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#include "mupdf/fitz.h"
#include <jbig2.h>
typedef struct fz_jbig2d_s fz_jbig2d;
struct fz_jbig2_globals_s
{
fz_storable storable;
Jbig2GlobalCtx *gctx;
};
struct fz_jbig2d_s
{
fz_stream *chain;
Jbig2Ctx *ctx;
fz_jbig2_globals *gctx;
Jbig2Image *page;
int idx;
unsigned char buffer[4096];
};
static void
fz_drop_jbig2_globals(fz_context *ctx, fz_jbig2_globals *globals)
{
fz_drop_storable(ctx, &globals->storable);
}
static void
close_jbig2d(fz_context *ctx, void *state_)
{
fz_jbig2d *state = (fz_jbig2d *)state_;
if (state->page)
jbig2_release_page(state->ctx, state->page);
if (state->gctx)
fz_drop_jbig2_globals(ctx, state->gctx);
jbig2_ctx_free(state->ctx);
fz_drop_stream(ctx, state->chain);
fz_free(ctx, state);
}
static int
next_jbig2d(fz_context *ctx, fz_stream *stm, int len)
{
fz_jbig2d *state = stm->state;
unsigned char tmp[4096];
unsigned char *buf = state->buffer;
unsigned char *p = buf;
unsigned char *ep;
unsigned char *s;
int x, w, n;
if (len > sizeof(state->buffer))
len = sizeof(state->buffer);
ep = buf + len;
if (!state->page)
{
while (1)
{
n = fz_read(ctx, state->chain, tmp, sizeof tmp);
if (n == 0)
break;
jbig2_data_in(state->ctx, tmp, n);
}
jbig2_complete_page(state->ctx);
state->page = jbig2_page_out(state->ctx);
if (!state->page)
fz_throw(ctx, FZ_ERROR_GENERIC, "jbig2_page_out failed");
}
s = state->page->data;
w = state->page->height * state->page->stride;
x = state->idx;
while (p < ep && x < w)
*p++ = s[x++] ^ 0xff;
state->idx = x;
stm->rp = buf;
stm->wp = p;
if (p == buf)
return EOF;
stm->pos += p - buf;
return *stm->rp++;
}
static int
error_callback(void *data, const char *msg, Jbig2Severity severity, int32_t seg_idx)
{
fz_context *ctx = data;
if (severity == JBIG2_SEVERITY_FATAL)
fz_warn(ctx, "jbig2dec error: %s (segment %d)", msg, seg_idx);
else if (severity == JBIG2_SEVERITY_WARNING)
fz_warn(ctx, "jbig2dec warning: %s (segment %d)", msg, seg_idx);
return 0;
}
fz_jbig2_globals *
fz_load_jbig2_globals(fz_context *ctx, unsigned char *data, int size)
{
fz_jbig2_globals *globals = fz_malloc_struct(ctx, fz_jbig2_globals);
Jbig2Ctx *jctx = jbig2_ctx_new(NULL, JBIG2_OPTIONS_EMBEDDED, NULL, error_callback, ctx);
jbig2_data_in(jctx, data, size);
FZ_INIT_STORABLE(globals, 1, fz_drop_jbig2_globals_imp);
globals->gctx = jbig2_make_global_ctx(jctx);
return globals;
}
void
fz_drop_jbig2_globals_imp(fz_context *ctx, fz_storable *globals_)
{
fz_jbig2_globals *globals = (fz_jbig2_globals *)globals_;
jbig2_global_ctx_free(globals->gctx);
fz_free(ctx, globals);
}
fz_stream *
fz_open_jbig2d(fz_context *ctx, fz_stream *chain, fz_jbig2_globals *globals)
{
fz_jbig2d *state = NULL;
fz_var(state);
fz_try(ctx)
{
state = fz_malloc_struct(ctx, fz_jbig2d);
state->ctx = NULL;
state->gctx = globals;
state->chain = chain;
state->ctx = jbig2_ctx_new(NULL, JBIG2_OPTIONS_EMBEDDED, globals ? globals->gctx : NULL, error_callback, ctx);
state->page = NULL;
state->idx = 0;
}
fz_catch(ctx)
{
if (state)
{
fz_drop_jbig2_globals(ctx, state->gctx);
if (state->ctx)
jbig2_ctx_free(state->ctx);
}
fz_free(ctx, state);
fz_drop_stream(ctx, chain);
fz_rethrow(ctx);
}
return fz_new_stream(ctx, state, next_jbig2d, close_jbig2d);
}
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