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<h1>requant.c</h1><a href="requant_8c.html">Go to the documentation of this file.</a><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*</span>
<a name="l00002"></a>00002 <span class="comment"> Copyright (c) 2005, The Musepack Development Team</span>
<a name="l00003"></a>00003 <span class="comment"> All rights reserved.</span>
<a name="l00004"></a>00004 <span class="comment"></span>
<a name="l00005"></a>00005 <span class="comment"> Redistribution and use in source and binary forms, with or without</span>
<a name="l00006"></a>00006 <span class="comment"> modification, are permitted provided that the following conditions are</span>
<a name="l00007"></a>00007 <span class="comment"> met:</span>
<a name="l00008"></a>00008 <span class="comment"></span>
<a name="l00009"></a>00009 <span class="comment"> * Redistributions of source code must retain the above copyright</span>
<a name="l00010"></a>00010 <span class="comment"> notice, this list of conditions and the following disclaimer.</span>
<a name="l00011"></a>00011 <span class="comment"></span>
<a name="l00012"></a>00012 <span class="comment"> * Redistributions in binary form must reproduce the above</span>
<a name="l00013"></a>00013 <span class="comment"> copyright notice, this list of conditions and the following</span>
<a name="l00014"></a>00014 <span class="comment"> disclaimer in the documentation and/or other materials provided</span>
<a name="l00015"></a>00015 <span class="comment"> with the distribution.</span>
<a name="l00016"></a>00016 <span class="comment"></span>
<a name="l00017"></a>00017 <span class="comment"> * Neither the name of the The Musepack Development Team nor the</span>
<a name="l00018"></a>00018 <span class="comment"> names of its contributors may be used to endorse or promote</span>
<a name="l00019"></a>00019 <span class="comment"> products derived from this software without specific prior</span>
<a name="l00020"></a>00020 <span class="comment"> written permission.</span>
<a name="l00021"></a>00021 <span class="comment"></span>
<a name="l00022"></a>00022 <span class="comment"> THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS</span>
<a name="l00023"></a>00023 <span class="comment"> "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT</span>
<a name="l00024"></a>00024 <span class="comment"> LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR</span>
<a name="l00025"></a>00025 <span class="comment"> A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT</span>
<a name="l00026"></a>00026 <span class="comment"> OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,</span>
<a name="l00027"></a>00027 <span class="comment"> SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT</span>
<a name="l00028"></a>00028 <span class="comment"> LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,</span>
<a name="l00029"></a>00029 <span class="comment"> DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY</span>
<a name="l00030"></a>00030 <span class="comment"> THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT</span>
<a name="l00031"></a>00031 <span class="comment"> (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE</span>
<a name="l00032"></a>00032 <span class="comment"> OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.</span>
<a name="l00033"></a>00033 <span class="comment">*/</span>
<a name="l00034"></a>00034
<a name="l00038"></a>00038
<a name="l00039"></a>00039 <span class="preprocessor">#include <<a class="code" href="mpcdec_8h.html">mpcdec/mpcdec.h</a>></span>
<a name="l00040"></a>00040 <span class="preprocessor">#include <<a class="code" href="internal_8h.html">mpcdec/internal.h</a>></span>
<a name="l00041"></a>00041
<a name="l00042"></a>00042 <span class="comment">/* C O N S T A N T S */</span>
<a name="l00043"></a>00043 <span class="comment">// bits per sample for chosen quantizer</span>
<a name="l00044"></a><a class="code" href="requant_8c.html#a2">00044</a> <span class="keyword">const</span> mpc_uint32_t <a class="code" href="requant_8h.html#a3">Res_bit</a> [18] = {
<a name="l00045"></a>00045 0, 0, 0, 0, 0, 0, 0, 0, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
<a name="l00046"></a>00046 };
<a name="l00047"></a>00047
<a name="l00048"></a>00048 <span class="comment">// coefficients for requantization</span>
<a name="l00049"></a>00049 <span class="comment">// 65536/step bzw. 65536/(2*D+1)</span>
<a name="l00050"></a>00050
<a name="l00051"></a><a class="code" href="requant_8c.html#a0">00051</a> <span class="preprocessor">#define _(X) MAKE_MPC_SAMPLE_EX(X,14)</span>
<a name="l00052"></a>00052 <span class="preprocessor"></span>
<a name="l00053"></a><a class="code" href="requant_8c.html#a3">00053</a> <span class="keyword">const</span> <a class="code" href="math_8h.html#a16">MPC_SAMPLE_FORMAT</a> <a class="code" href="requant_8h.html#a4">__Cc</a> [1 + 18] = {
<a name="l00054"></a>00054 <a class="code" href="requant_8c.html#a0">_</a>(111.285962475327f), <span class="comment">// 32768/2/255*sqrt(3)</span>
<a name="l00055"></a>00055 <a class="code" href="requant_8c.html#a0">_</a>(65536.000000000000f), <a class="code" href="requant_8c.html#a0">_</a>(21845.333333333332f), <a class="code" href="requant_8c.html#a0">_</a>(13107.200000000001f), <a class="code" href="requant_8c.html#a0">_</a>(9362.285714285713f),
<a name="l00056"></a>00056 <a class="code" href="requant_8c.html#a0">_</a>(7281.777777777777f), <a class="code" href="requant_8c.html#a0">_</a>(4369.066666666666f), <a class="code" href="requant_8c.html#a0">_</a>(2114.064516129032f), <a class="code" href="requant_8c.html#a0">_</a>(1040.253968253968f),
<a name="l00057"></a>00057 <a class="code" href="requant_8c.html#a0">_</a>(516.031496062992f), <a class="code" href="requant_8c.html#a0">_</a>(257.003921568627f), <a class="code" href="requant_8c.html#a0">_</a>(128.250489236790f), <a class="code" href="requant_8c.html#a0">_</a>(64.062561094819f),
<a name="l00058"></a>00058 <a class="code" href="requant_8c.html#a0">_</a>(32.015632633121f), <a class="code" href="requant_8c.html#a0">_</a>(16.003907203907f), <a class="code" href="requant_8c.html#a0">_</a>(8.000976681723f), <a class="code" href="requant_8c.html#a0">_</a>(4.000244155527f),
<a name="l00059"></a>00059 <a class="code" href="requant_8c.html#a0">_</a>(2.000061037018f), <a class="code" href="requant_8c.html#a0">_</a>(1.000015259021f)
<a name="l00060"></a>00060 };
<a name="l00061"></a>00061
<a name="l00062"></a>00062 <span class="preprocessor">#undef _</span>
<a name="l00063"></a>00063 <span class="preprocessor"></span>
<a name="l00064"></a>00064 <span class="comment">// offset for requantization</span>
<a name="l00065"></a>00065 <span class="comment">// 2*D+1 = steps of quantizer</span>
<a name="l00066"></a><a class="code" href="requant_8c.html#a4">00066</a> <span class="keyword">const</span> mpc_int32_t <a class="code" href="requant_8h.html#a5">__Dc</a> [1 + 18] = {
<a name="l00067"></a>00067 2,
<a name="l00068"></a>00068 0, 1, 2, 3, 4, 7, 15, 31, 63,
<a name="l00069"></a>00069 127, 255, 511, 1023, 2047, 4095, 8191, 16383, 32767
<a name="l00070"></a>00070 };
<a name="l00071"></a>00071
<a name="l00072"></a>00072 <span class="preprocessor">#ifdef MPC_FIXED_POINT</span>
<a name="l00073"></a>00073 <span class="preprocessor"></span><span class="keyword">static</span> mpc_uint32_t find_shift(<span class="keywordtype">double</span> fval)
<a name="l00074"></a>00074 {
<a name="l00075"></a>00075 mpc_int64_t val = (mpc_int64_t)fval;
<a name="l00076"></a>00076 <span class="keywordflow">if</span> (val<0) val = -val;
<a name="l00077"></a>00077 mpc_uint32_t ptr = 0;
<a name="l00078"></a>00078 <span class="keywordflow">while</span>(val) {val>>=1;ptr++;}
<a name="l00079"></a>00079
<a name="l00080"></a>00080 <span class="keywordflow">return</span> ptr > 31 ? 0 : 31 - ptr;
<a name="l00081"></a>00081 }
<a name="l00082"></a>00082 <span class="preprocessor">#endif</span>
<a name="l00083"></a>00083 <span class="preprocessor"></span>
<a name="l00084"></a>00084 <span class="comment">/* F U N C T I O N S */</span>
<a name="l00085"></a>00085
<a name="l00086"></a><a class="code" href="requant_8c.html#a1">00086</a> <span class="preprocessor">#define SET_SCF(N,X) d->SCF[N] = MAKE_MPC_SAMPLE_EX(X,d->SCF_shift[N] = (unsigned char)find_shift(X));</span>
<a name="l00087"></a>00087 <span class="preprocessor"></span>
<a name="l00088"></a>00088 <span class="keywordtype">void</span>
<a name="l00089"></a><a class="code" href="requant_8c.html#a5">00089</a> <a class="code" href="mpcdec_8h.html#a16">mpc_decoder_scale_output</a>(<a class="code" href="structmpc__decoder__t.html">mpc_decoder</a> *d, <span class="keywordtype">double</span> factor)
<a name="l00090"></a>00090 {
<a name="l00091"></a>00091 mpc_int32_t n;
<a name="l00092"></a>00092 <span class="keywordtype">double</span> f1;
<a name="l00093"></a>00093 <span class="keywordtype">double</span> f2;
<a name="l00094"></a>00094 <span class="preprocessor">#ifndef MPC_FIXED_POINT</span>
<a name="l00095"></a>00095 <span class="preprocessor"></span> factor *= 1.0 / (double)(1<<(<a class="code" href="math_8h.html#a0">MPC_FIXED_POINT_SHIFT</a>-1));
<a name="l00096"></a>00096 <span class="preprocessor">#else</span>
<a name="l00097"></a>00097 <span class="preprocessor"></span> factor *= 1.0 / (double)(1<<(16 - <a class="code" href="math_8h.html#a0">MPC_FIXED_POINT_SHIFT</a>));
<a name="l00098"></a>00098 <span class="preprocessor">#endif</span>
<a name="l00099"></a>00099 <span class="preprocessor"></span> f1 = f2 = factor;
<a name="l00100"></a>00100
<a name="l00101"></a>00101 <span class="comment">// handles +1.58...-98.41 dB, where's scf[n] / scf[n-1] = 1.20050805774840750476</span>
<a name="l00102"></a>00102
<a name="l00103"></a>00103 <a class="code" href="requant_8c.html#a1">SET_SCF</a>(1,factor);
<a name="l00104"></a>00104
<a name="l00105"></a>00105 f1 *= 0.83298066476582673961;
<a name="l00106"></a>00106 f2 *= 1/0.83298066476582673961;
<a name="l00107"></a>00107
<a name="l00108"></a>00108 <span class="keywordflow">for</span> ( n = 1; n <= 128; n++ ) {
<a name="l00109"></a>00109 <a class="code" href="requant_8c.html#a1">SET_SCF</a>((<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>)(1+n),f1);
<a name="l00110"></a>00110 <a class="code" href="requant_8c.html#a1">SET_SCF</a>((<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>)(1-n),f2);
<a name="l00111"></a>00111 f1 *= 0.83298066476582673961;
<a name="l00112"></a>00112 f2 *= 1/0.83298066476582673961;
<a name="l00113"></a>00113 }
<a name="l00114"></a>00114 }
<a name="l00115"></a>00115
<a name="l00116"></a>00116 <span class="keyword">static</span> <span class="keywordtype">void</span>
<a name="l00117"></a>00117 mpc_decoder_quantisierungsmodes(<a class="code" href="structmpc__decoder__t.html">mpc_decoder</a> *d) <span class="comment">// conversion: index -> quantizer (bitstream reading)</span>
<a name="l00118"></a>00118 { <span class="comment">// conversion: quantizer -> index (bitstream writing)</span>
<a name="l00119"></a>00119 mpc_int32_t Band = 0;
<a name="l00120"></a>00120 mpc_int32_t i;
<a name="l00121"></a>00121
<a name="l00122"></a>00122 <span class="keywordflow">do</span> {
<a name="l00123"></a>00123 d-><a class="code" href="structmpc__decoder__t.html#z0_21">Q_bit</a> [Band] = 4;
<a name="l00124"></a>00124 <span class="keywordflow">for</span> ( i = 0; i < 16-1; i++ )
<a name="l00125"></a>00125 d-><a class="code" href="structmpc__decoder__t.html#z0_22">Q_res</a> [Band] [i] = i;
<a name="l00126"></a>00126 d-><a class="code" href="structmpc__decoder__t.html#z0_22">Q_res</a> [Band][i] = 17;
<a name="l00127"></a>00127 Band++;
<a name="l00128"></a>00128 } <span class="keywordflow">while</span> ( Band < 11 );
<a name="l00129"></a>00129
<a name="l00130"></a>00130 <span class="keywordflow">do</span> {
<a name="l00131"></a>00131 d-><a class="code" href="structmpc__decoder__t.html#z0_21">Q_bit</a> [Band] = 3;
<a name="l00132"></a>00132 <span class="keywordflow">for</span> ( i = 0; i < 8-1; i++ )
<a name="l00133"></a>00133 d-><a class="code" href="structmpc__decoder__t.html#z0_22">Q_res</a> [Band] [i] = i;
<a name="l00134"></a>00134 d-><a class="code" href="structmpc__decoder__t.html#z0_22">Q_res</a> [Band] [i] = 17;
<a name="l00135"></a>00135 Band++;
<a name="l00136"></a>00136 } <span class="keywordflow">while</span> ( Band < 23 );
<a name="l00137"></a>00137
<a name="l00138"></a>00138 <span class="keywordflow">do</span> {
<a name="l00139"></a>00139 d-><a class="code" href="structmpc__decoder__t.html#z0_21">Q_bit</a> [Band] = 2;
<a name="l00140"></a>00140 <span class="keywordflow">for</span> ( i = 0; i < 4-1; i++ )
<a name="l00141"></a>00141 d-><a class="code" href="structmpc__decoder__t.html#z0_22">Q_res</a> [Band] [i] = i;
<a name="l00142"></a>00142 d-><a class="code" href="structmpc__decoder__t.html#z0_22">Q_res</a> [Band] [i] = 17;
<a name="l00143"></a>00143 Band++;
<a name="l00144"></a>00144 } <span class="keywordflow">while</span> ( Band < 32 );
<a name="l00145"></a>00145 }
<a name="l00146"></a>00146
<a name="l00147"></a>00147 <span class="keywordtype">void</span>
<a name="l00148"></a><a class="code" href="requant_8c.html#a7">00148</a> <a class="code" href="internal_8h.html#a4">mpc_decoder_initialisiere_quantisierungstabellen</a>(<a class="code" href="structmpc__decoder__t.html">mpc_decoder</a> *d, <span class="keywordtype">double</span> scale_factor)
<a name="l00149"></a>00149 {
<a name="l00150"></a>00150 mpc_decoder_quantisierungsmodes(d);
<a name="l00151"></a>00151 <a class="code" href="mpcdec_8h.html#a16">mpc_decoder_scale_output</a>(d, scale_factor);
<a name="l00152"></a>00152 }
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