*/
static int png_image_header ( struct image *image, struct png_context *png,
size_t len ) {
- struct png_image_header ihdr;
+ const struct png_image_header *ihdr;
struct png_interlace interlace;
unsigned int pass;
/* Sanity check */
- if ( len != sizeof ( ihdr ) ) {
+ if ( len != sizeof ( *ihdr ) ) {
DBGC ( image, "PNG %s invalid IHDR length %zd\n",
image->name, len );
return -EINVAL;
}
/* Extract image header */
- copy_from_user ( &ihdr, image->data, png->offset, len );
+ ihdr = ( image->data + png->offset );
DBGC ( image, "PNG %s %dx%d depth %d type %d compression %d filter %d "
- "interlace %d\n", image->name, ntohl ( ihdr.width ),
- ntohl ( ihdr.height ), ihdr.depth, ihdr.colour_type,
- ihdr.compression, ihdr.filter, ihdr.interlace );
+ "interlace %d\n", image->name, ntohl ( ihdr->width ),
+ ntohl ( ihdr->height ), ihdr->depth, ihdr->colour_type,
+ ihdr->compression, ihdr->filter, ihdr->interlace );
/* Sanity checks */
- if ( ihdr.compression >= PNG_COMPRESSION_UNKNOWN ) {
+ if ( ihdr->compression >= PNG_COMPRESSION_UNKNOWN ) {
DBGC ( image, "PNG %s unknown compression method %d\n",
- image->name, ihdr.compression );
+ image->name, ihdr->compression );
return -ENOTSUP;
}
- if ( ihdr.filter >= PNG_FILTER_UNKNOWN ) {
+ if ( ihdr->filter >= PNG_FILTER_UNKNOWN ) {
DBGC ( image, "PNG %s unknown filter method %d\n",
- image->name, ihdr.filter );
+ image->name, ihdr->filter );
return -ENOTSUP;
}
- if ( ihdr.interlace >= PNG_INTERLACE_UNKNOWN ) {
+ if ( ihdr->interlace >= PNG_INTERLACE_UNKNOWN ) {
DBGC ( image, "PNG %s unknown interlace method %d\n",
- image->name, ihdr.interlace );
+ image->name, ihdr->interlace );
return -ENOTSUP;
}
/* Allocate pixel buffer */
- png->pixbuf = alloc_pixbuf ( ntohl ( ihdr.width ),
- ntohl ( ihdr.height ) );
+ png->pixbuf = alloc_pixbuf ( ntohl ( ihdr->width ),
+ ntohl ( ihdr->height ) );
if ( ! png->pixbuf ) {
DBGC ( image, "PNG %s could not allocate pixel buffer\n",
image->name );
}
/* Extract bit depth */
- png->depth = ihdr.depth;
+ png->depth = ihdr->depth;
if ( ( png->depth == 0 ) ||
( ( png->depth & ( png->depth - 1 ) ) != 0 ) ) {
DBGC ( image, "PNG %s invalid depth %d\n",
}
/* Calculate number of channels */
- png->colour_type = ihdr.colour_type;
+ png->colour_type = ihdr->colour_type;
png->channels = 1;
- if ( ! ( ihdr.colour_type & PNG_COLOUR_TYPE_PALETTE ) ) {
- if ( ihdr.colour_type & PNG_COLOUR_TYPE_RGB )
+ if ( ! ( ihdr->colour_type & PNG_COLOUR_TYPE_PALETTE ) ) {
+ if ( ihdr->colour_type & PNG_COLOUR_TYPE_RGB )
png->channels += 2;
- if ( ihdr.colour_type & PNG_COLOUR_TYPE_ALPHA )
+ if ( ihdr->colour_type & PNG_COLOUR_TYPE_ALPHA )
png->channels += 1;
}
/* Calculate number of interlace passes */
- png->passes = png_interlace_passes[ihdr.interlace];
+ png->passes = png_interlace_passes[ihdr->interlace];
/* Calculate length of raw data buffer */
for ( pass = 0 ; pass < png->passes ; pass++ ) {
*/
static int png_palette ( struct image *image, struct png_context *png,
size_t len ) {
- size_t offset = png->offset;
- struct png_palette_entry palette;
+ const struct png_palette_entry *palette;
unsigned int i;
/* Populate palette */
+ palette = ( image->data + png->offset );
for ( i = 0 ; i < ( sizeof ( png->palette ) /
sizeof ( png->palette[0] ) ) ; i++ ) {
/* Stop when we run out of palette data */
- if ( len < sizeof ( palette ) )
+ if ( len < sizeof ( *palette ) )
break;
/* Extract palette entry */
- copy_from_user ( &palette, image->data, offset,
- sizeof ( palette ) );
- png->palette[i] = ( ( palette.red << 16 ) |
- ( palette.green << 8 ) |
- ( palette.blue << 0 ) );
+ png->palette[i] = ( ( palette->red << 16 ) |
+ ( palette->green << 8 ) |
+ ( palette->blue << 0 ) );
DBGC2 ( image, "PNG %s palette entry %d is %#06x\n",
image->name, i, png->palette[i] );
/* Move to next entry */
- offset += sizeof ( palette );
- len -= sizeof ( palette );
+ palette++;
+ len -= sizeof ( *palette );
}
return 0;
*/
static int png_unfilter_pass ( struct image *image, struct png_context *png,
struct png_interlace *interlace ) {
- size_t offset = png->raw.offset;
size_t pixel_len = png_pixel_len ( png );
size_t scanline_len = png_scanline_len ( png, interlace );
+ uint8_t *data = ( png->raw.data + png->raw.offset );
struct png_filter *filter;
unsigned int scanline;
unsigned int byte;
- uint8_t filter_type;
- uint8_t left;
- uint8_t above;
- uint8_t above_left;
- uint8_t current;
+ unsigned int filter_type;
+ unsigned int left;
+ unsigned int above;
+ unsigned int above_left;
/* On the first scanline of a pass, above bytes are assumed to
* be zero.
for ( scanline = 0 ; scanline < interlace->height ; scanline++ ) {
/* Extract filter byte and determine filter type */
- copy_from_user ( &filter_type, png->raw.data, offset++,
- sizeof ( filter_type ) );
+ filter_type = *(data++);
if ( filter_type >= ( sizeof ( png_filters ) /
sizeof ( png_filters[0] ) ) ) {
DBGC ( image, "PNG %s unknown filter type %d\n",
for ( byte = 0 ; byte < ( scanline_len - 1 ) ; byte++ ) {
/* Extract predictor bytes, if applicable */
- if ( byte >= pixel_len ) {
- copy_from_user ( &left, png->raw.data,
- ( offset - pixel_len ),
- sizeof ( left ) );
- }
- if ( scanline > 0 ) {
- copy_from_user ( &above, png->raw.data,
- ( offset - scanline_len ),
- sizeof ( above ) );
- }
+ if ( byte >= pixel_len )
+ left = *( data - pixel_len );
+ if ( scanline > 0 )
+ above = *( data - scanline_len );
if ( ( scanline > 0 ) && ( byte >= pixel_len ) ) {
- copy_from_user ( &above_left, png->raw.data,
- ( offset - scanline_len -
- pixel_len ),
- sizeof ( above_left ) );
+ above_left = *( data - scanline_len -
+ pixel_len );
}
/* Unfilter current byte */
- copy_from_user ( ¤t, png->raw.data,
- offset, sizeof ( current ) );
- current = filter->unfilter ( current, left, above,
- above_left );
- copy_to_user ( png->raw.data, offset++,
- ¤t, sizeof ( current ) );
+ *data = filter->unfilter ( *data, left, above,
+ above_left );
+ data++;
}
}
/* Update offset */
- png->raw.offset = offset;
+ png->raw.offset = ( ( ( void * ) data ) - png->raw.data );
return 0;
}
static void png_pixels_pass ( struct image *image,
struct png_context *png,
struct png_interlace *interlace ) {
- size_t raw_offset = png->raw.offset;
uint8_t channel[png->channels];
int is_indexed = ( png->colour_type & PNG_COLOUR_TYPE_PALETTE );
int is_rgb = ( png->colour_type & PNG_COLOUR_TYPE_RGB );
int has_alpha = ( png->colour_type & PNG_COLOUR_TYPE_ALPHA );
- size_t pixbuf_y_offset;
- size_t pixbuf_offset;
- size_t pixbuf_x_stride;
- size_t pixbuf_y_stride;
- size_t raw_stride;
+ const uint8_t *data = ( png->raw.data + png->raw.offset );
+ size_t data_stride;
+ unsigned int pixbuf_y_index;
+ unsigned int pixbuf_index;
+ unsigned int pixbuf_x_stride;
+ unsigned int pixbuf_y_stride;
unsigned int y;
unsigned int x;
unsigned int c;
* as a bit depth of 8 with a stride of more than one.
*/
depth = png->depth;
- raw_stride = ( ( depth + 7 ) / 8 );
+ data_stride = ( ( depth + 7 ) / 8 );
if ( depth > 8 )
depth = 8;
max = ( ( 1 << depth ) - 1 );
/* Calculate pixel buffer offset and strides */
- pixbuf_y_offset = ( ( ( interlace->y_indent * png->pixbuf->width ) +
- interlace->x_indent ) * sizeof ( pixel ) );
- pixbuf_x_stride = ( interlace->x_stride * sizeof ( pixel ) );
- pixbuf_y_stride = ( interlace->y_stride * png->pixbuf->width *
- sizeof ( pixel ) );
+ pixbuf_y_index = ( ( ( interlace->y_indent * png->pixbuf->width ) +
+ interlace->x_indent ) );
+ pixbuf_x_stride = interlace->x_stride;
+ pixbuf_y_stride = ( interlace->y_stride * png->pixbuf->width );
DBGC2 ( image, "PNG %s pass %d %dx%d at (%d,%d) stride (%d,%d)\n",
image->name, interlace->pass, interlace->width,
interlace->height, interlace->x_indent, interlace->y_indent,
for ( y = 0 ; y < interlace->height ; y++ ) {
/* Skip filter byte */
- raw_offset++;
+ data++;
/* Iterate over each pixel in turn */
bits = depth;
- pixbuf_offset = pixbuf_y_offset;
+ pixbuf_index = pixbuf_y_index;
for ( x = 0 ; x < interlace->width ; x++ ) {
/* Extract sample value */
current <<= depth;
bits -= depth;
if ( ! bits ) {
- copy_from_user ( ¤t,
- png->raw.data,
- raw_offset,
- sizeof ( current ) );
- raw_offset += raw_stride;
+ current = *data;
+ data += data_stride;
bits = 8;
}
}
/* Store pixel */
- copy_to_user ( png->pixbuf->data, pixbuf_offset,
- &pixel, sizeof ( pixel ) );
- pixbuf_offset += pixbuf_x_stride;
+ png->pixbuf->data[pixbuf_index] = pixel;
+ pixbuf_index += pixbuf_x_stride;
}
/* Move to next output row */
- pixbuf_y_offset += pixbuf_y_stride;
+ pixbuf_y_index += pixbuf_y_stride;
}
/* Update offset */
- png->raw.offset = raw_offset;
+ png->raw.offset = ( ( ( const void * ) data ) - png->raw.data );
}
/**
*/
static int png_pixbuf ( struct image *image, struct pixel_buffer **pixbuf ) {
struct png_context *png;
- struct png_chunk_header header;
- struct png_chunk_footer footer;
+ const struct png_chunk_header *header;
+ const struct png_chunk_footer *footer;
size_t remaining;
size_t chunk_len;
int rc;
/* Extract chunk header */
remaining = ( image->len - png->offset );
- if ( remaining < ( sizeof ( header ) + sizeof ( footer ) ) ) {
+ if ( remaining < ( sizeof ( *header ) + sizeof ( *footer ) ) ){
DBGC ( image, "PNG %s truncated chunk header/footer "
"at offset %zd\n", image->name, png->offset );
rc = -EINVAL;
goto err_truncated;
}
- copy_from_user ( &header, image->data, png->offset,
- sizeof ( header ) );
- png->offset += sizeof ( header );
+ header = ( image->data + png->offset );
+ png->offset += sizeof ( *header );
/* Validate chunk length */
- chunk_len = ntohl ( header.len );
- if ( chunk_len > ( remaining - sizeof ( header ) -
- sizeof ( footer ) ) ) {
+ chunk_len = ntohl ( header->len );
+ if ( chunk_len > ( remaining - sizeof ( *header ) -
+ sizeof ( *footer ) ) ) {
DBGC ( image, "PNG %s truncated chunk data at offset "
"%zd\n", image->name, png->offset );
rc = -EINVAL;
}
/* Handle chunk */
- if ( ( rc = png_chunk ( image, png, header.type,
+ if ( ( rc = png_chunk ( image, png, header->type,
chunk_len ) ) != 0 )
goto err_chunk;
/* Move to next chunk */
- png->offset += ( chunk_len + sizeof ( footer ) );
+ png->offset += ( chunk_len + sizeof ( *footer ) );
} while ( png->offset < image->len );
/* Check that we finished with an IEND chunk */
- if ( header.type != htonl ( PNG_TYPE_IEND ) ) {
+ if ( header->type != htonl ( PNG_TYPE_IEND ) ) {
DBGC ( image, "PNG %s did not finish with IEND\n",
image->name );
rc = -EINVAL;
* @ret rc Return status code
*/
static int png_probe ( struct image *image ) {
- struct png_signature signature;
+ const struct png_signature *signature;
/* Sanity check */
- if ( image->len < sizeof ( signature ) ) {
+ if ( image->len < sizeof ( *signature ) ) {
DBGC ( image, "PNG %s is too short\n", image->name );
return -ENOEXEC;
}
/* Check signature */
- copy_from_user ( &signature, image->data, 0, sizeof ( signature ) );
- if ( memcmp ( &signature, &png_signature, sizeof ( signature ) ) != 0 ){
+ signature = image->data;
+ if ( memcmp ( signature, &png_signature, sizeof ( *signature ) ) != 0 ){
DBGC ( image, "PNG %s has invalid signature\n", image->name );
return -ENOEXEC;
}