function p = gsm_pitch(file)
% Syntax: p = gsm_pitch(filename)
%
% Reads EID file (text form) of GSM HR and retrieves the pitch information for
% voiced frames. For unvoiced frames, it is set to 0. The length of p is
% 4 times the number of frames, as we have a pitch information for each
% subframe. Filename is a string with usually 'something.eid'


psrLagTbl =[ ...
  126, 128, 130, 132, 134, 136, 138, 139,...
  140, 141, 142, 143, 144, 145, 146, 147,...
  148, 149, 150, 151, 152, 153, 154, 155,...
  156, 157, 158, 159, 160, 161, 162, 163,...
  164, 165, 166, 167, 168, 169, 170, 171,...
  172, 173, 174, 175, 176, 177, 178, 179,...
  180, 181, 182, 183, 184, 185, 186, 187,...
  188, 189, 190, 191, 192, 193, 194, 195,...
  196, 197, 198, 199, 200, 201, 202, 203,...
  204, 205, 206, 207, 208, 209, 210, 212,...
  214, 216, 218, 220, 222, 224, 226, 228,...
  230, 232, 234, 236, 238, 240, 242, 244,...
  246, 248, 250, 252, 254, 256, 258, 260,...
  262, 264, 266, 268, 270, 272, 274, 276,...
  278, 280, 282, 284, 286, 288, 290, 292,...
  294, 296, 298, 300, 303, 306, 309, 312,...
  315, 318, 321, 324, 327, 330, 333, 336,...
  339, 342, 345, 348, 351, 354, 357, 360,...
  363, 366, 369, 372, 375, 378, 381, 384,...
  387, 390, 393, 396, 399, 402, 405, 408,...
  411, 414, 417, 420, 423, 426, 429, 432,...
  435, 438, 441, 444, 447, 450, 453, 456,...
  459, 462, 465, 468, 471, 474, 477, 480,...
  483, 486, 489, 492, 495, 498, 501, 504,...
  507, 510, 513, 516, 519, 522, 525, 528,...
  531, 534, 537, 540, 546, 552, 558, 564,...
  570, 576, 582, 588, 594, 600, 606, 612,...
  618, 624, 630, 636, 642, 648, 654, 660,...
  666, 672, 678, 684, 690, 696, 702, 708,...
  714, 720, 726, 732, 738, 744, 750, 756,...
  762, 768, 774, 780, 786, 792, 798, 804,...
  810, 816, 822, 828, 834, 840, 846, 852      ];

fid = fopen (file, 'r');
gsm = fscanf (fid, '%d', [18, inf]);	% lines to columns, one line = 18 items
gsm = gsm';				% now one line in file = one line in matrix

frames = size (gsm,1);
p=zeros(1, 4*frames);
icur_sfrm=1;

for icur_frm=1:frames,
  if (gsm(icur_frm,1) == 0),	% UNVOICED
    p(icur_sfrm) = 0;
    p(icur_sfrm+1) = 0;
    p(icur_sfrm+2) = 0;
    p(icur_sfrm+3) = 0;
  
  else				% VOICED
    index1 = gsm(icur_frm, 7) + 1;		% absolute coding, +1 for Matlab
    index2 = index1 + gsm(icur_frm, 8) - 8;	% differential coding 
    index3 = index2 + gsm(icur_frm, 9) - 8;	% diff. c.
    index4 = index3 + gsm(icur_frm, 10) - 8;	% diff. c. 
  
    p(icur_sfrm) = psrLagTbl(index1);
    p(icur_sfrm+1) = psrLagTbl(index2);
    p(icur_sfrm+2) = psrLagTbl(index3);
    p(icur_sfrm+3) = psrLagTbl(index4);
    
  end	% of if voiced/unvoiced

  icur_sfrm = icur_sfrm + 4;

end	% of for
  
p = p / 6;     % division  by os factor