static int
pdf_image_size(fz_context *ctx, pdf_image *im)
{
if (im == NULL)
return 0;
return sizeof(*im) + fz_pixmap_size(ctx, im->tile) + (im->buffer && im->buffer->buffer ? im->buffer->buffer->cap : 0);
}
fz_pixmap *
fz_image_get_pixmap(fz_context *ctx, fz_image *image, int w, int h)
{
fz_pixmap *tile;
fz_stream *stm;
int l2factor;
fz_image_key key;
int native_l2factor;
int indexed;
fz_image_key *keyp;
/* Check for 'simple' images which are just pixmaps */
if (image->buffer == NULL)
{
tile = image->tile;
if (!tile)
return NULL;
return fz_keep_pixmap(ctx, tile); /* That's all we can give you! */
}
/* Ensure our expectations for tile size are reasonable */
if (w > image->w)
w = image->w;
if (h > image->h)
h = image->h;
/* What is our ideal factor? */
if (w == 0 || h == 0)
l2factor = 0;
else
for (l2factor=0; image->w>>(l2factor+1) >= w && image->h>>(l2factor+1) >= h && l2factor < 8; l2factor++);
/* Can we find any suitable tiles in the cache? */
key.refs = 1;
key.image = image;
key.l2factor = l2factor;
do
{
tile = fz_find_item(ctx, fz_free_pixmap_imp, &key, &fz_image_store_type);
if (tile)
return tile;
key.l2factor--;
}
while (key.l2factor >= 0);
/* We need to make a new one. */
/* First check for ones that we can't decode using streams */
switch (image->buffer->params.type)
{
case FZ_IMAGE_PNG:
tile = fz_load_png(ctx, image->buffer->buffer->data, image->buffer->buffer->len);
break;
case FZ_IMAGE_TIFF:
tile = fz_load_tiff(ctx, image->buffer->buffer->data, image->buffer->buffer->len);
break;
default:
native_l2factor = l2factor;
stm = fz_open_image_decomp_stream(ctx, image->buffer, &native_l2factor);
indexed = fz_colorspace_is_indexed(image->colorspace);
tile = fz_decomp_image_from_stream(ctx, stm, image, 0, indexed, l2factor, native_l2factor);
break;
}
/* Now we try to cache the pixmap. Any failure here will just result
* in us not caching. */
fz_var(keyp);
fz_try(ctx)
{
fz_pixmap *existing_tile;
keyp = fz_malloc_struct(ctx, fz_image_key);
keyp->refs = 1;
keyp->image = fz_keep_image(ctx, image);
keyp->l2factor = l2factor;
existing_tile = fz_store_item(ctx, keyp, tile, fz_pixmap_size(ctx, tile), &fz_image_store_type);
if (existing_tile)
{
/* We already have a tile. This must have been produced by a
* racing thread. We'll throw away ours and use that one. */
fz_drop_pixmap(ctx, tile);
tile = existing_tile;
}
}
fz_always(ctx)
{
fz_drop_image_key(ctx, keyp);
}
fz_catch(ctx)
{
/* Do nothing */
}
return tile;
}
static fz_pixmap *
decomp_image_from_stream(fz_context *ctx, fz_stream *stm, pdf_image *image, int in_line, int indexed, int l2factor, int native_l2factor, int cache)
{
fz_pixmap *tile = NULL;
fz_pixmap *existing_tile;
int stride, len, i;
unsigned char *samples = NULL;
int f = 1<<native_l2factor;
int w = (image->base.w + f-1) >> native_l2factor;
int h = (image->base.h + f-1) >> native_l2factor;
pdf_image_key *key = NULL;
fz_var(tile);
fz_var(samples);
fz_var(key);
fz_try(ctx)
{
tile = fz_new_pixmap(ctx, image->base.colorspace, w, h);
tile->interpolate = image->interpolate;
stride = (w * image->n * image->base.bpc + 7) / 8;
samples = fz_malloc_array(ctx, h, stride);
len = fz_read(stm, samples, h * stride);
if (len < 0)
{
fz_throw(ctx, "cannot read image data");
}
/* Make sure we read the EOF marker (for inline images only) */
if (in_line)
{
unsigned char tbuf[512];
fz_try(ctx)
{
int tlen = fz_read(stm, tbuf, sizeof tbuf);
if (tlen > 0)
fz_warn(ctx, "ignoring garbage at end of image");
}
fz_catch(ctx)
{
fz_warn(ctx, "ignoring error at end of image");
}
}
/* Pad truncated images */
if (len < stride * h)
{
fz_warn(ctx, "padding truncated image");
memset(samples + len, 0, stride * h - len);
}
/* Invert 1-bit image masks */
if (image->imagemask)
{
/* 0=opaque and 1=transparent so we need to invert */
unsigned char *p = samples;
len = h * stride;
for (i = 0; i < len; i++)
p[i] = ~p[i];
}
fz_unpack_tile(tile, samples, image->n, image->base.bpc, stride, indexed);
fz_free(ctx, samples);
samples = NULL;
if (image->usecolorkey)
pdf_mask_color_key(tile, image->n, image->colorkey);
if (indexed)
{
fz_pixmap *conv;
fz_decode_indexed_tile(tile, image->decode, (1 << image->base.bpc) - 1);
conv = pdf_expand_indexed_pixmap(ctx, tile);
fz_drop_pixmap(ctx, tile);
tile = conv;
}
else
{
fz_decode_tile(tile, image->decode);
}
}
fz_always(ctx)
{
fz_close(stm);
}
fz_catch(ctx)
{
if (tile)
fz_drop_pixmap(ctx, tile);
fz_free(ctx, samples);
fz_rethrow(ctx);
}
/* Now apply any extra subsampling required */
if (l2factor - native_l2factor > 0)
{
if (l2factor - native_l2factor > 8)
l2factor = native_l2factor + 8;
fz_subsample_pixmap(ctx, tile, l2factor - native_l2factor);
}
if (!cache)
return tile;
/* Now we try to cache the pixmap. Any failure here will just result
* in us not caching. */
fz_try(ctx)
{
key = fz_malloc_struct(ctx, pdf_image_key);
key->refs = 1;
key->image = fz_keep_image(ctx, &image->base);
key->l2factor = l2factor;
existing_tile = fz_store_item(ctx, key, tile, fz_pixmap_size(ctx, tile), &pdf_image_store_type);
if (existing_tile)
{
/* We already have a tile. This must have been produced by a
* racing thread. We'll throw away ours and use that one. */
fz_drop_pixmap(ctx, tile);
tile = existing_tile;
}
}
fz_always(ctx)
{
pdf_drop_image_key(ctx, key);
}
fz_catch(ctx)
{
/* Do nothing */
}
return tile;
}
static fz_pixmap *
decomp_image_banded(fz_context *ctx, fz_stream *stm, pdf_image *image, int indexed, int l2factor, int native_l2factor, int cache)
{
fz_pixmap *tile = NULL, *part = NULL;
int w = (image->base.w + (1 << l2factor) - 1) >> l2factor;
int h = (image->base.h + (1 << l2factor) - 1) >> l2factor;
int part_h, orig_h = image->base.h;
int band = 1 << fz_maxi(8, l2factor);
fz_var(tile);
fz_var(part);
fz_try(ctx)
{
tile = fz_new_pixmap(ctx, image->base.colorspace, w, h);
tile->interpolate = image->interpolate;
tile->has_alpha = 0; /* SumatraPDF: allow optimizing non-alpha pixmaps */
/* decompress the image in bands of 256 lines */
for (part_h = h; part_h > 0; part_h -= band >> l2factor)
{
image->base.h = part_h > band >> l2factor ? band : (orig_h - 1) % band + 1;
part = decomp_image_from_stream(ctx, fz_keep_stream(stm), image, -1, indexed, l2factor, native_l2factor, 0);
memcpy(tile->samples + (h - part_h) * tile->w * tile->n, part->samples, part->h * part->w * part->n);
tile->has_alpha |= part->has_alpha; /* SumatraPDF: allow optimizing non-alpha pixmaps */
fz_drop_pixmap(ctx, part);
part = NULL;
}
/* cf. http://bugs.ghostscript.com/show_bug.cgi?id=693517 */
if (image->usecolorkey && image->base.mask)
pdf_unblend_masked_tile(ctx, tile, image);
}
fz_always(ctx)
{
image->base.h = orig_h;
fz_close(stm);
}
fz_catch(ctx)
{
fz_drop_pixmap(ctx, part);
fz_drop_pixmap(ctx, tile);
fz_rethrow(ctx);
}
if (cache)
{
pdf_image_key *key = NULL;
fz_var(key);
fz_try(ctx)
{
key = fz_malloc_struct(ctx, pdf_image_key);
key->refs = 1;
key->image = fz_keep_image(ctx, &image->base);
key->l2factor = l2factor;
fz_store_item(ctx, key, tile, fz_pixmap_size(ctx, tile), &pdf_image_store_type);
}
fz_always(ctx)
{
pdf_drop_image_key(ctx, key);
}
fz_catch(ctx) { }
}
return tile;
}