--- /dev/null
+/* MikMod sound library (c) 2003-2015 Raphael Assenat and others -
+ * see AUTHORS file for a complete list.
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+/* amiga Powerpack PP20 decompression support
+ *
+ * Code from Heikki Orsila's amigadepack 0.02
+ * based on code by Stuart Caie <kyzer@4u.net>
+ * This software is in the Public Domain
+ *
+ * Modified for xmp by Claudio Matsuoka, 08/2007
+ * - merged mld's checks from the old depack sources. Original credits:
+ * - corrupt file and data detection
+ * (thanks to Don Adan and Dirk Stoecker for help and infos)
+ * - implemeted "efficiency" checks
+ * - further detection based on code by Georg Hoermann
+ *
+ * Modified for xmp by Claudio Matsuoka, 05/2013
+ * - decryption code removed
+ *
+ * Modified for libmikmod by O. Sezer, Apr. 2015, with a few extra bits
+ * from the libmodplug library by Olivier Lapicque.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include <stdio.h>
+#ifdef HAVE_MEMORY_H
+#include <memory.h>
+#endif
+#include <string.h>
+
+#include "mikmod_internals.h"
+
+#ifdef SUNOS
+extern int fprintf(FILE *, const char *, ...);
+#endif
+
+#define PP_READ_BITS(nbits, var) do { \
+ bit_cnt = (nbits); \
+ while (bits_left < bit_cnt) { \
+ if (buf_src < src) return 0; /* out of source bits */ \
+ bit_buffer |= (*--buf_src << bits_left); \
+ bits_left += 8; \
+ } \
+ (var) = 0; \
+ bits_left -= bit_cnt; \
+ while (bit_cnt--) { \
+ (var) = ((var) << 1) | (bit_buffer & 1); \
+ bit_buffer >>= 1; \
+ } \
+} while(0)
+
+#define PP_BYTE_OUT(byte) do { \
+ if (out <= dest) return 0; /* output overflow */ \
+ *--out = (byte); \
+ written++; \
+} while (0)
+
+static BOOL ppDecrunch(const UBYTE *src, UBYTE *dest,
+ const UBYTE *offset_lens,
+ ULONG src_len, ULONG dest_len,
+ UBYTE skip_bits)
+{
+ ULONG bit_buffer, x, todo, offbits, offset, written;
+ const UBYTE *buf_src;
+ UBYTE *out, *dest_end, bits_left, bit_cnt;
+
+ /* set up input and output pointers */
+ buf_src = src + src_len;
+ out = dest_end = dest + dest_len;
+
+ written = 0;
+ bit_buffer = 0;
+ bits_left = 0;
+
+ /* skip the first few bits */
+ PP_READ_BITS(skip_bits, x);
+
+ /* while there are input bits left */
+ while (written < dest_len) {
+ PP_READ_BITS(1, x);
+ if (x == 0) {
+ /* 1bit==0: literal, then match. 1bit==1: just match */
+ todo = 1; do { PP_READ_BITS(2, x); todo += x; } while (x == 3);
+ while (todo--) { PP_READ_BITS(8, x); PP_BYTE_OUT(x); }
+
+ /* should we end decoding on a literal, break out of the main loop */
+ if (written == dest_len) break;
+ }
+
+ /* match: read 2 bits for initial offset bitlength / match length */
+ PP_READ_BITS(2, x);
+ offbits = offset_lens[x];
+ todo = x+2;
+ if (x == 3) {
+ PP_READ_BITS(1, x);
+ if (x==0) offbits = 7;
+ PP_READ_BITS(offbits, offset);
+ do { PP_READ_BITS(3, x); todo += x; } while (x == 7);
+ }
+ else {
+ PP_READ_BITS(offbits, offset);
+ }
+ if ((out + offset) >= dest_end) return 0; /* match overflow */
+ while (todo--) { x = out[offset]; PP_BYTE_OUT(x); }
+ }
+
+ /* all output bytes written without error */
+ return 1;
+ /* return (src == buf_src) ? 1 : 0; */
+}
+
+BOOL PP20_Unpack(MREADER* reader, void** out, long* outlen)
+{
+ ULONG srclen, destlen;
+ UBYTE *destbuf, *srcbuf;
+ UBYTE tmp[4], skip;
+ BOOL ret;
+
+ /* 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'
+ */
+
+ _mm_fseek(reader,0,SEEK_END);
+ srclen = _mm_ftell(reader);
+ if (srclen < 256) return 0;
+ /* file length should be a multiple of 4 */
+ if (srclen & 3) return 0;
+
+ _mm_rewind(reader);
+ if (_mm_read_I_ULONG(reader) != 0x30325050) /* 'PP20' */
+ return 0;
+
+ _mm_fseek(reader,srclen-4,SEEK_SET);
+ _mm_read_UBYTES(tmp,4,reader);
+ destlen = tmp[0] << 16;
+ destlen |= tmp[1] << 8;
+ destlen |= tmp[2];
+ skip = tmp[3];
+
+ _mm_fseek(reader,4,SEEK_SET);
+ _mm_read_UBYTES(tmp,4,reader);
+
+ /* original pp20 only support efficiency
+ * from 9 9 9 9 up to 9 10 12 13, afaik,
+ * but the xfd detection code says this...
+ *
+ * move.l 4(a0),d0
+ * cmp.b #9,d0
+ * blo.b .Exit
+ * and.l #$f0f0f0f0,d0
+ * bne.s .Exit
+ */
+ if ((tmp[0] < 9) || (tmp[0] & 0xf0)) return 0;
+ if ((tmp[1] < 9) || (tmp[1] & 0xf0)) return 0;
+ if ((tmp[2] < 9) || (tmp[2] & 0xf0)) return 0;
+ if ((tmp[3] < 9) || (tmp[3] & 0xf0)) return 0;
+
+ if ((destlen < 512) || (destlen > 0x400000) || (destlen > 16*srclen))
+ return 0;
+ if ((destbuf = (UBYTE*)MikMod_malloc(destlen)) == NULL)
+ return 0;
+
+ srclen -= 12;
+ if ((srcbuf = (UBYTE*)MikMod_malloc(srclen)) == NULL) {
+ MikMod_free(destbuf);
+ return 0;
+ }
+ _mm_read_UBYTES(srcbuf,srclen,reader);
+
+ ret = ppDecrunch(srcbuf, destbuf, tmp, srclen, destlen, skip);
+ MikMod_free(srcbuf);
+
+ if (!ret) {
+ MikMod_free(destbuf);
+ }
+ else {
+ *out = destbuf;
+ *outlen = destlen;
+ }
+ return ret;
+}
projects / dosdemo / blobdiff