Commit 822f6e41 authored by Christophe Massiot's avatar Christophe Massiot

SMPTE RDD 08 (OP-47 subtitles)

parent 1216e99d
/*****************************************************************************
* rdd08.h: SMPTE RDD 8 Teletext Subtitles for HDTV (aka OP-47)
*****************************************************************************
* Copyright (C) 2016 OpenHeadend
*
* Authors: Christophe Massiot <cmassiot@openheadend.tv>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject
* to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*****************************************************************************/
/*
* Normative references:
* - SMPTE RDD 8-2008
*/
#ifndef __BITSTREAM_SMPTE_RDD08_H__
#define __BITSTREAM_SMPTE_RDD08_H__
#include <stdint.h> /* uint8_t, uint16_t, etc... */
#include <stdbool.h> /* bool */
#ifdef __cplusplus
extern "C"
{
#endif
/*****************************************************************************
* SMPTE RDD 8 Subtitling Distribution Packet
*****************************************************************************/
#define RDD08SDP_HEADER_SIZE 8
#define RDD08SDP_FOOTER_SIZE 4
#define RDD08SDP_B_SIZE 45
#define RDD08SDP_IDENT1 0x51
#define RDD08SDP_IDENT2 0x15
#define RDD08SDP_FOOTER 0x74
#define RDD08SDP_FORMAT_WST 0x2
static inline uint8_t rdd08sdp_get_length(const uint16_t *p_rdd08)
{
return p_rdd08[2] & 0xff;
}
static inline uint8_t rdd08sdp_get_format(const uint16_t *p_rdd08)
{
return p_rdd08[3] & 0xff;
}
static inline uint8_t rdd08sdp_get_a(const uint16_t *p_rdd08, uint8_t n)
{
return p_rdd08[4 + n] & 0xff;
}
static inline uint8_t rdd08sdpa_get_line(uint8_t i_rdd08a)
{
return i_rdd08a & 0x1f;
}
static inline bool rdd08sdpa_get_field(uint8_t i_rdd08a)
{
return i_rdd08a & 0x80;
}
static inline uint16_t *rdd08sdp_get_b(const uint16_t *p_rdd08, uint8_t n)
{
const uint16_t *b = p_rdd08 + RDD08SDP_HEADER_SIZE;
unsigned int i;
for (i = 0; i < n; i++)
if (rdd08sdp_get_a(p_rdd08, i))
b += RDD08SDP_B_SIZE;
return (uint16_t *)b;
}
static inline uint8_t rdd08sdp_get_footer(const uint16_t *p_rdd08)
{
uint8_t i_length = rdd08sdp_get_length(p_rdd08);
return p_rdd08[i_length - 4] & 0xff;
}
static inline uint16_t rdd08sdp_get_counter(const uint16_t *p_rdd08)
{
uint8_t i_length = rdd08sdp_get_length(p_rdd08);
return ((p_rdd08[i_length - 3] & 0xff) << 8) |
(p_rdd08[i_length - 2] & 0xff);
}
static inline bool rdd08sdp_check_cs(const uint16_t *p_rdd08)
{
uint8_t i_length = rdd08sdp_get_length(p_rdd08);
uint8_t i_cs = 0;
unsigned int i;
for (i = 0; i < i_length; i++)
i_cs += p_rdd08[i] & 0xff;
return !i_cs;
}
static inline bool rdd08sdp_validate(const uint16_t *p_rdd08)
{
uint8_t i_length = rdd08sdp_get_length(p_rdd08);
const uint16_t *b = rdd08sdp_get_b(p_rdd08, 5);
return b <= p_rdd08 + i_length - 4;
}
#ifdef __cplusplus
}
#endif
#endif
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