/*
* Video On Demand Samples
*
* Copyright (C) 2015 Microchip Technology Germany II GmbH & Co. KG
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*
* You may also obtain this software under a propriety license from Microchip.
* Please contact Microchip for further information.
*
*/
/*----------------------------------------------------------*/
/*! \file
* \brief This file contains static helper C-functions to parse TS packets.
*/
/*----------------------------------------------------------*/
#ifndef TSPACKET_H
#define TSPACKET_H
//#define TS_PATTERN_CHECK
#include
#include
#include
/*----------------------------------------------------------*/
/*!
* \brief Handles a transport stream packet of 188 bytes
*/
/*----------------------------------------------------------*/
class CTsPacket
{
private:
static const uint32_t ADAPTION_FIELD_CONTROL__RESERVED = (0x00 << 4);
static const uint32_t ADAPTION_FIELD_CONTROL__PAYLOAD_ONLY = (0x01 << 4);
static const uint32_t ADAPTION_FIELD_CONTROL__NO_PAYLOAD = (0x02 << 4);
static const uint32_t ADAPTION_FIELD_CONTROL__BOTH = (0x03 << 4);
static const uint32_t program_stream_map = 0xBC;
static const uint32_t padding_stream = 0xBE;
static const uint32_t private_stream_2 = 0xBF;
static const uint32_t ECM = 0xF0;
static const uint32_t EMM = 0xF1;
static const uint32_t DSMCC_stream = 0xF2;
static const uint32_t H222_stream = 0xF8;
static const uint32_t program_stream_directory = 0xFF;
static const uint32_t PROGRAM_ASSOSICIATION_SECTION = 0x00;
static const uint32_t PROGRAM_MAP_SECTION = 0x02;
static const uint32_t ISO_IEC_11172_AUDIO = 0x03;
static const uint32_t ISO_IEC_13818_2_Video = 0x02;
static const uint32_t ISO_IEC_13818_3_AUDIO = 0x04;
static const uint32_t ISO_IEC_13818_1_RESERVED = 0x1B;
static const uint8_t PCR_FLAG = 0x10;
public:
static const uint32_t PID_INVALID = 0xFFFF;
static const uint32_t PCR_INVALID = 0xFFFFFFFF;
static const uint32_t PCR_TICKS_PER_SEC = 45000;
static const uint8_t TS_PACKET_LEN = 188;
/*----------------------------------------------------------*/
/*! \brief extract continuity counter
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static uint32_t GetContinuityCounter(uint8_t *pTs)
{
return (pTs[3] & 0xF);
}
/*----------------------------------------------------------*/
/*! \brief get array index where ES payload
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static uint32_t GetElementaryPayloadStart(uint8_t *pTs)
{
uint32_t nRet = GetPayloadStart(pTs); // index to TS payload
if (GetHasPesHeader(pTs)) {
nRet += 3 + 1 + 2 + 1 + 1; // packet start(3) + stream_id(1) + PES_packet_length(2) + PES_scampling...(1) + PTS_DTS_flags...(1)
nRet += (pTs[nRet] & 0xFF) + 1; // PES_header_data_length
}
return nRet;
}
/*----------------------------------------------------------*/
/*! \brief check if there is a discontinuity in the stream
*
* \param pTs - uint8_t array containing TS packet
* \param nLastDiscontinuityCounter - preceding counter
*/
/*----------------------------------------------------------*/
static bool GetHasDiscontinuity(uint8_t *pTs,
uint32_t nLastDiscontinuityCounter)
{
nLastDiscontinuityCounter = (nLastDiscontinuityCounter + 1) & 0xF;
return (pTs[3] & 0xF) != nLastDiscontinuityCounter;
}
/*----------------------------------------------------------*/
/*! \brief check if a TS packet has the given PID
*
* \param pTs - uint8_t array containing TS packet
* \param nPid - PID to check for
*
* \return true if PID is equal
*/
/*----------------------------------------------------------*/
static bool GetHasPid(uint8_t *pTs, uint32_t nPid)
{
return nPid == GetPid(pTs);
}
/*----------------------------------------------------------*/
/*! \brief check if a TS packet contains a PAT
*
* \param pTs - uint8_t array containing TS packet
*
* \return true if PAT is contained
*/
/*----------------------------------------------------------*/
static bool GetIsPat(uint8_t *pTs)
{
if (!GetHasPid(pTs, 0))
return false;
uint32_t nPat = GetPayloadStart(pTs); // start of PSI
nPat += 1 + (0xFF & pTs[nPat]); // pouint32_ter_field
return (pTs[nPat] == PROGRAM_ASSOSICIATION_SECTION); // table_id
}
/*----------------------------------------------------------*/
/*! \brief gets the PMT PID from the n-th program of a PAT
* packet
*
* \param pTs - uint8_t array containing TS packet
* \param nPrg - number of program
*
* \return true if PAT is contained
*/
/*----------------------------------------------------------*/
static uint32_t GetPmtPidFromPat(uint8_t *pTs, uint32_t nPrg)
{
uint32_t nPat = GetPayloadStart(pTs); // PSI
nPat += 1 + (0xFF & pTs[nPat]); // pouint32_ter_field
return ((0x1F & pTs[nPat + 10 + nPrg * 4]) << 8) + // program_map_PID (high uint8_t *)
(0xFF & pTs[nPat + 10 + nPrg * 4 + 1]); // program_map_PID (low uint8_t *)
}
/*----------------------------------------------------------*/
/*! \brief gets the audio PID from a PMT packet
*
* \param pTs - uint8_t array containing TS packet
*
* \return PID of 1st audio channel
*/
/*----------------------------------------------------------*/
static uint32_t GetAudioPidFromPmt(uint8_t *pTs)
{
uint32_t nPmt = GetPayloadStart(pTs); // PSI
nPmt += 1 + (0xFF & pTs[nPmt]); // pouint32_ter_field
if (PROGRAM_MAP_SECTION != pTs[nPmt]) // check table_id
return PID_INVALID;
uint32_t section_length = ((0x0F & pTs[nPmt + 1]) << 8) +
(0xFF & pTs[nPmt + 2]);
uint32_t program_info_length = ((0x0F & pTs[nPmt + 10]) << 8) +
(0xFF & pTs[nPmt + 11]);
uint32_t n = nPmt + 12 + program_info_length;
while (n < section_length + nPmt + 2) { // run through all streams
uint32_t stream_type = pTs[n];
uint32_t elementary_pid = ((0x1F & pTs[n + 1]) << 8) + (0xFF & pTs[n + 2]);
uint32_t ES_info_length = ((0x0F & pTs[n + 3]) << 8) + (0xFF & pTs[n + 4]);
if (ISO_IEC_11172_AUDIO == stream_type
|| ISO_IEC_13818_3_AUDIO == stream_type) {
return elementary_pid;
}
n += 5 + ES_info_length; // switch to next stream
}
return PID_INVALID; // no audio stream found
}
/*----------------------------------------------------------*/
/*! \brief gets the audio PID from a PMT packet
*
* \param pTs - uint8_t array containing TS packet
*
* \return PID of 1st audio channel
*/
/*----------------------------------------------------------*/
static uint32_t GetVideoPidFromPmt(uint8_t *pTs)
{
uint32_t nPmt = GetPayloadStart(pTs); // PSI
nPmt += 1 + (0xFF & pTs[nPmt]); // pouint32_ter_field
if (PROGRAM_MAP_SECTION != pTs[nPmt]) // check table_id
return PID_INVALID;
uint32_t section_length = ((0x0F & pTs[nPmt + 1]) << 8) +
(0xFF & pTs[nPmt + 2]);
uint32_t program_info_length = ((0x0F & pTs[nPmt + 10]) << 8) +
(0xFF & pTs[nPmt + 11]);
uint32_t n = nPmt + 12 + program_info_length;
while (n < section_length + nPmt + 2) { // run through all streams
uint32_t stream_type = pTs[n];
uint32_t elementary_pid = ((0x1F & pTs[n + 1]) << 8) + (0xFF & pTs[n + 2]);
uint32_t ES_info_length = ((0x0F & pTs[n + 3]) << 8) + (0xFF & pTs[n + 4]);
if (ISO_IEC_13818_2_Video == stream_type
|| ISO_IEC_13818_1_RESERVED == stream_type) {
return elementary_pid;
}
n += 5 + ES_info_length; // switch to next stream
}
return PID_INVALID; // no audio stream found
}
/*----------------------------------------------------------*/
/*! \brief checks if TS packet is the start of an I frame
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static bool GetIsStartOfIFrame(uint8_t *pTs)
{
uint32_t n = GetPayloadStart(pTs);
for (; n < 188 - 4; n++) // search for IDR (instantaneous decoder refresh)
if (0 == pTs[n] && 0 == pTs[n + 1] && 1 == pTs[n + 2]
&& (5 == (pTs[n + 3] & 0x1F)))
return true;
return false;
}
/*----------------------------------------------------------*/
/*! \brief check if TS packet contains a PES header
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static bool GetHasPesHeader(uint8_t *pTs)
{
if (!GetIsPayloadUnitStart(pTs))
return false;
uint32_t nPes = GetPayloadStart(pTs);
return !(0 != pTs[nPes ] ||
0 != pTs[nPes + 1] ||
1 != pTs[nPes + 2] || // is it a PES Header?
program_stream_map == pTs[nPes + 3] ||
padding_stream == pTs[nPes + 3] ||
private_stream_2 == pTs[nPes + 3] ||
ECM == pTs[nPes + 3] ||
EMM == pTs[nPes + 3] ||
program_stream_directory == pTs[nPes + 3] ||
DSMCC_stream == pTs[nPes + 3] ||
H222_stream == pTs[nPes + 3] ||
0 == (0x80 & pTs[nPes + 7]));
}
/*----------------------------------------------------------*/
/*! \brief check if TS packet contains a PTS
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static bool GetHasPts(uint8_t *pTs)
{
if (!GetHasPesHeader(pTs))
return false;
uint32_t nPes = GetPayloadStart(pTs);
return (0 != ((pTs[nPes + 7] & 0x80))); // PTS_DTS_flags is 0x2 or 0x3
}
/*----------------------------------------------------------*/
/*! \brief get PCR from a packet if available
*
* \param pTs - uint8_t array containing TS packet
*
* \return PCR or PCR_INVALID if packet contains no PCR
*/
/*----------------------------------------------------------*/
static uint32_t GetPcr(uint8_t *pTs)
{
switch ((pTs[3] & 0x30)) { // check if packet contains adaption field
case ADAPTION_FIELD_CONTROL__PAYLOAD_ONLY:
case ADAPTION_FIELD_CONTROL__RESERVED:
return PCR_INVALID;
default:
break;
}
if (0 == pTs[4]) // 0 == adaption_field_length ?
return PCR_INVALID;
if (PCR_FLAG != (pTs[5] & PCR_FLAG)) // 1 == PCR_flag ?
return PCR_INVALID;
return (pTs[6] << 24) || (pTs[7] << 16) || (pTs[8] << 8) || (pTs[9]);
}
/*----------------------------------------------------------*/
/*! \brief check if a TS packet has sync uint8_t *
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static bool GetHasSyncByte(uint8_t *pTs)
{
return 0x47 == pTs[0];
}
/*----------------------------------------------------------*/
/*! \brief check if TS packet starts a new payload unit
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static bool GetIsPayloadUnitStart(uint8_t *pTs)
{
return (0 != (pTs[1] & 0x40));
}
/*----------------------------------------------------------*/
/*! \brief get arry index of payload start in packet
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static uint32_t GetPayloadStart(uint8_t *pTs)
{
switch ((pTs[3] & 0x30)) {
case ADAPTION_FIELD_CONTROL__PAYLOAD_ONLY:
return 4;
case ADAPTION_FIELD_CONTROL__BOTH:
return 4 + 1 + (pTs[4] & 0xFF);
case ADAPTION_FIELD_CONTROL__RESERVED:
case ADAPTION_FIELD_CONTROL__NO_PAYLOAD:
return 188;
}
return TS_PACKET_LEN;
}
/*----------------------------------------------------------*/
/*! \brief get PES packet length from packet
*
* \param pTs - uint8_t array containing TS packet
* \return length of PES packet in uint8_t *s
*/
/*----------------------------------------------------------*/
static uint32_t GetPesPacketLength(uint8_t *pTs)
{
uint32_t nPes = GetPayloadStart(pTs);
return ((pTs[nPes + 4] & 0xFF) << 8) + (pTs[nPes + 5] & 0xFF);
}
/*----------------------------------------------------------*/
/*! \brief extract PID from a TS packet
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static uint32_t GetPid(uint8_t *pTs)
{
return (((uint32_t)pTs[1] & 0x1F) << 8) + ((uint32_t)pTs[2] & 0xFF);
}
/*----------------------------------------------------------*/
/*! \brief extract PTS from a TS packet in 45 kHz units
*
* \param pTs - uint8_t array containing TS packet
*/
/*----------------------------------------------------------*/
static uint32_t GetPts(uint8_t *pTs)
{
uint32_t nPes = GetPayloadStart(pTs);
return ((pTs[nPes + 9] & 0x0E) << 28) +
((pTs[nPes + 10] & 0xFF) << 21) +
((pTs[nPes + 11] & 0xFE) << 13) +
((pTs[nPes + 12] & 0xFF) << 6) +
((pTs[nPes + 13] & 0xFF) >> 2);
}
/*----------------------------------------------------------*/
/*! \brief calculate CRC from a memory area
*
* \param pSrc - start of memory area
* \param nLen - length of memory area in bytes
*/
/*----------------------------------------------------------*/
static uint32_t GetCrc32(uint8_t *pSrc, int nLen)
{
static const uint32_t CrcTable[256] = {
0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
};
uint32_t nCrc = 0xFFFFFFFF;
while (nLen--)
nCrc = (nCrc << 8) ^ CrcTable[((nCrc >> 24) ^ *pSrc++) & 0xFF ];
return nCrc;
}
/*----------------------------------------------------------*/
/*! \brief calculate a PMT packet for a program containing
* one video and one audio stream
*
* \param pTs - pointer to TS packet to store result
* \param nAPid - PID of audio
* \param nAPid - PID of video
* \param nAPid - PID of PMT
*/
/*----------------------------------------------------------*/
static void CreatePmt(uint8_t *pTs, uint32_t nAPid, uint32_t nVPid,
uint32_t nPPid)
{
if (NULL == pTs)
return;
pTs[0] = 0x47; // packet start
pTs[1] = (1 << 6) | // Payload Unit start indicator, PID = 0;
(nPPid >> 8); // PMT PID (HB)
pTs[2] = nPPid & 0xFF; // PMT PID (LB)
pTs[3] = (1 << 4); // no adaption field
pTs[4] = 0; // PointerField: new section
uint8_t *pPmt = pTs + 5; // pointer to PMT section
pPmt[0] = 0x02; // Table ID: Program Map Section
uint16_t wSectionLength =
12 - 3 + // section until program info length
5 + // video entry
5 + // audio entry
4; // CRC
pPmt[1] = (1 << 7) | // section syntax indicator
(3 << 4) | // reserved
(wSectionLength >> 8); // section syntax 1, section length
pPmt[2] = wSectionLength & 0xFF;
pPmt[3] = (nPPid >> 8); // program number (HB)
pPmt[4] = nPPid & 0xFF; // program number (LB)
pPmt[5] = (3 << 6) | 1; // version, current/next
pPmt[6] = 0; // section number
pPmt[7] = 0; // last section number
pPmt[8] = (7 << 5) | // reserved
(nVPid >> 8); // PCR PID, assuming video has PCR
pPmt[9] = nVPid & 0xFF; // PCR PID (LB)
pPmt[10] = (0xF << 4) | // reserved
(0); // program info length
pPmt[11] = 0;
// video
pPmt[12] = 27; // stream type = video
pPmt[13] = (7 << 5) | // reserved
(nVPid >> 8); // ES PID (HB)
pPmt[14] = nVPid & 0xFF; // ES PID (LB)
pPmt[15] = (0xF << 4) | // reserved
(0); // ES Info length
pPmt[16] = 0; // ES Info length
// audio
pPmt[17] = 3; // stream type = audio
pPmt[18] = (7 << 5) | // reserved
(nAPid >> 8); // ES PID
pPmt[19] = nAPid & 0xFF;
pPmt[20] = (0xF << 4) | // reserved
(0); // ES Info
pPmt[21] = 0;
// CRC
uint32_t nCrc = GetCrc32(pPmt,
wSectionLength + 3 - 4);// Crc for entire pmt section
pPmt[wSectionLength + 3 - 4 + 0] = (nCrc >> 24) & 0xFF;
pPmt[wSectionLength + 3 - 4 + 1] = (nCrc >> 16) & 0xFF;
pPmt[wSectionLength + 3 - 4 + 2] = (nCrc >> 8) & 0xFF;
pPmt[wSectionLength + 3 - 4 + 3] = (nCrc) & 0xFF;
}
/*----------------------------------------------------------*/
/*! \brief calculate a stuffing packet
*
* \param pTs - pointer to TS packet to store result
* \param nPatternCount - Actual pattern packet count, shall be incremented each time.
*/
/*----------------------------------------------------------*/
static void CreateStuffing(uint8_t *pTs, uint32_t nPatternCount)
{
pTs[0] = 0x47;
pTs[1] = 0x1F;
pTs[2] = 0xFF;
pTs[3] = 0x00;
#ifdef TS_PATTERN_CHECK
memcpy(&pTs[4], &nPatternCount, sizeof(nPatternCount));
uint8_t startByte = (uint8_t)(nPatternCount & 0xFF);
for (uint8_t i = 8; i < 188; i++) {
pTs[i] = startByte + i;
}
#endif
}
};
#endif //TSPACKET_H