCAlphabetSize, HUFFMAN_CODE); + } + JXL_JPEG_VERIFY_LEN(total_count); + std::vector<bool> values_seen(256, false); + for (int i = 0; i < total_count; ++i) { + int value = ReadUint8(data, pos); + if (!is_ac_table) { + JXL_JPEG_VERIFY_INPUT(value, 0, kJpegDCAlphabetSize - 1, HUFFMAN_CODE); + } + if (values_seen[value]) { + return JXL_FAILURE("Duplicate Huffman code value %d", value); + } + values_seen[value] = true; + huff.values[i] = value; + } + // Add an invalid symbol that will have the all 1 code. + ++huff.counts[max_depth]; + huff.values[total_count] = kJpegHuffmanAlphabetSize; + space -= (1 << (kJpegHuffmanMaxBitLength - max_depth)); + if (space < 0) { + return JXL_FAILURE("Invalid Huffman code lengths."); + } else if (space > 0 && huff_lut[0].value != 0xffff) { + // Re-initialize the values to an invalid symbol so that we can recognize + // it when reading the bit stream using a Huffman code with space > 0. + for (int i = 0; i < kJpegHuffmanLutSize; ++i) { + huff_lut[i].bits = 0; + huff_lut[i].value = 0xffff; + } + } + huff.is_last = (*pos == start_pos + marker_len); + if (mode == JpegReadMode::kReadAll) { + BuildJpegHuffmanTable(&huff.counts[0], &huff.values[0], huff_lut); + } + jpg->huffman_code.push_back(huff); + } + JXL_JPEG_VERIFY_MARKER_END(); + return true; +} + +// Reads the Define Quantization Table (DQT) marker segment and fills in *jpg +// with the parsed data. +bool ProcessDQT(const uint8_t* data, const size_t len, size_t* pos, + JPEGData* jpg) { + const size_t start_pos = *pos; + JXL_JPEG_VERIFY_LEN(2); + size_t marker_len = ReadUint16(data, pos); + if (marker_len == 2) { + return JXL_FAILURE("DQT marker: no quantization table found"); + } + while (*pos < start_pos + marker_len && jpg->quant.size() < kMaxQuantTables) { + JXL_JPEG_VERIFY_LEN(1); + int quant_table_index = ReadUint8(data, pos); + int quant_table_precision = quant_table_index >> 4; + JXL_JPEG_VERIFY_INPUT(quant_table_precision, 0, 1, QUANT_TBL_PRECISION); + quant_table_index &= 0xf; + JXL_JPEG_VERIFY_INPUT(quant_table_index, 0, 3, QUANT_TBL_INDEX); + JXL_JPEG_VERIFY_LEN((quant_table_precision + 1) * kDCTBlockSize); + JPEGQuantTable table; + table.index = quant_table_index; + table.precision = quant_table_precision; + for (size_t i = 0; i < kDCTBlockSize; ++i) { + int quant_val = + quant_table_precision ? ReadUint16(data, pos) : ReadUint8(data, pos); + JXL_JPEG_VERIFY_INPUT(quant_val, 1, 65535, QUANT_VAL); + table.values[kJPEGNaturalOrder[i]] = quant_val; + } + table.is_last = (*pos == start_pos + marker_len); + jpg->quant.push_back(table); + } + JXL_JPEG_VERIFY_MARKER_END(); + return true; +} + +// Reads the DRI marker and saves the restart interval into *jpg. +bool ProcessDRI(const uint8_t* data, const size_t len, size_t* pos, + bool* found_dri, JPEGData* jpg) { + if (*found_dri) { + return JXL_FAILURE("Duplicate DRI marker."); + } + *found_dri = true; + const size_t start_pos = *pos; + JXL_JPEG_VERIFY_LEN(4); + size_t marker_len = ReadUint16(data, pos); + int restart_interval = ReadUint16(data, pos); + jpg->restart_interval = restart_interval; + JXL_JPEG_VERIFY_MARKER_END(); + return true; +} + +// Saves the APP marker segment as a string to *jpg. +bool ProcessAPP(const uint8_t* data, const size_t len, size_t* pos, + JPEGData* jpg) { + JXL_JPEG_VERIFY_LEN(2); + size_t marker_len = ReadUint16(data, pos); + JXL_JPEG_VERIFY_INPUT(marker_len, 2, 65535, MARKER_LEN); + JXL_JPEG_VERIFY_LEN(marker_len - 2); + JXL_DASSERT(*pos >= 3); + // Save the marker type together with the app data. + const uint8_t* app_str_start = data + *pos - 3; + std::vector<uint8_t> app_str(app_str_start, app_str_start + marker_len + 1); + *pos += marker_len - 2; + jpg->app_data.push_back(app_str); + return true; +} + +// Saves the COM marker segment as a string to *jpg. +bool ProcessCOM(const uint8_t* data, const size_t len, size_t* pos, + JPEGData* jpg) { + JXL_JPEG_VERIFY_LEN(2); + size_t marker_len = ReadUint16(data, pos); + JXL_JPEG_VERIFY_INPUT(marker_len, 2, 65535, MARKER_LEN); + JXL_JPEG_VERIFY_LEN(marker_len - 2); + const uint8_t* com_str_start = data + *pos - 3; + std::vector<uint8_t> com_str(com_str_start, com_str_start + marker_len + 1); + *pos += marker_len - 2; + jpg->com_data.push_back(com_str); + return true; +} + +// Helper structure to read bits from the entropy coded data segment. +struct BitReaderState { + BitReaderState(const uint8_t* data, const size_t len, size_t pos) + : data_(data), len_(len) { + Reset(pos); + } + + void Reset(size_t pos) { + pos_ = pos; + val_ = 0; + bits_left_ = 0; + next_marker_pos_ = len_ - 2; + FillBitWindow(); + } + + // Returns the next byte and skips the 0xff/0x00 escape sequences. + uint8_t GetNextByte() { + if (pos_ >= next_marker_pos_) { + ++pos_; + return 0; + } + uint8_t c = data_[pos_++]; + if (c == 0xff) { + uint8_t escape = data_[pos_]; + if (escape == 0) { + ++pos_; + } else { + // 0xff was followed by a non-zero byte, which means that we found the + // start of the next marker segment. + next_marker_pos_ = pos_ - 1; + } + } + return c; + } + + void FillBitWindow() { + if (bits_left_ <= 16) { + while (bits_left_ <= 56) { + val_ <<= 8; + val_ |= (uint64_t)GetNextByte(); + bits_left_ += 8; + } + } + } + + int ReadBits(int nbits) { + FillBitWindow(); + uint64_t val = (val_ >> (bits_left_ - nbits)) & ((1ULL << nbits) - 1); + bits_left_ -= nbits; + return val; + } + + // Sets *pos to the next stream position where parsing should continue. + // Enqueue the padding bits seen (0 or 1). + // Returns false if there is inconsistent or invalid padding or the stream + // ended too early. + bool FinishStream(JPEGData* jpg, size_t* pos) { + int npadbits = bits_left_ & 7; + if (npadbits > 0) { + uint64_t padmask = (1ULL << npadbits) - 1; + uint64_t padbits = (val_ >> (bits_left_ - npadbits)) & padmask; + if (padbits != padmask) { + jpg->has_zero_padding_bit = true; + } + for (int i = npadbits - 1; i >= 0; --i) { + jpg->padding_bits.push_back((padbits >> i) & 1); + } + } + // Give back some bytes that we did not use. + int unused_bytes_left = bits_left_ >> 3; + while (unused_bytes_left-- > 0) { + --pos_; + // If we give back a 0 byte, we need to check if it was a 0xff/0x00 escape + // sequence, and if yes, we need to give back one more byte. + if (pos_ < next_marker_pos_ && data_[pos_] == 0 && + data_[pos_ - 1] == 0xff) { + --pos_; + } + } + if (pos_ > next_marker_pos_) { + // Data ran out before the scan was complete. + return JXL_FAILURE("Unexpected end of scan."); + } + *pos = pos_; + return true; + } + + const uint8_t* data_; + const size_t len_; + size_t pos_; + uint64_t val_; + int bits_left_; + size_t next_marker_pos_; +}; + +// Returns the next Huffman-coded symbol. +int ReadSymbol(const HuffmanTableEntry* table, BitReaderState* br) { + int nbits; + br->FillBitWindow(); + int val = (br->val_ >> (br->bits_left_ - 8)) & 0xff; + table += val; + nbits = table->bits - 8; + if (nbits > 0) { + br->bits_left_ -= 8; + table += table->value; + val = (br->val_ >> (br->bits_left_ - nbits)) & ((1 << nbits) - 1); + table += val; + } + br->bits_left_ -= table->bits; + return table->value; +} + +/** + * Returns the DC diff or AC value for extra bits value x and prefix code s. + * + * CCITT Rec. T.81 (1992 E) + * Table F.1 – Difference magnitude categories for DC coding + * SSSS | DIFF values + * ------+-------------------------- + * 0 | 0 + * 1 | –1, 1 + * 2 | –3, –2, 2, 3 + * 3 | –7..–4, 4..7 + * ......|.......................... + * 11 | –2047..–1024, 1024..2047 + * + * CCITT Rec. T.81 (1992 E) + * Table F.2 – Categories assigned to coefficient values + * [ Same as Table F.1, but does not include SSSS equal to 0 and 11] + * + * + * CCITT Rec. T.81 (1992 E) + * F.1.2.1.1 Structure of DC code table + * For each category,... additional bits... appended... to uniquely identify + * which difference... occurred... When DIFF is positive... SSSS... bits of DIFF + * are appended. When DIFF is negative... SSSS... bits of (DIFF – 1) are + * appended... Most significant bit... is 0 for negative differences and 1 for + * positive differences. + * + * In other words the upper half of extra bits range represents DIFF as is. + * The lower half represents the negative DIFFs with an offset. + */ +int HuffExtend(int x, int s) { + JXL_DASSERT(s >= 1); + int half = 1 << (s - 1); + if (x >= half) { + JXL_DASSERT(x < (1 << s)); + return x; + } else { + return x - (1 << s) + 1; + } +} + +// Decodes one 8x8 block of DCT coefficients from the bit stream. +bool DecodeDCTBlock(const HuffmanTableEntry* dc_huff, + const HuffmanTableEntry* ac_huff, int Ss, int Se, int Al, + int* eobrun, bool* reset_state, int* num_zero_runs, + BitReaderState* br, JPEGData* jpg, coeff_t* last_dc_coeff, + coeff_t* coeffs) { + // Nowadays multiplication is even faster than variable shift. + int Am = 1 << Al; + bool eobrun_allowed = Ss > 0; + if (Ss == 0) { + int s = ReadSymbol(dc_huff, br); + if (s >= kJpegDCAlphabetSize) { + return JXL_FAILURE("Invalid Huffman symbol %d for DC coefficient.", s); + } + int diff = 0; + if (s > 0) { + int bits = br->ReadBits(s); + diff = HuffExtend(bits, s); + } + int coeff = diff + *last_dc_coeff; + const int dc_coeff = coeff * Am; + coeffs[0] = dc_coeff; + // TODO(eustas): is there a more elegant / explicit way to check this? + if (dc_coeff != coeffs[0]) { + return JXL_FAILURE("Invalid DC coefficient %d", dc_coeff); + } + *last_dc_coeff = coeff; + ++Ss; + } + if (Ss > Se) { + return true; + } + if (*eobrun > 0) { + --(*eobrun); + return true; + } + *num_zero_runs = 0; + for (int k = Ss; k <= Se; k++) { + int sr = ReadSymbol(ac_huff, br); + if (sr >= kJpegHuffmanAlphabetSize) { + return JXL_FAILURE("Invalid Huffman symbol %d for AC coefficient %d", sr, + k); + } + int r = sr >> 4; + int s = sr & 15; + if (s > 0) { + k += r; + if (k > Se) { + return JXL_FAILURE("Out-of-band coefficient %d band was %d-%d", k, Ss, + Se); + } + if (s + Al >= kJpegDCAlphabetSize) { + return JXL_FAILURE( + "Out of range AC coefficient value: s = %d Al = %d k = %d", s, Al, + k); + } + int bits = br->ReadBits(s); + int coeff = HuffExtend(bits, s); + coeffs[kJPEGNaturalOrder[k]] = coeff * Am; + *num_zero_runs = 0; + } else if (r == 15) { + k += 15; + ++(*num_zero_runs); + } else { + if (eobrun_allowed && k == Ss && *eobrun == 0) { + // We have two end-of-block runs right after each other, so we signal + // the jpeg encoder to force a state reset at this point. + *reset_state = true; + } + *eobrun = 1 << r; + if (r > 0) { + if (!eobrun_allowed) { + return JXL_FAILURE("End-of-block run crossing DC coeff."); + } + *eobrun += br->ReadBits(r); + } + break; + } + } + --(*eobrun); + return true; +} + +bool RefineDCTBlock(const HuffmanTableEntry* ac_huff, int Ss, int Se, int Al, + int* eobrun, bool* reset_state, BitReaderState* br, + JPEGData* jpg, coeff_t* coeffs) { + // Nowadays multiplication is even faster than variable shift. + int Am = 1 << Al; + bool eobrun_allowed = Ss > 0; + if (Ss == 0) { + int s = br->ReadBits(1); + coeff_t dc_coeff = coeffs[0]; + dc_coeff |= s * Am; + coeffs[0] = dc_coeff; + ++Ss; + } + if (Ss > Se) { + return true; + } + int p1 = Am; + int m1 = -Am; + int k = Ss; + int r; + int s; + bool in_zero_run = false; + if (*eobrun <= 0) { + for (; k <= Se; k++) { + s = ReadSymbol(ac_huff, br); + if (s >= kJpegHuffmanAlphabetSize) { + return JXL_FAILURE("Invalid Huffman symbol %d for AC coefficient %d", s, + k); + } + r = s >> 4; + s &= 15; + if (s) { + if (s != 1) { + return JXL_FAILURE("Invalid Huffman symbol %d for AC coefficient %d", + s, k); + } + s = br->ReadBits(1) ? p1 : m1; + in_zero_run = false; + } else { + if (r != 15) { + if (eobrun_allowed && k == Ss && *eobrun == 0) { + // We have two end-of-block runs right after each other, so we + // signal the jpeg encoder to force a state reset at this point. + *reset_state = true; + } + *eobrun = 1 << r; + if (r > 0) { + if (!eobrun_allowed) { + return JXL_FAILURE("End-of-block run crossing DC coeff."); + } + *eobrun += br->ReadBits(r); + } + break; + } + in_zero_run = true; + } + do { + coeff_t thiscoef = coeffs[kJPEGNaturalOrder[k]]; + if (thiscoef != 0) { + if (br->ReadBits(1)) { + if ((thiscoef & p1) == 0) { + if (thiscoef >= 0) { + thiscoef += p1; + } else { + thiscoef += m1; + } + } + } + coeffs[kJPEGNaturalOrder[k]] = thiscoef; + } else { + if (--r < 0) { + break; + } + } + k++; + } while (k <= Se); + if (s) { + if (k > Se) { + return JXL_FAILURE("Out-of-band coefficient %d band was %d-%d", k, Ss, + Se); + } + coeffs[kJPEGNaturalOrder[k]] = s; + } + } + } + if (in_zero_run) { + return JXL_FAILURE("Extra zero run before end-of-block."); + } + if (*eobrun > 0) { + for (; k <= Se; k++) { + coeff_t thiscoef = coeffs[kJPEGNaturalOrder[k]]; + if (thiscoef != 0) { + if (br->ReadBits(1)) { + if ((thiscoef & p1) == 0) { + if (thiscoef >= 0) { + thiscoef += p1; + } else { + thiscoef += m1; + } + } + } + coeffs[kJPEGNaturalOrder[k]] = thiscoef; + } + } + } + --(*eobrun); + return true; +} + +bool ProcessRestart(const uint8_t* data, const size_t len, + int* next_restart_marker, BitReaderState* br, + JPEGData* jpg) { + size_t pos = 0; + if (!br->FinishStream(jpg, &pos)) { + return JXL_FAILURE("Invalid scan"); + } + int expected_marker = 0xd0 + *next_restart_marker; + JXL_JPEG_EXPECT_MARKER(); + int marker = data[pos + 1]; + if (marker != expected_marker) { + return JXL_FAILURE("Did not find expected restart marker %d actual %d", + expected_marker, marker); + } + br->Reset(pos + 2); + *next_restart_marker += 1; + *next_restart_marker &= 0x7; + return true; +} + +bool ProcessScan(const uint8_t* data, const size_t len, + const std::vector<HuffmanTableEntry>& dc_huff_lut, + const std::vector<HuffmanTableEntry>& ac_huff_lut, + uint16_t scan_progression[kMaxComponents][kDCTBlockSize], + bool is_progressive, size_t* pos, JPEGData* jpg) { + if (!ProcessSOS(data, len, pos, jpg)) { + return false; + } + JPEGScanInfo* scan_info = &jpg->scan_info.back(); + bool is_interleaved = (scan_info->num_components > 1); + int max_h_samp_factor = 1; + int max_v_samp_factor = 1; + for (size_t i = 0; i < jpg->components.size(); ++i) { + max_h_samp_factor = + std::max(max_h_samp_factor, jpg->components[i].h_samp_factor); + max_v_samp_factor = + std::max(max_v_samp_factor, jpg->components[i].v_samp_factor); + } + + int MCU_rows = DivCeil(jpg->height, max_v_samp_factor * 8); + int MCUs_per_row = DivCeil(jpg->width, max_h_samp_factor * 8); + if (!is_interleaved) { + const JPEGComponent& c = jpg->components[scan_info->components[0].comp_idx]; + MCUs_per_row = DivCeil(jpg->width * c.h_samp_factor, 8 * max_h_samp_factor); + MCU_rows = DivCeil(jpg->height * c.v_samp_factor, 8 * max_v_samp_factor); + } + coeff_t last_dc_coeff[kMaxComponents] = {0}; + BitReaderState br(data, len, *pos); + int restarts_to_go = jpg->restart_interval; + int next_restart_marker = 0; + int eobrun = -1; + int block_scan_index = 0; + 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 uint16_t scan_bitmask = Ah == 0 ? (0xffff << Al) : (1u << Al); + const uint16_t refinement_bitmask = (1 << Al) - 1; + for (size_t i = 0; i < scan_info->num_components; ++i) { + int comp_idx = scan_info->components[i].comp_idx; + for (int k = Ss; k <= Se; ++k) { + if (scan_progression[comp_idx][k] & scan_bitmask) { + return JXL_FAILURE( + "Overlapping scans: component=%d k=%d prev_mask: %u cur_mask %u", + comp_idx, k, scan_progression[i][k], scan_bitmask); + } + if (scan_progression[comp_idx][k] & refinement_bitmask) { + return JXL_FAILURE( + "Invalid scan order, a more refined scan was already done: " + "component=%d k=%d prev_mask=%u cur_mask=%u", + comp_idx, k, scan_progression[i][k], scan_bitmask); + } + scan_progression[comp_idx][k] |= scan_bitmask; + } + } + if (Al > 10) { + return JXL_FAILURE("Scan parameter Al=%d is not supported.", Al); + } + for (int mcu_y = 0; mcu_y < MCU_rows; ++mcu_y) { + for (int mcu_x = 0; mcu_x < MCUs_per_row; ++mcu_x) { + // Handle the restart intervals. + if (jpg->restart_interval > 0) { + if (restarts_to_go == 0) { + if (ProcessRestart(data, len, &next_restart_marker, &br, jpg)) { + restarts_to_go = jpg->restart_interval; + memset(static_cast<void*>(last_dc_coeff), 0, sizeof(last_dc_coeff)); + if (eobrun > 0) { + return JXL_FAILURE("End-of-block run too long."); + } + eobrun = -1; // fresh start + } else { + return JXL_FAILURE("Could not process restart."); + } + } + --restarts_to_go; + } + // Decode one MCU. + for (size_t i = 0; i < scan_info->num_components; ++i) { + JPEGComponentScanInfo* si = &scan_info->components[i]; + JPEGComponent* c = &jpg->components[si->comp_idx]; + const HuffmanTableEntry* dc_lut = + &dc_huff_lut[si->dc_tbl_idx * kJpegHuffmanLutSize]; + const HuffmanTableEntry* ac_lut = + &ac_huff_lut[si->ac_tbl_idx * kJpegHuffmanLutSize]; + int nblocks_y = is_interleaved ? c->v_samp_factor : 1; + int nblocks_x = is_interleaved ? c->h_samp_factor : 1; + for (int iy = 0; iy < nblocks_y; ++iy) { + for (int ix = 0; ix < nblocks_x; ++ix) { + int block_y = mcu_y * nblocks_y + iy; + int block_x = mcu_x * nblocks_x + ix; + int block_idx = block_y * c->width_in_blocks + block_x; + bool reset_state = false; + int num_zero_runs = 0; + coeff_t* coeffs = &c->coeffs[block_idx * kDCTBlockSize]; + if (Ah == 0) { + if (!DecodeDCTBlock(dc_lut, ac_lut, Ss, Se, Al, &eobrun, + &reset_state, &num_zero_runs, &br, jpg, + &last_dc_coeff[si->comp_idx], coeffs)) { + return false; + } + } else { + if (!RefineDCTBlock(ac_lut, Ss, Se, Al, &eobrun, &reset_state, + &br, jpg, coeffs)) { + return false; + } + } + if (reset_state) { + scan_info->reset_points.emplace_back(block_scan_index); + } + if (num_zero_runs > 0) { + JPEGScanInfo::ExtraZeroRunInfo info; + info.block_idx = block_scan_index; + info.num_extra_zero_runs = num_zero_runs; + scan_info->extra_zero_runs.push_back(info); + } + ++block_scan_index; + } + } + } + } + } + if (eobrun > 0) { + return JXL_FAILURE("End-of-block run too long."); + } + if (!br.FinishStream(jpg, pos)) { + return JXL_FAILURE("Invalid scan."); + } + if (*pos > len) { + return JXL_FAILURE("Unexpected end of file during scan. pos=%" PRIuS + " len=%" PRIuS, + *pos, len); + } + return true; +} + +// Changes the quant_idx field of the components to refer to the index of the +// quant table in the jpg->quant array. +bool FixupIndexes(JPEGData* jpg) { + for (size_t i = 0; i < jpg->components.size(); ++i) { + JPEGComponent* c = &jpg->components[i]; + bool found_index = false; + for (size_t j = 0; j < jpg->quant.size(); ++j) { + if (jpg->quant[j].index == c->quant_idx) { + c->quant_idx = j; + found_index = true; + break; + } + } + if (!found_index) { + return JXL_FAILURE("Quantization table with index %u not found", + c->quant_idx); + } + } + return true; +} + +size_t FindNextMarker(const uint8_t* data, const size_t len, size_t pos) { + // kIsValidMarker[i] == 1 means (0xc0 + i) is a valid marker. + static const uint8_t kIsValidMarker[] = { + 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, + 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, + }; + size_t num_skipped = 0; + while (pos + 1 < len && (data[pos] != 0xff || data[pos + 1] < 0xc0 || + !kIsValidMarker[data[pos + 1] - 0xc0])) { + ++pos; + ++num_skipped; + } + return num_skipped; +} + +} // namespace + +bool ReadJpeg(const uint8_t* data, const size_t len, JpegReadMode mode, + JPEGData* jpg) { + size_t pos = 0; + // Check SOI marker. + JXL_JPEG_EXPECT_MARKER(); + int marker = data[pos + 1]; + pos += 2; + if (marker != 0xd8) { + return JXL_FAILURE("Did not find expected SOI marker, actual=%d", marker); + } + int lut_size = kMaxHuffmanTables * kJpegHuffmanLutSize; + std::vector<HuffmanTableEntry> dc_huff_lut(lut_size); + std::vector<HuffmanTableEntry> ac_huff_lut(lut_size); + bool found_sof = false; + bool found_dri = false; + uint16_t scan_progression[kMaxComponents][kDCTBlockSize] = {{0}}; + + jpg->padding_bits.resize(0); + bool is_progressive = false; // default + do { + // Read next marker. + size_t num_skipped = FindNextMarker(data, len, pos); + if (num_skipped > 0) { + // Add a fake marker to indicate arbitrary in-between-markers data. + jpg->marker_order.push_back(0xff); + jpg->inter_marker_data.emplace_back(data + pos, data + pos + num_skipped); + pos += num_skipped; + } + JXL_JPEG_EXPECT_MARKER(); + marker = data[pos + 1]; + pos += 2; + bool ok = true; + switch (marker) { + case 0xc0: + case 0xc1: + case 0xc2: + is_progressive = (marker == 0xc2); + ok = ProcessSOF(data, len, mode, &pos, jpg); + found_sof = true; + break; + case 0xc4: + ok = ProcessDHT(data, len, mode, &dc_huff_lut, &ac_huff_lut, &pos, jpg); + break; + case 0xd0: + case 0xd1: + case 0xd2: + case 0xd3: + case 0xd4: + case 0xd5: + case 0xd6: + case 0xd7: + // RST markers do not have any data. + break; + case 0xd9: + // Found end marker. + break; + case 0xda: + if (mode == JpegReadMode::kReadAll) { + ok = ProcessScan(data, len, dc_huff_lut, ac_huff_lut, + scan_progression, is_progressive, &pos, jpg); + } + break; + case 0xdb: + ok = ProcessDQT(data, len, &pos, jpg); + break; + case 0xdd: + ok = ProcessDRI(data, len, &pos, &found_dri, jpg); + break; + 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: + if (mode != JpegReadMode::kReadTables) { + ok = ProcessAPP(data, len, &pos, jpg); + } + break; + case 0xfe: + if (mode != JpegReadMode::kReadTables) { + ok = ProcessCOM(data, len, &pos, jpg); + } + break; + default: + return JXL_FAILURE("Unsupported marker: %d pos=%" PRIuS " len=%" PRIuS, + marker, pos, len); + } + if (!ok) { + return false; + } + jpg->marker_order.push_back(marker); + if (mode == JpegReadMode::kReadHeader && found_sof) { + break; + } + } while (marker != 0xd9); + + if (!found_sof) { + return JXL_FAILURE("Missing SOF marker."); + } + + // Supplemental checks. + if (mode == JpegReadMode::kReadAll) { + if (pos < len) { + jpg->tail_data = std::vector<uint8_t>(data + pos, data + len); + } + if (!FixupIndexes(jpg)) { + return false; + } + if (jpg->huffman_code.empty()) { + // Section B.2.4.2: "If a table has never been defined for a particular + // destination, then when this destination is specified in a scan header, + // the results are unpredictable." + return JXL_FAILURE("Need at least one Huffman code table."); + } + if (jpg->huffman_code.size() >= kMaxDHTMarkers) { + return JXL_FAILURE("Too many Huffman tables."); + } + } + return true; +} + +} // namespace jpeg +} // namespace jxl |