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Part 2 of 2 of Kenan Gillet's 'make ff_qcelp_lspf2lpc
more general' changeset. This one relocates the QCELP especific code to the qcelpdec.* files. Originally committed as revision 17800 to svn://svn.ffmpeg.org/ffmpeg/trunk
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@ -29,15 +29,6 @@
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#include "libavutil/mathematics.h"
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/**
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* initial coefficient to perform bandwidth expansion on LPC
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*
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* @note: 0.9883 looks like an approximation of 253/256.
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*
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* TIA/EIA/IS-733 2.4.3.3.6 6
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*/
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#define QCELP_BANDWITH_EXPANSION_COEFF 0.9883
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/**
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* Computes the Pa / (1 + z(-1)) or Qa / (1 - z(-1)) coefficients
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* needed for LSP to LPC conversion.
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@ -84,37 +75,7 @@ void ff_celp_lspf2lpc(const double *lspf, float *lpc)
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double paf = pa[i+1] + pa[i];
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double qaf = qa[i+1] - qa[i];
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lpc[i ] = 0.5 * (paf+qaf);
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lpc[9-i] = 0.5 * (paf-qaf);
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}
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}
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/**
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* Reconstructs LPC coefficients from the line spectral pair frequencies
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* and performs bandwidth expansion.
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*
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* @param lspf line spectral pair frequencies
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* @param lpc linear predictive coding coefficients
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*
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* @note: bandwith_expansion_coeff could be precalculated into a table
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* but it seems to be slower on x86
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*
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* TIA/EIA/IS-733 2.4.3.3.5
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*/
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void ff_qcelp_lspf2lpc(const float *lspf, float *lpc)
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{
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double lsf[10];
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double bandwith_expansion_coeff = QCELP_BANDWITH_EXPANSION_COEFF;
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int i;
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for (i=0; i<10; i++)
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lsf[i] = cos(M_PI * lspf[i]);
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ff_celp_lspf2lpc(lsf, lpc);
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for (i=0; i<10; i++)
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{
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lpc[i] *= bandwith_expansion_coeff;
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bandwith_expansion_coeff *= QCELP_BANDWITH_EXPANSION_COEFF;
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lpc[i ] = 0.5*(paf+qaf);
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lpc[9-i] = 0.5*(paf-qaf);
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}
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}
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@ -550,4 +550,13 @@ static const double qcelp_rnd_fir_coefs[11] = {
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*/
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#define QCELP_LSP_OCTAVE_PREDICTOR 29.0/32
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/**
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* initial coefficient to perform bandwidth expansion on LPC
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*
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* @note: 0.9883 looks like an approximation of 253/256.
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*
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* TIA/EIA/IS-733 2.4.3.3.6 6
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*/
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#define QCELP_BANDWITH_EXPANSION_COEFF 0.9883
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#endif /* AVCODEC_QCELPDATA_H */
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@ -79,7 +79,7 @@ typedef struct
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*
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* TIA/EIA/IS-733 2.4.3.3.5
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*/
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void ff_qcelp_lspf2lpc(const float *lspf, float *lpc);
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void ff_celp_lspf2lpc(const double *lspf, float *lpc);
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static void weighted_vector_sumf(float *out, const float *in_a,
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const float *in_b, float weight_coeff_a,
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@ -584,6 +584,36 @@ static void apply_pitch_filters(QCELPContext *q, float *cdn_vector)
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}
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}
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/**
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* Reconstructs LPC coefficients from the line spectral pair frequencies
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* and performs bandwidth expansion.
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*
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* @param lspf line spectral pair frequencies
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* @param lpc linear predictive coding coefficients
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*
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* @note: bandwith_expansion_coeff could be precalculated into a table
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* but it seems to be slower on x86
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*
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* TIA/EIA/IS-733 2.4.3.3.5
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*/
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void lspf2lpc(const float *lspf, float *lpc)
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{
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double lsf[10];
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double bandwith_expansion_coeff = QCELP_BANDWITH_EXPANSION_COEFF;
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int i;
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for (i=0; i<10; i++)
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lsf[i] = cos(M_PI * lspf[i]);
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ff_celp_lspf2lpc(lsf, lpc);
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for (i=0; i<10; i++)
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{
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lpc[i] *= bandwith_expansion_coeff;
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bandwith_expansion_coeff *= QCELP_BANDWITH_EXPANSION_COEFF;
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}
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}
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/**
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* Interpolates LSP frequencies and computes LPC coefficients
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* for a given bitrate & pitch subframe.
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@ -612,12 +642,12 @@ void interpolate_lpc(QCELPContext *q, const float *curr_lspf, float *lpc,
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{
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weighted_vector_sumf(interpolated_lspf, curr_lspf, q->prev_lspf,
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weight, 1.0 - weight, 10);
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ff_qcelp_lspf2lpc(interpolated_lspf, lpc);
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lspf2lpc(interpolated_lspf, lpc);
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}else if(q->bitrate >= RATE_QUARTER ||
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(q->bitrate == I_F_Q && !subframe_num))
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ff_qcelp_lspf2lpc(curr_lspf, lpc);
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lspf2lpc(curr_lspf, lpc);
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else if(q->bitrate == SILENCE && !subframe_num)
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ff_qcelp_lspf2lpc(q->prev_lspf, lpc);
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lspf2lpc(q->prev_lspf, lpc);
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}
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static qcelp_packet_rate buf_size2bitrate(const int buf_size)
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