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bug in gflSaveBitmapIntoMemory() (tiff only?)
Posted: Sat Mar 24, 2007 5:48 pm
by stolarz
Code: Select all
unsigned char* data;
unsigned long length;
gflSaveBitmapIntoMemory(&data, &length, ...
I don't know if it's only for tiff but with tiff and lzw 'length' is bigger than the actual allocated block of memory. therefore
Code: Select all
unsigned char * new_block = malloc(length);
for (int i=0; i<length; i++) new_block[i] = data[i];
causes my proggy to crash. I wrote a simple test program that loaded a picture (a big one, 2304 x 1728) and saved to memory and also saved to disk. saved picture's disk size was 11106543 bytes and picture in mem had 11120367 bytes.
i temporarily solved this with
Code: Select all
data = gflMemoryRealloc(data, length);
and copying the data to new location does'n crash anymore.
kRyszard
BTW: why is that the controls on this page are sometimes in english and sometimes in french? they were even in russian once!
Re: bug in gflSaveBitmapIntoMemory() (tiff only?)
Posted: Sun Mar 25, 2007 11:30 pm
by XnTriq
stolarz wrote:BTW: why is that the controls on this page are sometimes in english and sometimes in french? they were even in russian once!
[Bug] Forum language (DFLS)
what if...
Posted: Mon Mar 26, 2007 9:42 am
by stolarz
yeah, and what if length is less than the size of allocated memory? gflRealloc will crop my data
Re: bug in gflSaveBitmapIntoMemory() (tiff only?)
Posted: Tue Mar 27, 2007 1:45 am
by xnview
stolarz wrote:Code: Select all
unsigned char* data;
unsigned long length;
gflSaveBitmapIntoMemory(&data, &length, ...
I don't know if it's only for tiff but with tiff and lzw 'length' is bigger than the actual allocated block of memory. therefore
Code: Select all
unsigned char * new_block = malloc(length);
for (int i=0; i<length; i++) new_block[i] = data[i];
causes my proggy to crash. I wrote a simple test program that loaded a picture (a big one, 2304 x 1728) and saved to memory and also saved to disk. saved picture's disk size was 11106543 bytes and picture in mem had 11120367 bytes.
i temporarily solved this with
Code: Select all
data = gflMemoryRealloc(data, length);
and copying the data to new location does'n crash anymore.
Could you send me your test program?
Re: bug in gflSaveBitmapIntoMemory() (tiff only?)
Posted: Tue Mar 27, 2007 5:47 pm
by stolarz
xnview wrote:Could you send me your test program?
emm.... d'you mean the source? or the executable?
here's the source:
Code: Select all
#include <stdio>
#include "libgfl.h"
void main() {
printf("hello\n");
GFL_ERROR init = gflLibraryInit();
if (GFL_NO_ERROR != init) {
printf("error: %d\n", init);
return;
}
printf("init ok\n");
gflEnableLZW(GFL_TRUE);
printf("version: %s\n", gflGetVersion());
printf("version of libformat: %s\n", gflGetVersionOfLibformat());
GFL_ERROR e1;
int tiff = gflGetFormatIndexByName("tiff");
printf("format index: %d\n", tiff);
// load picture
GFL_BITMAP *thebitmap = NULL;
GFL_LOAD_PARAMS lp1;
gflGetDefaultLoadParams(&lp1);
lp1.FormatIndex = -1;
e1 = gflLoadBitmap("DSC04034.jpg", &thebitmap, &lp1, NULL);
if (GFL_NO_ERROR != e1) {
printf("error: %d\n", e1);
} else {
GFL_SAVE_PARAMS sp1;
// save to disk
printf("saving to file\n");
gflGetDefaultSaveParams(&sp1);
sp1.FormatIndex = tiff;
sp1.Compression = GFL_LZW;
e1 = gflSaveBitmap("dsc04034.tiff", thebitmap, &sp1);
if (GFL_NO_ERROR == e1) {
printf("saved\n");
} else {
printf("error: %d\n", e1);
}
// save to mem
printf("saving to mem\n");
gflGetDefaultSaveParams(&sp1);
sp1.FormatIndex = tiff;
sp1.Compression = GFL_LZW;
unsigned char* data;
unsigned long length;
e1 = gflSaveBitmapIntoMemory(&data, &length, thebitmap, &sp1);
if (GFL_NO_ERROR == e1) {
printf("saved %d bytes\n", length);
gflMemoryFree(data);
printf("mem freed\n");
} else {
printf("error: %d\n", e1);
}
printf("freeing bitmap\n");
gflFreeBitmap(thebitmap);
printf("freed\n");
}
gflLibraryExit();
}
the result is usually sth like:
Code: Select all
hello
init ok
version: 2.67
version of libformat: 4.77
format index: 2
saving to file
saved
saving to mem
saved 11120367 bytes
mem freed
freeing bitmap
freed
i tried other formats aswell. the results are:
Code: Select all
2304 x 1728, tiff:
disk - 11106543
mem - 11120367
480 x 640, tiff:
disk - 948768
mem - 949792
480 x 640, tiff, no lzw:
disk - 922872
mem - 923896
480 x 640, jpeg:
both same sizes - 37635
png - same sizes...
Oh, I said the program crashes on:
Code: Select all
char u = data[length-1];
printf("%d\n", u);
well this time it didn't, but possibly it depends on the compiler. for this little proggy i used Borland Free CmdLine Tools but previously i was using microsoft's some kind of .NET thing to write managed wrapper for gfl...
Re: bug in gflSaveBitmapIntoMemory() (tiff only?)
Posted: Wed Mar 28, 2007 12:54 pm
by xnview
stolarz wrote:xnview wrote:Could you send me your test program?
emm.... d'you mean the source? or the executable?
here's the source:
I've tried but have no crash...
Re: bug in gflSaveBitmapIntoMemory() (tiff only?)
Posted: Wed Mar 28, 2007 7:30 pm
by stolarz
xnview wrote:I've tried but have no crash...
Yes, but the sizes in mem and disk differ and it's just a matter of luck if there is a crash or not because of different memory allocating algorithms: your first malloc in a program actually allocates smallest allocable block, like f.e. 0x1000 bytes, so
Code: Select all
char* a = (char*) malloc(0x10);
char b = a[0xfff];
doesn't cause the memory protection fault, but followed by
Code: Select all
char* c = (char*)malloc(0xf00);
char* d = (char*)malloc(0x10);
char e = d[0x100];
may cause errors.
Re: bug in gflSaveBitmapIntoMemory() (tiff only?)
Posted: Thu Mar 29, 2007 7:11 am
by xnview
stolarz wrote:xnview wrote:I've tried but have no crash...
Yes, but the sizes in mem and disk differ and it's just a matter of luck if there
Ok, it's a little bug...
is a crash or not because of different memory allocating algorithms: your first malloc in a program actually allocates smallest allocable block, like f.e. 0x1000 bytes, so
Code: Select all
char* a = (char*) malloc(0x10);
char b = a[0xfff];
doesn't cause the memory protection fault, but followed by
Code: Select all
char* c = (char*)malloc(0xf00);
char* d = (char*)malloc(0x10);
char e = d[0x100];
may cause errors.
I can't reproduce the crash
Send me a PM with your email, i would like to send you a test version...