text: /*
  Copyright (C) 2006  Adam Charrett
  Copyright (C) 2011-2012  Michael Krufky
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
  
  This library 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
  Lesser General Public License for more details.
  
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  
  mgt.c
  
  Decode PSIP Master Guide Table.
  
  */
  #include "config.h"
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <stdbool.h>
  #include <string.h>
  
  #if defined(HAVE_INTTYPES_H)
  #include <inttypes.h>
  #elif defined(HAVE_STDINT_H)
  #include <stdint.h>
  #endif
  
  #include <assert.h>
  
  #include "../dvbpsi.h"
  #include "../dvbpsi_private.h"
  #include "../psi.h"
  #include "../descriptor.h"
  #include "../demux.h"
  
  #include "atsc_mgt.h"
  
  typedef struct dvbpsi_atsc_mgt_decoder_s
  {
      DVBPSI_DECODER_COMMON
  
      dvbpsi_atsc_mgt_callback      pf_mgt_callback;
      void *                        p_cb_data;
  
      dvbpsi_atsc_mgt_t             current_mgt;
      dvbpsi_atsc_mgt_t *           p_building_mgt;
  
  } dvbpsi_atsc_mgt_decoder_t;
  
  static dvbpsi_descriptor_t *dvbpsi_atsc_MGTAddDescriptor(
                                                 dvbpsi_atsc_mgt_t *p_mgt,
                                                 uint8_t i_tag, uint8_t i_length,
                                                 uint8_t *p_data);
  
  static dvbpsi_atsc_mgt_table_t *dvbpsi_atsc_MGTAddTable(dvbpsi_atsc_mgt_t* p_mgt,
  						 uint16_t i_table_type,
  						 uint16_t i_table_type_pid,
  						 uint8_t  i_table_type_version,
  						 uint32_t i_number_bytes);
  
  static dvbpsi_descriptor_t *dvbpsi_atsc_MGTTableAddDescriptor(
                                                 dvbpsi_atsc_mgt_table_t *p_table,
                                                 uint8_t i_tag, uint8_t i_length,
                                                 uint8_t *p_data);
  
  static void dvbpsi_atsc_GatherMGTSections(dvbpsi_t * p_dvbpsi,
                                            dvbpsi_decoder_t *p_decoder,
                                            dvbpsi_psi_section_t * p_section);
  
  static void dvbpsi_atsc_DecodeMGTSections(dvbpsi_atsc_mgt_t* p_mgt,
                                dvbpsi_psi_section_t* p_section);
  
  /*****************************************************************************
   * dvbpsi_atsc_AttachMGT
   *****************************************************************************
   * Initialize a MGT subtable decoder.
   *****************************************************************************/
  bool dvbpsi_atsc_AttachMGT(dvbpsi_t *p_dvbpsi, uint8_t i_table_id, uint16_t i_extension,
                             dvbpsi_atsc_mgt_callback pf_callback, void* p_cb_data)
  {
      assert(p_dvbpsi);
      assert(p_dvbpsi->p_decoder);
  
      dvbpsi_demux_t *p_demux = (dvbpsi_demux_t*)p_dvbpsi->p_decoder;
  
      if (dvbpsi_demuxGetSubDec(p_demux, i_table_id, i_extension))
      {
          dvbpsi_error(p_dvbpsi, "ATSC MGT decoder",
                       "Already a decoder for (table_id == 0x%02x extension == 0x%04x)",
                       i_table_id, i_extension);
          return false;
      }
  
      dvbpsi_atsc_mgt_decoder_t*  p_mgt_decoder;
      p_mgt_decoder = (dvbpsi_atsc_mgt_decoder_t*) dvbpsi_decoder_new(NULL,
                                                    0, true, sizeof(dvbpsi_atsc_mgt_decoder_t));
      if(p_mgt_decoder == NULL)
          return false;
  
      dvbpsi_demux_subdec_t* p_subdec;
      p_subdec = dvbpsi_NewDemuxSubDecoder(i_table_id, i_extension, dvbpsi_atsc_DetachMGT,
                                           dvbpsi_atsc_GatherMGTSections, DVBPSI_DECODER(p_mgt_decoder));
      if (p_subdec == NULL)
      {
          dvbpsi_decoder_delete(DVBPSI_DECODER(p_mgt_decoder));
          return false;
      }
  
      /* Attach the subtable decoder to the demux */
      dvbpsi_AttachDemuxSubDecoder(p_demux, p_subdec);
  
      /* MGT decoder information */
      p_mgt_decoder->pf_mgt_callback = pf_callback;
      p_mgt_decoder->p_cb_data = p_cb_data;
      p_mgt_decoder->p_building_mgt = NULL;
  
      return true;
  }
  
  /*****************************************************************************
   * dvbpsi_atsc_DetachMGT
   *****************************************************************************
   * Close a MGT decoder.
   *****************************************************************************/
  void dvbpsi_atsc_DetachMGT(dvbpsi_t *p_dvbpsi, uint8_t i_table_id, uint16_t i_extension)
  {
      assert(p_dvbpsi);
      assert(p_dvbpsi->p_decoder);
  
      dvbpsi_demux_t *p_demux = (dvbpsi_demux_t *) p_dvbpsi->p_decoder;
  
      dvbpsi_demux_subdec_t* p_subdec;
      p_subdec = dvbpsi_demuxGetSubDec(p_demux, i_table_id, i_extension);
      if (p_subdec == NULL)
      {
          dvbpsi_error(p_dvbpsi, "ATSC MGT Decoder",
                           "No such MGT decoder (table_id == 0x%02x,"
                           "extension == 0x%04x)",
                           i_table_id, i_extension);
          return;
      }
  
      dvbpsi_atsc_mgt_decoder_t* p_mgt_decoder;
      p_mgt_decoder = (dvbpsi_atsc_mgt_decoder_t*)p_subdec->p_decoder;
      if (!p_mgt_decoder)
          return;
  
      if (p_mgt_decoder->p_building_mgt)
          dvbpsi_atsc_DeleteMGT(p_mgt_decoder->p_building_mgt);
      p_mgt_decoder->p_building_mgt = NULL;
  
      dvbpsi_DetachDemuxSubDecoder(p_demux, p_subdec);
      dvbpsi_DeleteDemuxSubDecoder(p_subdec);
  }
  
  /*****************************************************************************
   * dvbpsi_atsc_InitMGT
   *****************************************************************************
   * Initialize a pre-allocated dvbpsi_atsc_mgt_t structure.
   *****************************************************************************/
  void dvbpsi_atsc_InitMGT(dvbpsi_atsc_mgt_t* p_mgt, uint8_t i_table_id, uint16_t i_extension,
                           uint8_t i_version, uint8_t i_protocol, bool b_current_next)
  {
      assert(p_mgt);
  
      p_mgt->i_table_id = i_table_id;
      p_mgt->i_extension = i_extension;
  
      p_mgt->i_version = i_version;
      p_mgt->b_current_next = b_current_next;
      p_mgt->i_protocol = i_protocol;
      p_mgt->p_first_table = NULL;
      p_mgt->p_first_descriptor = NULL;
  }
  
  dvbpsi_atsc_mgt_t *dvbpsi_atsc_NewMGT(uint8_t i_table_id, uint16_t i_extension,
                                        uint8_t i_version, uint8_t i_protocol, bool b_current_next)
  {
      dvbpsi_atsc_mgt_t* p_mgt;
      p_mgt = (dvbpsi_atsc_mgt_t*)calloc(1, sizeof(dvbpsi_atsc_mgt_t));
      if (p_mgt != NULL)
          dvbpsi_atsc_InitMGT(p_mgt, i_table_id, i_extension, i_version, i_protocol, b_current_next);
      return p_mgt;
  }
  
  /*****************************************************************************
   * dvbpsi_atsc_EmptyMGT
   *****************************************************************************
   * Clean a dvbpsi_atsc_mgt_t structure.
   *****************************************************************************/
  void dvbpsi_atsc_EmptyMGT(dvbpsi_atsc_mgt_t* p_mgt)
  {
    dvbpsi_atsc_mgt_table_t* p_table = p_mgt->p_first_table;
  
    while(p_table != NULL)
    {
      dvbpsi_atsc_mgt_table_t* p_tmp = p_table->p_next;
      dvbpsi_DeleteDescriptors(p_table->p_first_descriptor);
      free(p_table);
      p_table = p_tmp;
    }
    dvbpsi_DeleteDescriptors(p_mgt->p_first_descriptor);
    p_mgt->p_first_table = NULL;
    p_mgt->p_first_descriptor = NULL;
  }
  
  void dvbpsi_atsc_DeleteMGT(dvbpsi_atsc_mgt_t *p_mgt)
  {
      if (p_mgt)
          dvbpsi_atsc_EmptyMGT(p_mgt);
      free(p_mgt);
      p_mgt = NULL;
  }
  
  /*****************************************************************************
   * dvbpsi_atsc_MGTAddDescriptor
   *****************************************************************************
   * Add a descriptor to the MGT table.
   *****************************************************************************/
  static dvbpsi_descriptor_t *dvbpsi_atsc_MGTAddDescriptor(
                                                 dvbpsi_atsc_mgt_t *p_mgt,
                                                 uint8_t i_tag, uint8_t i_length,
                                                 uint8_t *p_data)
  {
      dvbpsi_descriptor_t * p_descriptor
                          = dvbpsi_NewDescriptor(i_tag, i_length, p_data);
      if (p_descriptor == NULL)
          return NULL;
  
      p_mgt->p_first_descriptor = dvbpsi_AddDescriptor(p_mgt->p_first_descriptor,
                                                       p_descriptor);
      assert(p_mgt->p_first_descriptor);
      if (p_mgt->p_first_descriptor == NULL)
          return NULL;
  
      return p_descriptor;
  }
  
  /*****************************************************************************
   * dvbpsi_atsc_MGTAddTable
   *****************************************************************************
   * Add a Table description at the end of the MGT.
   *****************************************************************************/
  static dvbpsi_atsc_mgt_table_t *dvbpsi_atsc_MGTAddTable(dvbpsi_atsc_mgt_t* p_mgt,
  						 uint16_t i_table_type,
  						 uint16_t i_table_type_pid,
  						 uint8_t  i_table_type_version,
  						 uint32_t i_number_bytes)
  {
    dvbpsi_atsc_mgt_table_t * p_table
                  = (dvbpsi_atsc_mgt_table_t*)malloc(sizeof(dvbpsi_atsc_mgt_table_t));
    if(p_table)
    {
      p_table->i_table_type = i_table_type;
      p_table->i_table_type_pid = i_table_type_pid;
      p_table->i_table_type_version = i_table_type_version;
      p_table->i_number_bytes = i_number_bytes;
  
      p_table->p_first_descriptor = NULL;
      p_table->p_next = NULL;
  
      if(p_mgt->p_first_table== NULL)
      {
        p_mgt->p_first_table = p_table;
      }
      else
      {
        dvbpsi_atsc_mgt_table_t * p_last_table = p_mgt->p_first_table;
        while(p_last_table->p_next != NULL)
          p_last_table = p_last_table->p_next;
        p_last_table->p_next = p_table;
      }
    }
  
    return p_table;
  }
  
  /*****************************************************************************
   * dvbpsi_MGTTableAddDescriptor
   *****************************************************************************
   * Add a descriptor in the MGT table description.
   *****************************************************************************/
  static dvbpsi_descriptor_t *dvbpsi_atsc_MGTTableAddDescriptor(
                                                 dvbpsi_atsc_mgt_table_t *p_table,
                                                 uint8_t i_tag, uint8_t i_length,
                                                 uint8_t *p_data)
  {
    dvbpsi_descriptor_t * p_descriptor
                          = dvbpsi_NewDescriptor(i_tag, i_length, p_data);
    if(p_descriptor)
    {
      if(p_table->p_first_descriptor == NULL)
      {
        p_table->p_first_descriptor = p_descriptor;
      }
      else
      {
        dvbpsi_descriptor_t * p_last_descriptor = p_table->p_first_descriptor;
        while(p_last_descriptor->p_next != NULL)
          p_last_descriptor = p_last_descriptor->p_next;
        p_last_descriptor->p_next = p_descriptor;
      }
    }
  
    return p_descriptor;
  }
  
  /*****************************************************************************
   * dvbpsi_ReInitMGT                                                          *
   *****************************************************************************/
  static void dvbpsi_ReInitMGT(dvbpsi_atsc_mgt_decoder_t *p_decoder, const bool b_force)
  {
      assert(p_decoder);
  
      dvbpsi_decoder_reset(DVBPSI_DECODER(p_decoder), b_force);
  
      /* Force redecoding */
      if (b_force)
      {
          /* Free structures */
          if (p_decoder->p_building_mgt)
              dvbpsi_atsc_DeleteMGT(p_decoder->p_building_mgt);
      }
      p_decoder->p_building_mgt = NULL;
  }
  
  static bool dvbpsi_CheckMGT(dvbpsi_t *p_dvbpsi, dvbpsi_atsc_mgt_decoder_t *p_decoder,
                              dvbpsi_psi_section_t *p_section)
  {
      bool b_reinit = false;
  
      assert(p_dvbpsi);
      assert(p_decoder);
  
      if (p_decoder->p_building_mgt->i_table_id_ext != p_section->i_extension)
      {
          /* transport_stream_id */
          dvbpsi_error(p_dvbpsi, "ATSC MGT decoder",
                       "'transport_stream_id' differs"
                       " whereas no TS discontinuity has occured");
          b_reinit = true;
      }
      else if (p_decoder->p_building_mgt->i_version != p_section->i_version)
      {
          /* version_number */
          dvbpsi_error(p_dvbpsi, "ATSC MGT decoder",
                       "'version_number' differs"
                       " whereas no discontinuity has occured");
          b_reinit = true;
      }
      else if (p_decoder->i_last_section_number != p_section->i_last_number)
      {
          /* last_section_number */
          dvbpsi_error(p_dvbpsi, "ATSC MGT decoder",
                       "'last_section_number' differs"
                       " whereas no discontinuity has occured");
          b_reinit = true;
      }
  
      return b_reinit;
  }
  
  static bool dvbpsi_AddSectionMGT(dvbpsi_t *p_dvbpsi, dvbpsi_atsc_mgt_decoder_t *p_decoder,
                                   dvbpsi_psi_section_t* p_section)
  {
      assert(p_dvbpsi);
      assert(p_decoder);
      assert(p_section);
  
      /* Initialize the structures if it's the first section received */
      if (!p_decoder->p_building_mgt)
      {
          p_decoder->p_building_mgt = dvbpsi_atsc_NewMGT(p_section->i_table_id,
                                                         p_section->i_extension,
                                                         p_section->i_version,
                                                         p_section->p_payload_start[0],
                                                         p_section->b_current_next);
          if (!p_decoder->p_building_mgt)
              return false;
  
          p_decoder->i_last_section_number = p_section->i_last_number;
      }
  
      /* Add to linked list of sections */
      if (dvbpsi_decoder_psi_section_add(DVBPSI_DECODER(p_decoder), p_section))
          dvbpsi_debug(p_dvbpsi, "ATSC MGT decoder", "overwrite section number %d",
                       p_section->i_number);
      return true;
  }
  
  /*****************************************************************************
   * dvbpsi_atsc_GatherMGTSections
   *****************************************************************************
   * Callback for the subtable demultiplexor.
   *****************************************************************************/
  static void dvbpsi_atsc_GatherMGTSections(dvbpsi_t * p_dvbpsi,
                                dvbpsi_decoder_t *p_decoder,
                                dvbpsi_psi_section_t * p_section)
  {
      assert(p_dvbpsi);
      assert(p_dvbpsi->p_decoder);
  
      if (!dvbpsi_CheckPSISection(p_dvbpsi, p_section, 0xC7, "ATSC MGT decoder"))
      {
          dvbpsi_DeletePSISections(p_section);
          return;
      }
  
      /* We have a valid MGT section */
      dvbpsi_demux_t *p_demux = (dvbpsi_demux_t *) p_dvbpsi->p_decoder;
      dvbpsi_atsc_mgt_decoder_t * p_mgt_decoder = (dvbpsi_atsc_mgt_decoder_t*)p_decoder;
      if (!p_mgt_decoder)
      {
          dvbpsi_error(p_dvbpsi, "ATSC MGT decoder", "No decoder specified");
          dvbpsi_DeletePSISections(p_section);
          return;
      }
  
      /* TS discontinuity check */
      if (p_demux->b_discontinuity)
      {
          dvbpsi_ReInitMGT(p_mgt_decoder, true);
          p_mgt_decoder->b_discontinuity = false;
          p_demux->b_discontinuity = false;
      }
      else
      {
          /* Perform a few sanity checks */
          if (p_mgt_decoder->p_building_mgt)
          {
              if (dvbpsi_CheckMGT(p_dvbpsi, p_mgt_decoder, p_section))
                  dvbpsi_ReInitMGT(p_mgt_decoder, true);
          }
          else
          {
              if (   (p_mgt_decoder->b_current_valid)
                  && (p_mgt_decoder->current_mgt.i_version == p_section->i_version)
                  && (p_mgt_decoder->current_mgt.b_current_next ==
                                                 p_section->b_current_next))
              {
                  /* Don't decode since this version is already decoded */
                  dvbpsi_debug(p_dvbpsi, "ATSC MGT decoder",
                               "ignoring already decoded section %d",
                               p_section->i_number);
                  dvbpsi_DeletePSISections(p_section);
                  return;
              }
  #if 0 /* Do we need to signal b_current_next here? or later */
              if ((p_mgt_decoder->b_current_valid) &&
                  (p_mgt_decoder->current_mgt.i_version == p_section->i_version))
              {
                  /* Signal a new MGT if the previous one wasn't active */
                  if ((!p_mgt_decoder->current_mgt.b_current_next) &&
                       (p_section->b_current_next))
                  {
                      dvbpsi_atsc_mgt_t * p_mgt = (dvbpsi_atsc_mgt_t*)malloc(sizeof(dvbpsi_atsc_mgt_t));
                      if (p_mgt)
                      {
                          p_mgt_decoder->current_mgt.b_current_next = true;
                          *p_mgt = p_mgt_decoder->current_mgt;
                          p_mgt_decoder->pf_mgt_callback(p_mgt_decoder->p_cb_data, p_mgt);
                      }
                      else
                          dvbpsi_error(p_dvbpsi, "ATSC MGT decoder", "Could not signal new ATSC MGT.");
                  }
              }
              dvbpsi_DeletePSISections(p_section);
              return;
  #endif
          }
      }
  
      /* Add section to MGT */
      if (!dvbpsi_AddSectionMGT(p_dvbpsi, p_mgt_decoder, p_section))
      {
          dvbpsi_error(p_dvbpsi, "ATSC MGT decoder", "failed decoding section %d",
                       p_section->i_number);
          dvbpsi_DeletePSISections(p_section);
          return;
      }
  
      /* Check if we have all the sections */
      if (dvbpsi_decoder_psi_sections_completed(DVBPSI_DECODER(p_mgt_decoder)))
      {
          assert(p_mgt_decoder->pf_mgt_callback);
  
          /* Save the current information */
          p_mgt_decoder->current_mgt = *p_mgt_decoder->p_building_mgt;
          p_mgt_decoder->b_current_valid = true;
          /* Decode the sections */
          dvbpsi_atsc_DecodeMGTSections(p_mgt_decoder->p_building_mgt,
                                        p_mgt_decoder->p_sections);
          /* signal the new MGT */
          p_mgt_decoder->pf_mgt_callback(p_mgt_decoder->p_cb_data,
                                         p_mgt_decoder->p_building_mgt);
          /* Delete sections and Reinitialize the structures */
          dvbpsi_ReInitMGT(p_mgt_decoder, false);
          assert(p_mgt_decoder->p_sections == NULL);
      }
  }
  
  /*****************************************************************************
   * dvbpsi_DecodeMGTSection
   *****************************************************************************
   * MGT decoder.
   *****************************************************************************/
  static void dvbpsi_atsc_DecodeMGTSections(dvbpsi_atsc_mgt_t* p_mgt,
                                            dvbpsi_psi_section_t* p_section)
  {
    uint8_t *p_byte, *p_end;
  
    while(p_section)
    {
      uint16_t i_tables_defined = (p_section->p_payload_start[1] << 8) |
                                  (p_section->p_payload_start[2]);
      uint16_t i_tables_count = 0;
      uint16_t i_length = 0;
  
      for(p_byte = p_section->p_payload_start + 3;
          ((p_byte + 6) < p_section->p_payload_end) && (i_tables_count < i_tables_defined);
          i_tables_count ++)
      {
  	dvbpsi_atsc_mgt_table_t* p_table;
  	uint16_t i_table_type         = ((uint16_t)(p_byte[0]) << 8) |
  	                                ((uint16_t)(p_byte[1]));
  	uint16_t i_table_type_pid     = ((uint16_t)(p_byte[2] & 0x1f) << 8) |
  	                                ((uint16_t)(p_byte[3] & 0xff));
  	uint8_t  i_table_type_version = ((uint8_t) (p_byte[4] & 0x1f));
  	uint32_t i_number_bytes       = ((uint32_t)(p_byte[5] << 24)) |
                                          ((uint32_t)(p_byte[6] << 16)) |
                                          ((uint32_t)(p_byte[7] <<  8)) |
                                          ((uint32_t)(p_byte[8]));
          i_length = ((uint16_t)(p_byte[9] & 0xf) <<8) | p_byte[10];
  
          p_table = dvbpsi_atsc_MGTAddTable(p_mgt,
  					  i_table_type,
  					  i_table_type_pid,
  					  i_table_type_version,
  					  i_number_bytes);
  
          /* Table descriptors */
          p_byte += 11;
          p_end = p_byte + i_length;
          if( p_end > p_section->p_payload_end ) break;
  
          while(p_byte + 2 <= p_end)
          {
              uint8_t i_tag = p_byte[0];
              uint8_t i_len = p_byte[1];
              if(i_len + 2 <= p_end - p_byte)
                dvbpsi_atsc_MGTTableAddDescriptor(p_table, i_tag, i_len, p_byte + 2);
              p_byte += 2 + i_len;
          }
      }
  
      /* Table descriptors */
      i_length = ((uint16_t)(p_byte[0] & 0xf) <<8) | p_byte[1];
      p_byte += 2;
      p_end = p_byte + i_length;
  
      while(p_byte + 2 <= p_end)
      {
          uint8_t i_tag = p_byte[0];
          uint8_t i_len = p_byte[1];
          if(i_length + 2 <= p_end - p_byte)
            dvbpsi_atsc_MGTAddDescriptor(p_mgt, i_tag, i_len, p_byte + 2);
          p_byte += 2 + i_len;
      }
      p_section = p_section->p_next;
    }
  }
  