Add Speex playback support. Patch from FS #5607 thanks to Frederik Vestre.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@12241 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 192 insertions, 0 deletions

diff --git a/apps/codecs/libspeex/stereo.c b/apps/codecs/libspeex/stereo.c
new file mode 100644
index 0000000000..72adb45f73
--- /dev/null
+++ b/apps/codecs/libspeex/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_approx.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=0.0, 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 / (1.0+balance);
+   e_right = e_sum-e_left;
+
+   e_left  = spx_sqrtf(e_left/(e_tot+.01));
+   e_right = spx_sqrtf(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 = spx_exp(sign*.25*tmp);
+
+   tmp = speex_bits_unpack_unsigned(bits, 2);
+   stereo->e_ratio = e_ratio_quant[tmp];
+
+   return 0;
+}