/*****************************************************************************
 * s2.h: ETSI EN 302 307 DVB-S2
 *****************************************************************************
 * Copyright (C) 2025 VideoLAN
 *
 * Authors: Christophe Massiot <cmassiot@upipe.org>
 *
 * 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:
 *  - ETSI EN 302 307 V1.2.1 (2009-08) (DVB-S2)
 */

#ifndef __BITSTREAM_DVB_S2_H__
#define __BITSTREAM_DVB_S2_H__

#include <bitstream/common.h>
#include <bitstream/mpeg/psi/psi.h>

#ifdef __cplusplus
extern "C"
{
#endif

/*****************************************************************************
 * BBFrame section
 *****************************************************************************
 * The only receiver of BBFrames that we have carries BBFrames in MPEG-TS,
 * in private sections of a specific PID.
 *****************************************************************************/
#define S2BBFRAMES_PID              0x010e
#define S2BBFRAMES_TABLE_ID         0x80
#define S2BBFRAMES_HEADER_SIZE      4
#define S2BBFRAMES_HEADER_COUNTER   0xb8

static inline uint8_t s2bbframes_get_counter(const uint8_t *p)
{
    return p[3];
}

static inline uint8_t *s2bbframes_get_bbframe(const uint8_t *p)
{
    return (uint8_t *)&p[4];
}

static inline uint16_t s2bbframes_get_length(const uint8_t *p)
{
    return psi_get_length(p) + PSI_HEADER_SIZE - S2BBFRAMES_HEADER_SIZE;
}

static inline bool s2bbframes_validate(const uint8_t *p)
{
    if (psi_get_syntax(p) || psi_get_tableid(p) != S2BBFRAMES_TABLE_ID)
        return false;

    return true;
}

/*****************************************************************************
 * BBFrame 8-bit CRC
 *****************************************************************************/
static const uint32_t s2bbcrc_table[256] = {
    0x00, 0xd5, 0x7f, 0xaa, 0xfe, 0x2b, 0x81, 0x54, 0x29, 0xfc, 0x56, 0x83,
    0xd7, 0x02, 0xa8, 0x7d, 0x52, 0x87, 0x2d, 0xf8, 0xac, 0x79, 0xd3, 0x06,
    0x7b, 0xae, 0x04, 0xd1, 0x85, 0x50, 0xfa, 0x2f, 0xa4, 0x71, 0xdb, 0x0e,
    0x5a, 0x8f, 0x25, 0xf0, 0x8d, 0x58, 0xf2, 0x27, 0x73, 0xa6, 0x0c, 0xd9,
    0xf6, 0x23, 0x89, 0x5c, 0x08, 0xdd, 0x77, 0xa2, 0xdf, 0x0a, 0xa0, 0x75,
    0x21, 0xf4, 0x5e, 0x8b, 0x9d, 0x48, 0xe2, 0x37, 0x63, 0xb6, 0x1c, 0xc9,
    0xb4, 0x61, 0xcb, 0x1e, 0x4a, 0x9f, 0x35, 0xe0, 0xcf, 0x1a, 0xb0, 0x65,
    0x31, 0xe4, 0x4e, 0x9b, 0xe6, 0x33, 0x99, 0x4c, 0x18, 0xcd, 0x67, 0xb2,
    0x39, 0xec, 0x46, 0x93, 0xc7, 0x12, 0xb8, 0x6d, 0x10, 0xc5, 0x6f, 0xba,
    0xee, 0x3b, 0x91, 0x44, 0x6b, 0xbe, 0x14, 0xc1, 0x95, 0x40, 0xea, 0x3f,
    0x42, 0x97, 0x3d, 0xe8, 0xbc, 0x69, 0xc3, 0x16, 0xef, 0x3a, 0x90, 0x45,
    0x11, 0xc4, 0x6e, 0xbb, 0xc6, 0x13, 0xb9, 0x6c, 0x38, 0xed, 0x47, 0x92,
    0xbd, 0x68, 0xc2, 0x17, 0x43, 0x96, 0x3c, 0xe9, 0x94, 0x41, 0xeb, 0x3e,
    0x6a, 0xbf, 0x15, 0xc0, 0x4b, 0x9e, 0x34, 0xe1, 0xb5, 0x60, 0xca, 0x1f,
    0x62, 0xb7, 0x1d, 0xc8, 0x9c, 0x49, 0xe3, 0x36, 0x19, 0xcc, 0x66, 0xb3,
    0xe7, 0x32, 0x98, 0x4d, 0x30, 0xe5, 0x4f, 0x9a, 0xce, 0x1b, 0xb1, 0x64,
    0x72, 0xa7, 0x0d, 0xd8, 0x8c, 0x59, 0xf3, 0x26, 0x5b, 0x8e, 0x24, 0xf1,
    0xa5, 0x70, 0xda, 0x0f, 0x20, 0xf5, 0x5f, 0x8a, 0xde, 0x0b, 0xa1, 0x74,
    0x09, 0xdc, 0x76, 0xa3, 0xf7, 0x22, 0x88, 0x5d, 0xd6, 0x03, 0xa9, 0x7c,
    0x28, 0xfd, 0x57, 0x82, 0xff, 0x2a, 0x80, 0x55, 0x01, 0xd4, 0x7e, 0xab,
    0x84, 0x51, 0xfb, 0x2e, 0x7a, 0xaf, 0x05, 0xd0, 0xad, 0x78, 0xd2, 0x07,
    0x53, 0x86, 0x2c, 0xf9
};

static uint8_t s2bbcrc_check(const uint8_t *p, uint8_t size)
{
    uint8_t crc = 0;
    while (size--)
        crc = s2bbcrc_table[crc ^ *p++];
    return crc;
}

/*****************************************************************************
 * BBFrame header
 *****************************************************************************/
#define S2BBH_SIZE                      10

#define S2BBH_TSGS_GENERICPACKETIZED    0
#define S2BBH_TSGS_GENERICCONTINUOUS    1
#define S2BBH_TSGS_RESERVED             2
#define S2BBH_TSGS_TRANSPORT            3

#define S2BBH_RO_35                     0
#define S2BBH_RO_25                     1
#define S2BBH_RO_20                     2
#define S2BBH_RO_RESERVED               3

#define S2BBH_DFL_MAX                   58112

static inline uint8_t s2bbh_get_tsgs(const uint8_t *p)
{
    return p[0] >> 6;
}

static inline bool s2bbh_is_sis(const uint8_t *p)
{
    return !!(p[0] & 0x20);
}

static inline bool s2bbh_is_ccm(const uint8_t *p)
{
    return !!(p[0] & 0x10);
}

static inline bool s2bbh_has_issyi(const uint8_t *p)
{
    return !!(p[0] & 0x8);
}

static inline bool s2bbh_has_npd(const uint8_t *p)
{
    return !!(p[0] & 0x4);
}

static inline uint8_t s2bbh_get_ro(const uint8_t *p)
{
    return p[0] & 0x3;
}

static inline uint8_t s2bbh_get_mis(const uint8_t *p)
{
    return p[1];
}

static inline uint16_t s2bbh_get_upl(const uint8_t *p)
{
    return (p[2] << 8) | p[3];
}

static inline uint16_t s2bbh_get_dfl(const uint8_t *p)
{
    return (p[4] << 8) | p[5];
}

static inline uint8_t s2bbh_get_sync(const uint8_t *p)
{
    return p[6];
}

static inline uint16_t s2bbh_get_syncd(const uint8_t *p)
{
    return (p[7] << 8) | p[8];
}

static inline bool s2bbh_validate(const uint8_t *p)
{
    if (s2bbh_get_dfl(p) > S2BBH_DFL_MAX ||
        s2bbcrc_check(p, 10) != 0)
        return false;

    return true;
}

/*****************************************************************************
 * BBFrame data field
 *****************************************************************************/
#define S2BBDF_ISSY_MAX_SIZE    3
#define S2BBDF_NPD_SIZE         1

#ifdef __cplusplus
}
#endif

#endif