Can someone, *please*, explain the movie (and subtitle) hash algorithms in plain english?
I've checked the Wiki and although there are code examples they mostly don't work out-of-the-box. The only one I've been able to manage to compile properly is the C++ and the results I get are not even close to what SubDownloaderFrame.py is reporting.
So now I don't understand, in plain language, what the movie hash algorithm is supposed to be. I'm baffled.
I think it would be a good addition to the Wiki and the docs, personally.
I now have a command line tool that can't actually do anything because as much as I've moved things around none of the resulting hashes actually work.
FWIW, if anyone not in Windows wants to try and compile the C++ this is the code that finally did it for me (again, not working for me at the moment, the hashes are all wrong):
Code: Select all
#include <inttypes.h> // The actual library that contains the proper data types
#include <iostream>
#include <fstream>
using namespace std;
int MAX(int x, int y)
{
if((x) > (y))
return x;
else
return y;
}
uint64_t compute_hash(ifstream& f)
{
uint64_t hash, fsize;
f.seekg(0, ios::end);
fsize = f.tellg();
f.seekg(0, ios::beg);
hash = fsize;
int tmp;
int i;
for(tmp = 0, i = 0; i < 65536/sizeof(tmp) && f.read((char*)&tmp, sizeof(tmp)); i++, hash += tmp);
f.seekg(MAX(0, (uint64_t)fsize - 65536), ios::beg);
for(tmp = 0, i = 0; i < 65536/sizeof(tmp) && f.read((char*)&tmp, sizeof(tmp)); i++, hash += tmp);
return hash;
}
int main(int argc, char *argv)
{
ifstream f;
uint64_t myhash;
f.open("/Volumes/video/TV/Lost/Lost S03E01.avi", ios::in|ios::binary|ios::ate); // Replace as adequate, obviously
if (!f.is_open()) {
cerr << "Error opening file" << endl;
return 1;
}
myhash = compute_hash(f);
typedef char TCHAR;
// Set a test var to ensure datatype is unsigned 64 int
TCHAR *test = "1234567890123456789";
printf("in main(): test = <%s>\n", test);
printf("sizeof(uint64_t) = %d\n", sizeof(uint64_t));
// Try all possible printf combinations we can think of
printf("I64d: %I64d\n", myhash); // Borland BCC or MS VC++
printf("Ld: %Ld\n", myhash); // Borland BCC
printf("lld: %lld\n", myhash); // gcc
printf("I64x: %016I64x(hex)\n", myhash); // Borland BCC or Microsoft VC++ */
printf("Lx: %016Lx(hex)\n", myhash);// Borland BCC
printf("llx: %016llx(hex)\n", myhashç); // gcc
f.close();
return 0;
}
Supposedly, at least the very last one of the results should be giving me the proper result in gcc. But no. Because from SubDownloader what is being reported as the moviehash is 332c83338820e4f6.in main(): test = <1234567890123456789>
sizeof(uint64_t) = 8
I64d: I64d
Ld: -1152560871
lld: 8279544385817
I64x: 000000000000000I64x(hex)
Lx: 00000000bb4d5119(hex)
llx: 00000787bb4d5119(hex)
I may be missing something non-obvious here. Could someone help me? English or spanish is OK. I just need to know the actual algorihtm for the movie hash in plain language. No code.
