application_signalling_descriptor.h 3.5 KB

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  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_APPLICATION_SIGNALLING_DESCRIPTOR
  22. #define _UCSI_DVB_APPLICATION_SIGNALLING_DESCRIPTOR 1
  23. #ifdef __cplusplus
  24. extern "C"
  25. {
  26. #endif
  27. #include <libucsi/descriptor.h>
  28. #include <libucsi/endianops.h>
  29. /**
  30. * dvb_application_signalling_descriptor structure.
  31. */
  32. struct dvb_application_signalling_descriptor {
  33. struct descriptor d;
  34. /* struct dvb_application_signalling_entry entries[] */
  35. } __ucsi_packed;
  36. /**
  37. * An entry in the entries field of a dvb_application_signalling_descriptor.
  38. */
  39. struct dvb_application_signalling_entry {
  40. uint16_t application_type;
  41. EBIT2(uint8_t reserved : 3; ,
  42. uint8_t AIT_version_number : 5; );
  43. } __ucsi_packed;
  44. /**
  45. * Process a dvb_application_signalling_descriptor.
  46. *
  47. * @param d Generic descriptor pointer.
  48. * @return dvb_application_signalling_descriptor pointer, or NULL on error.
  49. */
  50. static inline struct dvb_application_signalling_descriptor*
  51. dvb_application_signalling_descriptor_codec(struct descriptor* d)
  52. {
  53. uint32_t pos = 0;
  54. uint32_t len = d->len;
  55. uint8_t* buf = (uint8_t*) d + 2;
  56. pos += sizeof(struct dvb_application_signalling_descriptor) - 2;
  57. if (len % sizeof(struct dvb_application_signalling_entry))
  58. return NULL;
  59. while(pos < len) {
  60. bswap16(buf+pos);
  61. pos+=3;
  62. }
  63. return (struct dvb_application_signalling_descriptor*) d;
  64. }
  65. /**
  66. * Iterator for the entries field of a dvb_application_signalling_descriptor.
  67. *
  68. * @param d dvb_application_signalling_descriptor pointer.
  69. * @param pos Variable containing a pointer to the current dvb_application_signalling_entry.
  70. */
  71. #define dvb_application_signalling_descriptor_entries_for_each(d, pos) \
  72. for ((pos) = dvb_application_signalling_descriptor_entries_first(d); \
  73. (pos); \
  74. (pos) = dvb_application_signalling_descriptor_entries_next(d, pos))
  75. /******************************** PRIVATE CODE ********************************/
  76. static inline struct dvb_application_signalling_entry*
  77. dvb_application_signalling_descriptor_entries_first(struct dvb_application_signalling_descriptor *d)
  78. {
  79. if (d->d.len == 0)
  80. return NULL;
  81. return (struct dvb_application_signalling_entry *)
  82. ((uint8_t*) d + sizeof(struct dvb_application_signalling_descriptor));
  83. }
  84. static inline struct dvb_application_signalling_entry*
  85. dvb_application_signalling_descriptor_entries_next(struct dvb_application_signalling_descriptor *d,
  86. struct dvb_application_signalling_entry *pos)
  87. {
  88. uint8_t *end = (uint8_t*) d + 2 + d->d.len;
  89. uint8_t *next = (uint8_t *) pos + sizeof(struct dvb_application_signalling_entry);
  90. if (next >= end)
  91. return NULL;
  92. return (struct dvb_application_signalling_entry *) next;
  93. }
  94. #ifdef __cplusplus
  95. }
  96. #endif
  97. #endif