/* -*- c++ -*- */

/*

 * Copyright 2002 Free Software Foundation, Inc.

 * 

 * This file is part of GNU Radio

 * 

 * GNU Radio 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, or (at your option)

 * any later version.

 * 

 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to

 * the Free Software Foundation, Inc., 51 Franklin Street,

 * Boston, MA 02110-1301, USA.

 */

#include <GrAtscTrellisEncoder.h>

// typedefs for fundamental i/o types

typedef atsc_mpeg_packet_rs_encoded        iType;

typedef atsc_data_segment                oType;

static const int NUMBER_OF_OUTPUTS = 1;        // # of output streams (almost always one)

GrAtscTrellisEncoder::GrAtscTrellisEncoder ()

  : VrHistoryProc<iType,oType> (NUMBER_OF_OUTPUTS), last_start(-1)

{

  // 1 + number of extra input elements at which we look.  This is

  // used by the superclass's forecast routine to get us the correct

  // range on our inputs.

  //

  // We need our input to be aligned on a 12-segment boundary,

  // to ensure satisfaction, ask for 11 more

  history = 1 + (atsci_trellis_encoder::NCODERS - 1);

  // any other init here.

  // Let the bottom end know we must produce output in multiples of 12 segments.  

  setOutputSize (atsci_trellis_encoder::NCODERS);

}

GrAtscTrellisEncoder::~GrAtscTrellisEncoder ()

{

  // Anything that isn't automatically cleaned up...

}

/*

 * This is the real work horse.  In general this interface can handle

 * multiple streams of input and output, but we almost always

 * use a single input and output stream.

 */

int 

GrAtscTrellisEncoder::work (VrSampleRange output, void *ao[],

                            VrSampleRange inputs[], void *ai[])

{

  // If we have state that persists across invocations (e.g., we have

  // instance variables that we modify), we must use the sync method

  // to indicate to the scheduler that our output must be computed in

  // order.  This doesn't keep other things from being run in

  // parallel, it just means that at any given time, there is only a

  // single thread working this code, and that the scheduler will

  // ensure that we are asked to produce output that is contiguous and

  // that will be presented to us in order of increasing time.

  // We have state, the current state of the encoders, hence

  // we must use sync.

  sync (output.index);

  // construct some nicer i/o pointers to work with.

  iType *in  = ((iType **) ai)[0];

  oType *out = ((oType **) ao)[0];

#if 0

  cerr << "@@@ GrAtscTrellisEncoder: output.index = " << output.index

       << " output.size = " << output.size

       << " sum = " << output.index + output.size

       << " \t[in  = " << in << "]"

       << endl;

#endif  

  assert (output.size % atsci_trellis_encoder::NCODERS == 0);

  // find the first mod 12 boundary to begin decoding

  int start;

  for (start = 0; start < atsci_trellis_encoder::NCODERS; start++){

    plinfo::sanity_check (in[start].pli);

    assert (in[start].pli.regular_seg_p ());

    if ((in[start].pli.segno () % atsci_trellis_encoder::NCODERS) == 0)

      break;

  }

  if (start == atsci_trellis_encoder::NCODERS){

    // we didn't find a mod 12 boundary.  There's some kind of problem

    // upstream of us (not yet sync'd??)

    cerr << "!!!GrAtscTrellisEncoder: no mod-12 boundary found\7\n";

    start = 0;

  }

  else if (start != last_start){

    cerr << "GrAtscTrellisEncoder: new starting offset = " << start

         << " output.index = " << output.index << endl;

    last_start = start;

  }

  // FIXME paranoid check for problem

  for (unsigned int i = 0; i < output.size; i++){

    plinfo::sanity_check (in[i + start].pli);

  }

  // We must produce output.size units of output.

  for (unsigned int i = 0; i < output.size; i += atsci_trellis_encoder::NCODERS){

    // primitive does 12 segments at a time.

    // pipeline info is handled in the primitive.

    encoder.encode (&out[i], &in[i + start]);

  }

#if 0

  // FIXME paranoid check for problem

  for (unsigned int i = 0; i < output.size; i++){

    plinfo::sanity_check (out[i].pli);

    assert (out[i].pli.regular_seg_p ());

  }

#endif

  // Return the number of units we produced.

  // Note that for all intents and purposes, it is an error to

  // produce less than you are asked for.

  return output.size;        

}