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 speex_decode_stereo(float *data, int frame_size, SpeexStereoState *_stereo) { int i; spx_word32_t balance; spx_word16_t e_left, e_right, e_ratio; RealSpeexStereoState *stereo = (RealSpeexStereoState*)_stereo; COMPATIBILITY_HACK(stereo); balance=stereo->balance; e_ratio=stereo->e_ratio; /* These two are Q14, with max value just below 2. */ e_right = DIV32(QCONST32(1., 22), spx_sqrt(MULT16_32_Q15(e_ratio, ADD32(QCONST32(1., 16), balance)))); e_left = SHR32(MULT16_16(spx_sqrt(balance), e_right), 8); for (i=frame_size-1;i>=0;i--) { spx_word16_t tmp=data[i]; stereo->smooth_left = EXTRACT16(PSHR32(MAC16_16(MULT16_16(stereo->smooth_left, QCONST16(0.98, 15)), e_left, QCONST16(0.02, 15)), 15)); stereo->smooth_right = EXTRACT16(PSHR32(MAC16_16(MULT16_16(stereo->smooth_right, QCONST16(0.98, 15)), e_right, QCONST16(0.02, 15)), 15)); data[2*i] = (float)MULT16_16_P14(stereo->smooth_left, tmp); data[2*i+1] = (float)MULT16_16_P14(stereo->smooth_right, tmp); } }