⭐ 欢迎来到虫虫下载站! | 📦 资源下载 📁 资源专辑 ℹ️ 关于我们
⭐ 虫虫下载站

📄 dec_if.c

📁 ffmpeg源码分析
💻 C
📖 第 1 页 / 共 2 页
字号:
/*
 *===================================================================
 *  3GPP AMR Wideband Floating-point Speech Codec
 *===================================================================
 */
#include <stdlib.h>
#include <memory.h>
#include "typedef.h"
#include "dec_if.h"
#include "if_rom.h"
#include "dec.h"

#define L_FRAME16k   320            /* Frame size at 16kHz  */
#define MODE_7k       0             /* modes                */
#define MODE_9k       1
#define MODE_12k      2
#define MODE_14k      3
#define MODE_16k      4
#define MODE_18k      5
#define MODE_20k      6
#define MODE_23k      7
#define MODE_24k      8
#define MRDTX        10
#define NUM_OF_MODES 11
#define LOST_FRAME   14
#define MRNO_DATA    15
#define EHF_MASK     (Word16)0x0008 /* homing frame pattern */

typedef struct
{
   Word16 reset_flag_old;     /* previous was homing frame  */
   Word16 prev_ft;            /* previous frame type        */
   Word16 prev_mode;          /* previous mode              */
   void *decoder_state;       /* Points decoder state       */
} WB_dec_if_state;

Word16 nb_of_param_first[NUM_OF_SPMODES]=
{
	9,  14, 15,
	15, 15, 19,
	19, 19, 19
};

extern const Word16 mode_7k[];
extern const Word16 mode_9k[];
extern const Word16 mode_12k[];
extern const Word16 mode_14k[];
extern const Word16 mode_16k[];
extern const Word16 mode_18k[];
extern const Word16 mode_20k[];
extern const Word16 mode_23k[];
extern const Word16 mode_24k[];
extern const Word16 mode_DTX[];

extern const Word16 nb_of_param[];

extern const Word16 dfh_M7k[];
extern const Word16 dfh_M9k[];
extern const Word16 dfh_M12k[];
extern const Word16 dfh_M14k[];
extern const Word16 dfh_M16k[];
extern const Word16 dfh_M18k[];
extern const Word16 dfh_M20k[];
extern const Word16 dfh_M23k[];
extern const Word16 dfh_M24k[];

/* overall table with the parameters of the
   decoder homing frames for all modes */

extern const Word16 *dhf[10];

/*
 * Decoder_Interface_Homing_Frame_test
 *
 * Parameters:
 *    input_frame    I: input parameters
 *    mode           I: speech mode
 *
 * Function:
 *    Check parameters for matching homing frame
 *
 * Returns:
 *    If homing frame
 */
Word16 D_IF_homing_frame_test(Word16 input_frame[], Word16 mode)
{

   if (mode != MODE_24k)
   {
      /* perform test for COMPLETE parameter frame */
      return (Word16)!memcmp(input_frame, dhf[mode], nb_of_param[mode] * sizeof(Word16));
   }
   else
   {
      /* discard high-band energy */
      return (Word16)!(
         (memcmp(input_frame, dhf[MODE_24k], 19 * sizeof(Word16))) |
         (memcmp(input_frame + 20, dhf[MODE_24k] + 20, 11 * sizeof(Word16))) |
         (memcmp(input_frame + 32, dhf[MODE_24k] + 32, 11 * sizeof(Word16))) |
         (memcmp(input_frame + 44, dhf[MODE_24k] + 44, 11 * sizeof(Word16))) );

   }
}


Word16 D_IF_homing_frame_test_first(Word16 input_frame[], Word16 mode)
{
   /* perform test for FIRST SUBFRAME of parameter frame ONLY */
   return (Word16)!memcmp(input_frame, dhf[mode], nb_of_param_first[mode] * sizeof(Word16));
}

#ifdef IF2
/*
 * D_IF_conversion
 *
 *
 * Parameters:
 *    param             O: AMR parameters
 *    stream            I: input bitstream
 *    frame_type        O: frame type
 *    speech_mode       O: speech mode in DTX
 *    fqi               O: frame quality indicator
 *
 * Function:
 *    Unpacks IF2 octet stream
 *
 * Returns:
 *    mode              used mode
 */
Word16 D_IF_conversion(Word16 *param, UWord8 *stream, UWord8 *frame_type,
                       Word16 *speech_mode, Word16 *fqi)
{
   Word32 mode;
   Word32 j;
   Word16 const *mask;

   memset(param, 0, PRMNO_24k << 1);
   mode = *stream >> 4;
   /* SID indication IF2 corresponds to mode 10 */
   if (mode == 9)
   {
      mode ++;
   }

   *fqi = (Word16)((*stream >> 3) & 0x1);
   *stream <<= (HEADER_SIZE - 1);

   switch (mode)
   {
   case MRDTX:
      mask = mode_DTX;

      for (j = HEADER_SIZE; j < T_NBBITS_SID; j++)
      {
         if (*stream & 0x80)
         {
            param[*mask] = (Word16)(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;
      }

      *stream <<= 1;

      /* speech mode indicator */
      *speech_mode = (Word16)(*stream >> 4);
      break;

   case MRNO_DATA:
      *frame_type = RX_NO_DATA;
      break;

   case LOST_FRAME:
      *frame_type = RX_SPEECH_LOST;
      break;

   case MODE_7k:
      mask = mode_7k;

      for (j = HEADER_SIZE; j < T_NBBITS_7k; j++)
      {
         if ( *stream & 0x80 )
         {
            param[*mask] = (Word16)(param[*mask] + *(mask + 1));
         }
         mask += 2;

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

      *frame_type = RX_SPEECH_GOOD;
      break;

   case MODE_9k:
      mask = mode_9k;

      for (j = HEADER_SIZE; j < T_NBBITS_9k; j++)
      {
         if (*stream & 0x80)
         {
            param[*mask] = (Word16)(param[*mask] + *(mask + 1));
         }
         mask += 2;

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

      *frame_type = RX_SPEECH_GOOD;
      break;

   case MODE_12k:
      mask = mode_12k;

      for (j = HEADER_SIZE; j < T_NBBITS_12k; j++)
      {
         if (*stream & 0x80)
         {
            param[*mask] = (Word16)(param[*mask] + *(mask + 1));
         }
         mask += 2;

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

      *frame_type = RX_SPEECH_GOOD;
      break;

   case MODE_14k:
      mask = mode_14k;

      for (j = HEADER_SIZE; j < T_NBBITS_14k; j++)
      {
         if (*stream & 0x80)
         {
            param[*mask] = (Word16)(param[*mask] + *(mask + 1));
         }

         mask += 2;

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

      *frame_type = RX_SPEECH_GOOD;
      break;

   case MODE_16k:
      mask = mode_16k;

      for (j = HEADER_SIZE; j < T_NBBITS_16k; j++)
      {
         if (*stream & 0x80)
         {
            param[*mask] = (Word16)(param[*mask] + *(mask + 1));
         }

         mask += 2;

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

      *frame_type = RX_SPEECH_GOOD;
      break;

   case MODE_18k:
      mask = mode_18k;

      for (j = HEADER_SIZE; j < T_NBBITS_18k; j++)
      {
         if (*stream & 0x80)
         {
            param[*mask] = (Word16)(param[*mask] + *(mask + 1));
         }

         mask += 2;

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

      *frame_type = RX_SPEECH_GOOD;
      break;

   case MODE_20k:
      mask = mode_20k;

      for (j = HEADER_SIZE; j < T_NBBITS_20k; j++)
      {
         if (*stream & 0x80)
         {
            param[*mask] = (Word16)(param[*mask] + *(mask + 1));
         }

         mask += 2;

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

      *frame_type = RX_SPEECH_GOOD;
      break;

   case MODE_23k:
      mask = mode_23k;

      for (j = HEADER_SIZE; j < T_NBBITS_23k; j++)
      {
         if (*stream & 0x80)
         {
            param[*mask] = (Word16)(param[*mask] + *(mask + 1));
         }

         mask += 2;

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

      }

      *frame_type = RX_SPEECH_GOOD;
      break;

   case MODE_24k:
      mask = mode_24k;

      for (j = HEADER_SIZE; j < T_NBBITS_24k; j++)
      {
         if (*stream & 0x80)
         {
            param[*mask] = (Word16)(param[*mask] + *(mask + 1));
         }

         mask += 2;

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

      }

      *frame_type = RX_SPEECH_GOOD;
      break;

   default:
      *frame_type = RX_SPEECH_LOST;
      *fqi = 0;
      break;

   }

   if (*fqi == 0)
   {
      if (*frame_type == RX_SPEECH_GOOD)
      {
         *frame_type = RX_SPEECH_BAD;
      }
      if ((*frame_type == RX_SID_FIRST) | (*frame_type == RX_SID_UPDATE))
      {
         *frame_type = RX_SID_BAD;
      }
   }

   return (Word16)mode;
}

#else

/*
 * D_IF_mms_conversion
 *
 *
 * Parameters:
 *    param             O: AMR parameters
 *    stream            I: input bitstream
 *    frame_type        O: frame type
 *    speech_mode       O: speech mode in DTX
 *    fqi               O: frame quality indicator
 *
 * Function:
 *    Unpacks MMS formatted octet stream (see RFC 3267, section 5.3)
 *
 * Returns:
 *    mode              used mode
 */
Word16 D_IF_mms_conversion(Word16 *param, UWord8 *stream, UWord8 *frame_type,
                           Word16 *speech_mode, Word16 *fqi)
{
   Word32 mode;
   Word32 j;
   Word16 const *mask;

   memset(param, 0, PRMNO_24k << 1);

   *fqi = (Word16)((*stream >> 2) & 0x01);
   mode = (Word32)((*stream >> 3) & 0x0F);

   /* SID indication IF2 corresponds to mode 10 */
   if (mode == 9)
   {
      mode ++;
   }

   stream++;

   switch (mode)
   {
   case MRDTX:
      mask = mode_DTX;

      for (j = 1; j <= NBBITS_SID; j++)
      {

⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -