uint32 hio_read24b(HIO_HANDLE *h)
{
if (HIO_HANDLE_TYPE(h) == HIO_HANDLE_TYPE_FILE) {
return read24b(h->f);
} else {
ptrdiff_t can_read = CAN_READ(h);
if (can_read >= 3) {
uint32 n = readmem24b(h->start + h->pos);
h->pos += 3;
return n;
} else {
h->pos += can_read;
return EOF;
}
}
}
static int decrunch_pp(FILE *f, FILE *fo)
{
uint8 *packed /*, *unpacked */;
int plen, unplen;
struct stat st;
if (fo == NULL)
goto err;
if (fstat(fileno(f), &st) < 0)
goto err;
plen = st.st_size;
//counter = 0;
/* Amiga longwords are only on even addresses.
* The pp20 data format has the length stored in a longword
* after the packed data, so I guess a file that is not even
* is probl not a valid pp20 file. Thanks for Don Adan for
* reminding me on this! - mld
*/
if ((plen != (plen / 2) * 2)) {
/*fprintf(stderr, "filesize not even\n");*/
goto err;
}
packed = malloc(plen);
if (packed == NULL) {
/*fprintf(stderr, "can't allocate memory for packed data\n");*/
goto err;
}
if (fread(packed, 1, plen, f) != plen) {
goto err1;
}
/* Hmmh... original pp20 only support efficiency from 9 9 9 9 up to 9 10 12 13, afaik
* but the xfd detection code says this... *sigh*
*
* move.l 4(a0),d0
* cmp.b #9,d0
* blo.b .Exit
* and.l #$f0f0f0f0,d0
* bne.s .Exit
*/
if (((packed[4] < 9) || (packed[5] < 9) || (packed[6] < 9) || (packed[7] < 9))) {
/*fprintf(stderr, "invalid efficiency\n");*/
goto err1;
}
if (((readmem24b(packed +4) * 256 + packed[7]) & 0xf0f0f0f0) != 0 ) {
/*fprintf(stderr, "invalid efficiency(?)\n");*/
goto err1;
}
unplen = readmem24b(packed + plen - 4);
if (!unplen) {
/*fprintf(stderr, "not a powerpacked file\n");*/
goto err1;
}
if (ppdepack (packed, plen, fo) == -1) {
/*fprintf(stderr, "error while decrunching data...");*/
goto err1;
}
free (packed);
return 0;
err1:
free(packed);
err:
return -1;
}
static int ppdepack(uint8 *data, size_t len, FILE *fo)
{
/* PP FORMAT:
* 1 longword identifier 'PP20' or 'PX20'
* [1 word checksum (if 'PX20') $ssss]
* 1 longword efficiency $eeeeeeee
* X longwords crunched file $cccccccc,$cccccccc,...
* 1 longword decrunch info 'decrlen' << 8 | '8 bits other info'
*/
int success=0;
uint8 *output /*, crypted*/;
uint32 outlen;
if (len < 16) {
/*fprintf(stderr, "File is too short to be a PP file (%u bytes)\n", len);*/
return -1;
}
if (data[0]=='P' && data[1]=='P' && data[2]=='2' && data[3]=='0') {
if (len & 0x03) {
/*fprintf(stderr, "File length is not a multiple of 4\n");*/
return -1;
}
/*crypted = 0;*/
}
#if 0
else if (data[0]=='P' && data[1]=='X' && data[2]=='2' && data[3]=='0') {
if ((len-2) & 0x03) {
/*fprintf(stderr, "(file length - 2) is not a multiple of 4\n");*/
return -1;
}
crypted = 1;
}
#endif
else {
/*fprintf(stderr, "File does not have the PP signature\n");*/
return -1;
}
outlen = readmem24b(data + len - 4);
/* fprintf(stderr, "decrunched length = %u bytes\n", outlen); */
output = (uint8 *) malloc(outlen);
if (output == NULL) {
/*fprintf(stderr, "out of memory!\n");*/
return -1;
}
/* if (crypted == 0) { */
/*fprintf(stderr, "not encrypted, decrunching anyway\n"); */
if (ppDecrunch(&data[8], output, &data[4], len-12, outlen, data[len-1])) {
/* fprintf(stderr, "Decrunch successful! "); */
savefile(fo, (void *) output, outlen);
} else {
success=-1;
}
/*} else {
success=-1;
}*/
free(output);
return success;
}
