[devel] Reformatted/rearranged pngvalid.c to assist use of progressive reader.
diff --git a/ANNOUNCE b/ANNOUNCE
index 9e646ee..3a4094b 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -369,6 +369,7 @@
Revised CMakeLists.txt to make symlinks instead of copies when installing.
Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
Implemented memory checks within pngvalid
+ Reformatted/rearranged pngvalid.c to assist use of progressive reader.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net:
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diff --git a/CHANGES b/CHANGES
index a4e0e29..cc83f07 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3006,6 +3006,7 @@
Revised CMakeLists.txt to make symlinks instead of copies when installing.
Changed PNG_LIB_NAME from pngNN to libpngNN in CMakeLists.txt (Philip Lowman)
Implemented memory checks within pngvalid
+ Reformatted/rearranged pngvalid.c to assist use of progressive reader.
Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit
diff --git a/pngvalid.c b/pngvalid.c
index ac9e3c0..6171915 100644
--- a/pngvalid.c
+++ b/pngvalid.c
@@ -882,7 +882,6 @@
store_error, store_warning, &ps->read_memory_pool, store_malloc,
store_free);
store_read_set(ps, id);
- png_set_read_fn(ps->pread, ps, store_read);
if (ppi != NULL)
*ppi = ps->piread = png_create_info_struct(ps->pread);
@@ -1349,8 +1348,6 @@
Try
{
- png_set_read_fn(ppSafe, pm, modifier_read);
-
pm->state = modifier_start;
pm->bit_depth = 0;
pm->colour_type = 255;
@@ -1843,152 +1840,162 @@
make_error(&pm->this, 6, 3, 4);
}
-
+/* A single test run checking the standard image to ensure it is not damaged. */
static void
-test_standard(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
+standard_test(png_store* PNG_CONST ps, png_byte PNG_CONST colour_type,
+ png_byte PNG_CONST bit_depth)
+{
+ context(ps, fault);
+ png_structp pp;
+ png_infop pi;
+
+ /* Get a png_struct for writing the image. */
+ pp = set_store_for_read(ps, &pi, FILEID(colour_type, bit_depth),
+ "standard");
+
+ if (pp == NULL)
+ return;
+
+ /* Do the honourable write stuff, protected by a local catch */
+ Try
+ {
+ png_uint_32 h = standard_height(pp, colour_type, bit_depth), y;
+ size_t cb;
+
+ /* Introduce the correct read function. */
+ png_set_read_fn(ps->pread, ps, store_read);
+
+ /* Check the header values: */
+ png_read_info(pp, pi);
+
+ if (png_get_image_width(pp, pi) !=
+ standard_width(pp, colour_type, bit_depth))
+ png_error(pp, "validate: image width changed");
+
+ if (png_get_image_height(pp, pi) != h)
+ png_error(pp, "validate: image height changed");
+
+ if (png_get_bit_depth(pp, pi) != bit_depth)
+ png_error(pp, "validate: bit depth changed");
+
+ if (png_get_color_type(pp, pi) != colour_type)
+ png_error(pp, "validate: color type changed");
+
+ if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE)
+ png_error(pp, "validate: filter type changed");
+
+ if (png_get_interlace_type(pp, pi) != PNG_INTERLACE_NONE)
+ png_error(pp, "validate: interlacing changed");
+
+ if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE)
+ png_error(pp, "validate: compression type changed");
+
+ if (png_set_interlace_handling(pp) != 1)
+ png_error(pp, "validate: interlacing unexpected");
+
+ if (colour_type == 3) /* palette */
+ {
+ png_colorp pal;
+ int num;
+
+ if (png_get_PLTE(pp, pi, &pal, &num) & PNG_INFO_PLTE)
+ {
+ int i;
+
+ if (num != 256)
+ png_error(pp,
+ "validate: color type 3 PLTE chunk size changed");
+
+ for (i=0; i<num; ++i)
+ if (pal[i].red != i || pal[i].green != i || pal[i].blue != i)
+ png_error(pp, "validate: color type 3 PLTE chunk changed");
+ }
+
+ else
+ png_error(pp, "validate: missing PLTE with color type 3");
+ }
+
+ cb = standard_rowsize(pp, colour_type, bit_depth);
+ png_start_read_image(pp);
+
+ if (png_get_rowbytes(pp, pi) != cb)
+ png_error(pp, "validate: row size changed");
+
+ else for (y=0; y<h; ++y)
+ {
+ png_byte std[STD_ROWMAX];
+ png_byte read[STD_ROWMAX];
+ png_byte display[STD_ROWMAX];
+
+ standard_row(pp, std, colour_type, bit_depth, y);
+ png_read_row(pp, read, display);
+
+ if (memcmp(std, read, cb) != 0)
+ {
+ char msg[64];
+ sprintf(msg, "validate: PNG image row %d (of %d) changed", y,
+ h);
+ png_error(pp, msg);
+ }
+
+ if (memcmp(std, display, cb) != 0)
+ {
+ char msg[64];
+ sprintf(msg, "validate: transformed row %d (of %d) changed", y,
+ h);
+ png_error(pp, msg);
+ }
+ }
+
+ png_read_end(pp, pi);
+
+ store_read_reset(ps);
+ }
+
+ Catch(fault)
+ {
+ store_read_reset(ps);
+ if (ps != fault) Throw fault;
+ }
+}
+
+static int
+test_standard(png_modifier* PNG_CONST pm, png_byte PNG_CONST colour_type,
int PNG_CONST bdloIn, int PNG_CONST bdhi)
{
volatile int bdlo = bdloIn;
for (; bdlo <= bdhi; ++bdlo)
{
- context(ps, fault);
- PNG_CONST png_byte bit_depth = DEPTH(bdlo);
- png_structp pp;
- png_infop pi;
+ standard_test(&pm->this, colour_type, DEPTH(bdlo));
- /* Get a png_struct for writing the image. */
- pp = set_store_for_read(ps, &pi, FILEID(colour_type, bit_depth),
- "standard");
-
- if (pp == NULL)
- return;
-
- /* Do the honourable write stuff, protected by a local catch */
- Try
- {
- png_uint_32 h = standard_height(pp, colour_type, bit_depth), y;
- size_t cb;
-
- /* Check the header values: */
- png_read_info(pp, pi);
-
- if (png_get_image_width(pp, pi) !=
- standard_width(pp, colour_type, bit_depth))
- png_error(pp, "validate: image width changed");
-
- if (png_get_image_height(pp, pi) != h)
- png_error(pp, "validate: image height changed");
-
- if (png_get_bit_depth(pp, pi) != bit_depth)
- png_error(pp, "validate: bit depth changed");
-
- if (png_get_color_type(pp, pi) != colour_type)
- png_error(pp, "validate: color type changed");
-
- if (png_get_filter_type(pp, pi) != PNG_FILTER_TYPE_BASE)
- png_error(pp, "validate: filter type changed");
-
- if (png_get_interlace_type(pp, pi) != PNG_INTERLACE_NONE)
- png_error(pp, "validate: interlacing changed");
-
- if (png_get_compression_type(pp, pi) != PNG_COMPRESSION_TYPE_BASE)
- png_error(pp, "validate: compression type changed");
-
- if (png_set_interlace_handling(pp) != 1)
- png_error(pp, "validate: interlacing unexpected");
-
- if (colour_type == 3) /* palette */
- {
- png_colorp pal;
- int num;
-
- if (png_get_PLTE(pp, pi, &pal, &num) & PNG_INFO_PLTE)
- {
- int i;
-
- if (num != 256)
- png_error(pp,
- "validate: color type 3 PLTE chunk size changed");
-
- for (i=0; i<num; ++i)
- if (pal[i].red != i || pal[i].green != i || pal[i].blue != i)
- png_error(pp, "validate: color type 3 PLTE chunk changed");
- }
-
- else
- png_error(pp, "validate: missing PLTE with color type 3");
- }
-
- cb = standard_rowsize(pp, colour_type, bit_depth);
- png_start_read_image(pp);
-
- if (png_get_rowbytes(pp, pi) != cb)
- png_error(pp, "validate: row size changed");
-
- else for (y=0; y<h; ++y)
- {
- png_byte std[STD_ROWMAX];
- png_byte read[STD_ROWMAX];
- png_byte display[STD_ROWMAX];
-
- standard_row(pp, std, colour_type, bit_depth, y);
- png_read_row(pp, read, display);
-
- if (memcmp(std, read, cb) != 0)
- {
- char msg[64];
- sprintf(msg, "validate: PNG image row %d (of %d) changed", y,
- h);
- png_error(pp, msg);
- }
-
- if (memcmp(std, display, cb) != 0)
- {
- char msg[64];
- sprintf(msg, "validate: transformed row %d (of %d) changed", y,
- h);
- png_error(pp, msg);
- }
- }
-
- png_read_end(pp, pi);
-
- store_read_reset(ps);
- }
-
- Catch(fault)
- {
- store_read_reset(ps);
- if (ps != fault) Throw fault;
- }
+ if (fail(pm))
+ return 0;
}
+
+ return 1; /*keep going*/
}
static void
perform_standard_test(png_modifier *pm)
{
- test_standard(&pm->this, 0, 0, 4);
-
- if (fail(pm))
+ /* 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))
return;
- test_standard(&pm->this, 2, 3, 4);
-
- if (fail(pm))
+ if (!test_standard(pm, 2, 3, 4))
return;
- test_standard(&pm->this, 3, 0, 3);
-
- if (fail(pm))
+ if (!test_standard(pm, 3, 0, 3))
return;
- test_standard(&pm->this, 4, 3, 4);
-
- if (fail(pm))
+ if (!test_standard(pm, 4, 3, 4))
return;
- test_standard(&pm->this, 6, 3, 4);
+ if (!test_standard(pm, 6, 3, 4))
+ return;
}
@@ -2135,7 +2142,9 @@
pm->modifications = &me->this;
}
-/* maxabs: maximum absolute error as a fraction
+/* A single test run checking a gamma transformation.
+ *
+ * maxabs: maximum absolute error as a fraction
* maxout: maximum output error in the output units
* maxpc: maximum percentage error (as a percentage)
*/
@@ -2174,6 +2183,9 @@
pp = set_modifier_for_read(pm, &pi, FILEID(colour_type, bit_depth), name);
if (pp == NULL) Throw &pm->this;
+ /* Se the correct read function. */
+ png_set_read_fn(pp, pm, modifier_read);
+
/* Set up gamma processing. */
png_set_gamma(pp, screen_gamma, file_gamma);
