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Text File  |  2002-10-03  |  4.3 KB  |  133 lines
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  4. ddddmmmmGGGGSSSSMMMMDDDDeeeeccccooooddddeeee((((3333ddddmmmm))))                                              ddddmmmmGGGGSSSSMMMMDDDDeeeeccccooooddddeeee((((3333ddddmmmm))))
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  8. NNNNAAAAMMMMEEEE
  9.      dmGSMDecode - implements the European GSM 06.10 provisional standard for
  10.      full-rate speech transcoding, prI-ETS 300 036, which uses RPE/LTP
  11.      (regular pulse excitation/long term prediction) coding at 13 kbit/s.
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  14. SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
  15.      ####iiiinnnncccclllluuuuddddeeee <<<<ddddmmmmeeeeddddiiiiaaaa////ddddmmmm____aaaauuuuddddiiiioooouuuuttttiiiillll....hhhh>>>>
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  17.      DDDDMMMMssssttttaaaattttuuuussss ddddmmmmGGGGSSSSMMMMDDDDeeeeccccooooddddeeee((((DDDDMMMMGGGGSSSSMMMMddddeeeeccccooooddddeeeerrrr hhhhaaaannnnddddlllleeee,,,,
  18.                           uuuunnnnssssiiiiggggnnnneeeedddd cccchhhhaaaarrrr ****iiiibbbbuuuuffff,,,, sssshhhhoooorrrrtttt ****oooobbbbuuuuffff,,,, iiiinnnntttt nnnnuuuummmmSSSSaaaammmmpppplllleeeessss))))
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  21. PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRR
  22.      _h_a_n_d_l_e    DDDDMMMMGGGGSSSSMMMMddddeeeeccccooooddddeeeerrrr structure, created by ddddmmmmGGGGSSSSMMMMDDDDeeeeccccooooddddeeeerrrrCCCCrrrreeeeaaaatttteeee((((3333ddddmmmm)))),
  23.                specifies the signal processing parameters.
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  26.      _i_b_u_f      pointer to input compressed data buffer, an array of a multiple
  27.                of 33 bytes. The data format is unsigned char (8-bit).
  28.  
  29.  
  30.      _o_b_u_f      pointer to output sample data buffer, an array of size of a
  31.                multiple of 160.  The data format is short (16-bit).  The
  32.                samples are assumed to be two's complement.  The sampling rate
  33.                must be 8 kHz.
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  36.      _n_u_m_S_a_m_p_l_e_s
  37.                number of sample in the output buffer to be generated.  the
  38.                value of numSamples passed to the GSM decode/decode routines
  39.                must always be a multiple of 160.  The compressed bitstrem
  40.                buffer consists of a multiple of 33 bytes.
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  43. RRRREEEETTTTUUUURRRRNNNNEEEEDDDD VVVVAAAALLLLUUUUEEEE
  44.      Returns DDDDMMMM____FFFFAAAAIIIILLLLUUUURRRREEEE or DDDDMMMM____SSSSUUUUCCCCCCCCEEEESSSSSSSS.
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  47. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
  48.      ddddmmmmGGGGSSSSMMMMDDDDeeeeccccooooddddeeee((((3333ddddmmmm)))) implements the GSM 06.10 decompression.
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  52. NNNNOOOOTTTTEEEE
  53.      The compressed bitrate now is 13200 bits/s.  This is not the same as
  54.      standard specification of 13000 bits/s because the first 4 bits of each
  55.      33 byte are not useful information bits.  This bits arrangement was
  56.      adopted using the original scheme by Jutta Degener (jutta@cs.tu-
  57.      berlin.de) and Carsten Bormann (cabo@cs.tu-berlin.de), Communications and
  58.      Operating Systems Research Group, TU Berlin for compatibility with
  59.      typical UNIX applications.  And may be modify later.
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  63.                                                                         PPPPaaaaggggeeee 1111
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  70. ddddmmmmGGGGSSSSMMMMDDDDeeeeccccooooddddeeee((((3333ddddmmmm))))                                              ddddmmmmGGGGSSSSMMMMDDDDeeeeccccooooddddeeee((((3333ddddmmmm))))
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  73.  
  74.      GSM algorithm was developed for sampling rate of 8 kHz.
  75.  
  76.  
  77. SSSSEEEEEEEE AAAALLLLSSSSOOOO
  78.      dmGSMDecoderCreate(3dm), dmGSMDecoderDestroy(3dm), dmGSMEncode(3dm), ETSI
  79.      GSM 06.10 standard.
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  129.                                                                         PPPPaaaaggggeeee 2222
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