diff options
Diffstat (limited to 'media/libstagefright/codecs/amrwbenc/src/isp_isf.c')
| -rw-r--r-- | media/libstagefright/codecs/amrwbenc/src/isp_isf.c | 94 |
1 files changed, 47 insertions, 47 deletions
diff --git a/media/libstagefright/codecs/amrwbenc/src/isp_isf.c b/media/libstagefright/codecs/amrwbenc/src/isp_isf.c index b4ba408..56798e0 100644 --- a/media/libstagefright/codecs/amrwbenc/src/isp_isf.c +++ b/media/libstagefright/codecs/amrwbenc/src/isp_isf.c @@ -18,11 +18,11 @@ * File: isp_isf.c * * * * Description: * -* Isp_isf Transformation isp to isf * -* Isf_isp Transformation isf to isp * +* Isp_isf Transformation isp to isf * +* Isf_isp Transformation isf to isp * * * -* The transformation from isp[i] to isf[i] and isf[i] to isp[i] * -* are approximated by a look-up table and interpolation * +* The transformation from isp[i] to isf[i] and isf[i] to isp[i] * +* are approximated by a look-up table and interpolation * * * ************************************************************************/ @@ -31,59 +31,59 @@ #include "isp_isf.tab" /* Look-up table for transformations */ void Isp_isf( - Word16 isp[], /* (i) Q15 : isp[m] (range: -1<=val<1) */ - Word16 isf[], /* (o) Q15 : isf[m] normalized (range: 0.0<=val<=0.5) */ - Word16 m /* (i) : LPC order */ - ) + Word16 isp[], /* (i) Q15 : isp[m] (range: -1<=val<1) */ + Word16 isf[], /* (o) Q15 : isf[m] normalized (range: 0.0<=val<=0.5) */ + Word16 m /* (i) : LPC order */ + ) { - Word32 i, ind; - Word32 L_tmp; - ind = 127; /* beging at end of table -1 */ - for (i = (m - 1); i >= 0; i--) - { - if (i >= (m - 2)) - { /* m-2 is a constant */ - ind = 127; /* beging at end of table -1 */ - } - /* find value in table that is just greater than isp[i] */ - while (table[ind] < isp[i]) - ind--; - /* acos(isp[i])= ind*128 + ( ( isp[i]-table[ind] ) * slope[ind] )/2048 */ - L_tmp = vo_L_mult(vo_sub(isp[i], table[ind]), slope[ind]); - isf[i] = vo_round((L_tmp << 4)); /* (isp[i]-table[ind])*slope[ind])>>11 */ - isf[i] = add1(isf[i], (ind << 7)); - } - isf[m - 1] = (isf[m - 1] >> 1); - return; + Word32 i, ind; + Word32 L_tmp; + ind = 127; /* beging at end of table -1 */ + for (i = (m - 1); i >= 0; i--) + { + if (i >= (m - 2)) + { /* m-2 is a constant */ + ind = 127; /* beging at end of table -1 */ + } + /* find value in table that is just greater than isp[i] */ + while (table[ind] < isp[i]) + ind--; + /* acos(isp[i])= ind*128 + ( ( isp[i]-table[ind] ) * slope[ind] )/2048 */ + L_tmp = vo_L_mult(vo_sub(isp[i], table[ind]), slope[ind]); + isf[i] = vo_round((L_tmp << 4)); /* (isp[i]-table[ind])*slope[ind])>>11 */ + isf[i] = add1(isf[i], (ind << 7)); + } + isf[m - 1] = (isf[m - 1] >> 1); + return; } void Isf_isp( - Word16 isf[], /* (i) Q15 : isf[m] normalized (range: 0.0<=val<=0.5) */ - Word16 isp[], /* (o) Q15 : isp[m] (range: -1<=val<1) */ - Word16 m /* (i) : LPC order */ - ) + Word16 isf[], /* (i) Q15 : isf[m] normalized (range: 0.0<=val<=0.5) */ + Word16 isp[], /* (o) Q15 : isp[m] (range: -1<=val<1) */ + Word16 m /* (i) : LPC order */ + ) { - Word16 offset; - Word32 i, ind, L_tmp; + Word16 offset; + Word32 i, ind, L_tmp; - for (i = 0; i < m - 1; i++) - { - isp[i] = isf[i]; - } - isp[m - 1] = (isf[m - 1] << 1); + for (i = 0; i < m - 1; i++) + { + isp[i] = isf[i]; + } + isp[m - 1] = (isf[m - 1] << 1); - for (i = 0; i < m; i++) - { - ind = (isp[i] >> 7); /* ind = b7-b15 of isf[i] */ - offset = (Word16) (isp[i] & 0x007f); /* offset = b0-b6 of isf[i] */ + for (i = 0; i < m; i++) + { + ind = (isp[i] >> 7); /* ind = b7-b15 of isf[i] */ + offset = (Word16) (isp[i] & 0x007f); /* offset = b0-b6 of isf[i] */ - /* isp[i] = table[ind]+ ((table[ind+1]-table[ind])*offset) / 128 */ - L_tmp = vo_L_mult(vo_sub(table[ind + 1], table[ind]), offset); - isp[i] = add1(table[ind], (Word16)((L_tmp >> 8))); - } + /* isp[i] = table[ind]+ ((table[ind+1]-table[ind])*offset) / 128 */ + L_tmp = vo_L_mult(vo_sub(table[ind + 1], table[ind]), offset); + isp[i] = add1(table[ind], (Word16)((L_tmp >> 8))); + } - return; + return; } |