fft-test: Reduce variable scope where sensibly possible

Also merge variable declaration and initialization.

libavcodec/fft-test.c

@@ -65,16 +65,13 @@ static struct {
 
 static void fft_ref_init(int nbits, int inverse)
 {
-    int n, i;
-    double c1, s1, alpha;
+    int i, n = 1 << nbits;
 
-    n = 1 << nbits;
     exptab = av_malloc((n / 2) * sizeof(*exptab));
 
     for (i = 0; i < (n/2); i++) {
-        alpha = 2 * M_PI * (float)i / (float)n;
-        c1 = cos(alpha);
-        s1 = sin(alpha);
+        double alpha = 2 * M_PI * (float)i / (float)n;
+        double c1 = cos(alpha), s1 = sin(alpha);
         if (!inverse)
             s1 = -s1;
         exptab[i].re = c1;
@@ -84,18 +81,16 @@ static void fft_ref_init(int nbits, int inverse)
 
 static void fft_ref(FFTComplex *tabr, FFTComplex *tab, int nbits)
 {
-    int n, i, j, k, n2;
-    double tmp_re, tmp_im, s, c;
-    FFTComplex *q;
+    int i, j;
+    int n  = 1 << nbits;
+    int n2 = n >> 1;
 
-    n = 1 << nbits;
-    n2 = n >> 1;
     for (i = 0; i < n; i++) {
-        tmp_re = 0;
-        tmp_im = 0;
-        q = tab;
+        double tmp_re = 0, tmp_im = 0;
+        FFTComplex *q = tab;
         for (j = 0; j < n; j++) {
-            k = (i * j) & (n - 1);
+            double s, c;
+            int k = (i * j) & (n - 1);
             if (k >= n2) {
                 c = -exptab[k - n2].re;
                 s = -exptab[k - n2].im;
@@ -114,15 +109,13 @@ static void fft_ref(FFTComplex *tabr, FFTComplex *tab, int nbits)
 #if CONFIG_MDCT
 static void imdct_ref(FFTSample *out, FFTSample *in, int nbits)
 {
-    int n = 1<<nbits;
-    int k, i, a;
-    double sum, f;
+    int i, k, n = 1 << nbits;
 
     for (i = 0; i < n; i++) {
-        sum = 0;
+        double sum = 0;
         for (k = 0; k < n/2; k++) {
-            a = (2 * i + 1 + (n / 2)) * (2 * k + 1);
-            f = cos(M_PI * a / (double)(2 * n));
+            int a = (2 * i + 1 + (n / 2)) * (2 * k + 1);
+            double f = cos(M_PI * a / (double)(2 * n));
             sum += f * in[k];
         }
         out[i] = REF_SCALE(-sum, nbits - 2);
@@ -132,15 +125,13 @@ static void imdct_ref(FFTSample *out, FFTSample *in, int nbits)
 /* NOTE: no normalisation by 1 / N is done */
 static void mdct_ref(FFTSample *output, FFTSample *input, int nbits)
 {
-    int n = 1<<nbits;
-    int k, i;
-    double a, s;
+    int i, k, n = 1 << nbits;
 
     /* do it by hand */
     for (k = 0; k < n/2; k++) {
-        s = 0;
+        double s = 0;
         for (i = 0; i < n; i++) {
-            a = (2*M_PI*(2*i+1+n/2)*(2*k+1) / (4 * n));
+            double a = (2 * M_PI * (2 * i + 1 + n / 2) * (2 * k + 1) / (4 * n));
             s += input[i] * cos(a);
         }
         output[k] = REF_SCALE(s, nbits - 1);
@@ -152,15 +143,13 @@ static void mdct_ref(FFTSample *output, FFTSample *input, int nbits)
 #if CONFIG_DCT
 static void idct_ref(float *output, float *input, int nbits)
 {
-    int n = 1<<nbits;
-    int k, i;
-    double a, s;
+    int i, k, n = 1 << nbits;
 
     /* do it by hand */
     for (i = 0; i < n; i++) {
-        s = 0.5 * input[0];
+        double s = 0.5 * input[0];
         for (k = 1; k < n; k++) {
-            a = M_PI*k*(i+0.5) / n;
+            double a = M_PI * k * (i + 0.5) / n;
             s += input[k] * cos(a);
         }
         output[i] = 2 * s / n;
@@ -168,15 +157,13 @@ static void idct_ref(float *output, float *input, int nbits)
 }
 static void dct_ref(float *output, float *input, int nbits)
 {
-    int n = 1<<nbits;
-    int k, i;
-    double a, s;
+    int i, k, n = 1 << nbits;
 
     /* do it by hand */
     for (k = 0; k < n; k++) {
-        s = 0;
+        double s = 0;
         for (i = 0; i < n; i++) {
-            a = M_PI*k*(i+0.5) / n;
+            double a = M_PI * k * (i + 0.5) / n;
             s += input[i] * cos(a);
         }
         output[k] = s;
@@ -193,10 +180,8 @@ static FFTSample frandom(AVLFG *prng)
 
 static int check_diff(FFTSample *tab1, FFTSample *tab2, int n, double scale)
 {
-    int i;
-    double max= 0;
-    double error= 0;
-    int err = 0;
+    int i, err = 0;
+    double error = 0, max = 0;
 
     for (i = 0; i < n; i++) {
         double e = fabsf(tab1[i] - (tab2[i] / scale)) / RANGE;
@@ -242,27 +227,23 @@ int main(int argc, char **argv)
 {
     FFTComplex *tab, *tab1, *tab_ref;
     FFTSample *tab2;
-    int it, i, c;
-    int cpuflags;
-    int do_speed = 0;
-    int err = 1;
     enum tf_transform transform = TRANSFORM_FFT;
-    int do_inverse = 0;
     FFTContext s1, *s = &s1;
     FFTContext m1, *m = &m1;
 #if FFT_FLOAT
     RDFTContext r1, *r = &r1;
     DCTContext d1, *d = &d1;
-    int fft_size_2;
 #endif /* FFT_FLOAT */
-    int fft_nbits, fft_size;
+    int it, i, err = 1;
+    int do_speed = 0, do_inverse = 0;
+    int fft_nbits = 9, fft_size;
     double scale = 1.0;
     AVLFG prng;
+
     av_lfg_init(&prng, 1);
 
-    fft_nbits = 9;
     for(;;) {
-        c = getopt(argc, argv, "hsimrdn:f:c:");
+        int c = getopt(argc, argv, "hsimrdn:f:c:");
         if (c == -1)
             break;
         switch(c) {
@@ -291,12 +272,14 @@ int main(int argc, char **argv)
             scale = atof(optarg);
             break;
         case 'c':
-            cpuflags = av_parse_cpu_flags(optarg);
+        {
+            int cpuflags = av_parse_cpu_flags(optarg);
             if (cpuflags < 0)
                 return 1;
             av_set_cpu_flags_mask(cpuflags);
             break;
         }
+        }
     }
 
     fft_size = 1 << fft_nbits;
@@ -388,7 +371,8 @@ int main(int argc, char **argv)
 #if FFT_FLOAT
 #if CONFIG_RDFT
     case TRANSFORM_RDFT:
-        fft_size_2 = fft_size >> 1;
+    {
+        int fft_size_2 = fft_size >> 1;
         if (do_inverse) {
             tab1[         0].im = 0;
             tab1[fft_size_2].im = 0;
@@ -418,6 +402,7 @@ int main(int argc, char **argv)
             err = check_diff((float *)tab_ref, (float *)tab2, fft_size, 1.0);
         }
         break;
+    }
 #endif /* CONFIG_RDFT */
 #if CONFIG_DCT
     case TRANSFORM_DCT: