sp_enc.cpp

实现3GPP的GSM中AMR语音的CODECS。

 Local Variables Needed:
    None.

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 This function frees the memory used for state memory.

------------------------------------------------------------------------------
 REQUIREMENTS

 None.

------------------------------------------------------------------------------
 REFERENCES

 sp_enc.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE

 Note: Original function name of Speech_Encode_Frame_exit was changed to
       GSMEncodeFrameExit in the Code section.

void Speech_Encode_Frame_exit (void **state_data)
{

    Speech_Encode_FrameState **state =
        (Speech_Encode_FrameState **) state_data;

  if (state == NULL || *state == NULL)
      return;

  Pre_Process_exit(&(*state)->pre_state);
  cod_amr_exit(&(*state)->cod_amr_state);

  setCounter((*state)->complexityCounter);
  WMOPS_output(0);
  setCounter(0); // set counter to global counter

  // deallocate memory
  free(*state);
  *state = NULL;

  return;
}

------------------------------------------------------------------------------
 RESOURCES USED [optional]

 When the code is written for a specific target processor the
 the resources used should be documented below.

 HEAP MEMORY USED: x bytes

 STACK MEMORY USED: x bytes

 CLOCK CYCLES: (cycle count equation for this function) + (variable
                used to represent cycle count for each subroutine
                called)
     where: (cycle count variable) = cycle count for [subroutine
                                     name]

------------------------------------------------------------------------------
 CAUTION [optional]
 [State any special notes, constraints or cautions for users of this function]

------------------------------------------------------------------------------
*/

void GSMEncodeFrameExit(void **state_data)
{

    Speech_Encode_FrameState **state =
        (Speech_Encode_FrameState **) state_data;

    if (state == NULL || *state == NULL)
        return;

    Pre_Process_exit(&(*state)->pre_state);
    cod_amr_exit(&(*state)->cod_amr_state);

    /* deallocate memory */
    oscl_free(*state);
    *state = NULL;

    return;
}

/****************************************************************************/

/*
------------------------------------------------------------------------------
 FUNCTION NAME: Speech_Encode_Frame_First
------------------------------------------------------------------------------

 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    st = pointer to a structure of type Speech_Encode_FrameState that contains
            the post filter states
    new_speech = pointer to buffer of length L_FRAME that contains
                 the speech input (Word16)

 Outputs:
    The structure of type Speech_Encode_FrameState pointed to by st is updated.

 Returns:
    return_value = 0 (int)

 Global Variables Used:
    None.

 Local Variables Needed:
    None.

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 This function encodes the first frame of speech. It calls the pre-processing
 filter and the first frame encoder.

------------------------------------------------------------------------------
 REQUIREMENTS

 None.

------------------------------------------------------------------------------
 REFERENCES

 sp_enc.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE

int Speech_Encode_Frame_First (
    Speech_Encode_FrameState *st,  // i/o : post filter states
    Word16 *new_speech)            // i   : speech input
{
#if !defined(NO13BIT)
   Word16 i;
#endif

   setCounter(st->complexityCounter);

#if !defined(NO13BIT)
  // Delete the 3 LSBs (13-bit input)
  for (i = 0; i < L_NEXT; i++)
  {
     new_speech[i] = new_speech[i] & 0xfff8;
  }
#endif

  // filter + downscaling
  Pre_Process (st->pre_state, new_speech, L_NEXT);

  cod_amr_first(st->cod_amr_state, new_speech);

  Init_WMOPS_counter (); // reset WMOPS counter for the new frame

  return 0;
}


------------------------------------------------------------------------------
 RESOURCES USED [optional]

 When the code is written for a specific target processor the
 the resources used should be documented below.

 HEAP MEMORY USED: x bytes

 STACK MEMORY USED: x bytes

 CLOCK CYCLES: (cycle count equation for this function) + (variable
                used to represent cycle count for each subroutine
                called)
     where: (cycle count variable) = cycle count for [subroutine
                                     name]

------------------------------------------------------------------------------
 CAUTION [optional]
 [State any special notes, constraints or cautions for users of this function]

------------------------------------------------------------------------------
*/

void Speech_Encode_Frame_First(
    Speech_Encode_FrameState *st,  /* i/o : post filter states       */
    Word16 *new_speech)            /* i   : speech input             */
{
#if !defined(NO13BIT)
    Word16 i;
#endif

#if !defined(NO13BIT)
    /* Delete the 3 LSBs (13-bit input) */
    for (i = 0; i < L_NEXT; i++)
    {
        new_speech[i] = new_speech[i] & 0xfff8;
    }
#endif

    /* filter + downscaling */
    Pre_Process(st->pre_state, new_speech, L_NEXT);

    cod_amr_first(st->cod_amr_state, new_speech);

    return;
}

/*
------------------------------------------------------------------------------
 FUNCTION NAME: cod_amr
------------------------------------------------------------------------------
 INPUT AND OUTPUT DEFINITIONS

 Inputs:
    state_data = a void pointer to the post filter states
    mode = AMR mode of type enum Mode
    new_speech = pointer to buffer of length L_FRAME that contains
             the speech input of type Word16
    serial = pointer to the serial bit stream of type Word16
    usedMode = pointer to the used mode of type enum Mode

 Outputs:
    serial -> encoded serial bit stream
    The value pointed to by usedMode is updated.

 Returns:
    return_value = 0 (int)

 Global Variables Used:
    None.

 Local Variables Needed:
    None.

------------------------------------------------------------------------------
 FUNCTION DESCRIPTION

 This function is the entry point to the GSM AMR encoder. The following
 operations are performed to generate one encoded frame: First, the incoming
 audio samples are passed through the pre-processing filter where they are
 filtered and downscaled. A call is then made to the main encoder cod_amr().
 This generates the set of encoded parameters which include the LSP, adaptive
 codebook, and fixed codebook quantization indices (addresses and gains). The
 generated parameters are then converted to serial bits.

------------------------------------------------------------------------------
 REQUIREMENTS

 None.

------------------------------------------------------------------------------
 REFERENCES

 sp_enc.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001

------------------------------------------------------------------------------
 PSEUDO-CODE
 Note: Original function name of Speech_Encode_Frame was changed to
       GSMEncodeFrame in the Code section.

int Speech_Encode_Frame (
    void *state_data,             // i/o : post filter states
    enum Mode mode,               // i   : speech coder mode
    Word16 *new_speech,           // i   : speech input
    Word16 *serial,               // o   : serial bit stream
    enum Mode *usedMode           // o   : used speech coder mode
    )
{

  Speech_Encode_FrameState *st =
     (Speech_Encode_FrameState *) state_data;

  Word16 prm[MAX_PRM_SIZE];   // Analysis parameters
  Word16 syn[L_FRAME];        // Buffer for synthesis speech
  Word16 i;

  setCounter(st->complexityCounter);
  Reset_WMOPS_counter (); // reset WMOPS counter for the new frame
  // initialize the serial output frame to zero
  for (i = 0; i < MAX_SERIAL_SIZE; i++)
  {
    serial[i] = 0;
  }
#if !defined(NO13BIT)
  // Delete the 3 LSBs (13-bit input)
  for (i = 0; i < L_FRAME; i++)
  {
     new_speech[i] = new_speech[i] & 0xfff8;


  }
#endif

  // filter + downscaling
  Pre_Process (st->pre_state, new_speech, L_FRAME);

  // Call the speech encoder
  cod_amr(st->cod_amr_state, mode, new_speech, prm, usedMode, syn);

  // Parameters to serial bits
  Prm2bits (*usedMode, prm, &serial[0]);

  fwc();
  setCounter(0); // set counter to global counter

  return 0;
}

------------------------------------------------------------------------------
 RESOURCES USED [optional]

 When the code is written for a specific target processor the
 the resources used should be documented below.

 HEAP MEMORY USED: x bytes

 STACK MEMORY USED: x bytes

 CLOCK CYCLES: (cycle count equation for this function) + (variable
                used to represent cycle count for each subroutine
                called)
     where: (cycle count variable) = cycle count for [subroutine
                                     name]

------------------------------------------------------------------------------
 CAUTION [optional]
 [State any special notes, constraints or cautions for users of this function]

------------------------------------------------------------------------------
*/

void GSMEncodeFrame(
    void *state_data,             /* i/o : post filter states          */
    enum Mode mode,               /* i   : speech coder mode           */
    Word16 *new_speech,           /* i   : speech input                */
    Word16 *serial,               /* o   : serial bit stream           */
    enum Mode *usedMode           /* o   : used speech coder mode      */
)
{

    Speech_Encode_FrameState *st =
        (Speech_Encode_FrameState *) state_data;

    Word16 prm[MAX_PRM_SIZE];   /* Analysis parameters.                 */
    Word16 syn[L_FRAME];        /* Buffer for synthesis speech          */
    Word16 i;

    /* initialize the serial output frame to zero */
    for (i = 0; i < MAX_SERIAL_SIZE; i++)
    {
        serial[i] = 0;
    }
#if !defined(NO13BIT)
    /* Delete the 3 LSBs (13-bit input) */
    for (i = 0; i < L_FRAME; i++)
    {
        new_speech[i] = new_speech[i] & 0xfff8;
    }
#endif

    /* filter + downscaling */
    Pre_Process(st->pre_state, new_speech, L_FRAME);

    /* Call the speech encoder */
    cod_amr(st->cod_amr_state, mode, new_speech, prm, usedMode, syn);

    /* Parameters to serial bits */
    Prm2bits(*usedMode, prm, &serial[0]);

    return;
}