This time really check in the new routines :-)
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Jack Jansen
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dd8a6eac57
commit
a90805f1c0
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@ -33,7 +33,7 @@ OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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#include "allobjects.h"
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#include "modsupport.h"
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/* Code shamelessly stealen from sox,
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/* Code shamelessly stolen from sox,
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** (c) Craig Reese, Joe Campbell and Jeff Poskanzer 1989 */
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#define MINLIN -32768
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@ -270,44 +270,187 @@ audioop_rms(self, args)
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return newintobject(val);
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}
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double _sum2(a, b, len)
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short *a;
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short *b;
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int len;
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{
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int i;
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double sum = 0.0;
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for( i=0; i<len; i++) {
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sum = sum + (double)a[i]*(double)b[i];
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}
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return sum;
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}
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/*
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** Findfit tries to locate a sample within another sample. Its main use
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** is in echo-cancellation (to find the feedback of the output signal in
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** the input signal).
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** The method used is as follows:
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**
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** let R be the reference signal (length n) and A the input signal (length N)
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** with N > n, and let all sums be over i from 0 to n-1.
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**
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** Now, for each j in {0..N-n} we compute a factor fj so that -fj*R matches A
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** as good as possible, i.e. sum( (A[j+i]+fj*R[i])^2 ) is minimal. This
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** equation gives fj = sum( A[j+i]R[i] ) / sum(R[i]^2).
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**
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** Next, we compute the relative distance between the original signal and
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** the modified signal and minimize that over j:
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** vj = sum( (A[j+i]-fj*R[i])^2 ) / sum( A[j+i]^2 ) =>
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** vj = ( sum(A[j+i]^2)*sum(R[i]^2) - sum(A[j+i]R[i])^2 ) / sum( A[j+i]^2 )
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**
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** In the code variables correspond as follows:
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** cp1 A
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** cp2 R
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** len1 N
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** len2 n
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** aj_m1 A[j-1]
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** aj_lm1 A[j+n-1]
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** sum_ri_2 sum(R[i]^2)
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** sum_aij_2 sum(A[i+j]^2)
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** sum_aij_ri sum(A[i+j]R[i])
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**
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** sum_ri is calculated once, sum_aij_2 is updated each step and sum_aij_ri
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** is completely recalculated each step.
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*/
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static object *
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audioop_rms2(self, args)
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audioop_findfit(self, args)
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object *self;
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object *args;
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{
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signed char *cp1, *cp2;
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int len1, len2, size, val1, val2;
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int i;
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float sum_squares = 0.0;
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short *cp1, *cp2;
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int len1, len2;
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int j, best_j;
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double aj_m1, aj_lm1;
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double sum_ri_2, sum_aij_2, sum_aij_ri, result, best_result, factor;
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if ( !getargs(args, "(s#s#i)", &cp1, &len1, &cp2, &len2, &size) )
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if ( !getargs(args, "(s#s#)", &cp1, &len1, &cp2, &len2) )
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return 0;
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if ( size != 1 && size != 2 && size != 4 ) {
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err_setstr(AudioopError, "Size should be 1, 2 or 4");
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if ( len1 & 1 || len2 & 1 ) {
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err_setstr(AudioopError, "Strings should be even-sized");
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return 0;
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}
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len1 >>= 1;
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len2 >>= 1;
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if ( len1 < len2 ) {
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err_setstr(AudioopError, "First sample should be longer");
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return 0;
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}
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sum_ri_2 = _sum2(cp2, cp2, len2);
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sum_aij_2 = _sum2(cp1, cp1, len2);
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sum_aij_ri = _sum2(cp1, cp2, len2);
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result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) / sum_aij_2;
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best_result = result;
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best_j = 0;
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j = 0;
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for ( j=1; j<=len1-len2; j++) {
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aj_m1 = (double)cp1[j-1];
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aj_lm1 = (double)cp1[j+len2-1];
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sum_aij_2 = sum_aij_2 + aj_lm1*aj_lm1 - aj_m1*aj_m1;
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sum_aij_ri = _sum2(cp1+j, cp2, len2);
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result = (sum_ri_2*sum_aij_2 - sum_aij_ri*sum_aij_ri) / sum_aij_2;
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if ( result < best_result ) {
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best_result = result;
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best_j = j;
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}
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}
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factor = _sum2(cp1+best_j, cp2, len2) / sum_ri_2;
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return mkvalue("(if)", best_j, factor);
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}
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/*
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** findfactor finds a factor f so that the energy in A-fB is minimal.
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** See the comment for findfit for details.
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*/
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static object *
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audioop_findfactor(self, args)
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object *self;
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object *args;
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{
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short *cp1, *cp2;
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int len1, len2;
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double sum_ri_2, sum_aij_ri, result;
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if ( !getargs(args, "(s#s#)", &cp1, &len1, &cp2, &len2) )
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return 0;
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if ( len1 & 1 || len2 & 1 ) {
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err_setstr(AudioopError, "Strings should be even-sized");
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return 0;
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}
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if ( len1 != len2 ) {
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err_setstr(AudioopError, "Samples should be same size");
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return 0;
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}
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for ( i=0; i<len1; i+= size) {
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if ( size == 1 ) {
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val1 = (int)*CHARP(cp1, i);
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val2 = (int)*CHARP(cp2, i);
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} else if ( size == 2 ) {
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val1 = (int)*SHORTP(cp1, i);
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val2 = (int)*SHORTP(cp2, i);
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} else if ( size == 4 ) {
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val1 = (int)*LONGP(cp1, i);
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val2 = (int)*LONGP(cp2, i);
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}
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sum_squares += (float)val1*(float)val2;
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len2 >>= 1;
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sum_ri_2 = _sum2(cp2, cp2, len2);
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sum_aij_ri = _sum2(cp1, cp2, len2);
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result = sum_aij_ri / sum_ri_2;
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return newfloatobject(result);
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}
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/*
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** findmax returns the index of the n-sized segment of the input sample
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** that contains the most energy.
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*/
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static object *
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audioop_findmax(self, args)
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object *self;
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object *args;
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{
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short *cp1;
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int len1, len2;
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int j, best_j;
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double aj_m1, aj_lm1;
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double result, best_result;
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if ( !getargs(args, "(s#i)", &cp1, &len1, &len2) )
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return 0;
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if ( len1 & 1 ) {
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err_setstr(AudioopError, "Strings should be even-sized");
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return 0;
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}
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if ( len1 == 0 )
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val1 = 0;
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else
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val1 = (int)sqrt(sum_squares / (float)(len1/size));
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return newintobject(val1);
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len1 >>= 1;
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if ( len1 < len2 ) {
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err_setstr(AudioopError, "Input sample should be longer");
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return 0;
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}
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result = _sum2(cp1, cp1, len2);
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best_result = result;
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best_j = 0;
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j = 0;
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for ( j=1; j<=len1-len2; j++) {
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aj_m1 = (double)cp1[j-1];
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aj_lm1 = (double)cp1[j+len2-1];
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result = result + aj_lm1*aj_lm1 - aj_m1*aj_m1;
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if ( result > best_result ) {
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best_result = result;
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best_j = j;
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}
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}
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return newintobject(best_j);
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}
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static object *
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@ -678,6 +821,44 @@ audioop_bias(self, args)
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return rv;
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}
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static object *
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audioop_lin2lin(self, args)
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object *self;
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object *args;
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{
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signed char *cp;
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unsigned char *ncp;
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int len, size, size2, val;
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object *rv;
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int i, j;
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if ( !getargs(args, "(s#ii)",
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&cp, &len, &size, &size2) )
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return 0;
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if ( (size != 1 && size != 2 && size != 4) ||
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(size2 != 1 && size2 != 2 && size2 != 4)) {
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err_setstr(AudioopError, "Size should be 1, 2 or 4");
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return 0;
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}
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rv = newsizedstringobject(NULL, (len/size)*size2);
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if ( rv == 0 )
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return 0;
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ncp = (unsigned char *)getstringvalue(rv);
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for ( i=0, j=0; i < len; i += size, j += size2 ) {
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if ( size == 1 ) val = ((int)*CHARP(cp, i)) << 8;
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else if ( size == 2 ) val = (int)*SHORTP(cp, i);
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else if ( size == 4 ) val = ((int)*LONGP(cp, i)) >> 16;
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if ( size2 == 1 ) *CHARP(ncp, j) = (signed char)(val >> 8);
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else if ( size2 == 2 ) *SHORTP(ncp, j) = (short)(val);
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else if ( size2 == 4 ) *LONGP(ncp, j) = (long)(val<<16);
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}
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return rv;
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}
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static object *
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audioop_lin2ulaw(self, args)
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object *self;
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@ -1088,13 +1269,16 @@ static struct methodlist audioop_methods[] = {
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{ "maxpp", audioop_maxpp },
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{ "avgpp", audioop_avgpp },
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{ "rms", audioop_rms },
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{ "rms2", audioop_rms2 },
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{ "findfit", audioop_findfit },
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{ "findmax", audioop_findmax },
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{ "findfactor", audioop_findfactor },
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{ "cross", audioop_cross },
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{ "mul", audioop_mul },
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{ "add", audioop_add },
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{ "bias", audioop_bias },
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{ "ulaw2lin", audioop_ulaw2lin },
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{ "lin2ulaw", audioop_lin2ulaw },
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{ "lin2lin", audioop_lin2lin },
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{ "adpcm2lin", audioop_adpcm2lin },
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{ "lin2adpcm", audioop_lin2adpcm },
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{ "adpcm32lin", audioop_adpcm32lin },
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