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Do not hardcode filter order in ff_acelp_lspd2lpc() 

Originally committed as revision 20485 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Vitor Sessak 2009-11-09 12:06:19 +00:00
parent 91cc5d3767
commit e26d131845
3 changed files with 14 additions and 13 deletions
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21
libavcodec/lsp.c
View File

@ -155,20 +155,19 @@ static void lsp2polyf(const double *lsp, double *f, int lp_half_order)
}
}
void ff_acelp_lspd2lpc(const double *lsp, float *lpc)
void ff_acelp_lspd2lpc(const double *lsp, float *lpc, int lp_half_order)
{
double pa[6], qa[6];
int i;
double pa[lp_half_order+1], qa[lp_half_order+1];
float *lpc2 = lpc + (lp_half_order << 1) - 1;
lsp2polyf(lsp, pa, 5);
lsp2polyf(lsp + 1, qa, 5);
lsp2polyf(lsp, pa, lp_half_order);
lsp2polyf(lsp + 1, qa, lp_half_order);
for (i=4; i>=0; i--)
{
double paf = pa[i+1] + pa[i];
double qaf = qa[i+1] - qa[i];
while (lp_half_order--) {
double paf = pa[lp_half_order+1] + pa[lp_half_order];
double qaf = qa[lp_half_order+1] - qa[lp_half_order];
lpc[i ] = 0.5*(paf+qaf);
lpc[9-i] = 0.5*(paf-qaf);
lpc [ lp_half_order] = 0.5*(paf+qaf);
lpc2[-lp_half_order] = 0.5*(paf-qaf);
}
}

4
libavcodec/lsp.h
View File

@ -86,8 +86,10 @@ void ff_acelp_lp_decode(int16_t* lp_1st, int16_t* lp_2nd, const int16_t* lsp_2nd
* @param lsp line spectral pairs in cosine domain
* @param lpc linear predictive coding coefficients
*
* @note buffers should have a minimux size of 2*lp_half_order elements.
*
* TIA/EIA/IS-733 2.4.3.3.5
*/
void ff_acelp_lspd2lpc(const double *lsp, float *lpc);
void ff_acelp_lspd2lpc(const double *lsp, float *lpc, int lp_half_order);
#endif /* AVCODEC_LSP_H */

2
libavcodec/qcelpdec.c
View File

@ -578,7 +578,7 @@ static void lspf2lpc(const float *lspf, float *lpc)
for (i=0; i<10; i++)
lsp[i] = cos(M_PI * lspf[i]);
ff_acelp_lspd2lpc(lsp, lpc);
ff_acelp_lspd2lpc(lsp, lpc, 5);
for (i=0; i<10; i++)
{