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127 lines
3.8 KiB
127 lines
3.8 KiB
/*****************************************************************************
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* rdd08.h: SMPTE RDD 8 Teletext Subtitles for HDTV (aka OP-47)
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*****************************************************************************
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* Copyright (C) 2016 OpenHeadend
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*
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* Authors: Christophe Massiot <cmassiot@openheadend.tv>
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject
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* to the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
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* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
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* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
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* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*****************************************************************************/
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/*
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* Normative references:
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* - SMPTE RDD 8-2008
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*/
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#ifndef __BITSTREAM_SMPTE_RDD08_H__
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#define __BITSTREAM_SMPTE_RDD08_H__
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#include <stdint.h> /* uint8_t, uint16_t, etc... */
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#include <stdbool.h> /* bool */
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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/*****************************************************************************
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* SMPTE RDD 8 Subtitling Distribution Packet
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*****************************************************************************/
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#define RDD08SDP_HEADER_SIZE 9
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#define RDD08SDP_FOOTER_SIZE 4
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#define RDD08SDP_B_SIZE 45
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#define RDD08SDP_IDENT1 0x0151
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#define RDD08SDP_IDENT2 0x0115
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#define RDD08SDP_FOOTER 0x0274
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#define RDD08SDP_FORMAT_WST 0x0102
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#define RDD08SDP_FRAMING_CODE 0x0227
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static inline uint8_t rdd08sdp_get_length(const uint16_t *p_rdd08)
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{
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return p_rdd08[2] & 0xff;
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}
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static inline uint16_t rdd08sdp_get_format(const uint16_t *p_rdd08)
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{
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return p_rdd08[3];
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}
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static inline uint8_t rdd08sdp_get_a(const uint16_t *p_rdd08, uint8_t n)
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{
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return p_rdd08[4 + n] & 0xff;
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}
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static inline uint8_t rdd08sdpa_get_line(uint8_t i_rdd08a)
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{
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return i_rdd08a & 0x1f;
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}
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static inline bool rdd08sdpa_get_field(uint8_t i_rdd08a)
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{
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return i_rdd08a & 0x80;
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}
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static inline uint16_t *rdd08sdp_get_b(const uint16_t *p_rdd08, uint8_t n)
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{
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const uint16_t *b = p_rdd08 + RDD08SDP_HEADER_SIZE;
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unsigned int i;
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for (i = 0; i < n; i++)
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if (rdd08sdp_get_a(p_rdd08, i))
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b += RDD08SDP_B_SIZE;
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return (uint16_t *)b;
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}
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static inline uint16_t rdd08sdp_get_footer(const uint16_t *p_rdd08)
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{
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uint8_t i_length = rdd08sdp_get_length(p_rdd08);
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return p_rdd08[i_length - 4];
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}
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static inline uint16_t rdd08sdp_get_counter(const uint16_t *p_rdd08)
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{
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uint8_t i_length = rdd08sdp_get_length(p_rdd08);
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return ((p_rdd08[i_length - 3] & 0xff) << 8) |
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(p_rdd08[i_length - 2] & 0xff);
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}
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static inline bool rdd08sdp_check_cs(const uint16_t *p_rdd08)
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{
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uint8_t i_length = rdd08sdp_get_length(p_rdd08);
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uint8_t i_cs = 0;
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unsigned int i;
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for (i = 0; i < i_length; i++)
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i_cs += p_rdd08[i] & 0xff;
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return !i_cs;
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}
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static inline bool rdd08sdp_validate(const uint16_t *p_rdd08)
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{
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uint8_t i_length = rdd08sdp_get_length(p_rdd08);
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const uint16_t *b = rdd08sdp_get_b(p_rdd08, 5);
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return b <= p_rdd08 + i_length - 4;
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}
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#ifdef __cplusplus
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}
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#endif
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#endif
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