Add a png viewer plugin

Author: Christophe Gouiran
Flyspray: FS#9493


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22037 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 1334 insertions, 0 deletions

diff --git a/apps/plugins/png/inflate.c b/apps/plugins/png/inflate.c
new file mode 100644
index 0000000000..2cf6f972a4
--- /dev/null
+++ b/apps/plugins/png/inflate.c
@@ -0,0 +1,1334 @@
+/* inflate.c -- zlib decompression
+ * Copyright (C) 1995-2005 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ * Change history:
+ *
+ * 1.2.beta0    24 Nov 2002
+ * - First version -- complete rewrite of inflate to simplify code, avoid
+ *   creation of window when not needed, minimize use of window when it is
+ *   needed, make inffast.c even faster, implement gzip decoding, and to
+ *   improve code readability and style over the previous zlib inflate code
+ *
+ * 1.2.beta1    25 Nov 2002
+ * - Use pointers for available input and output checking in inffast.c
+ * - Remove input and output counters in inffast.c
+ * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
+ * - Remove unnecessary second byte pull from length extra in inffast.c
+ * - Unroll direct copy to three copies per loop in inffast.c
+ *
+ * 1.2.beta2    4 Dec 2002
+ * - Change external routine names to reduce potential conflicts
+ * - Correct filename to inffixed.h for fixed tables in inflate.c
+ * - Make hbuf[] unsigned char to match parameter type in inflate.c
+ * - Change strm->next_out[-state.offset] to *(strm->next_out - state.offset)
+ *   to avoid negation problem on Alphas (64 bit) in inflate.c
+ *
+ * 1.2.beta3    22 Dec 2002
+ * - Add comments on state.bits assertion in inffast.c
+ * - Add comments on op field in inftrees.h
+ * - Fix bug in reuse of allocated window after inflateReset()
+ * - Remove bit fields--back to byte structure for speed
+ * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
+ * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
+ * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
+ * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
+ * - Use local copies of stream next and avail values, as well as local bit
+ *   buffer and bit count in inflate()--for speed when inflate_fast() not used
+ *
+ * 1.2.beta4    1 Jan 2003
+ * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
+ * - Move a comment on output buffer sizes from inffast.c to inflate.c
+ * - Add comments in inffast.c to introduce the inflate_fast() routine
+ * - Rearrange window copies in inflate_fast() for speed and simplification
+ * - Unroll last copy for window match in inflate_fast()
+ * - Use local copies of window variables in inflate_fast() for speed
+ * - Pull out common write == 0 case for speed in inflate_fast()
+ * - Make op and len in inflate_fast() unsigned for consistency
+ * - Add FAR to lcode and dcode declarations in inflate_fast()
+ * - Simplified bad distance check in inflate_fast()
+ * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
+ *   source file infback.c to provide a call-back interface to inflate for
+ *   programs like gzip and unzip -- uses window as output buffer to avoid
+ *   window copying
+ *
+ * 1.2.beta5    1 Jan 2003
+ * - Improved inflateBack() interface to allow the caller to provide initial
+ *   input in strm.
+ * - Fixed stored blocks bug in inflateBack()
+ *
+ * 1.2.beta6    4 Jan 2003
+ * - Added comments in inffast.c on effectiveness of POSTINC
+ * - Typecasting all around to reduce compiler warnings
+ * - Changed loops from while (1) or do {} while (1) to for (;;), again to
+ *   make compilers happy
+ * - Changed type of window in inflateBackInit() to unsigned char *
+ *
+ * 1.2.beta7    27 Jan 2003
+ * - Changed many types to unsigned or unsigned short to avoid warnings
+ * - Added inflateCopy() function
+ *
+ * 1.2.0        9 Mar 2003
+ * - Changed inflateBack() interface to provide separate opaque descriptors
+ *   for the in() and out() functions
+ * - Changed inflateBack() argument and in_func typedef to swap the length
+ *   and buffer address return values for the input function
+ * - Check next_in and next_out for Z_NULL on entry to inflate()
+ *
+ * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
+ */
+
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+#include "plugin.h"
+#include "png.h"
+
+#ifdef MAKEFIXED
+#  ifndef BUILDFIXED
+#    define BUILDFIXED
+#  endif
+#endif
+
+struct inflate_state state;
+
+/* function prototypes */
+local void fixedtables OF((void));
+local int updatewindow OF((z_streamp strm, unsigned out));
+#ifdef BUILDFIXED
+   void makefixed OF((void));
+#endif
+local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
+                              unsigned len));
+
+int ZEXPORT inflateReset(strm)
+z_streamp strm;
+{
+    //struct inflate_state FAR *state;
+
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    //state = strm->state;
+    strm->total_in = strm->total_out = state.total = 0;
+    strm->msg = Z_NULL;
+    strm->adler = 1;        /* to support ill-conceived Java test suite */
+    state.mode = HEAD;
+    state.last = 0;
+    state.havedict = 0;
+    state.dmax = 32768U;
+    state.head = Z_NULL;
+    state.wsize = 0;
+    state.whave = 0;
+    state.write = 0;
+    state.hold = 0;
+    state.bits = 0;
+    state.lencode = state.distcode = state.next = state.codes;
+    //DEBUGF("inflate: reset\n");
+    return Z_OK;
+}
+
+int ZEXPORT inflatePrime(strm, bits, value)
+z_streamp strm;
+int bits;
+int value;
+{
+    //struct inflate_state FAR *state;
+
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    //state = (struct inflate_state FAR *)strm->state;
+    if (bits > 16 || state.bits + bits > 32) return Z_STREAM_ERROR;
+    value &= (1L << bits) - 1;
+    state.hold += value << state.bits;
+    state.bits += bits;
+    return Z_OK;
+}
+
+int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
+z_streamp strm;
+int windowBits;
+const char *version;
+int stream_size;
+{
+    //struct inflate_state FAR *state;
+
+    if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+        stream_size != (int)(sizeof(z_stream)))
+        return Z_VERSION_ERROR;
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    strm->msg = Z_NULL;                 /* in case we return an error */
+    //if (strm->zalloc == (alloc_func)0) {
+    //    strm->zalloc = zcalloc;
+    //    strm->opaque = (voidpf)0;
+    //}
+    //if (strm->zfree == (free_func)0) strm->zfree = zcfree;
+    //state = (struct inflate_state FAR *)
+    //        ZALLOC(strm, 1, sizeof(struct inflate_state));
+    //if (state == Z_NULL) return Z_MEM_ERROR;
+    //DEBUGF("inflate: allocated\n");
+    //strm->state = (struct internal_state FAR *)state;
+    if (windowBits < 0) {
+        state.wrap = 0;
+        windowBits = -windowBits;
+    }
+    else {
+        state.wrap = (windowBits >> 4) + 1;
+#ifdef GUNZIP
+        if (windowBits < 48) windowBits &= 15;
+#endif
+    }
+    if (windowBits < 8 || windowBits > 15) {
+        //ZFREE(strm, state);
+        //strm->state = Z_NULL;
+        return Z_STREAM_ERROR;
+    }
+    state.wbits = (unsigned)windowBits;
+    state.window = Z_NULL;
+    return inflateReset(strm);
+}
+
+int ZEXPORT inflateInit_(strm, version, stream_size)
+z_streamp strm;
+const char *version;
+int stream_size;
+{
+    return inflateInit2_(strm, DEF_WBITS, version, stream_size);
+}
+
+/*
+   Return state with length and distance decoding tables and index sizes set to
+   fixed code decoding.  Normally this returns fixed tables from inffixed.h.
+   If BUILDFIXED is defined, then instead this routine builds the tables the
+   first time it's called, and returns those tables the first time and
+   thereafter.  This reduces the size of the code by about 2K bytes, in
+   exchange for a little execution time.  However, BUILDFIXED should not be
+   used for threaded applications, since the rewriting of the tables and virgin
+   may not be thread-safe.
+ */
+local void fixedtables(void)
+//struct inflate_state FAR *state;
+{
+#ifdef BUILDFIXED
+    static int virgin = 1;
+    static code *lenfix, *distfix;
+    static code fixed[544];
+
+    /* build fixed huffman tables if first call (may not be thread safe) */
+    if (virgin) {
+        unsigned sym, bits;
+        static code *next;
+
+        /* literal/length table */
+        sym = 0;
+        while (sym < 144) state.lens[sym++] = 8;
+        while (sym < 256) state.lens[sym++] = 9;
+        while (sym < 280) state.lens[sym++] = 7;
+        while (sym < 288) state.lens[sym++] = 8;
+        next = fixed;
+        lenfix = next;
+        bits = 9;
+        inflate_table(LENS, state.lens, 288, &(next), &(bits), state.work);
+
+        /* distance table */
+        sym = 0;
+        while (sym < 32) state.lens[sym++] = 5;
+        distfix = next;
+        bits = 5;
+        inflate_table(DISTS, state.lens, 32, &(next), &(bits), state.work);
+
+        /* do this just once */
+        virgin = 0;
+    }
+#else /* !BUILDFIXED */
+#   include "inffixed.h"
+#endif /* BUILDFIXED */
+    state.lencode = lenfix;
+    state.lenbits = 9;
+    state.distcode = distfix;
+    state.distbits = 5;
+}
+
+#ifdef MAKEFIXED
+#include <stdio.h>
+
+/*
+   Write out the inffixed.h that is #include'd above.  Defining MAKEFIXED also
+   defines BUILDFIXED, so the tables are built on the fly.  makefixed() writes
+   those tables to stdout, which would be piped to inffixed.h.  A small program
+   can simply call makefixed to do this:
+
+    void makefixed(void);
+
+    int main(void)
+    {
+        makefixed();
+        return 0;
+    }
+
+   Then that can be linked with zlib built with MAKEFIXED defined and run:
+
+    a.out > inffixed.h
+ */
+void makefixed()
+{
+    unsigned low, size;
+    struct inflate_state state;
+
+    fixedtables(&state);
+    puts("    /* inffixed.h -- table for decoding fixed codes");
+    puts("     * Generated automatically by makefixed().");
+    puts("     */");
+    puts("");
+    puts("    /* WARNING: this file should *not* be used by applications.");
+    puts("       It is part of the implementation of this library and is");
+    puts("       subject to change. Applications should only use zlib.h.");
+    puts("     */");
+    puts("");
+    size = 1U << 9;
+    printf("    static const code lenfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 7) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits,
+               state.lencode[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+    size = 1U << 5;
+    printf("\n    static const code distfix[%u] = {", size);
+    low = 0;
+    for (;;) {
+        if ((low % 6) == 0) printf("\n        ");
+        printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
+               state.distcode[low].val);
+        if (++low == size) break;
+        putchar(',');
+    }
+    puts("\n    };");
+}
+#endif /* MAKEFIXED */
+
+/*
+   Update the window with the last wsize (normally 32K) bytes written before
+   returning.  If window does not exist yet, create it.  This is only called
+   when a window is already in use, or when output has been written during this
+   inflate call, but the end of the deflate stream has not been reached yet.
+   It is also called to create a window for dictionary data when a dictionary
+   is loaded.
+
+   Providing output buffers larger than 32K to inflate() should provide a speed
+   advantage, since only the last 32K of output is copied to the sliding window
+   upon return from inflate(), and since all distances after the first 32K of
+   output will fall in the output data, making match copies simpler and faster.
+   The advantage may be dependent on the size of the processor's data caches.
+ */
+local int updatewindow(strm, out)
+z_streamp strm;
+unsigned out;
+{
+    //struct inflate_state FAR *state;
+    unsigned copy, dist;
+
+    //state = (struct inflate_state FAR *)strm->state;
+
+    /* if it hasn't been done already, allocate space for the window */
+    if (state.window == Z_NULL) {
+        state.window = (unsigned char FAR *)
+                        ZALLOC(strm, 1U << state.wbits,
+                               sizeof(unsigned char));
+        if (state.window == Z_NULL) return 1;
+    }
+
+    /* if window not in use yet, initialize */
+    if (state.wsize == 0) {
+        state.wsize = 1U << state.wbits;
+        state.write = 0;
+        state.whave = 0;
+    }
+
+    /* copy state.wsize or less output bytes into the circular window */
+    copy = out - strm->avail_out;
+    if (copy >= state.wsize) {
+        zmemcpy(state.window, strm->next_out - state.wsize, state.wsize);
+        state.write = 0;
+        state.whave = state.wsize;
+    }
+    else {
+        dist = state.wsize - state.write;
+        if (dist > copy) dist = copy;
+        zmemcpy(state.window + state.write, strm->next_out - copy, dist);
+        copy -= dist;
+        if (copy) {
+            zmemcpy(state.window, strm->next_out - copy, copy);
+            state.write = copy;
+            state.whave = state.wsize;
+        }
+        else {
+            state.write += dist;
+            if (state.write == state.wsize) state.write = 0;
+            if (state.whave < state.wsize) state.whave += dist;
+        }
+    }
+    return 0;
+}
+
+/* Macros for inflate(): */
+
+/* check function to use adler32() for zlib or crc32() for gzip */
+#ifdef GUNZIP
+#  define UPDATE(check, buf, len) \
+    (state.flags ? crc32(check, buf, len) : adler32(check, buf, len))
+#else
+#  define UPDATE(check, buf, len) adler32(check, buf, len)
+#endif
+
+/* check macros for header crc */
+#ifdef GUNZIP
+#  define CRC2(check, word) \
+    do { \
+        hbuf[0] = (unsigned char)(word); \
+        hbuf[1] = (unsigned char)((word) >> 8); \
+        check = crc32(check, hbuf, 2); \
+    } while (0)
+
+#  define CRC4(check, word) \
+    do { \
+        hbuf[0] = (unsigned char)(word); \
+        hbuf[1] = (unsigned char)((word) >> 8); \
+        hbuf[2] = (unsigned char)((word) >> 16); \
+        hbuf[3] = (unsigned char)((word) >> 24); \
+        check = crc32(check, hbuf, 4); \
+    } while (0)
+#endif
+
+/* Load registers with state in inflate() for speed */
+#define LOAD() \
+    do { \
+        put = strm->next_out; \
+        left = strm->avail_out; \
+        next = strm->next_in; \
+        have = strm->avail_in; \
+        hold = state.hold; \
+        bits = state.bits; \
+    } while (0)
+
+/* Restore state from registers in inflate() */
+#define RESTORE() \
+    do { \
+        strm->next_out = put; \
+        strm->avail_out = left; \
+        strm->next_in = next; \
+        strm->avail_in = have; \
+        state.hold = hold; \
+        state.bits = bits; \
+    } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+    do { \
+        hold = 0; \
+        bits = 0; \
+    } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflate()
+   if there is no input available. */
+#define PULLBYTE() \
+    do { \
+        if (have == 0) goto inf_leave; \
+        have--; \
+        hold += (unsigned long)(*next++) << bits; \
+        bits += 8; \
+    } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator.  If there is
+   not enough available input to do that, then return from inflate(). */
+#define NEEDBITS(n) \
+    do { \
+        while (bits < (unsigned)(n)) \
+            PULLBYTE(); \
+    } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+    ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+    do { \
+        hold >>= (n); \
+        bits -= (unsigned)(n); \
+    } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+    do { \
+        hold >>= bits & 7; \
+        bits -= bits & 7; \
+    } while (0)
+
+/* Reverse the bytes in a 32-bit value */
+#define REVERSE(q) \
+    ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
+     (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
+
+/*
+   inflate() uses a state machine to process as much input data and generate as
+   much output data as possible before returning.  The state machine is
+   structured roughly as follows:
+
+    for (;;) switch (state) {
+    ...
+    case STATEn:
+        if (not enough input data or output space to make progress)
+            return;
+        ... make progress ...
+        state = STATEm;
+        break;
+    ...
+    }
+
+   so when inflate() is called again, the same case is attempted again, and
+   if the appropriate resources are provided, the machine proceeds to the
+   next state.  The NEEDBITS() macro is usually the way the state evaluates
+   whether it can proceed or should return.  NEEDBITS() does the return if
+   the requested bits are not available.  The typical use of the BITS macros
+   is:
+
+        NEEDBITS(n);
+        ... do something with BITS(n) ...
+        DROPBITS(n);
+
+   where NEEDBITS(n) either returns from inflate() if there isn't enough
+   input left to load n bits into the accumulator, or it continues.  BITS(n)
+   gives the low n bits in the accumulator.  When done, DROPBITS(n) drops
+   the low n bits off the accumulator.  INITBITS() clears the accumulator
+   and sets the number of available bits to zero.  BYTEBITS() discards just
+   enough bits to put the accumulator on a byte boundary.  After BYTEBITS()
+   and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
+
+   NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
+   if there is no input available.  The decoding of variable length codes uses
+   PULLBYTE() directly in order to pull just enough bytes to decode the next
+   code, and no more.
+
+   Some states loop until they get enough input, making sure that enough
+   state information is maintained to continue the loop where it left off
+   if NEEDBITS() returns in the loop.  For example, want, need, and keep
+   would all have to actually be part of the saved state in case NEEDBITS()
+   returns:
+
+    case STATEw:
+        while (want < need) {
+            NEEDBITS(n);
+            keep[want++] = BITS(n);
+            DROPBITS(n);
+        }
+        state = STATEx;
+    case STATEx:
+
+   As shown above, if the next state is also the next case, then the break
+   is omitted.
+
+   A state may also return if there is not enough output space available to
+   complete that state.  Those states are copying stored data, writing a
+   literal byte, and copying a matching string.
+
+   When returning, a "goto inf_leave" is used to update the total counters,
+   update the check value, and determine whether any progress has been made
+   during that inflate() call in order to return the proper return code.
+   Progress is defined as a change in either strm->avail_in or strm->avail_out.
+   When there is a window, goto inf_leave will update the window with the last
+   output written.  If a goto inf_leave occurs in the middle of decompression
+   and there is no window currently, goto inf_leave will create one and copy
+   output to the window for the next call of inflate().
+
+   In this implementation, the flush parameter of inflate() only affects the
+   return code (per zlib.h).  inflate() always writes as much as possible to
+   strm->next_out, given the space available and the provided input--the effect
+   documented in zlib.h of Z_SYNC_FLUSH.  Furthermore, inflate() always defers
+   the allocation of and copying into a sliding window until necessary, which
+   provides the effect documented in zlib.h for Z_FINISH when the entire input
+   stream available.  So the only thing the flush parameter actually does is:
+   when flush is set to Z_FINISH, inflate() cannot return Z_OK.  Instead it
+   will return Z_BUF_ERROR if it has not reached the end of the stream.
+ */
+
+extern void cb_progress(int current, int total);
+
+int ZEXPORT inflate(strm, flush)
+z_streamp strm;
+int flush;
+{
+    //struct inflate_state FAR *state;
+    unsigned char FAR *next;    /* next input */
+    unsigned char FAR *put;     /* next output */
+    unsigned have, left;        /* available input and output */
+    unsigned long hold;         /* bit buffer */
+    unsigned bits;              /* bits in bit buffer */
+    unsigned in, out;           /* save starting available input and output */
+    unsigned copy;              /* number of stored or match bytes to copy */
+    unsigned char FAR *from;    /* where to copy match bytes from */
+    code this;                  /* current decoding table entry */
+    code last;                  /* parent table entry */
+    unsigned len;               /* length to copy for repeats, bits to drop */
+    int ret;                    /* return code */
+#ifdef GUNZIP
+    unsigned char hbuf[4];      /* buffer for gzip header crc calculation */
+#endif
+    static const unsigned short order[19] = /* permutation of code lengths */
+        {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+    if (strm == Z_NULL || strm->next_out == Z_NULL ||
+        (strm->next_in == Z_NULL && strm->avail_in != 0))
+        return Z_STREAM_ERROR;
+
+    uInt insize = strm->avail_in;
+
+    //state = (struct inflate_state FAR *)strm->state;
+    if (state.mode == TYPE) state.mode = TYPEDO;      /* skip check */
+    LOAD();
+    in = have;
+    out = left;
+    ret = Z_OK;
+    for (;;) {
+        switch (state.mode) {
+        case HEAD:
+            if (state.wrap == 0) {
+                state.mode = TYPEDO;
+                break;
+            }
+            NEEDBITS(16);
+#ifdef GUNZIP
+            if ((state.wrap & 2) && hold == 0x8b1f) {  /* gzip header */
+                state.check = crc32(0L, Z_NULL, 0);
+                CRC2(state.check, hold);
+                INITBITS();
+                state.mode = FLAGS;
+                break;
+            }
+            state.flags = 0;           /* expect zlib header */
+            if (state.head != Z_NULL)
+                state.head->done = -1;
+            if (!(state.wrap & 1) ||   /* check if zlib header allowed */
+#else
+            if (
+#endif
+                ((BITS(8) << 8) + (hold >> 8)) % 31) {
+                strm->msg = (char *)"incorrect header check";
+                state.mode = BAD;
+                break;
+            }
+            if (BITS(4) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state.mode = BAD;
+                break;
+            }
+            DROPBITS(4);
+            len = BITS(4) + 8;
+            if (len > state.wbits) {
+                strm->msg = (char *)"invalid window size";
+                state.mode = BAD;
+                break;
+            }
+            state.dmax = 1U << len;
+            //DEBUGF("inflate:   zlib header ok\n");
+            strm->adler = state.check = adler32(0L, Z_NULL, 0);
+            state.mode = hold & 0x200 ? DICTID : TYPE;
+            INITBITS();
+            break;
+#ifdef GUNZIP
+        case FLAGS:
+            NEEDBITS(16);
+            state.flags = (int)(hold);
+            if ((state.flags & 0xff) != Z_DEFLATED) {
+                strm->msg = (char *)"unknown compression method";
+                state.mode = BAD;
+                break;
+            }
+            if (state.flags & 0xe000) {
+                strm->msg = (char *)"unknown header flags set";
+                state.mode = BAD;
+                break;
+            }
+            if (state.head != Z_NULL)
+                state.head->text = (int)((hold >> 8) & 1);
+            if (state.flags & 0x0200) CRC2(state.check, hold);
+            INITBITS();
+            state.mode = TIME;
+        case TIME:
+            NEEDBITS(32);
+            if (state.head != Z_NULL)
+                state.head->time = hold;
+            if (state.flags & 0x0200) CRC4(state.check, hold);
+            INITBITS();
+            state.mode = OS;
+        case OS:
+            NEEDBITS(16);
+            if (state.head != Z_NULL) {
+                state.head->xflags = (int)(hold & 0xff);
+                state.head->os = (int)(hold >> 8);
+            }
+            if (state.flags & 0x0200) CRC2(state.check, hold);
+            INITBITS();
+            state.mode = EXLEN;
+        case EXLEN:
+            if (state.flags & 0x0400) {
+                NEEDBITS(16);
+                state.length = (unsigned)(hold);
+                if (state.head != Z_NULL)
+                    state.head->extra_len = (unsigned)hold;
+                if (state.flags & 0x0200) CRC2(state.check, hold);
+                INITBITS();
+            }
+            else if (state.head != Z_NULL)
+                state.head->extra = Z_NULL;
+            state.mode = EXTRA;
+        case EXTRA:
+            if (state.flags & 0x0400) {
+                copy = state.length;
+                if (copy > have) copy = have;
+                if (copy) {
+                    if (state.head != Z_NULL &&
+                        state.head->extra != Z_NULL) {
+                        len = state.head->extra_len - state.length;
+                        zmemcpy(state.head->extra + len, next,
+                                len + copy > state.head->extra_max ?
+                                state.head->extra_max - len : copy);
+                    }
+                    if (state.flags & 0x0200)
+                        state.check = crc32(state.check, next, copy);
+                    have -= copy;
+                    next += copy;
+                    state.length -= copy;
+                }
+                if (state.length) goto inf_leave;
+            }
+            state.length = 0;
+            state.mode = NAME;
+        case NAME:
+            if (state.flags & 0x0800) {
+                if (have == 0) goto inf_leave;
+                copy = 0;
+                do {
+                    len = (unsigned)(next[copy++]);
+                    if (state.head != Z_NULL &&
+                            state.head->name != Z_NULL &&
+                            state.length < state.head->name_max)
+                        state.head->name[state.length++] = len;
+                } while (len && copy < have);
+                if (state.flags & 0x0200)
+                    state.check = crc32(state.check, next, copy);
+                have -= copy;
+                next += copy;
+                if (len) goto inf_leave;
+            }
+            else if (state.head != Z_NULL)
+                state.head->name = Z_NULL;
+            state.length = 0;
+            state.mode = COMMENT;
+        case COMMENT:
+            if (state.flags & 0x1000) {
+                if (have == 0) goto inf_leave;
+                copy = 0;
+                do {
+                    len = (unsigned)(next[copy++]);
+                    if (state.head != Z_NULL &&
+                            state.head->comment != Z_NULL &&
+                            state.length < state.head->comm_max)
+                        state.head->comment[state.length++] = len;
+                } while (len && copy < have);
+                if (state.flags & 0x0200)
+                    state.check = crc32(state.check, next, copy);
+                have -= copy;
+                next += copy;
+                if (len) goto inf_leave;
+            }
+            else if (state.head != Z_NULL)
+                state.head->comment = Z_NULL;
+            state.mode = HCRC;
+        case HCRC:
+            if (state.flags & 0x0200) {
+                NEEDBITS(16);
+                if (hold != (state.check & 0xffff)) {
+                    strm->msg = (char *)"header crc mismatch";
+                    state.mode = BAD;
+                    break;
+                }
+                INITBITS();
+            }
+            if (state.head != Z_NULL) {
+                state.head->hcrc = (int)((state.flags >> 9) & 1);
+                state.head->done = 1;
+            }
+            strm->adler = state.check = crc32(0L, Z_NULL, 0);
+            state.mode = TYPE;
+            break;
+#endif
+        case DICTID:
+            NEEDBITS(32);
+            strm->adler = state.check = REVERSE(hold);
+            INITBITS();
+            state.mode = DICT;
+        case DICT:
+            if (state.havedict == 0) {
+                RESTORE();
+                return Z_NEED_DICT;
+            }
+            strm->adler = state.check = adler32(0L, Z_NULL, 0);
+            state.mode = TYPE;
+        case TYPE:
+            if (flush == Z_BLOCK) goto inf_leave;
+        case TYPEDO:
+            if (state.last) {
+                BYTEBITS();
+                state.mode = CHECK;
+                break;
+            }
+            NEEDBITS(3);
+            state.last = BITS(1);
+            DROPBITS(1);
+            switch (BITS(2)) {
+            case 0:                             /* stored block */
+                //DEBUGF("inflate:     stored block%s\n",
+                        //state.last ? " (last)" : "");
+                state.mode = STORED;
+                break;
+            case 1:                             /* fixed block */
+                fixedtables();
+                //DEBUGF("inflate:     fixed codes block%s\n",
+                        //state.last ? " (last)" : "");
+                state.mode = LEN;              /* decode codes */
+                break;
+            case 2:                             /* dynamic block */
+              //DEBUGF("inflate:     dynamic codes block%s\n",
+                        //state.last ? " (last)" : "");
+                state.mode = TABLE;
+                break;
+            case 3:
+                strm->msg = (char *)"invalid block type";
+                state.mode = BAD;
+            }
+            DROPBITS(2);
+            break;
+        case STORED:
+            BYTEBITS();                         /* go to byte boundary */
+            NEEDBITS(32);
+            if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+                strm->msg = (char *)"invalid stored block lengths";
+                state.mode = BAD;
+                break;
+            }
+            state.length = (unsigned)hold & 0xffff;
+            //DEBUGF("inflate:       stored length %u\n",
+                    //state.length);
+            INITBITS();
+            state.mode = COPY;
+        case COPY:
+            copy = state.length;
+            if (copy) {
+                if (copy > have) copy = have;
+                if (copy > left) copy = left;
+                if (copy == 0) goto inf_leave;
+                zmemcpy(put, next, copy);
+                have -= copy;
+                next += copy;
+                left -= copy;
+                put += copy;
+                state.length -= copy;
+                break;
+            }
+            //DEBUGF("inflate:       stored end\n");
+            state.mode = TYPE;
+            break;
+        case TABLE:
+            NEEDBITS(14);
+            state.nlen = BITS(5) + 257;
+            DROPBITS(5);
+            state.ndist = BITS(5) + 1;
+            DROPBITS(5);
+            state.ncode = BITS(4) + 4;
+            DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+            if (state.nlen > 286 || state.ndist > 30) {
+                strm->msg = (char *)"too many length or distance symbols";
+                state.mode = BAD;
+                break;
+            }
+#endif
+            //DEBUGF("inflate:       table sizes ok\n");
+            state.have = 0;
+            state.mode = LENLENS;
+        case LENLENS:
+            while (state.have < state.ncode) {
+                NEEDBITS(3);
+                state.lens[order[state.have++]] = (unsigned short)BITS(3);
+                DROPBITS(3);
+            }
+            while (state.have < 19)
+                state.lens[order[state.have++]] = 0;
+            state.next = state.codes;
+            state.lencode = (code const FAR *)(state.next);
+            state.lenbits = 7;
+            ret = inflate_table(CODES, state.lens, 19, &(state.next),
+                                &(state.lenbits), state.work);
+            if (ret) {
+                strm->msg = (char *)"invalid code lengths set";
+                state.mode = BAD;
+                break;
+            }
+            //DEBUGF("inflate:       code lengths ok\n");
+            state.have = 0;
+            state.mode = CODELENS;
+        case CODELENS:
+            while (state.have < state.nlen + state.ndist) {
+                for (;;) {
+                    this = state.lencode[BITS(state.lenbits)];
+                    if ((unsigned)(this.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                if (this.val < 16) {
+                    NEEDBITS(this.bits);
+                    DROPBITS(this.bits);
+                    state.lens[state.have++] = this.val;
+                }
+                else {
+                    if (this.val == 16) {
+                        NEEDBITS(this.bits + 2);
+                        DROPBITS(this.bits);
+                        if (state.have == 0) {
+                            strm->msg = (char *)"invalid bit length repeat";
+                            state.mode = BAD;
+                            break;
+                        }
+                        len = state.lens[state.have - 1];
+                        copy = 3 + BITS(2);
+                        DROPBITS(2);
+                    }
+                    else if (this.val == 17) {
+                        NEEDBITS(this.bits + 3);
+                        DROPBITS(this.bits);
+                        len = 0;
+                        copy = 3 + BITS(3);
+                        DROPBITS(3);
+                    }
+                    else {
+                        NEEDBITS(this.bits + 7);
+                        DROPBITS(this.bits);
+                        len = 0;
+                        copy = 11 + BITS(7);
+                        DROPBITS(7);
+                    }
+                    if (state.have + copy > state.nlen + state.ndist) {
+                        strm->msg = (char *)"invalid bit length repeat";
+                        state.mode = BAD;
+                        break;
+                    }
+                    while (copy--)
+                        state.lens[state.have++] = (unsigned short)len;
+                }
+            }
+
+            /* handle error breaks in while */
+            if (state.mode == BAD) break;
+
+            /* build code tables */
+            state.next = state.codes;
+            state.lencode = (code const FAR *)(state.next);
+            state.lenbits = 9;
+            ret = inflate_table(LENS, state.lens, state.nlen, &(state.next),
+                                &(state.lenbits), state.work);
+            if (ret) {
+                strm->msg = (char *)"invalid literal/lengths set";
+                state.mode = BAD;
+                break;
+            }
+            state.distcode = (code const FAR *)(state.next);
+            state.distbits = 6;
+            ret = inflate_table(DISTS, state.lens + state.nlen, state.ndist,
+                            &(state.next), &(state.distbits), state.work);
+            if (ret) {
+                strm->msg = (char *)"invalid distances set";
+                state.mode = BAD;
+                break;
+            }
+            //DEBUGF("inflate:       codes ok\n");
+            state.mode = LEN;
+        case LEN:
+            if (have >= 6 && left >= 258) {
+                RESTORE();
+                inflate_fast(strm, out);
+                LOAD();
+                break;
+            }
+            for (;;) {
+                this = state.lencode[BITS(state.lenbits)];
+                if ((unsigned)(this.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if (this.op && (this.op & 0xf0) == 0) {
+                last = this;
+                for (;;) {
+                    this = state.lencode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + this.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(this.bits);
+            state.length = (unsigned)this.val;
+            if ((int)(this.op) == 0) {
+                //DEBUGF(this.val >= 0x20 && this.val < 0x7f ?
+                        //"inflate:         literal '%c'\n" :
+                        //"inflate:         literal 0x%02x\n", this.val);
+                state.mode = LIT;
+                break;
+            }
+            if (this.op & 32) {
+              //DEBUGF("inflate:         end of block\n");
+                state.mode = TYPE;
+                break;
+            }
+            if (this.op & 64) {
+                strm->msg = (char *)"invalid literal/length code";
+                state.mode = BAD;
+                break;
+            }
+            state.extra = (unsigned)(this.op) & 15;
+            state.mode = LENEXT;
+        case LENEXT:
+            if (state.extra) {
+                NEEDBITS(state.extra);
+                state.length += BITS(state.extra);
+                DROPBITS(state.extra);
+            }
+            //DEBUGF("inflate:         length %u\n", state.length);
+            state.mode = DIST;
+        case DIST:
+            for (;;) {
+                this = state.distcode[BITS(state.distbits)];
+                if ((unsigned)(this.bits) <= bits) break;
+                PULLBYTE();
+            }
+            if ((this.op & 0xf0) == 0) {
+                last = this;
+                for (;;) {
+                    this = state.distcode[last.val +
+                            (BITS(last.bits + last.op) >> last.bits)];
+                    if ((unsigned)(last.bits + this.bits) <= bits) break;
+                    PULLBYTE();
+                }
+                DROPBITS(last.bits);
+            }
+            DROPBITS(this.bits);
+            if (this.op & 64) {
+                strm->msg = (char *)"invalid distance code";
+                state.mode = BAD;
+                break;
+            }
+            state.offset = (unsigned)this.val;
+            state.extra = (unsigned)(this.op) & 15;
+            state.mode = DISTEXT;
+        case DISTEXT:
+            if (state.extra) {
+                NEEDBITS(state.extra);
+                state.offset += BITS(state.extra);
+                DROPBITS(state.extra);
+            }
+#ifdef INFLATE_STRICT
+            if (state.offset > state.dmax) {
+                strm->msg = (char *)"invalid distance too far back";
+                state.mode = BAD;
+                break;
+            }
+#endif
+            if (state.offset > state.whave + out - left) {
+                strm->msg = (char *)"invalid distance too far back";
+                state.mode = BAD;
+                break;
+            }
+            //DEBUGF("inflate:         distance %u\n", state.offset);
+            state.mode = MATCH;
+        case MATCH:
+            if (left == 0) goto inf_leave;
+            copy = out - left;
+            if (state.offset > copy) {         /* copy from window */
+                copy = state.offset - copy;
+                if (copy > state.write) {
+                    copy -= state.write;
+                    from = state.window + (state.wsize - copy);
+                }
+                else
+                    from = state.window + (state.write - copy);
+                if (copy > state.length) copy = state.length;
+            }
+            else {                              /* copy from output */
+                from = put - state.offset;
+                copy = state.length;
+            }
+            if (copy > left) copy = left;
+            left -= copy;
+            state.length -= copy;
+            do {
+                *put++ = *from++;
+            } while (--copy);
+            if (state.length == 0) state.mode = LEN;
+            break;
+        case LIT:
+            if (left == 0) goto inf_leave;
+            *put++ = (unsigned char)(state.length);
+            left--;
+            state.mode = LEN;
+            break;
+        case CHECK:
+            if (state.wrap) {
+                NEEDBITS(32);
+                out -= left;
+                strm->total_out += out;
+                state.total += out;
+                if (out)
+                    strm->adler = state.check =
+                        UPDATE(state.check, put - out, out);
+                out = left;
+                if ((
+#ifdef GUNZIP
+                     state.flags ? hold :
+#endif
+                     REVERSE(hold)) != state.check) {
+                    strm->msg = (char *)"incorrect data check";
+                    state.mode = BAD;
+                    break;
+                }
+                INITBITS();
+                //DEBUGF("inflate:   check matches trailer\n");
+            }
+#ifdef GUNZIP
+            state.mode = LENGTH;
+        case LENGTH:
+            if (state.wrap && state.flags) {
+                NEEDBITS(32);
+                if (hold != (state.total & 0xffffffffUL)) {
+                    strm->msg = (char *)"incorrect length check";
+                    state.mode = BAD;
+                    break;
+                }
+                INITBITS();
+                Tracev((stderr, "inflate:   length matches trailer\n"));
+            }
+#endif
+            state.mode = DONE;
+        case DONE:
+            ret = Z_STREAM_END;
+            goto inf_leave;
+        case BAD:
+            ret = Z_DATA_ERROR;
+            goto inf_leave;
+        case ZMEM:
+            return Z_MEM_ERROR;
+        case SYNC:
+        default:
+            return Z_STREAM_ERROR;
+        }
+        //DEBUGF("%d / %d\n", strm->total_in, strm->avail_in);
+        if (rb->button_get(false) == PNG_MENU)
+          return PLUGIN_ABORT;
+        else cb_progress(insize - strm->avail_in, insize);
+    }
+
+    /*
+       Return from inflate(), updating the total counts and the check value.
+       If there was no progress during the inflate() call, return a buffer
+       error.  Call updatewindow() to create and/or update the window state.
+       Note: a memory error from inflate() is non-recoverable.
+     */
+  inf_leave:
+    RESTORE();
+    if (state.wsize || (state.mode < CHECK && out != strm->avail_out))
+        if (updatewindow(strm, out)) {
+            state.mode = ZMEM;
+            return Z_MEM_ERROR;
+        }
+    in -= strm->avail_in;
+    out -= strm->avail_out;
+    strm->total_in += in;
+    strm->total_out += out;
+    state.total += out;
+    if (state.wrap && out)
+        strm->adler = state.check =
+            UPDATE(state.check, strm->next_out - out, out);
+    strm->data_type = state.bits + (state.last ? 64 : 0) +
+                      (state.mode == TYPE ? 128 : 0);
+    if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
+        ret = Z_BUF_ERROR;
+    return ret;
+}
+
+int ZEXPORT inflateEnd(strm)
+z_streamp strm;
+{
+    //struct inflate_state FAR *state;
+    if (strm == Z_NULL /*|| strm->zfree == (free_func)0*/)
+        return Z_STREAM_ERROR;
+    //state = (struct inflate_state FAR *)strm->state;
+    //if (state.window != Z_NULL) ZFREE(strm, state.window);
+    //ZFREE(strm, strm->state);
+    //strm->state = Z_NULL;
+    //DEBUGF("inflate: end\n");
+    return Z_OK;
+}
+
+int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
+const Bytef *dictionary;
+uInt dictLength;
+{
+    //struct inflate_state FAR *state;
+    unsigned long id;
+
+    /* check state */
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    //state = (struct inflate_state FAR *)strm->state;
+    if (state.wrap != 0 && state.mode != DICT)
+        return Z_STREAM_ERROR;
+
+    /* check for correct dictionary id */
+    if (state.mode == DICT) {
+        id = adler32(0L, Z_NULL, 0);
+        id = adler32(id, dictionary, dictLength);
+        if (id != state.check)
+            return Z_DATA_ERROR;
+    }
+
+    /* copy dictionary to window */
+    if (updatewindow(strm, strm->avail_out)) {
+        state.mode = ZMEM;
+        return Z_MEM_ERROR;
+    }
+    if (dictLength > state.wsize) {
+        zmemcpy(state.window, dictionary + dictLength - state.wsize,
+                state.wsize);
+        state.whave = state.wsize;
+    }
+    else {
+        zmemcpy(state.window + state.wsize - dictLength, dictionary,
+                dictLength);
+        state.whave = dictLength;
+    }
+    state.havedict = 1;
+    //DEBUGF("inflate:   dictionary set\n");
+    return Z_OK;
+}
+
+int ZEXPORT inflateGetHeader(strm, head)
+z_streamp strm;
+gz_headerp head;
+{
+    //struct inflate_state FAR *state;
+
+    /* check state */
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    //state = (struct inflate_state FAR *)strm->state;
+    if ((state.wrap & 2) == 0) return Z_STREAM_ERROR;
+
+    /* save header structure */
+    state.head = head;
+    head->done = 0;
+    return Z_OK;
+}
+
+/*
+   Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff.  Return when found
+   or when out of input.  When called, *have is the number of pattern bytes
+   found in order so far, in 0..3.  On return *have is updated to the new
+   state.  If on return *have equals four, then the pattern was found and the
+   return value is how many bytes were read including the last byte of the
+   pattern.  If *have is less than four, then the pattern has not been found
+   yet and the return value is len.  In the latter case, syncsearch() can be
+   called again with more data and the *have state.  *have is initialized to
+   zero for the first call.
+ */
+local unsigned syncsearch(have, buf, len)
+unsigned FAR *have;
+unsigned char FAR *buf;
+unsigned len;
+{
+    unsigned got;
+    unsigned next;
+
+    got = *have;
+    next = 0;
+    while (next < len && got < 4) {
+        if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
+            got++;
+        else if (buf[next])
+            got = 0;
+        else
+            got = 4 - got;
+        next++;
+    }
+    *have = got;
+    return next;
+}
+
+int ZEXPORT inflateSync(strm)
+z_streamp strm;
+{
+    unsigned len;               /* number of bytes to look at or looked at */
+    unsigned long in, out;      /* temporary to save total_in and total_out */
+    unsigned char buf[4];       /* to restore bit buffer to byte string */
+    //struct inflate_state FAR *state;
+
+    /* check parameters */
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    //state = (struct inflate_state FAR *)strm->state;
+    if (strm->avail_in == 0 && state.bits < 8) return Z_BUF_ERROR;
+
+    /* if first time, start search in bit buffer */
+    if (state.mode != SYNC) {
+        state.mode = SYNC;
+        state.hold <<= state.bits & 7;
+        state.bits -= state.bits & 7;
+        len = 0;
+        while (state.bits >= 8) {
+            buf[len++] = (unsigned char)(state.hold);
+            state.hold >>= 8;
+            state.bits -= 8;
+        }
+        state.have = 0;
+        syncsearch(&(state.have), buf, len);
+    }
+
+    /* search available input */
+    len = syncsearch(&(state.have), strm->next_in, strm->avail_in);
+    strm->avail_in -= len;
+    strm->next_in += len;
+    strm->total_in += len;
+
+    /* return no joy or set up to restart inflate() on a new block */
+    if (state.have != 4) return Z_DATA_ERROR;
+    in = strm->total_in;  out = strm->total_out;
+    inflateReset(strm);
+    strm->total_in = in;  strm->total_out = out;
+    state.mode = TYPE;
+    return Z_OK;
+}
+
+/*
+   Returns true if inflate is currently at the end of a block generated by
+   Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
+   implementation to provide an additional safety check. PPP uses
+   Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
+   block. When decompressing, PPP checks that at the end of input packet,
+   inflate is waiting for these length bytes.
+ */
+int ZEXPORT inflateSyncPoint(strm)
+z_streamp strm;
+{
+    //struct inflate_state FAR *state;
+
+    if (strm == Z_NULL) return Z_STREAM_ERROR;
+    //state = (struct inflate_state FAR *)strm->state;
+    return state.mode == STORED && state.bits == 0;
+}