[devel] Revised pngvalid.c to test 16-to-8 bit-depth reduction.
diff --git a/pngvalid.c b/pngvalid.c
index b8a792f..9a3d524 100644
--- a/pngvalid.c
+++ b/pngvalid.c
@@ -145,7 +145,23 @@
log2depth(DEPTH_FROM_ID(id)), INTERLACE_FROM_ID(id));
}
-/* Convenience API to list valid formats: */
+/* Convenience API and defines to list valid formats. Note that 16 bit read and
+ * write support is required to do 16 bit read tests (we must be able to make a
+ * 16 bit image to test!)
+ */
+#ifdef PNG_WRITE_16BIT_SUPPORTED
+# define WRITE_BDHI 4
+# ifdef PNG_READ_16BIT_SUPPORTED
+# define READ_BDHI 4
+# define DO_16BIT
+# endif
+#else
+# define WRITE_BDHI 3
+#endif
+#ifndef DO_16BIT
+# define READ_BDHI 3
+#endif
+
static int
next_format(png_bytep colour_type, png_bytep bit_depth)
{
@@ -158,7 +174,11 @@
*bit_depth = (png_byte)(*bit_depth << 1);
/* Palette images are restricted to 8 bit depth */
- if (*bit_depth <= 8 || (*colour_type != 3 && *bit_depth <= 16))
+ if (*bit_depth <= 8
+# ifdef DO_16BIT
+ || (*colour_type != 3 && *bit_depth <= 16)
+# endif
+ )
return 1;
/* Move to the next color type, or return 0 at the end. */
@@ -1207,7 +1227,7 @@
/* Rely on the memset for all the other fields - there are no pointers */
}
-/* One modification strucutre must be provided for each chunk to be modified (in
+/* One modification structure must be provided for each chunk to be modified (in
* fact more than one can be provided if multiple separate changes are desired
* for a single chunk.) Modifications include adding a new chunk when a
* suitable chunk does not exist.
@@ -1920,11 +1940,11 @@
/* Arguments are colour_type, low bit depth, high bit depth
*/
- make_standard(ps, 0, 0, 4);
- make_standard(ps, 2, 3, 4);
- make_standard(ps, 3, 0, 3);
- make_standard(ps, 4, 3, 4);
- make_standard(ps, 6, 3, 4);
+ make_standard(ps, 0, 0, WRITE_BDHI);
+ make_standard(ps, 2, 3, WRITE_BDHI);
+ make_standard(ps, 3, 0, 3/*palette: max 8 bits*/);
+ make_standard(ps, 4, 3, WRITE_BDHI);
+ make_standard(ps, 6, 3, WRITE_BDHI);
}
/* Tests - individual test cases */
@@ -2111,19 +2131,19 @@
/* Need to do this here because we just write in this test. */
safecat(pm->this.test, sizeof pm->this.test, 0, "error test");
- if (!make_errors(pm, 0, 0, 4))
+ if (!make_errors(pm, 0, 0, WRITE_BDHI))
return;
- if (!make_errors(pm, 2, 3, 4))
+ if (!make_errors(pm, 2, 3, WRITE_BDHI))
return;
if (!make_errors(pm, 3, 0, 3))
return;
- if (!make_errors(pm, 4, 3, 4))
+ if (!make_errors(pm, 4, 3, WRITE_BDHI))
return;
- if (!make_errors(pm, 6, 3, 4))
+ if (!make_errors(pm, 6, 3, WRITE_BDHI))
return;
}
@@ -2537,19 +2557,19 @@
/* Test each colour type over the valid range of bit depths (expressed as
* log2(bit_depth) in turn, stop as soon as any error is detected.
*/
- if (!test_standard(pm, 0, 0, 4))
+ if (!test_standard(pm, 0, 0, READ_BDHI))
return;
- if (!test_standard(pm, 2, 3, 4))
+ if (!test_standard(pm, 2, 3, READ_BDHI))
return;
if (!test_standard(pm, 3, 0, 3))
return;
- if (!test_standard(pm, 4, 3, 4))
+ if (!test_standard(pm, 4, 3, READ_BDHI))
return;
- if (!test_standard(pm, 6, 3, 4))
+ if (!test_standard(pm, 6, 3, READ_BDHI))
return;
}
@@ -3284,7 +3304,7 @@
/* The only interesting cases are colour and grayscale, alpha is ignored here
* for overall speed. Only bit depths 8 and 16 are tested.
*/
- for (sbit=pm->sbitlow; sbit<16; ++sbit)
+ for (sbit=pm->sbitlow; sbit<(1<<READ_BDHI); ++sbit)
{
unsigned int i, j;
@@ -3311,6 +3331,7 @@
return;
}
+#ifdef DO_16BIT
gamma_transform_test(pm, 0, 16, pm->interlace_type,
1/pm->gammas[i], pm->gammas[j], sbit, speed,
pm->use_input_precision_sbit, 0/*strip16*/);
@@ -3324,12 +3345,17 @@
if (fail(pm))
return;
+#endif
}
}
}
}
}
+/* Note that this requires a 16 bit source image but produces 8 bit output, so
+ * we only need the 16bit write support.
+ */
+#ifdef PNG_WRITE_16BIT_SUPPORTED
static void perform_gamma_strip16_tests(png_modifier *pm, int speed)
{
# ifndef PNG_MAX_GAMMA_8
@@ -3382,6 +3408,7 @@
}
}
}
+#endif
static void
perform_gamma_test(png_modifier *pm, int speed, int summary)
@@ -3404,9 +3431,11 @@
printf(" 2 bit gray: %.5f\n", pm->error_gray_2);
printf(" 4 bit gray: %.5f\n", pm->error_gray_4);
printf(" 8 bit gray: %.5f\n", pm->error_gray_8);
- printf(" 16 bit gray: %.5f\n", pm->error_gray_16);
printf(" 8 bit color: %.5f\n", pm->error_color_8);
+#ifdef DO_16BIT
+ printf(" 16 bit gray: %.5f\n", pm->error_gray_16);
printf(" 16 bit color: %.5f\n", pm->error_color_16);
+#endif
}
/* The sbit tests produce much larger errors: */
@@ -3423,16 +3452,16 @@
printf(" 2 bit gray: %.5f\n", pm->error_gray_2);
printf(" 4 bit gray: %.5f\n", pm->error_gray_4);
printf(" 8 bit gray: %.5f\n", pm->error_gray_8);
+ printf(" 8 bit color: %.5f\n", pm->error_color_8);
}
+#ifdef DO_16BIT
printf(" 16 bit gray: %.5f\n", pm->error_gray_16);
-
- if (pm->sbitlow < 8U)
- printf(" 8 bit color: %.5f\n", pm->error_color_8);
-
printf(" 16 bit color: %.5f\n", pm->error_color_16);
+#endif
}
+#ifdef PNG_WRITE_16BIT_SUPPORTED
/* The 16 to 8 bit strip operations: */
pm->error_gray_2 = pm->error_gray_4 = pm->error_gray_8 = pm->error_gray_16 =
pm->error_color_8 = pm->error_color_16 = 0;
@@ -3443,6 +3472,7 @@
printf(" 16 bit gray: %.5f\n", pm->error_gray_16);
printf(" 16 bit color: %.5f\n", pm->error_color_16);
}
+#endif
}
/* main program */
