mqc.h 5.9 KB

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  1. /*
  2. * Copyright (c) 2002-2007, Communications and Remote Sensing Laboratory, Universite catholique de Louvain (UCL), Belgium
  3. * Copyright (c) 2002-2007, Professor Benoit Macq
  4. * Copyright (c) 2001-2003, David Janssens
  5. * Copyright (c) 2002-2003, Yannick Verschueren
  6. * Copyright (c) 2003-2007, Francois-Olivier Devaux and Antonin Descampe
  7. * Copyright (c) 2005, Herve Drolon, FreeImage Team
  8. * All rights reserved.
  9. *
  10. * Redistribution and use in source and binary forms, with or without
  11. * modification, are permitted provided that the following conditions
  12. * are met:
  13. * 1. Redistributions of source code must retain the above copyright
  14. * notice, this list of conditions and the following disclaimer.
  15. * 2. Redistributions in binary form must reproduce the above copyright
  16. * notice, this list of conditions and the following disclaimer in the
  17. * documentation and/or other materials provided with the distribution.
  18. *
  19. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
  20. * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22. * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  23. * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  24. * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  25. * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  26. * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  27. * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  28. * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  29. * POSSIBILITY OF SUCH DAMAGE.
  30. */
  31. #ifndef __MQC_H
  32. #define __MQC_H
  33. /**
  34. @file mqc.h
  35. @brief Implementation of an MQ-Coder (MQC)
  36. The functions in MQC.C have for goal to realize the MQ-coder operations. The functions
  37. in MQC.C are used by some function in T1.C.
  38. */
  39. /** @defgroup MQC MQC - Implementation of an MQ-Coder */
  40. /*@{*/
  41. /**
  42. This struct defines the state of a context.
  43. */
  44. typedef struct opj_mqc_state {
  45. /** the probability of the Least Probable Symbol (0.75->0x8000, 1.5->0xffff) */
  46. unsigned int qeval;
  47. /** the Most Probable Symbol (0 or 1) */
  48. int mps;
  49. /** next state if the next encoded symbol is the MPS */
  50. struct opj_mqc_state *nmps;
  51. /** next state if the next encoded symbol is the LPS */
  52. struct opj_mqc_state *nlps;
  53. } opj_mqc_state_t;
  54. #define MQC_NUMCTXS 19
  55. /**
  56. MQ coder
  57. */
  58. typedef struct opj_mqc {
  59. unsigned int c;
  60. unsigned int a;
  61. unsigned int ct;
  62. unsigned char *bp;
  63. unsigned char *start;
  64. unsigned char *end;
  65. opj_mqc_state_t *ctxs[MQC_NUMCTXS];
  66. opj_mqc_state_t **curctx;
  67. #ifdef MQC_PERF_OPT
  68. unsigned char *buffer;
  69. #endif
  70. } opj_mqc_t;
  71. /** @name Exported functions */
  72. /*@{*/
  73. /* ----------------------------------------------------------------------- */
  74. /**
  75. Create a new MQC handle
  76. @return Returns a new MQC handle if successful, returns NULL otherwise
  77. */
  78. opj_mqc_t* mqc_create(void);
  79. /**
  80. Destroy a previously created MQC handle
  81. @param mqc MQC handle to destroy
  82. */
  83. void mqc_destroy(opj_mqc_t *mqc);
  84. /**
  85. Return the number of bytes written/read since initialisation
  86. @param mqc MQC handle
  87. @return Returns the number of bytes already encoded
  88. */
  89. int mqc_numbytes(opj_mqc_t *mqc);
  90. /**
  91. Reset the states of all the context of the coder/decoder
  92. (each context is set to a state where 0 and 1 are more or less equiprobable)
  93. @param mqc MQC handle
  94. */
  95. void mqc_resetstates(opj_mqc_t *mqc);
  96. /**
  97. Set the state of a particular context
  98. @param mqc MQC handle
  99. @param ctxno Number that identifies the context
  100. @param msb The MSB of the new state of the context
  101. @param prob Number that identifies the probability of the symbols for the new state of the context
  102. */
  103. void mqc_setstate(opj_mqc_t *mqc, int ctxno, int msb, int prob);
  104. /**
  105. Initialize the encoder
  106. @param mqc MQC handle
  107. @param bp Pointer to the start of the buffer where the bytes will be written
  108. */
  109. void mqc_init_enc(opj_mqc_t *mqc, unsigned char *bp);
  110. /**
  111. Set the current context used for coding/decoding
  112. @param mqc MQC handle
  113. @param ctxno Number that identifies the context
  114. */
  115. #define mqc_setcurctx(mqc, ctxno) (mqc)->curctx = &(mqc)->ctxs[(int)(ctxno)]
  116. /**
  117. Encode a symbol using the MQ-coder
  118. @param mqc MQC handle
  119. @param d The symbol to be encoded (0 or 1)
  120. */
  121. void mqc_encode(opj_mqc_t *mqc, int d);
  122. /**
  123. Flush the encoder, so that all remaining data is written
  124. @param mqc MQC handle
  125. */
  126. void mqc_flush(opj_mqc_t *mqc);
  127. /**
  128. BYPASS mode switch, initialization operation.
  129. JPEG 2000 p 505.
  130. <h2>Not fully implemented and tested !!</h2>
  131. @param mqc MQC handle
  132. */
  133. void mqc_bypass_init_enc(opj_mqc_t *mqc);
  134. /**
  135. BYPASS mode switch, coding operation.
  136. JPEG 2000 p 505.
  137. <h2>Not fully implemented and tested !!</h2>
  138. @param mqc MQC handle
  139. @param d The symbol to be encoded (0 or 1)
  140. */
  141. void mqc_bypass_enc(opj_mqc_t *mqc, int d);
  142. /**
  143. BYPASS mode switch, flush operation
  144. <h2>Not fully implemented and tested !!</h2>
  145. @param mqc MQC handle
  146. @return Returns 1 (always)
  147. */
  148. int mqc_bypass_flush_enc(opj_mqc_t *mqc);
  149. /**
  150. RESET mode switch
  151. @param mqc MQC handle
  152. */
  153. void mqc_reset_enc(opj_mqc_t *mqc);
  154. /**
  155. RESTART mode switch (TERMALL)
  156. @param mqc MQC handle
  157. @return Returns 1 (always)
  158. */
  159. int mqc_restart_enc(opj_mqc_t *mqc);
  160. /**
  161. RESTART mode switch (TERMALL) reinitialisation
  162. @param mqc MQC handle
  163. */
  164. void mqc_restart_init_enc(opj_mqc_t *mqc);
  165. /**
  166. ERTERM mode switch (PTERM)
  167. @param mqc MQC handle
  168. */
  169. void mqc_erterm_enc(opj_mqc_t *mqc);
  170. /**
  171. SEGMARK mode switch (SEGSYM)
  172. @param mqc MQC handle
  173. */
  174. void mqc_segmark_enc(opj_mqc_t *mqc);
  175. /**
  176. Initialize the decoder
  177. @param mqc MQC handle
  178. @param bp Pointer to the start of the buffer from which the bytes will be read
  179. @param len Length of the input buffer
  180. */
  181. void mqc_init_dec(opj_mqc_t *mqc, unsigned char *bp, int len);
  182. /**
  183. Decode a symbol
  184. @param mqc MQC handle
  185. @return Returns the decoded symbol (0 or 1)
  186. */
  187. int mqc_decode(opj_mqc_t *const mqc);
  188. /* ----------------------------------------------------------------------- */
  189. /*@}*/
  190. /*@}*/
  191. #endif /* __MQC_H */