jpgd.h

// jpgd.h - C++ class for JPEG decompression.
// Richard Geldreich <richgel99@gmail.com>
// See jpgd.cpp for license (Public Domain or Apache 2.0).
#ifndef JPEG_DECODER_H
#define JPEG_DECODER_H
 
#include <assert.h>
#include <setjmp.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
 
#ifdef _MSC_VER
#define JPGD_NORETURN __declspec(noreturn)
#elif defined(__GNUC__)
#define JPGD_NORETURN __attribute__((noreturn))
#else
#define JPGD_NORETURN
#endif
 
#define JPGD_HUFF_TREE_MAX_LENGTH 512
#define JPGD_HUFF_CODE_SIZE_MAX_LENGTH 256
 
namespace jpgd
{
  typedef unsigned char uint8;
  typedef signed short int16;
  typedef unsigned short uint16;
  typedef unsigned int uint;
  typedef signed int int32;
 
  // Loads a JPEG image from a memory buffer or a file.
  // req_comps can be 1 (grayscale), 3 (RGB), or 4 (RGBA).
  // 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). 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. 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.
  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);
  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);
 
  // Success/failure error codes.
  enum jpgd_status
  {
    JPGD_SUCCESS = 0,
    JPGD_FAILED = -1,
    JPGD_DONE = 1,
    JPGD_BAD_DHT_COUNTS = -256,
    JPGD_BAD_DHT_INDEX,
    JPGD_BAD_DHT_MARKER,
    JPGD_BAD_DQT_MARKER,
    JPGD_BAD_DQT_TABLE,
    JPGD_BAD_PRECISION,
    JPGD_BAD_HEIGHT,
    JPGD_BAD_WIDTH,
    JPGD_TOO_MANY_COMPONENTS,
    JPGD_BAD_SOF_LENGTH,
    JPGD_BAD_VARIABLE_MARKER,
    JPGD_BAD_DRI_LENGTH,
    JPGD_BAD_SOS_LENGTH,
    JPGD_BAD_SOS_COMP_ID,
    JPGD_W_EXTRA_BYTES_BEFORE_MARKER,
    JPGD_NO_ARITHMITIC_SUPPORT,
    JPGD_UNEXPECTED_MARKER,
    JPGD_NOT_JPEG,
    JPGD_UNSUPPORTED_MARKER,
    JPGD_BAD_DQT_LENGTH,
    JPGD_TOO_MANY_BLOCKS,
    JPGD_UNDEFINED_QUANT_TABLE,
    JPGD_UNDEFINED_HUFF_TABLE,
    JPGD_NOT_SINGLE_SCAN,
    JPGD_UNSUPPORTED_COLORSPACE,
    JPGD_UNSUPPORTED_SAMP_FACTORS,
    JPGD_DECODE_ERROR,
    JPGD_BAD_RESTART_MARKER,
    JPGD_BAD_SOS_SPECTRAL,
    JPGD_BAD_SOS_SUCCESSIVE,
    JPGD_STREAM_READ,
    JPGD_NOTENOUGHMEM,
    JPGD_TOO_MANY_SCANS
  };
 
  // Input stream interface.
  // 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. 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.
  // 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. Call the get_total_bytes_read() method to
  // determine the actual size of the JPEG stream after successful decoding.
  class jpeg_decoder_stream
  {
  public:
    jpeg_decoder_stream() {}
    virtual ~jpeg_decoder_stream() {}
 
    // The read() method is called when the internal input buffer is empty.
    // Parameters:
    // pBuf - input buffer
    // max_bytes_to_read - maximum bytes that can be written to pBuf
    // pEOF_flag - set this to true if at end of stream (no more bytes remaining)
    // Returns -1 on error, otherwise return the number of bytes actually written to the buffer
    // (which may be 0). Notes: This method will be called in a loop until you set *pEOF_flag to
    // true or the internal buffer is full.
    virtual int read(uint8* pBuf, int max_bytes_to_read, bool* pEOF_flag) = 0;
  };
 
  // stdio FILE stream class.
  class jpeg_decoder_file_stream : public jpeg_decoder_stream
  {
    jpeg_decoder_file_stream(const jpeg_decoder_file_stream&);
    jpeg_decoder_file_stream& operator=(const jpeg_decoder_file_stream&);
 
    FILE* m_pFile;
    bool m_eof_flag, m_error_flag;
  public:
    jpeg_decoder_file_stream();
    virtual ~jpeg_decoder_file_stream();
 
    bool open(const char* Pfilename);
    void close();
 
    virtual int read(uint8* pBuf, int max_bytes_to_read, bool* pEOF_flag);
  };
 
  // Memory stream class.
  class jpeg_decoder_mem_stream : public jpeg_decoder_stream
  {
    const uint8* m_pSrc_data;
    uint m_ofs, m_size;
  public:
    jpeg_decoder_mem_stream() : m_pSrc_data(NULL), m_ofs(0), m_size(0) {}
    jpeg_decoder_mem_stream(const uint8* pSrc_data, uint size)
        : m_pSrc_data(pSrc_data), m_ofs(0), m_size(size)
    {
    }
 
    virtual ~jpeg_decoder_mem_stream() {}
 
    bool open(const uint8* pSrc_data, uint size);
    void close()
    {
      m_pSrc_data = NULL;
      m_ofs = 0;
      m_size = 0;
    }
 
    virtual int read(uint8* pBuf, int max_bytes_to_read, bool* pEOF_flag);
  };
 
  // Loads JPEG file from a jpeg_decoder_stream.
  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);
 
  enum
  {
    JPGD_IN_BUF_SIZE = 8192,
    JPGD_MAX_BLOCKS_PER_MCU = 10,
    JPGD_MAX_HUFF_TABLES = 8,
    JPGD_MAX_QUANT_TABLES = 4,
    JPGD_MAX_COMPONENTS = 4,
    JPGD_MAX_COMPS_IN_SCAN = 4,
    JPGD_MAX_BLOCKS_PER_ROW = 16384,
    JPGD_MAX_HEIGHT = 32768,
    JPGD_MAX_WIDTH = 32768
  };
 
  typedef int16 jpgd_quant_t;
  typedef int16 jpgd_block_coeff_t;
 
  class jpeg_decoder
  {
  public:
    enum
    {
      cFlagBoxChromaFiltering = 1,
      cFlagDisableSIMD = 2
    };
 
    // Call get_error_code() after constructing to determine if the stream is valid or not. You may
    // call the get_width(), get_height(), etc. 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.
    jpeg_decoder(jpeg_decoder_stream* pStream, uint32_t flags = 0);
 
    ~jpeg_decoder();
 
    // Call this method after constructing the object to begin decompression.
    // If JPGD_SUCCESS is returned you may then call decode() on each scanline.
 
    int begin_decoding();
 
    // Returns the next scan line.
    // For grayscale images, pScan_line will point to a buffer containing 8-bit pixels
    // (get_bytes_per_pixel() will return 1). 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). Returns
    // JPGD_SUCCESS if a scan line has been returned. Returns JPGD_DONE if all scan lines have been
    // returned. Returns JPGD_FAILED if an error occurred. Call get_error_code() for a more info.
    int decode(const void** pScan_line, uint* pScan_line_len);
 
    inline jpgd_status get_error_code() const { return m_error_code; }
 
    inline int get_width() const { return m_image_x_size; }
    inline int get_height() const { return m_image_y_size; }
 
    inline int get_num_components() const { return m_comps_in_frame; }
 
    inline int get_bytes_per_pixel() const { return m_dest_bytes_per_pixel; }
    inline int get_bytes_per_scan_line() const { return m_image_x_size * get_bytes_per_pixel(); }
 
    // Returns the total number of bytes actually consumed by the decoder (which should equal the
    // actual size of the JPEG file).
    inline int get_total_bytes_read() const { return m_total_bytes_read; }
  private:
    jpeg_decoder(const jpeg_decoder&);
    jpeg_decoder& operator=(const jpeg_decoder&);
 
    typedef void (*pDecode_block_func)(jpeg_decoder*, int, int, int);
 
    struct huff_tables
    {
      bool ac_table;
      uint look_up[256];
      uint look_up2[256];
      uint8 code_size[JPGD_HUFF_CODE_SIZE_MAX_LENGTH];
      uint tree[JPGD_HUFF_TREE_MAX_LENGTH];
    };
 
    struct coeff_buf
    {
      uint8* pData;
      int block_num_x, block_num_y;
      int block_len_x, block_len_y;
      int block_size;
    };
 
    struct mem_block
    {
      mem_block* m_pNext;
      size_t m_used_count;
      size_t m_size;
      char m_data[1];
    };
 
    jmp_buf m_jmp_state;
    uint32_t m_flags;
    mem_block* m_pMem_blocks;
    int m_image_x_size;
    int m_image_y_size;
    jpeg_decoder_stream* m_pStream;
 
    int m_progressive_flag;
 
    uint8 m_huff_ac[JPGD_MAX_HUFF_TABLES];
    uint8* m_huff_num[JPGD_MAX_HUFF_TABLES];      // pointer to number of Huffman codes per bit size
    uint8* m_huff_val[JPGD_MAX_HUFF_TABLES];      // pointer to Huffman codes per bit size
    jpgd_quant_t* m_quant[JPGD_MAX_QUANT_TABLES]; // pointer to quantization tables
    int m_scan_type; // Gray, Yh1v1, Yh1v2, Yh2v1, Yh2v2 (CMYK111, CMYK4114 no longer supported)
    int m_comps_in_frame;                   // # of components in frame
    int m_comp_h_samp[JPGD_MAX_COMPONENTS]; // component's horizontal sampling factor
    int m_comp_v_samp[JPGD_MAX_COMPONENTS]; // component's vertical sampling factor
    int m_comp_quant[JPGD_MAX_COMPONENTS];  // component's quantization table selector
    int m_comp_ident[JPGD_MAX_COMPONENTS];  // component's ID
    int m_comp_h_blocks[JPGD_MAX_COMPONENTS];
    int m_comp_v_blocks[JPGD_MAX_COMPONENTS];
    int m_comps_in_scan;                     // # of components in scan
    int m_comp_list[JPGD_MAX_COMPS_IN_SCAN]; // components in this scan
    int m_comp_dc_tab[JPGD_MAX_COMPONENTS];  // component's DC Huffman coding table selector
    int m_comp_ac_tab[JPGD_MAX_COMPONENTS];  // component's AC Huffman coding table selector
    int m_spectral_start;                    // spectral selection start
    int m_spectral_end;                      // spectral selection end
    int m_successive_low;                    // successive approximation low
    int m_successive_high;                   // successive approximation high
    int m_max_mcu_x_size;                    // MCU's max. X size in pixels
    int m_max_mcu_y_size;                    // MCU's max. Y size in pixels
    int m_blocks_per_mcu;
    int m_max_blocks_per_row;
    int m_mcus_per_row, m_mcus_per_col;
    int m_mcu_org[JPGD_MAX_BLOCKS_PER_MCU];
    int m_total_lines_left; // total # lines left in image
    int m_mcu_lines_left;   // total # lines left in this MCU
    int m_num_buffered_scanlines;
    int m_real_dest_bytes_per_scan_line;
    int m_dest_bytes_per_scan_line; // rounded up
    int m_dest_bytes_per_pixel;     // 4 (RGB) or 1 (Y)
    huff_tables* m_pHuff_tabs[JPGD_MAX_HUFF_TABLES];
    coeff_buf* m_dc_coeffs[JPGD_MAX_COMPONENTS];
    coeff_buf* m_ac_coeffs[JPGD_MAX_COMPONENTS];
    int m_eob_run;
    int m_block_y_mcu[JPGD_MAX_COMPONENTS];
    uint8* m_pIn_buf_ofs;
    int m_in_buf_left;
    int m_tem_flag;
 
    uint8 m_in_buf_pad_start[64];
    uint8 m_in_buf[JPGD_IN_BUF_SIZE + 128];
    uint8 m_in_buf_pad_end[64];
 
    int m_bits_left;
    uint m_bit_buf;
    int m_restart_interval;
    int m_restarts_left;
    int m_next_restart_num;
    int m_max_mcus_per_row;
    int m_max_blocks_per_mcu;
 
    int m_max_mcus_per_col;
    uint m_last_dc_val[JPGD_MAX_COMPONENTS];
    jpgd_block_coeff_t* m_pMCU_coefficients;
    int m_mcu_block_max_zag[JPGD_MAX_BLOCKS_PER_MCU];
    uint8* m_pSample_buf;
    uint8* m_pSample_buf_prev;
    int m_crr[256];
    int m_cbb[256];
    int m_crg[256];
    int m_cbg[256];
    uint8* m_pScan_line_0;
    uint8* m_pScan_line_1;
    jpgd_status m_error_code;
    int m_total_bytes_read;
 
    bool m_ready_flag;
    bool m_eof_flag;
    bool m_sample_buf_prev_valid;
    bool m_has_sse2;
 
    inline int check_sample_buf_ofs(int ofs) const
    {
      assert(ofs >= 0);
      assert(ofs < m_max_blocks_per_row * 64);
      return ofs;
    }
    void free_all_blocks();
    JPGD_NORETURN void stop_decoding(jpgd_status status);
    void* alloc(size_t n, bool zero = false);
    void* alloc_aligned(size_t nSize, uint32_t align = 16, bool zero = false);
    void word_clear(void* p, uint16 c, uint n);
    void prep_in_buffer();
    void read_dht_marker();
    void read_dqt_marker();
    void read_sof_marker();
    void skip_variable_marker();
    void read_dri_marker();
    void read_sos_marker();
    int next_marker();
    int process_markers();
    void locate_soi_marker();
    void locate_sof_marker();
    int locate_sos_marker();
    void init(jpeg_decoder_stream* pStream, uint32_t flags);
    void create_look_ups();
    void fix_in_buffer();
    void transform_mcu(int mcu_row);
    coeff_buf* coeff_buf_open(int block_num_x, int block_num_y, int block_len_x, int block_len_y);
    inline jpgd_block_coeff_t* coeff_buf_getp(coeff_buf* cb, int block_x, int block_y);
    void load_next_row();
    void decode_next_row();
    void make_huff_table(int index, huff_tables* pH);
    void check_quant_tables();
    void check_huff_tables();
    bool calc_mcu_block_order();
    int init_scan();
    void init_frame();
    void process_restart();
    void decode_scan(pDecode_block_func decode_block_func);
    void init_progressive();
    void init_sequential();
    void decode_start();
    void decode_init(jpeg_decoder_stream* pStream, uint32_t flags);
    void H2V2Convert();
    uint32_t H2V2ConvertFiltered();
    void H2V1Convert();
    void H2V1ConvertFiltered();
    void H1V2Convert();
    void H1V2ConvertFiltered();
    void H1V1Convert();
    void gray_convert();
    void find_eoi();
    inline uint get_char();
    inline uint get_char(bool* pPadding_flag);
    inline void stuff_char(uint8 q);
    inline uint8 get_octet();
    inline uint get_bits(int num_bits);
    inline uint get_bits_no_markers(int numbits);
    inline int huff_decode(huff_tables* pH);
    inline int huff_decode(huff_tables* pH, int& extrabits);
 
    // Clamps a value between 0-255.
    static inline uint8 clamp(int i)
    {
      if(static_cast<uint>(i) > 255)
        i = (((~i) >> 31) & 0xFF);
      return static_cast<uint8>(i);
    }
    int decode_next_mcu_row();
 
    static void decode_block_dc_first(jpeg_decoder* pD, int component_id, int block_x, int block_y);
    static void decode_block_dc_refine(jpeg_decoder* pD, int component_id, int block_x,
                                       int block_y);
    static void decode_block_ac_first(jpeg_decoder* pD, int component_id, int block_x, int block_y);
    static void decode_block_ac_refine(jpeg_decoder* pD, int component_id, int block_x,
                                       int block_y);
  };
 
} // namespace jpgd
 
#endif // JPEG_DECODER_H