diff options
Diffstat (limited to 'pjmedia/src/pjmedia-codec/speex/stereo.c')
| -rw-r--r-- | pjmedia/src/pjmedia-codec/speex/stereo.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/pjmedia/src/pjmedia-codec/speex/stereo.c b/pjmedia/src/pjmedia-codec/speex/stereo.c new file mode 100644 index 00000000..f18387e5 --- /dev/null +++ b/pjmedia/src/pjmedia-codec/speex/stereo.c @@ -0,0 +1,192 @@ +/* Copyright (C) 2002 Jean-Marc Valin + File: stereo.c + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + + - Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + + - Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + - Neither the name of the Xiph.org Foundation nor the names of its + contributors may be used to endorse or promote products derived from + this software without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR + CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, + EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +*/ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <speex/speex_stereo.h> +#include <speex/speex_callbacks.h> +#include "vq.h" +#include <math.h> + +/*float e_ratio_quant[4] = {1, 1.26, 1.587, 2};*/ +static const float e_ratio_quant[4] = {.25f, .315f, .397f, .5f}; + +void speex_encode_stereo(float *data, int frame_size, SpeexBits *bits) +{ + int i, tmp; + float e_left=0, e_right=0, e_tot=0; + float balance, e_ratio; + for (i=0;i<frame_size;i++) + { + e_left += ((float)data[2*i])*data[2*i]; + e_right += ((float)data[2*i+1])*data[2*i+1]; + data[i] = .5*(((float)data[2*i])+data[2*i+1]); + e_tot += ((float)data[i])*data[i]; + } + balance=(e_left+1)/(e_right+1); + e_ratio = e_tot/(1+e_left+e_right); + + /*Quantization*/ + speex_bits_pack(bits, 14, 5); + speex_bits_pack(bits, SPEEX_INBAND_STEREO, 4); + + balance=4*log(balance); + + /*Pack sign*/ + if (balance>0) + speex_bits_pack(bits, 0, 1); + else + speex_bits_pack(bits, 1, 1); + balance=floor(.5+fabs(balance)); + if (balance>30) + balance=31; + + speex_bits_pack(bits, (int)balance, 5); + + /*Quantize energy ratio*/ + tmp=vq_index(&e_ratio, e_ratio_quant, 1, 4); + speex_bits_pack(bits, tmp, 2); +} + +void speex_encode_stereo_int(spx_int16_t *data, int frame_size, SpeexBits *bits) +{ + int i, tmp; + float e_left=0, e_right=0, e_tot=0; + float balance, e_ratio; + for (i=0;i<frame_size;i++) + { + e_left += ((float)data[2*i])*data[2*i]; + e_right += ((float)data[2*i+1])*data[2*i+1]; + data[i] = .5*(((float)data[2*i])+data[2*i+1]); + e_tot += ((float)data[i])*data[i]; + } + balance=(e_left+1)/(e_right+1); + e_ratio = e_tot/(1+e_left+e_right); + + /*Quantization*/ + speex_bits_pack(bits, 14, 5); + speex_bits_pack(bits, SPEEX_INBAND_STEREO, 4); + + balance=4*log(balance); + + /*Pack sign*/ + if (balance>0) + speex_bits_pack(bits, 0, 1); + else + speex_bits_pack(bits, 1, 1); + balance=floor(.5+fabs(balance)); + if (balance>30) + balance=31; + + speex_bits_pack(bits, (int)balance, 5); + + /*Quantize energy ratio*/ + tmp=vq_index(&e_ratio, e_ratio_quant, 1, 4); + speex_bits_pack(bits, tmp, 2); +} + +void speex_decode_stereo(float *data, int frame_size, SpeexStereoState *stereo) +{ + float balance, e_ratio; + int i; + float e_tot=0, e_left, e_right, e_sum; + + balance=stereo->balance; + e_ratio=stereo->e_ratio; + for (i=frame_size-1;i>=0;i--) + { + e_tot += ((float)data[i])*data[i]; + } + e_sum=e_tot/e_ratio; + e_left = e_sum*balance / (1+balance); + e_right = e_sum-e_left; + + e_left = sqrt(e_left/(e_tot+.01)); + e_right = sqrt(e_right/(e_tot+.01)); + + for (i=frame_size-1;i>=0;i--) + { + float ftmp=data[i]; + stereo->smooth_left = .98*stereo->smooth_left + .02*e_left; + stereo->smooth_right = .98*stereo->smooth_right + .02*e_right; + data[2*i] = stereo->smooth_left*ftmp; + data[2*i+1] = stereo->smooth_right*ftmp; + } +} + +void speex_decode_stereo_int(spx_int16_t *data, int frame_size, SpeexStereoState *stereo) +{ + float balance, e_ratio; + int i; + float e_tot=0, e_left, e_right, e_sum; + + balance=stereo->balance; + e_ratio=stereo->e_ratio; + for (i=frame_size-1;i>=0;i--) + { + e_tot += ((float)data[i])*data[i]; + } + e_sum=e_tot/e_ratio; + e_left = e_sum*balance / (1+balance); + e_right = e_sum-e_left; + + e_left = sqrt(e_left/(e_tot+.01)); + e_right = sqrt(e_right/(e_tot+.01)); + + for (i=frame_size-1;i>=0;i--) + { + float ftmp=data[i]; + stereo->smooth_left = .98*stereo->smooth_left + .02*e_left; + stereo->smooth_right = .98*stereo->smooth_right + .02*e_right; + data[2*i] = stereo->smooth_left*ftmp; + data[2*i+1] = stereo->smooth_right*ftmp; + } +} + +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; +} |