1// jpgd.h - C++ class for JPEG decompression.
2// Richard Geldreich <richgel99@gmail.com>
3// See jpgd.cpp for license (Public Domain or Apache 2.0).
4#ifndef JPEG_DECODER_H
5#define JPEG_DECODER_H
6
7#include <stdlib.h>
8#include <stdio.h>
9#include <setjmp.h>
10#include <assert.h>
11#include <stdint.h>
12
13#ifdef _MSC_VER
14#define JPGD_NORETURN __declspec(noreturn)
15#elif defined(__GNUC__)
16#define JPGD_NORETURN __attribute__ ((noreturn))
17#else
18#define JPGD_NORETURN
19#endif
20
21#define JPGD_HUFF_TREE_MAX_LENGTH 512
22#define JPGD_HUFF_CODE_SIZE_MAX_LENGTH 256
23
24namespace jpgd
25{
26 typedef unsigned char uint8;
27 typedef signed short int16;
28 typedef unsigned short uint16;
29 typedef unsigned int uint;
30 typedef signed int int32;
31
32 // Loads a JPEG image from a memory buffer or a file.
33 // req_comps can be 1 (grayscale), 3 (RGB), or 4 (RGBA).
34 // On return, width/height will be set to the image's dimensions, and actual_comps will be set to the either 1 (grayscale) or 3 (RGB).
35 // Notes: For more control over where and how the source data is read, see the decompress_jpeg_image_from_stream() function below, or call the jpeg_decoder class directly.
36 // Requesting a 8 or 32bpp image is currently a little faster than 24bpp because the jpeg_decoder class itself currently always unpacks to either 8 or 32bpp.
37 unsigned char* decompress_jpeg_image_from_memory(const unsigned char* pSrc_data, int src_data_size, int* width, int* height, int* actual_comps, int req_comps, uint32_t flags = 0);
38 unsigned char* decompress_jpeg_image_from_file(const char* pSrc_filename, int* width, int* height, int* actual_comps, int req_comps, uint32_t flags = 0);
39
40 // Success/failure error codes.
41 enum jpgd_status
42 {
43 JPGD_SUCCESS = 0, JPGD_FAILED = -1, JPGD_DONE = 1,
44 JPGD_BAD_DHT_COUNTS = -256, JPGD_BAD_DHT_INDEX, JPGD_BAD_DHT_MARKER, JPGD_BAD_DQT_MARKER, JPGD_BAD_DQT_TABLE,
45 JPGD_BAD_PRECISION, JPGD_BAD_HEIGHT, JPGD_BAD_WIDTH, JPGD_TOO_MANY_COMPONENTS,
46 JPGD_BAD_SOF_LENGTH, JPGD_BAD_VARIABLE_MARKER, JPGD_BAD_DRI_LENGTH, JPGD_BAD_SOS_LENGTH,
47 JPGD_BAD_SOS_COMP_ID, JPGD_W_EXTRA_BYTES_BEFORE_MARKER, JPGD_NO_ARITHMITIC_SUPPORT, JPGD_UNEXPECTED_MARKER,
48 JPGD_NOT_JPEG, JPGD_UNSUPPORTED_MARKER, JPGD_BAD_DQT_LENGTH, JPGD_TOO_MANY_BLOCKS,
49 JPGD_UNDEFINED_QUANT_TABLE, JPGD_UNDEFINED_HUFF_TABLE, JPGD_NOT_SINGLE_SCAN, JPGD_UNSUPPORTED_COLORSPACE,
50 JPGD_UNSUPPORTED_SAMP_FACTORS, JPGD_DECODE_ERROR, JPGD_BAD_RESTART_MARKER,
51 JPGD_BAD_SOS_SPECTRAL, JPGD_BAD_SOS_SUCCESSIVE, JPGD_STREAM_READ, JPGD_NOTENOUGHMEM, JPGD_TOO_MANY_SCANS
52 };
53
54 // Input stream interface.
55 // Derive from this class to read input data from sources other than files or memory. Set m_eof_flag to true when no more data is available.
56 // The decoder is rather greedy: it will keep on calling this method until its internal input buffer is full, or until the EOF flag is set.
57 // It the input stream contains data after the JPEG stream's EOI (end of image) marker it will probably be pulled into the internal buffer.
58 // Call the get_total_bytes_read() method to determine the actual size of the JPEG stream after successful decoding.
59 class jpeg_decoder_stream
60 {
61 public:
62 jpeg_decoder_stream() { }
63 virtual ~jpeg_decoder_stream() { }
64
65 // The read() method is called when the internal input buffer is empty.
66 // Parameters:
67 // pBuf - input buffer
68 // max_bytes_to_read - maximum bytes that can be written to pBuf
69 // pEOF_flag - set this to true if at end of stream (no more bytes remaining)
70 // Returns -1 on error, otherwise return the number of bytes actually written to the buffer (which may be 0).
71 // Notes: This method will be called in a loop until you set *pEOF_flag to true or the internal buffer is full.
72 virtual int read(uint8* pBuf, int max_bytes_to_read, bool* pEOF_flag) = 0;
73 };
74
75 // stdio FILE stream class.
76 class jpeg_decoder_file_stream : public jpeg_decoder_stream
77 {
78 jpeg_decoder_file_stream(const jpeg_decoder_file_stream&);
79 jpeg_decoder_file_stream& operator =(const jpeg_decoder_file_stream&);
80
81 FILE* m_pFile;
82 bool m_eof_flag, m_error_flag;
83
84 public:
85 jpeg_decoder_file_stream();
86 virtual ~jpeg_decoder_file_stream();
87
88 bool open(const char* Pfilename);
89 void close();
90
91 virtual int read(uint8* pBuf, int max_bytes_to_read, bool* pEOF_flag);
92 };
93
94 // Memory stream class.
95 class jpeg_decoder_mem_stream : public jpeg_decoder_stream
96 {
97 const uint8* m_pSrc_data;
98 uint m_ofs, m_size;
99
100 public:
101 jpeg_decoder_mem_stream() : m_pSrc_data(NULL), m_ofs(0), m_size(0) { }
102 jpeg_decoder_mem_stream(const uint8* pSrc_data, uint size) : m_pSrc_data(pSrc_data), m_ofs(0), m_size(size) { }
103
104 virtual ~jpeg_decoder_mem_stream() { }
105
106 bool open(const uint8* pSrc_data, uint size);
107 void close() { m_pSrc_data = NULL; m_ofs = 0; m_size = 0; }
108
109 virtual int read(uint8* pBuf, int max_bytes_to_read, bool* pEOF_flag);
110 };
111
112 // Loads JPEG file from a jpeg_decoder_stream.
113 unsigned char* decompress_jpeg_image_from_stream(jpeg_decoder_stream* pStream, int* width, int* height, int* actual_comps, int req_comps, uint32_t flags = 0);
114
115 enum
116 {
117 JPGD_IN_BUF_SIZE = 8192, JPGD_MAX_BLOCKS_PER_MCU = 10, JPGD_MAX_HUFF_TABLES = 8, JPGD_MAX_QUANT_TABLES = 4,
118 JPGD_MAX_COMPONENTS = 4, JPGD_MAX_COMPS_IN_SCAN = 4, JPGD_MAX_BLOCKS_PER_ROW = 16384, JPGD_MAX_HEIGHT = 32768, JPGD_MAX_WIDTH = 32768
119 };
120
121 typedef int16 jpgd_quant_t;
122 typedef int16 jpgd_block_coeff_t;
123
124 class jpeg_decoder
125 {
126 public:
127 enum
128 {
129 cFlagBoxChromaFiltering = 1,
130 cFlagDisableSIMD = 2
131 };
132
133 // Call get_error_code() after constructing to determine if the stream is valid or not. You may call the get_width(), get_height(), etc.
134 // methods after the constructor is called. You may then either destruct the object, or begin decoding the image by calling begin_decoding(), then decode() on each scanline.
135 jpeg_decoder(jpeg_decoder_stream* pStream, uint32_t flags = 0);
136
137 ~jpeg_decoder();
138
139 // Call this method after constructing the object to begin decompression.
140 // If JPGD_SUCCESS is returned you may then call decode() on each scanline.
141
142 int begin_decoding();
143
144 // Returns the next scan line.
145 // For grayscale images, pScan_line will point to a buffer containing 8-bit pixels (get_bytes_per_pixel() will return 1).
146 // Otherwise, it will always point to a buffer containing 32-bit RGBA pixels (A will always be 255, and get_bytes_per_pixel() will return 4).
147 // Returns JPGD_SUCCESS if a scan line has been returned.
148 // Returns JPGD_DONE if all scan lines have been returned.
149 // Returns JPGD_FAILED if an error occurred. Call get_error_code() for a more info.
150 int decode(const void** pScan_line, uint* pScan_line_len);
151
152 inline jpgd_status get_error_code() const { return m_error_code; }
153
154 inline int get_width() const { return m_image_x_size; }
155 inline int get_height() const { return m_image_y_size; }
156
157 inline int get_num_components() const { return m_comps_in_frame; }
158
159 inline int get_bytes_per_pixel() const { return m_dest_bytes_per_pixel; }
160 inline int get_bytes_per_scan_line() const { return m_image_x_size * get_bytes_per_pixel(); }
161
162 // Returns the total number of bytes actually consumed by the decoder (which should equal the actual size of the JPEG file).
163 inline int get_total_bytes_read() const { return m_total_bytes_read; }
164
165 private:
166 jpeg_decoder(const jpeg_decoder&);
167 jpeg_decoder& operator =(const jpeg_decoder&);
168
169 typedef void (*pDecode_block_func)(jpeg_decoder*, int, int, int);
170
171 struct huff_tables
172 {
173 bool ac_table;
174 uint look_up[256];
175 uint look_up2[256];
176 uint8 code_size[JPGD_HUFF_CODE_SIZE_MAX_LENGTH];
177 uint tree[JPGD_HUFF_TREE_MAX_LENGTH];
178 };
179
180 struct coeff_buf
181 {
182 uint8* pData;
183 int block_num_x, block_num_y;
184 int block_len_x, block_len_y;
185 int block_size;
186 };
187
188 struct mem_block
189 {
190 mem_block* m_pNext;
191 size_t m_used_count;
192 size_t m_size;
193 char m_data[1];
194 };
195
196 jmp_buf m_jmp_state;
197 uint32_t m_flags;
198 mem_block* m_pMem_blocks;
199 int m_image_x_size;
200 int m_image_y_size;
201 jpeg_decoder_stream* m_pStream;
202
203 int m_progressive_flag;
204
205 uint8 m_huff_ac[JPGD_MAX_HUFF_TABLES];
206 uint8* m_huff_num[JPGD_MAX_HUFF_TABLES]; // pointer to number of Huffman codes per bit size
207 uint8* m_huff_val[JPGD_MAX_HUFF_TABLES]; // pointer to Huffman codes per bit size
208 jpgd_quant_t* m_quant[JPGD_MAX_QUANT_TABLES]; // pointer to quantization tables
209 int m_scan_type; // Gray, Yh1v1, Yh1v2, Yh2v1, Yh2v2 (CMYK111, CMYK4114 no longer supported)
210 int m_comps_in_frame; // # of components in frame
211 int m_comp_h_samp[JPGD_MAX_COMPONENTS]; // component's horizontal sampling factor
212 int m_comp_v_samp[JPGD_MAX_COMPONENTS]; // component's vertical sampling factor
213 int m_comp_quant[JPGD_MAX_COMPONENTS]; // component's quantization table selector
214 int m_comp_ident[JPGD_MAX_COMPONENTS]; // component's ID
215 int m_comp_h_blocks[JPGD_MAX_COMPONENTS];
216 int m_comp_v_blocks[JPGD_MAX_COMPONENTS];
217 int m_comps_in_scan; // # of components in scan
218 int m_comp_list[JPGD_MAX_COMPS_IN_SCAN]; // components in this scan
219 int m_comp_dc_tab[JPGD_MAX_COMPONENTS]; // component's DC Huffman coding table selector
220 int m_comp_ac_tab[JPGD_MAX_COMPONENTS]; // component's AC Huffman coding table selector
221 int m_spectral_start; // spectral selection start
222 int m_spectral_end; // spectral selection end
223 int m_successive_low; // successive approximation low
224 int m_successive_high; // successive approximation high
225 int m_max_mcu_x_size; // MCU's max. X size in pixels
226 int m_max_mcu_y_size; // MCU's max. Y size in pixels
227 int m_blocks_per_mcu;
228 int m_max_blocks_per_row;
229 int m_mcus_per_row, m_mcus_per_col;
230 int m_mcu_org[JPGD_MAX_BLOCKS_PER_MCU];
231 int m_total_lines_left; // total # lines left in image
232 int m_mcu_lines_left; // total # lines left in this MCU
233 int m_num_buffered_scanlines;
234 int m_real_dest_bytes_per_scan_line;
235 int m_dest_bytes_per_scan_line; // rounded up
236 int m_dest_bytes_per_pixel; // 4 (RGB) or 1 (Y)
237 huff_tables* m_pHuff_tabs[JPGD_MAX_HUFF_TABLES];
238 coeff_buf* m_dc_coeffs[JPGD_MAX_COMPONENTS];
239 coeff_buf* m_ac_coeffs[JPGD_MAX_COMPONENTS];
240 int m_eob_run;
241 int m_block_y_mcu[JPGD_MAX_COMPONENTS];
242 uint8* m_pIn_buf_ofs;
243 int m_in_buf_left;
244 int m_tem_flag;
245
246 uint8 m_in_buf_pad_start[64];
247 uint8 m_in_buf[JPGD_IN_BUF_SIZE + 128];
248 uint8 m_in_buf_pad_end[64];
249
250 int m_bits_left;
251 uint m_bit_buf;
252 int m_restart_interval;
253 int m_restarts_left;
254 int m_next_restart_num;
255 int m_max_mcus_per_row;
256 int m_max_blocks_per_mcu;
257
258 int m_max_mcus_per_col;
259 uint m_last_dc_val[JPGD_MAX_COMPONENTS];
260 jpgd_block_coeff_t* m_pMCU_coefficients;
261 int m_mcu_block_max_zag[JPGD_MAX_BLOCKS_PER_MCU];
262 uint8* m_pSample_buf;
263 uint8* m_pSample_buf_prev;
264 int m_crr[256];
265 int m_cbb[256];
266 int m_crg[256];
267 int m_cbg[256];
268 uint8* m_pScan_line_0;
269 uint8* m_pScan_line_1;
270 jpgd_status m_error_code;
271 int m_total_bytes_read;
272
273 bool m_ready_flag;
274 bool m_eof_flag;
275 bool m_sample_buf_prev_valid;
276 bool m_has_sse2;
277
278 inline int check_sample_buf_ofs(int ofs) const { assert(ofs >= 0); assert(ofs < m_max_blocks_per_row * 64); return ofs; }
279 void free_all_blocks();
280 JPGD_NORETURN void stop_decoding(jpgd_status status);
281 void* alloc(size_t n, bool zero = false);
282 void* alloc_aligned(size_t nSize, uint32_t align = 16, bool zero = false);
283 void word_clear(void* p, uint16 c, uint n);
284 void prep_in_buffer();
285 void read_dht_marker();
286 void read_dqt_marker();
287 void read_sof_marker();
288 void skip_variable_marker();
289 void read_dri_marker();
290 void read_sos_marker();
291 int next_marker();
292 int process_markers();
293 void locate_soi_marker();
294 void locate_sof_marker();
295 int locate_sos_marker();
296 void init(jpeg_decoder_stream* pStream, uint32_t flags);
297 void create_look_ups();
298 void fix_in_buffer();
299 void transform_mcu(int mcu_row);
300 coeff_buf* coeff_buf_open(int block_num_x, int block_num_y, int block_len_x, int block_len_y);
301 inline jpgd_block_coeff_t* coeff_buf_getp(coeff_buf* cb, int block_x, int block_y);
302 void load_next_row();
303 void decode_next_row();
304 void make_huff_table(int index, huff_tables* pH);
305 void check_quant_tables();
306 void check_huff_tables();
307 bool calc_mcu_block_order();
308 int init_scan();
309 void init_frame();
310 void process_restart();
311 void decode_scan(pDecode_block_func decode_block_func);
312 void init_progressive();
313 void init_sequential();
314 void decode_start();
315 void decode_init(jpeg_decoder_stream* pStream, uint32_t flags);
316 void H2V2Convert();
317 uint32_t H2V2ConvertFiltered();
318 void H2V1Convert();
319 void H2V1ConvertFiltered();
320 void H1V2Convert();
321 void H1V2ConvertFiltered();
322 void H1V1Convert();
323 void gray_convert();
324 void find_eoi();
325 inline uint get_char();
326 inline uint get_char(bool* pPadding_flag);
327 inline void stuff_char(uint8 q);
328 inline uint8 get_octet();
329 inline uint get_bits(int num_bits);
330 inline uint get_bits_no_markers(int numbits);
331 inline int huff_decode(huff_tables* pH);
332 inline int huff_decode(huff_tables* pH, int& extrabits);
333
334 // Clamps a value between 0-255.
335 static inline uint8 clamp(int i)
336 {
337 if (static_cast<uint>(i) > 255)
338 i = (((~i) >> 31) & 0xFF);
339 return static_cast<uint8>(i);
340 }
341 int decode_next_mcu_row();
342
343 static void decode_block_dc_first(jpeg_decoder* pD, int component_id, int block_x, int block_y);
344 static void decode_block_dc_refine(jpeg_decoder* pD, int component_id, int block_x, int block_y);
345 static void decode_block_ac_first(jpeg_decoder* pD, int component_id, int block_x, int block_y);
346 static void decode_block_ac_refine(jpeg_decoder* pD, int component_id, int block_x, int block_y);
347 };
348
349} // namespace jpgd
350
351#endif // JPEG_DECODER_H
352