c_stereo.h

关于AMR-WB+语音压缩编码的实现代码

/*-----------------------------------------------------------------*
 * Function coder_stereo                                            *
 * ~~~~~~~~~~~~~~~~~~~~                                            *
 *   ->Principle stereo coder routine (working at fs=12.8kHz).     *
 *                                                                 *
 * Note: HF band are encoded twice (2 channels) using 0.8kbps BWE. *
 *       Usage of 2xBWE for stereo provide better time domain      *
 *       stereo definition in HF without increasing the bit-rate.  *
 *       Another advantage is that the stereo decoder is limited   *
 *       to the lower band (fs=12.8kHz) and this reduce the        *
 *       overall complexity of the AMR-WB+ codec.  Also, this      *
 *       solution is not dependent of the AMR-WB+ mode where many  *
 *       different sampling frequencies are used (16, 24, 32 kHz). *
 *-----------------------------------------------------------------*/

#ifdef E_STEREO_2
void coder_stereo(float speech_hi[],    /* (i) : Mixed channel, hi */
                  float chan_hi[],      /* (i) : Right channel, hi */
                  float speech_2k[],    /* (i) : Mixed channel, lo */
                  float chan_2k[],      /* (i) : Right channel, lo */
                  int param[],  /* (o) : Encoded parameters */
                  int brMode, short d_tcx_serial[], Coder_State_Plus * st);  /* (i/o): Encoder states */
#else
void coder_stereo(float side_speech[],  /* (i) : L-R channel part (fs=12.8kHz) */
                  float speech[],       /* (i) : right channel part (fs=12.8kHz) */
                  float synth[], short param[], /* (o) : parameters */
                  float window[], Coder_State_Plus * st);    /* i/o : coder memory state */
#endif

/*-----------------------------------------------------------------*
 * Function  init_coder_stereo                                      *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~                                      *
 *   ->Initialization of variables for the stereo coder.           *
 *-----------------------------------------------------------------*/
void init_coder_stereo(Coder_State_Plus * st);       /* (i/o) : Encoder states. */

/*-----------------------------------------------------------------*
 * Function  end_prm_stereo									       *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~                                      *
 *   ->Encoding of stereo parameters.					           *
 *-----------------------------------------------------------------*/

void enc_prm_stereo(int param[],        /* (i) : parameters */
                    short serial[],     /* (o) : serial bits stream */
                    int nbits_pack      /* (i) : number of bits per packet of 20ms */
    );

/*-------------------------------------------------------------------*
 * Function  band_split												 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~										 *
 *   ->	Routine for splitting one frame into one high-frequency part *	
 *		and one low-frequency part.									 *
 *-------------------------------------------------------------------*/

void band_split(float *x_fb,    /* (i) : Full-band samples */
                float *x_hb,    /* (o) : Hi-band samples */
                float *x_lb,    /* (o) : Low-band samples */
                float *h,       /* (i) : Filter coefficients */
                int ncoeff      /* (i) : Number of filter coefficients */
    );

/*-------------------------------------------------------------------*
 * Function  lo_filt_design											 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~										 *
 *   ->	Design of Wiener filters for left/right channel for low-	 *
 *		frequency band (below 1 kHz). 								 *
 *-------------------------------------------------------------------*/

void lo_filt_design(float *spR, /* (i) : Speech input (R) */
                    float *spM, /* (i) : Speech input (M) */
                    float *filt_lo,     /* (o) : Filter coeff output */
                    Coder_State_Plus * st    /* (i/o): Filter states */
    );

/*-------------------------------------------------------------------*
 * Function  hi_filt_design											 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~										 *
 *   ->	Design of Wiener filters for left/right channel for hi-	 *
 *		frequency band (above 1 kHz). 								 *
 *-------------------------------------------------------------------*/

void hi_filt_design(float *spR, /* (i) : Speech input (R) */
                    float *spM, /* (i) : Speech input (M) */
                    float *filt_hi,     /* (o) : Filter coeff output */
                    Coder_State_Plus * st    /* (i/o): Filter states */
    );