Make it a bit clearer what's user-adjustable and what's not.

[qscale] / qscale.c

diff --git a/qscale.c b/qscale.c
index 0f9598f32a29de1fed6b8ba694802a4dae1810a1..336e8c2404e984322981c814d365b54c5fcf8d69 100644 (file)
--- a/qscale.c
+++ b/qscale.c
@@ -7,12 +7,16 @@
 
 #define CACHE_LINE_FACTOR 16
 
+#ifndef M_PI
+#define M_PI 3.14159265358979323846264
+#endif
+
 double sinc(double x)
 {
-       static const double cutoff = 1.220703668e-4;  // sqrt(sqrt(eps))
+       static const double cutoff = 1.220703668e-4;  /* sqrt(sqrt(eps)) */
 
        if (abs(x) < cutoff) {
-               // For small |x|, use Taylor series instead
+               /* For small |x|, use Taylor series instead */
                const double x2 = x * x;
                const double x4 = x2 * x2;
 
@@ -62,10 +66,10 @@ void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw
                        end = w - 1;
                }
 
-               // round up so we get a multiple of four for the SSE code
+               /* round up so we get a multiple of four for the SSE code */
                int num = (end - start + 1);
                if (num % 4 != 0) {
-                       // prefer aligning it if possible
+                       /* prefer aligning it if possible */
                        if (start % 4 != 0 && start % 4 <= num % 4) {
                                num += start % 4;
                                start -= start % 4;
@@ -105,17 +109,17 @@ void hscale(float *pix, unsigned char *npix, unsigned w, unsigned h, unsigned nw
                        float acc;
                        long tmp;
                        static const float low = 0.0, high = 255.0;
-                       asm (
+                       __asm__ (
                                "pxor %1, %1               \n"
                                "xor %2, %2                \n"
-                               ".lbl2:                    \n"
+                               "0:                        \n"
                                "movups (%4,%2),%%xmm1     \n"
                                "movups (%3,%2),%%xmm2     \n"
                                "mulps %%xmm2,%%xmm1       \n"
                                "addps %%xmm1,%1           \n"
                                "add $16,%2                \n"
                                "dec %5                    \n"
-                               "jnz .lbl2                 \n"
+                               "jnz 0b                    \n"
                                "haddps %1,%1              \n"
                                "haddps %1,%1              \n"
                                "maxss %6,%1               \n"
@@ -223,7 +227,7 @@ void vscale(unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nh
                         * xmm4: current filter coefficient
                         * xmm5, xmm6, xmm7: scratchpad
                         */
-                       asm (
+                       __asm__ (
                                /* clear */
                                "pxor %%xmm0, %%xmm0          \n"
                                "pxor %%xmm1, %%xmm1          \n"
@@ -231,7 +235,7 @@ void vscale(unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nh
                                "pxor %%xmm3, %%xmm3          \n"
 
                                /* main loop */
-                               ".lbl:                        \n"
+                               "0:                           \n"
                                
                                /* a zero is useful during unpacking */
                                "pxor %%xmm4, %%xmm4          \n"
@@ -290,7 +294,7 @@ void vscale(unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nh
                                "add $4, %2                   \n"
                                "add %3, %0                   \n"
                                "dec %1                       \n"
-                               "jnz .lbl                     \n"
+                               "jnz 0b                       \n"
 
                                /* store the values */
                                "movaps %%xmm0, (%4)          \n"
@@ -332,13 +336,27 @@ void vscale(unsigned char *pix, float *npix, unsigned w, unsigned h, unsigned nh
 
 int main(int argc, char **argv)
 {
+       /* user-settable parameters */
        unsigned nominal_w = atoi(argv[1]);
        unsigned nominal_h = atoi(argv[2]);
-
        unsigned samp_h0 = 2, samp_v0 = 2;
        unsigned samp_h1 = 1, samp_v1 = 1;
        unsigned samp_h2 = 1, samp_v2 = 1;
-       unsigned max_samp_h = 2, max_samp_v = 2;
+       unsigned jpeg_quality = 85;
+       /* end */
+
+       unsigned max_samp_h, max_samp_v;
+       max_samp_h = samp_h0;
+       if (samp_h1 > max_samp_h)
+               max_samp_h = samp_h1;
+       if (samp_h2 > max_samp_h)
+               max_samp_h = samp_h2;
+       
+       max_samp_v = samp_v0;
+       if (samp_v1 > max_samp_v)
+               max_samp_v = samp_v1;
+       if (samp_v2 > max_samp_v)
+               max_samp_v = samp_v2;
 
        unsigned nw0 = nominal_w * samp_h0 / max_samp_h, nh0 = nominal_h * samp_v0 / max_samp_v;
        unsigned nw1 = nominal_w * samp_h1 / max_samp_h, nh1 = nominal_h * samp_v1 / max_samp_v;
@@ -453,7 +471,7 @@ int main(int argc, char **argv)
                int i;
 
                for (i = 0; i < max_lines; ++i) {
-                       // simple edge extension
+                       /* simple edge extension */
                        int yline = i + blocks*DCTSIZE*cinfo.comp_info[0].v_samp_factor;
                        if (yline > nh0 - 1)
                                yline = nh0 - 1;