interf_dec.c

ffmpeg源码分析

/*
 * ===================================================================
 *  TS 26.104
 *  REL-5 V5.4.0 2004-03
 *  REL-6 V6.1.0 2004-03
 *  3GPP AMR Floating-point Speech Codec
 * ===================================================================
 *
 */

/*
 * interf_dec.c
 *
 *
 * Project:
 *     AMR Floating-Point Codec
 *
 * Contains:
 *    This module provides means to conversion from 3GPP or ETSI
 *    bitstream to AMR parameters
 */

/*
 * include files
 */
#include <stdlib.h>
#include <stdio.h>
#include <memory.h>
#include "typedef.h"
#include "sp_dec.h"
#include "interf_rom.h"
#include "rom_dec.h"

/*
 * definition of constants
 */
#define EHF_MASK 0x0008 /* encoder homing frame pattern */
typedef

struct
{
   int reset_flag_old;   /* previous was homing frame */


   enum RXFrameType prev_ft;   /* previous frame type */
   enum Mode prev_mode;   /* previous mode */
   void *decoder_State;   /* Points decoder state */


}dec_interface_State;

#ifdef ETSI


/*
 * Bin2Int
 *
 *
 * Parameters:
 *    no_of_bits        I: number of bits associated with value
 *    bits              O: address where bits are written
 *
 * Function:
 *    Read nuber of bits from the array and convert to integer.
 *
 * Returns:
 *    value
 */
static Word16 Bin2Int( Word16 no_of_bits, Word16 *bitstream )
{
   Word32 value, i, bit;


   value = 0;

   for ( i = 0; i < no_of_bits; i++ ) {
      value = value << 1;
      bit = *bitstream++;

      if ( bit == 0x1 )
         value = value + 1;
   }
   return( Word16 )( value );
}


/*
 * Bits2Prm
 *
 *
 * Parameters:
 *    mode              I: AMR mode
 *    bits              I: serial bits
 *    param             O: AMR parameters
 *
 * Function:
 *    Retrieves the vector of encoder parameters from
 *    the received serial bits in a frame.
 *
 * Returns:
 *    void
 */
static void Bits2Prm( enum Mode mode, Word16 bits[], Word16 prm[] )
{
   Word32 i;


   switch ( mode ) {
      case MR122:
         for ( i = 0; i < PRMNO_MR122; i++ ) {
            prm[i] = Bin2Int( bitno_MR122[i], bits );
            bits += bitno_MR122[i];
         }
         break;

      case MR102:
         for ( i = 0; i < PRMNO_MR102; i++ ) {
            prm[i] = Bin2Int( bitno_MR102[i], bits );
            bits += bitno_MR102[i];
         }
         break;

      case MR795:
         for ( i = 0; i < PRMNO_MR795; i++ ) {
            prm[i] = Bin2Int( bitno_MR795[i], bits );
            bits += bitno_MR795[i];
         }
         break;

      case MR74:
         for ( i = 0; i < PRMNO_MR74; i++ ) {
            prm[i] = Bin2Int( bitno_MR74[i], bits );
            bits += bitno_MR74[i];
         }
         break;

      case MR67:
         for ( i = 0; i < PRMNO_MR67; i++ ) {
            prm[i] = Bin2Int( bitno_MR67[i], bits );
            bits += bitno_MR67[i];
         }
         break;

      case MR59:
         for ( i = 0; i < PRMNO_MR59; i++ ) {
            prm[i] = Bin2Int( bitno_MR59[i], bits );
            bits += bitno_MR59[i];
         }
         break;

      case MR515:
         for ( i = 0; i < PRMNO_MR515; i++ ) {
            prm[i] = Bin2Int( bitno_MR515[i], bits );
            bits += bitno_MR515[i];
         }
         break;

      case MR475:
         for ( i = 0; i < PRMNO_MR475; i++ ) {
            prm[i] = Bin2Int( bitno_MR475[i], bits );
            bits += bitno_MR475[i];
         }
         break;

      case MRDTX:
         for ( i = 0; i < PRMNO_MRDTX; i++ ) {
            prm[i] = Bin2Int( bitno_MRDTX[i], bits );
            bits += bitno_MRDTX[i];
         }
         break;
   }
   return;
}

#else

#ifndef IF2

/*
 * DecoderMMS
 *
 *
 * Parameters:
 *    param             O: AMR parameters
 *    stream            I: input bitstream
 *    frame_type        O: frame type
 *    speech_mode       O: speech mode in DTX
 *
 * Function:
 *    AMR file storage format frame to decoder parameters
 *
 * Returns:
 *    mode              used mode
 */
enum Mode DecoderMMS( Word16 *param, UWord8 *stream, enum RXFrameType
                      *frame_type, enum Mode *speech_mode, Word16 *q_bit )
{
   enum Mode mode;
   Word32 j;
   Word16 *mask;


   memset( param, 0, PRMNO_MR122 <<1 );
   *q_bit = 0x01 & (*stream >> 2);
   mode = 0x0F & (*stream >> 3);
   stream++;

   if ( mode == MRDTX ) {
      mask = order_MRDTX;

      for ( j = 1; j < 36; j++ ) {
         if ( *stream & 0x80 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream <<= 1;
         else
            stream++;
      }

      /* get SID type bit */

      *frame_type = RX_SID_FIRST;
      if (*stream & 0x80)
         *frame_type = RX_SID_UPDATE;

      /* since there is update, use it */
      /* *frame_type = RX_SID_UPDATE; */

      /* speech mode indicator */
	  *speech_mode = (*stream >> 4) && 0x07;

   }
   else if ( mode == 15 ) {
      *frame_type = RX_NO_DATA;
   }
   else if ( mode == MR475 ) {
      mask = order_MR475;

      for ( j = 1; j < 96; j++ ) {
         if ( *stream & 0x80 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream <<= 1;
         else
            stream++;
      }
      *frame_type = RX_SPEECH_GOOD;
   }
   else if ( mode == MR515 ) {
      mask = order_MR515;

      for ( j = 1; j < 104; j++ ) {
         if ( *stream & 0x80 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream <<= 1;
         else
            stream++;
      }
      *frame_type = RX_SPEECH_GOOD;
   }
   else if ( mode == MR59 ) {
      mask = order_MR59;

      for ( j = 1; j < 119; j++ ) {
         if ( *stream & 0x80 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream <<= 1;
         else
            stream++;
      }
      *frame_type = RX_SPEECH_GOOD;
   }
   else if ( mode == MR67 ) {
      mask = order_MR67;

      for ( j = 1; j < 135; j++ ) {
         if ( *stream & 0x80 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream <<= 1;
         else
            stream++;
      }
      *frame_type = RX_SPEECH_GOOD;
   }
   else if ( mode == MR74 ) {
      mask = order_MR74;

      for ( j = 1; j < 149; j++ ) {
         if ( *stream & 0x80 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream <<= 1;
         else
            stream++;
      }
      *frame_type = RX_SPEECH_GOOD;
   }
   else if ( mode == MR795 ) {
      mask = order_MR795;

      for ( j = 1; j < 160; j++ ) {
         if ( *stream & 0x80 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream <<= 1;
         else
            stream++;
      }
      *frame_type = RX_SPEECH_GOOD;
   }
   else if ( mode == MR102 ) {
      mask = order_MR102;

      for ( j = 1; j < 205; j++ ) {
         if ( *stream & 0x80 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream <<= 1;
         else
            stream++;
      }
      *frame_type = RX_SPEECH_GOOD;
   }
   else if ( mode == MR122 ) {
      mask = order_MR122;

      for ( j = 1; j < 245; j++ ) {
         if ( *stream & 0x80 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream <<= 1;
         else
            stream++;
      }
      *frame_type = RX_SPEECH_GOOD;
   }
   else
      *frame_type = RX_SPEECH_BAD;
   return mode;
}

#else

/*
 * Decoder3GPP
 *
 *
 * Parameters:
 *    param             O: AMR parameters
 *    stream            I: input bitstream
 *    frame_type        O: frame type
 *    speech_mode       O: speech mode in DTX
 *
 * Function:
 *    Resets state memory
 *
 * Returns:
 *    mode              used mode
 */
enum Mode Decoder3GPP( Word16 *param, UWord8 *stream, enum RXFrameType
                      *frame_type, enum Mode *speech_mode )
{
   enum Mode mode;
   Word32 j;
   Word16 *mask;


   memset( param, 0, PRMNO_MR122 <<1 );
   mode = 0xF & *stream;
   *stream >>= 4;

   if ( mode == MRDTX ) {
      mask = order_MRDTX;

      for ( j = 5; j < 40; j++ ) {
         if ( *stream & 0x1 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream >>= 1;
         else
            stream++;
      }

      /* get SID type bit */

      *frame_type = RX_SID_FIRST;
      if (*stream)
         *frame_type = RX_SID_UPDATE;

      /* since there is update, use it */
      /* *frame_type = RX_SID_UPDATE; */
      stream++;

      /* speech mode indicator */
      *speech_mode = *stream;
   }
   else if ( mode == 15 ) {
      *frame_type = RX_NO_DATA;
   }
   else if ( mode == MR475 ) {
      mask = order_MR475;

      for ( j = 5; j < 100; j++ ) {
         if ( *stream & 0x1 )
            param[ * mask] = ( short )( param[ * mask] + *( mask + 1 ) );
         mask += 2;

         if ( j % 8 )
            *stream >>= 1;
         else
            stream++;
      }
      *frame_type = RX_SPEECH_GOOD;
   }
   else if ( mode == MR515 ) {
      mask = order_MR515;

      for ( j = 5; j < 108; j++ ) {