vbi_teletext_descriptor.h 3.0 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116
  1. /*
  2. * section and descriptor parser
  3. *
  4. * Copyright (C) 2005 Kenneth Aafloy (kenneth@linuxtv.org)
  5. * Copyright (C) 2005 Andrew de Quincey (adq_dvb@lidskialf.net)
  6. *
  7. * This library is free software; you can redistribute it and/or
  8. * modify it under the terms of the GNU Lesser General Public
  9. * License as published by the Free Software Foundation; either
  10. * version 2.1 of the License, or (at your option) any later version.
  11. *
  12. * This library is distributed in the hope that it will be useful,
  13. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15. * Lesser General Public License for more details.
  16. *
  17. * You should have received a copy of the GNU Lesser General Public
  18. * License along with this library; if not, write to the Free Software
  19. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  20. */
  21. #ifndef _UCSI_DVB_VBI_TELETEXT_DESCRIPTOR
  22. #define _UCSI_DVB_VBI_TELETEXT_DESCRIPTOR 1
  23. #ifdef __cplusplus
  24. extern "C"
  25. {
  26. #endif
  27. #include <libucsi/descriptor.h>
  28. #include <libucsi/endianops.h>
  29. #include <libucsi/types.h>
  30. /**
  31. * dvb_vbi_teletext_descriptor structure
  32. */
  33. struct dvb_vbi_teletext_descriptor {
  34. struct descriptor d;
  35. /* struct dvb_vbi_teletext_entry entries[] */
  36. } __ucsi_packed;
  37. /**
  38. * An entry in a dvb_vbi_teletext_descriptor structure.
  39. */
  40. struct dvb_vbi_teletext_entry {
  41. iso639lang_t language_code;
  42. EBIT2(uint8_t type : 5; ,
  43. uint8_t magazine_number: 3; );
  44. uint8_t page_number;
  45. } __ucsi_packed;
  46. /**
  47. * Process an dvb_vbi_teletext_descriptor.
  48. *
  49. * @param d Generic descriptor.
  50. * @return dvb_vbi_teletext_descriptor pointer, or NULL on error.
  51. */
  52. static inline struct dvb_vbi_teletext_descriptor*
  53. dvb_vbi_teletext_descriptor_codec(struct descriptor* d)
  54. {
  55. if (d->len % sizeof(struct dvb_vbi_teletext_entry))
  56. return NULL;
  57. return (struct dvb_vbi_teletext_descriptor*) d;
  58. }
  59. /**
  60. * Iterator for entries field of a dvb_vbi_teletext_descriptor.
  61. *
  62. * @param d Pointer to dvb_vbi_teletext_descriptor.
  63. * @param pos Variable holding a pointer to the current dvb_vbi_teletext_entry.
  64. */
  65. #define dvb_vbi_teletext_descriptor_entries_for_each(d, pos) \
  66. for ((pos) = dvb_vbi_teletext_descriptor_entries_first(d); \
  67. (pos); \
  68. (pos) = dvb_vbi_teletext_descriptor_entries_next(d, pos))
  69. /******************************** PRIVATE CODE ********************************/
  70. static inline struct dvb_vbi_teletext_entry*
  71. dvb_vbi_teletext_descriptor_entries_first(struct dvb_vbi_teletext_descriptor *d)
  72. {
  73. if (d->d.len == 0)
  74. return NULL;
  75. return (struct dvb_vbi_teletext_entry *)
  76. ((uint8_t*) d + sizeof(struct dvb_vbi_teletext_descriptor));
  77. }
  78. static inline struct dvb_vbi_teletext_entry*
  79. dvb_vbi_teletext_descriptor_entries_next(struct dvb_vbi_teletext_descriptor *d,
  80. struct dvb_vbi_teletext_entry *pos)
  81. {
  82. uint8_t *end = (uint8_t*) d + 2 + d->d.len;
  83. uint8_t *next = (uint8_t *) pos + sizeof(struct dvb_vbi_teletext_entry);
  84. if (next >= end)
  85. return NULL;
  86. return (struct dvb_vbi_teletext_entry *) next;
  87. }
  88. #ifdef __cplusplus
  89. }
  90. #endif
  91. #endif