自学教程：C++ speex_bits_unpack_unsigned函数代码示例

EXPORT int speex_std_stereo_request_handler(SpeexBits * bits, void *state,					    void *data){	(void)state;	RealSpeexStereoState *stereo;	spx_word16_t sign = 1, dexp;	int tmp;	stereo = (RealSpeexStereoState *) data;	COMPATIBILITY_HACK(stereo);	if (speex_bits_unpack_unsigned(bits, 1))		sign = -1;	dexp = speex_bits_unpack_unsigned(bits, 5);#ifndef FIXED_POINT	stereo->balance = exp(sign * .25 * dexp);#else	stereo->balance = spx_exp(MULT16_16(sign, SHL16(dexp, 9)));#endif	tmp = speex_bits_unpack_unsigned(bits, 2);	stereo->e_ratio = e_ratio_quant[tmp];	return 0;}

void lsp_unquant_nb(spx_lsp_t *lsp, int order, SpeexBits *bits){   int i, id;   for (i=0;i<order;i++)      lsp[i]=LSP_LINEAR(i);   id=speex_bits_unpack_unsigned(bits, 6);   for (i=0;i<10;i++)      lsp[i] = ADD32(lsp[i], LSP_DIV_256(cdbk_nb[id*10+i]));   id=speex_bits_unpack_unsigned(bits, 6);   for (i=0;i<5;i++)      lsp[i] = ADD16(lsp[i], LSP_DIV_512(cdbk_nb_low1[id*5+i]));   id=speex_bits_unpack_unsigned(bits, 6);   for (i=0;i<5;i++)      lsp[i] = ADD32(lsp[i], LSP_DIV_1024(cdbk_nb_low2[id*5+i]));   id=speex_bits_unpack_unsigned(bits, 6);   for (i=0;i<5;i++)      lsp[i+5] = ADD32(lsp[i+5], LSP_DIV_512(cdbk_nb_high1[id*5+i]));      id=speex_bits_unpack_unsigned(bits, 6);   for (i=0;i<5;i++)      lsp[i+5] = ADD32(lsp[i+5], LSP_DIV_1024(cdbk_nb_high2[id*5+i]));}

void split_cb_shape_sign_unquant(spx_sig_t *exc,const void *par,                      /* non-overlapping codebook */int   nsf,                      /* number of samples in subframe */SpeexBits *bits,char *stack,spx_int32_t *seed){   int i,j;   VARDECL(int *ind);   VARDECL(int *signs);   const signed char *shape_cb;   //int shape_cb_size;   int subvect_size, nb_subvect;   const split_cb_params *params;   int have_sign;   params = (const split_cb_params *) par;   subvect_size = params->subvect_size;   nb_subvect = params->nb_subvect;   //shape_cb_size = 1<<params->shape_bits;   shape_cb = params->shape_cb;   have_sign = params->have_sign;   ALLOC(ind, nb_subvect, int);   ALLOC(signs, nb_subvect, int);   /* Decode codewords and gains */   for (i=0;i<nb_subvect;i++)   {      if (have_sign)         signs[i] = speex_bits_unpack_unsigned(bits, 1);      else         signs[i] = 0;      ind[i] = speex_bits_unpack_unsigned(bits, params->shape_bits);   }   /* Compute decoded excitation */   for (i=0;i<nb_subvect;i++)   {      spx_word16_t s=1;      if (signs[i])         s=-1;#ifdef FIXED_POINT      if (s==1)      {         for (j=0;j<subvect_size;j++)            exc[subvect_size*i+j]=SHL32(EXTEND32(shape_cb[ind[i]*subvect_size+j]),SIG_SHIFT-5);      } else {         for (j=0;j<subvect_size;j++)            exc[subvect_size*i+j]=NEG32(SHL32(EXTEND32(shape_cb[ind[i]*subvect_size+j]),SIG_SHIFT-5));      }#else      for (j=0;j<subvect_size;j++)         exc[subvect_size*i+j]+=s*0.03125*shape_cb[ind[i]*subvect_size+j];      #endif   }}

int speex_std_vbr_quality_request_handler(SpeexBits *bits, void *state, void *data){   int qual;   qual = speex_bits_unpack_unsigned(bits, 4);   speex_encoder_ctl(data, SPEEX_SET_VBR_QUALITY, &qual);   return 0;}

int speex_std_enh_request_handler(SpeexBits *bits, void *state, void *data){   int enh;   enh = speex_bits_unpack_unsigned(bits, 1);   speex_decoder_ctl(data, SPEEX_SET_ENH, &enh);   return 0;}

int speex_std_high_mode_request_handler(SpeexBits *bits, void *state, void *data){   int m;   m = speex_bits_unpack_unsigned(bits, 4);   speex_encoder_ctl(data, SPEEX_SET_HIGH_MODE, &m);   return 0;}

int speex_std_char_handler(SpeexBits *bits, void *state, void *data){   unsigned char ch;   ch = speex_bits_unpack_unsigned(bits, 8);   _speex_putc(ch, data);   return 0;}

EXPORT int speex_std_low_mode_request_handler(SpeexBits *bits, void *state, void *data){   spx_int32_t m;   m = speex_bits_unpack_unsigned(bits, 4);   speex_encoder_ctl(data, SPEEX_SET_LOW_MODE, &m);   return 0;}

int speex_std_vbr_request_handler(SpeexBits *bits, void *state, void *data){   int vbr;   vbr = speex_bits_unpack_unsigned(bits, 1);   speex_encoder_ctl(data, SPEEX_SET_VBR, &vbr);   return 0;}

int speex_inband_handler(SpeexBits *bits, SpeexCallback *callback_list, void *state){   int id;   SpeexCallback *callback;   /*speex_bits_advance(bits, 5);*/   id=speex_bits_unpack_unsigned(bits, 4);   callback = callback_list+id;   if (callback->func)   {      return callback->func(bits, state, callback->data);   } else      /*If callback is not registered, skip the right number of bits*/   {      int adv;      if (id<2)         adv = 1;      else if (id<8)         adv = 4;      else if (id<10)         adv = 8;      else if (id<12)         adv = 16;      else if (id<14)         adv = 32;      else          adv = 64;      speex_bits_advance(bits, adv);   }   return 0;}

int speex_std_char_handler(SpeexBits *bits, void *state, void *data){   unsigned char ch;   ch = speex_bits_unpack_unsigned(bits, 8);   _speex_putc(ch, data);   /*printf("speex_std_char_handler ch=%x/n", ch);*/   return 0;}

void lsp_unquant_high(spx_lsp_t *lsp, int order, SpeexBits *bits){   int i, id;   for (i=0;i<order;i++)      lsp[i]=LSP_LINEAR_HIGH(i);   id=speex_bits_unpack_unsigned(bits, 6);   for (i=0;i<order;i++)      lsp[i] += LSP_DIV_256(high_lsp_cdbk[id*order+i]);   id=speex_bits_unpack_unsigned(bits, 6);   for (i=0;i<order;i++)      lsp[i] += LSP_DIV_512(high_lsp_cdbk2[id*order+i]);}

int speex_std_stereo_request_handler(SpeexBits *bits, void *state, void *data){   SpeexStereoState *stereo;   float sign=1;   int tmp;   stereo = (SpeexStereoState*)data;   if (speex_bits_unpack_unsigned(bits, 1))      sign=-1;   tmp = speex_bits_unpack_unsigned(bits, 5);   stereo->balance = exp(sign*.25*tmp);   tmp = speex_bits_unpack_unsigned(bits, 2);   stereo->e_ratio = e_ratio_quant[tmp];   return 0;}

/* This function will iterate frames & submodes in the Speex bits. * Returns 0 if a frame found, otherwise returns -1. */int speex_get_next_frame(SpeexBits *bits){    static const int inband_skip_table[NB_SUBMODES] =       {1, 1, 4, 4, 4, 4, 4, 4, 8, 8, 16, 16, 32, 32, 64, 64 };    static const int wb_skip_table[SB_SUBMODES] =       {SB_SUBMODE_BITS+1, 36, 112, 192, 352, -1, -1, -1};    unsigned submode;    unsigned nb_count = 0;    while (speex_bits_remaining(bits) >= 5) {	unsigned wb_count = 0;	unsigned bit_ptr = bits->bitPtr;	unsigned char_ptr = bits->charPtr;	/* WB frame */	while ((speex_bits_remaining(bits) >= 4)	    && speex_bits_unpack_unsigned(bits, 1))	{	    int advance;	    submode = speex_bits_unpack_unsigned(bits, 3);	    advance = wb_skip_table[submode];	    if (advance < 0) {		TRACE__((THIS_FUNC, "Invalid mode encountered. "			 "The stream is corrupted."));		return -1;	    } 	    TRACE__((THIS_FUNC, "WB layer skipped: %d bits", advance));	    advance -= (SB_SUBMODE_BITS+1);	    speex_bits_advance(bits, advance);	    bit_ptr = bits->bitPtr;	    char_ptr = bits->charPtr;	    /* Consecutive subband frames may not exceed 2 frames */	    if (++wb_count > 2)		return -1;	}	/* End of bits, return the frame */	if (speex_bits_remaining(bits) < 4) {	    TRACE__((THIS_FUNC, "End of stream"));	    return 0;	}	/* Stop iteration, return the frame */	if (nb_count > 0) {	    bits->bitPtr = bit_ptr;	    bits->charPtr = char_ptr;	    return 0;	}	/* Get control bits */	submode = speex_bits_unpack_unsigned(bits, 4);	TRACE__((THIS_FUNC, "Control bits: %d at %d", 		 submode, bits->charPtr*8+bits->bitPtr));	if (submode == 15) {	    TRACE__((THIS_FUNC, "Found submode: terminator"));	    return -1;	} else if (submode == 14) {	    /* in-band signal; next 4 bits contain signal id */	    submode = speex_bits_unpack_unsigned(bits, 4);	    TRACE__((THIS_FUNC, "Found submode: in-band %d bits", 		     inband_skip_table[submode]));	    speex_bits_advance(bits, inband_skip_table[submode]);	} else if (submode == 13) {	    /* user in-band; next 5 bits contain msg len */	    submode = speex_bits_unpack_unsigned(bits, 5);	    TRACE__((THIS_FUNC, "Found submode: user-band %d bytes", submode));	    speex_bits_advance(bits, submode * 8);	} else if (submode > 8) {	    TRACE__((THIS_FUNC, "Unknown sub-mode %d", submode));	    return -1;	} else {	    /* NB frame */	    unsigned int advance = submode;	    speex_mode_query(&speex_nb_mode, SPEEX_SUBMODE_BITS_PER_FRAME, &advance);	    if (advance < 0) {		TRACE__((THIS_FUNC, "Invalid mode encountered. "			 "The stream is corrupted."));		return -1;	    }	    TRACE__((THIS_FUNC, "Submode %d: %d bits", submode, advance));	    advance -= (NB_SUBMODE_BITS+1);	    speex_bits_advance(bits, advance);	    ++nb_count;	}    }    return 0;}

void pitch_unquant_3tap(    spx_sig_t exc[],                    /* Excitation */    int   start,                    /* Smallest pitch value allowed */    int   end,                      /* Largest pitch value allowed */    spx_word16_t pitch_coef,               /* Voicing (pitch) coefficient */    const void *par,    int   nsf,                      /* Number of samples in subframe */    int *pitch_val,    spx_word16_t *gain_val,    SpeexBits *bits,    char *stack,    int count_lost,    int subframe_offset,    spx_word16_t last_pitch_gain,    int cdbk_offset){    int i;    int pitch;    int gain_index;    spx_word16_t gain[3];    const signed char *gain_cdbk;    int gain_cdbk_size;    const ltp_params *params;    params = (const ltp_params*) par;    gain_cdbk_size = 1<<params->gain_bits;    gain_cdbk = params->gain_cdbk + 3*gain_cdbk_size*cdbk_offset;    pitch = speex_bits_unpack_unsigned(bits, params->pitch_bits);    pitch += start;    gain_index = speex_bits_unpack_unsigned(bits, params->gain_bits);    /*printf ("decode pitch: %d %d/n", pitch, gain_index);*/#ifdef FIXED_POINT    gain[0] = 32+(spx_word16_t)gain_cdbk[gain_index*3];    gain[1] = 32+(spx_word16_t)gain_cdbk[gain_index*3+1];    gain[2] = 32+(spx_word16_t)gain_cdbk[gain_index*3+2];#else    gain[0] = 0.015625*gain_cdbk[gain_index*3]+.5;    gain[1] = 0.015625*gain_cdbk[gain_index*3+1]+.5;    gain[2] = 0.015625*gain_cdbk[gain_index*3+2]+.5;#endif    if (count_lost && pitch > subframe_offset)    {        float gain_sum;        if (1) {            float tmp = count_lost < 4 ? GAIN_SCALING_1*last_pitch_gain : 0.4 * GAIN_SCALING_1 * last_pitch_gain;            if (tmp>.95)                tmp=.95;            gain_sum = GAIN_SCALING_1*gain_3tap_to_1tap(gain);            if (gain_sum > tmp) {                float fact = tmp/gain_sum;                for (i=0; i<3; i++)                    gain[i]*=fact;            }        }    }    *pitch_val = pitch;    gain_val[0]=gain[0];    gain_val[1]=gain[1];    gain_val[2]=gain[2];    {        spx_sig_t *e[3];        VARDECL(spx_sig_t *tmp2);        ALLOC(tmp2, 3*nsf, spx_sig_t);        e[0]=tmp2;        e[1]=tmp2+nsf;        e[2]=tmp2+2*nsf;        for (i=0; i<3; i++)        {            int j;            int pp=pitch+1-i;#if 0            for (j=0; j<nsf; j++)            {                if (j-pp<0)                    e[i][j]=exc[j-pp];                else if (j-pp-pitch<0)                    e[i][j]=exc[j-pp-pitch];                else                    e[i][j]=0;            }#else            {                int tmp1, tmp3;                tmp1=nsf;                if (tmp1>pp)                    tmp1=pp;                for (j=0; j<tmp1; j++)                    e[i][j]=exc[j-pp];                tmp3=nsf;                if (tmp3>pp+pitch)//.........这里部分代码省略.........

/* Default handler for user callbacks: skip it */int speex_default_user_handler(SpeexBits *bits, void *state, void *data){   int req_size = speex_bits_unpack_unsigned(bits, 4);   speex_bits_advance(bits, 5+8*req_size);   return 0;}