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Optimize A-Law and Mu-Law compressors
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@ -86,15 +86,15 @@ void AudioCompressor::fillLUT2()
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void AudioCompressor::fillALaw()
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{
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for (int i=-32768; i<32768; i++) {
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m_lut[i+32768] = ALaw_Encode(i);
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for (int i=-16384; i<16384; i++) {
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m_lut[i+16384] = ALaw_Encode(2*i);
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}
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}
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void AudioCompressor::fillULaw()
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{
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for (int i=-32768; i<32768; i++) {
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m_lut[i+32768] = MuLaw_Encode(i);
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for (int i=-16384; i<16384; i++) {
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m_lut[i+16384] = MuLaw_Encode(2*i);
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}
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}
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@ -107,7 +107,7 @@ int16_t AudioCompressor::compress(int16_t sample)
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int8_t AudioCompressor::compress8(int16_t sample)
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{
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return m_lut[sample + 32768];
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return m_lut[sample/2 + 16384];
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}
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/* http://dystopiancode.blogspot.com/2012/02/pcm-law-and-u-law-companding-algorithms.html
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@ -37,7 +37,7 @@ private:
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int8_t ALaw_Encode(int16_t number);
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int8_t MuLaw_Encode(int16_t number);
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int16_t m_lut[65536];
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int16_t m_lut[32768];
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static const uint16_t ALAW_MAX;
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static const uint16_t MULAW_MAX;
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static const uint16_t MULAW_BIAS;
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