Home | History | Annotate | Download | only in gdx2d
      1 // jpgd.h - C++ class for JPEG decompression.
      2 // Public domain, Rich Geldreich <richgel99 (at) gmail.com>
      3 #ifndef JPEG_DECODER_H
      4 #define JPEG_DECODER_H
      5 
      6 #include <stdlib.h>
      7 #include <stdio.h>
      8 #include <setjmp.h>
      9 
     10 #ifdef _MSC_VER
     11   #define JPGD_NORETURN __declspec(noreturn)
     12 #elif defined(__GNUC__)
     13   #define JPGD_NORETURN __attribute__ ((noreturn))
     14 #else
     15   #define JPGD_NORETURN
     16 #endif
     17 
     18 namespace jpgd
     19 {
     20   typedef unsigned char  uint8;
     21   typedef   signed short int16;
     22   typedef unsigned short uint16;
     23   typedef unsigned int   uint;
     24   typedef   signed int   int32;
     25 
     26   const char *failure_reason(void);
     27 
     28   // Loads a JPEG image from a memory buffer or a file.
     29   // req_comps can be 1 (grayscale), 3 (RGB), or 4 (RGBA).
     30   // 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).
     31   // 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.
     32   // 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.
     33   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);
     34   unsigned char *decompress_jpeg_image_from_file(const char *pSrc_filename, int *width, int *height, int *actual_comps, int req_comps);
     35 
     36   // Success/failure error codes.
     37   enum jpgd_status
     38   {
     39     JPGD_SUCCESS = 0, JPGD_FAILED = -1, JPGD_DONE = 1,
     40     JPGD_BAD_DHT_COUNTS = -256, JPGD_BAD_DHT_INDEX, JPGD_BAD_DHT_MARKER, JPGD_BAD_DQT_MARKER, JPGD_BAD_DQT_TABLE,
     41     JPGD_BAD_PRECISION, JPGD_BAD_HEIGHT, JPGD_BAD_WIDTH, JPGD_TOO_MANY_COMPONENTS,
     42     JPGD_BAD_SOF_LENGTH, JPGD_BAD_VARIABLE_MARKER, JPGD_BAD_DRI_LENGTH, JPGD_BAD_SOS_LENGTH,
     43     JPGD_BAD_SOS_COMP_ID, JPGD_W_EXTRA_BYTES_BEFORE_MARKER, JPGD_NO_ARITHMITIC_SUPPORT, JPGD_UNEXPECTED_MARKER,
     44     JPGD_NOT_JPEG, JPGD_UNSUPPORTED_MARKER, JPGD_BAD_DQT_LENGTH, JPGD_TOO_MANY_BLOCKS,
     45     JPGD_UNDEFINED_QUANT_TABLE, JPGD_UNDEFINED_HUFF_TABLE, JPGD_NOT_SINGLE_SCAN, JPGD_UNSUPPORTED_COLORSPACE,
     46     JPGD_UNSUPPORTED_SAMP_FACTORS, JPGD_DECODE_ERROR, JPGD_BAD_RESTART_MARKER, JPGD_ASSERTION_ERROR,
     47     JPGD_BAD_SOS_SPECTRAL, JPGD_BAD_SOS_SUCCESSIVE, JPGD_STREAM_READ, JPGD_NOTENOUGHMEM
     48   };
     49 
     50   // Input stream interface.
     51   // 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.
     52   // 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.
     53   // 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.
     54   // Call the get_total_bytes_read() method to determine the actual size of the JPEG stream after successful decoding.
     55   class jpeg_decoder_stream
     56   {
     57   public:
     58     jpeg_decoder_stream() { }
     59     virtual ~jpeg_decoder_stream() { }
     60 
     61     // The read() method is called when the internal input buffer is empty.
     62     // Parameters:
     63     // pBuf - input buffer
     64     // max_bytes_to_read - maximum bytes that can be written to pBuf
     65     // pEOF_flag - set this to true if at end of stream (no more bytes remaining)
     66     // Returns -1 on error, otherwise return the number of bytes actually written to the buffer (which may be 0).
     67     // Notes: This method will be called in a loop until you set *pEOF_flag to true or the internal buffer is full.
     68     virtual int read(uint8 *pBuf, int max_bytes_to_read, bool *pEOF_flag) = 0;
     69   };
     70 
     71   // stdio FILE stream class.
     72   class jpeg_decoder_file_stream : public jpeg_decoder_stream
     73   {
     74     jpeg_decoder_file_stream(const jpeg_decoder_file_stream &);
     75     jpeg_decoder_file_stream &operator =(const jpeg_decoder_file_stream &);
     76 
     77     FILE *m_pFile;
     78     bool m_eof_flag, m_error_flag;
     79 
     80   public:
     81     jpeg_decoder_file_stream();
     82     virtual ~jpeg_decoder_file_stream();
     83 
     84     bool open(const char *Pfilename);
     85     void close();
     86 
     87     virtual int read(uint8 *pBuf, int max_bytes_to_read, bool *pEOF_flag);
     88   };
     89 
     90   // Memory stream class.
     91   class jpeg_decoder_mem_stream : public jpeg_decoder_stream
     92   {
     93     const uint8 *m_pSrc_data;
     94     uint m_ofs, m_size;
     95 
     96   public:
     97     jpeg_decoder_mem_stream() : m_pSrc_data(NULL), m_ofs(0), m_size(0) { }
     98     jpeg_decoder_mem_stream(const uint8 *pSrc_data, uint size) : m_pSrc_data(pSrc_data), m_ofs(0), m_size(size) { }
     99 
    100     virtual ~jpeg_decoder_mem_stream() { }
    101 
    102     bool open(const uint8 *pSrc_data, uint size);
    103     void close() { m_pSrc_data = NULL; m_ofs = 0; m_size = 0; }
    104 
    105     virtual int read(uint8 *pBuf, int max_bytes_to_read, bool *pEOF_flag);
    106   };
    107 
    108   // Loads JPEG file from a jpeg_decoder_stream.
    109   unsigned char *decompress_jpeg_image_from_stream(jpeg_decoder_stream *pStream, int *width, int *height, int *actual_comps, int req_comps);
    110 
    111   enum
    112   {
    113     JPGD_IN_BUF_SIZE = 8192, JPGD_MAX_BLOCKS_PER_MCU = 10, JPGD_MAX_HUFF_TABLES = 8, JPGD_MAX_QUANT_TABLES = 4,
    114     JPGD_MAX_COMPONENTS = 4, JPGD_MAX_COMPS_IN_SCAN = 4, JPGD_MAX_BLOCKS_PER_ROW = 8192, JPGD_MAX_HEIGHT = 16384, JPGD_MAX_WIDTH = 16384
    115   };
    116 
    117   typedef int16 jpgd_quant_t;
    118   typedef int16 jpgd_block_t;
    119 
    120   class jpeg_decoder
    121   {
    122   public:
    123     // Call get_error_code() after constructing to determine if the stream is valid or not. You may call the get_width(), get_height(), etc.
    124     // 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.
    125     jpeg_decoder(jpeg_decoder_stream *pStream);
    126 
    127     ~jpeg_decoder();
    128 
    129     // Call this method after constructing the object to begin decompression.
    130     // If JPGD_SUCCESS is returned you may then call decode() on each scanline.
    131     int begin_decoding();
    132 
    133     // Returns the next scan line.
    134     // For grayscale images, pScan_line will point to a buffer containing 8-bit pixels (get_bytes_per_pixel() will return 1).
    135     // 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).
    136     // Returns JPGD_SUCCESS if a scan line has been returned.
    137     // Returns JPGD_DONE if all scan lines have been returned.
    138     // Returns JPGD_FAILED if an error occurred. Call get_error_code() for a more info.
    139     int decode(const void** pScan_line, uint* pScan_line_len);
    140 
    141     inline jpgd_status get_error_code() const { return m_error_code; }
    142 
    143     inline int get_width() const { return m_image_x_size; }
    144     inline int get_height() const { return m_image_y_size; }
    145 
    146     inline int get_num_components() const { return m_comps_in_frame; }
    147 
    148     inline int get_bytes_per_pixel() const { return m_dest_bytes_per_pixel; }
    149     inline int get_bytes_per_scan_line() const { return m_image_x_size * get_bytes_per_pixel(); }
    150 
    151     // Returns the total number of bytes actually consumed by the decoder (which should equal the actual size of the JPEG file).
    152     inline int get_total_bytes_read() const { return m_total_bytes_read; }
    153 
    154   private:
    155     jpeg_decoder(const jpeg_decoder &);
    156     jpeg_decoder &operator =(const jpeg_decoder &);
    157 
    158     typedef void (*pDecode_block_func)(jpeg_decoder *, int, int, int);
    159 
    160     struct huff_tables
    161     {
    162       bool ac_table;
    163       uint  look_up[256];
    164       uint  look_up2[256];
    165       uint8 code_size[256];
    166       uint  tree[512];
    167     };
    168 
    169     struct coeff_buf
    170     {
    171       uint8 *pData;
    172       int block_num_x, block_num_y;
    173       int block_len_x, block_len_y;
    174       int block_size;
    175     };
    176 
    177     struct mem_block
    178     {
    179       mem_block *m_pNext;
    180       size_t m_used_count;
    181       size_t m_size;
    182       char m_data[1];
    183     };
    184 
    185     jmp_buf m_jmp_state;
    186     mem_block *m_pMem_blocks;
    187     int m_image_x_size;
    188     int m_image_y_size;
    189     jpeg_decoder_stream *m_pStream;
    190     int m_progressive_flag;
    191     uint8 m_huff_ac[JPGD_MAX_HUFF_TABLES];
    192     uint8* m_huff_num[JPGD_MAX_HUFF_TABLES];      // pointer to number of Huffman codes per bit size
    193     uint8* m_huff_val[JPGD_MAX_HUFF_TABLES];      // pointer to Huffman codes per bit size
    194     jpgd_quant_t* m_quant[JPGD_MAX_QUANT_TABLES]; // pointer to quantization tables
    195     int m_scan_type;                              // Gray, Yh1v1, Yh1v2, Yh2v1, Yh2v2 (CMYK111, CMYK4114 no longer supported)
    196     int m_comps_in_frame;                         // # of components in frame
    197     int m_comp_h_samp[JPGD_MAX_COMPONENTS];       // component's horizontal sampling factor
    198     int m_comp_v_samp[JPGD_MAX_COMPONENTS];       // component's vertical sampling factor
    199     int m_comp_quant[JPGD_MAX_COMPONENTS];        // component's quantization table selector
    200     int m_comp_ident[JPGD_MAX_COMPONENTS];        // component's ID
    201     int m_comp_h_blocks[JPGD_MAX_COMPONENTS];
    202     int m_comp_v_blocks[JPGD_MAX_COMPONENTS];
    203     int m_comps_in_scan;                          // # of components in scan
    204     int m_comp_list[JPGD_MAX_COMPS_IN_SCAN];      // components in this scan
    205     int m_comp_dc_tab[JPGD_MAX_COMPONENTS];       // component's DC Huffman coding table selector
    206     int m_comp_ac_tab[JPGD_MAX_COMPONENTS];       // component's AC Huffman coding table selector
    207     int m_spectral_start;                         // spectral selection start
    208     int m_spectral_end;                           // spectral selection end
    209     int m_successive_low;                         // successive approximation low
    210     int m_successive_high;                        // successive approximation high
    211     int m_max_mcu_x_size;                         // MCU's max. X size in pixels
    212     int m_max_mcu_y_size;                         // MCU's max. Y size in pixels
    213     int m_blocks_per_mcu;
    214     int m_max_blocks_per_row;
    215     int m_mcus_per_row, m_mcus_per_col;
    216     int m_mcu_org[JPGD_MAX_BLOCKS_PER_MCU];
    217     int m_total_lines_left;                       // total # lines left in image
    218     int m_mcu_lines_left;                         // total # lines left in this MCU
    219     int m_real_dest_bytes_per_scan_line;
    220     int m_dest_bytes_per_scan_line;               // rounded up
    221     int m_dest_bytes_per_pixel;                   // 4 (RGB) or 1 (Y)
    222     huff_tables* m_pHuff_tabs[JPGD_MAX_HUFF_TABLES];
    223     coeff_buf* m_dc_coeffs[JPGD_MAX_COMPONENTS];
    224     coeff_buf* m_ac_coeffs[JPGD_MAX_COMPONENTS];
    225     int m_eob_run;
    226     int m_block_y_mcu[JPGD_MAX_COMPONENTS];
    227     uint8* m_pIn_buf_ofs;
    228     int m_in_buf_left;
    229     int m_tem_flag;
    230     bool m_eof_flag;
    231     uint8 m_in_buf_pad_start[128];
    232     uint8 m_in_buf[JPGD_IN_BUF_SIZE + 128];
    233     uint8 m_in_buf_pad_end[128];
    234     int m_bits_left;
    235     uint m_bit_buf;
    236     int m_restart_interval;
    237     int m_restarts_left;
    238     int m_next_restart_num;
    239     int m_max_mcus_per_row;
    240     int m_max_blocks_per_mcu;
    241     int m_expanded_blocks_per_mcu;
    242     int m_expanded_blocks_per_row;
    243     int m_expanded_blocks_per_component;
    244     bool  m_freq_domain_chroma_upsample;
    245     int m_max_mcus_per_col;
    246     uint m_last_dc_val[JPGD_MAX_COMPONENTS];
    247     jpgd_block_t* m_pMCU_coefficients;
    248     int m_mcu_block_max_zag[JPGD_MAX_BLOCKS_PER_MCU];
    249     uint8* m_pSample_buf;
    250     int m_crr[256];
    251     int m_cbb[256];
    252     int m_crg[256];
    253     int m_cbg[256];
    254     uint8* m_pScan_line_0;
    255     uint8* m_pScan_line_1;
    256     jpgd_status m_error_code;
    257     bool m_ready_flag;
    258     int m_total_bytes_read;
    259 
    260     void free_all_blocks();
    261     JPGD_NORETURN void stop_decoding(jpgd_status status);
    262     void *alloc(size_t n, bool zero = false);
    263     void word_clear(void *p, uint16 c, uint n);
    264     void prep_in_buffer();
    265     void read_dht_marker();
    266     void read_dqt_marker();
    267     void read_sof_marker();
    268     void skip_variable_marker();
    269     void read_dri_marker();
    270     void read_sos_marker();
    271     int next_marker();
    272     int process_markers();
    273     void locate_soi_marker();
    274     void locate_sof_marker();
    275     int locate_sos_marker();
    276     void init(jpeg_decoder_stream * pStream);
    277     void create_look_ups();
    278     void fix_in_buffer();
    279     void transform_mcu(int mcu_row);
    280     void transform_mcu_expand(int mcu_row);
    281     coeff_buf* coeff_buf_open(int block_num_x, int block_num_y, int block_len_x, int block_len_y);
    282     inline jpgd_block_t *coeff_buf_getp(coeff_buf *cb, int block_x, int block_y);
    283     void load_next_row();
    284     void decode_next_row();
    285     void make_huff_table(int index, huff_tables *pH);
    286     void check_quant_tables();
    287     void check_huff_tables();
    288     void calc_mcu_block_order();
    289     int init_scan();
    290     void init_frame();
    291     void process_restart();
    292     void decode_scan(pDecode_block_func decode_block_func);
    293     void init_progressive();
    294     void init_sequential();
    295     void decode_start();
    296     void decode_init(jpeg_decoder_stream * pStream);
    297     void H2V2Convert();
    298     void H2V1Convert();
    299     void H1V2Convert();
    300     void H1V1Convert();
    301     void gray_convert();
    302     void expanded_convert();
    303     void find_eoi();
    304     inline uint get_char();
    305     inline uint get_char(bool *pPadding_flag);
    306     inline void stuff_char(uint8 q);
    307     inline uint8 get_octet();
    308     inline uint get_bits(int num_bits);
    309     inline uint get_bits_no_markers(int numbits);
    310     inline int huff_decode(huff_tables *pH);
    311     inline int huff_decode(huff_tables *pH, int& extrabits);
    312     static inline uint8 clamp(int i);
    313     static void decode_block_dc_first(jpeg_decoder *pD, int component_id, int block_x, int block_y);
    314     static void decode_block_dc_refine(jpeg_decoder *pD, int component_id, int block_x, int block_y);
    315     static void decode_block_ac_first(jpeg_decoder *pD, int component_id, int block_x, int block_y);
    316     static void decode_block_ac_refine(jpeg_decoder *pD, int component_id, int block_x, int block_y);
    317   };
    318 
    319 } // namespace jpgd
    320 
    321 #endif // JPEG_DECODER_H