// picoPNG version 20080503 (cleaned up and ported to c by kaitek)
// Copyright (c) 2005-2008 Lode Vandevenne
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
// misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
#include <common.h>
#include <malloc.h>
#include "picopng.h"
/*************************************************************************************************/
typedef struct png_alloc_node {
struct png_alloc_node *prev, *next;
void *addr;
size_t size;
} png_alloc_node_t;
png_alloc_node_t *png_alloc_head = NULL;
png_alloc_node_t *png_alloc_tail = NULL;
static png_alloc_node_t *png_alloc_find_node(void *addr)
{
png_alloc_node_t *node;
for (node = png_alloc_head; node; node = node->next)
if (node->addr == addr)
break;
return node;
}
static void png_alloc_add_node(void *addr, size_t size)
{
png_alloc_node_t *node;
if (png_alloc_find_node(addr))
return;
node = malloc(sizeof (png_alloc_node_t));
node->addr = addr;
node->size = size;
node->prev = png_alloc_tail;
node->next = NULL;
png_alloc_tail = node;
if (node->prev)
node->prev->next = node;
if (!png_alloc_head)
png_alloc_head = node;
}
static void png_alloc_remove_node(png_alloc_node_t *node)
{
if (node->prev)
node->prev->next = node->next;
if (node->next)
node->next->prev = node->prev;
if (node == png_alloc_head)
png_alloc_head = node->next;
if (node == png_alloc_tail)
png_alloc_tail = node->prev;
node->prev = node->next = node->addr = NULL;
free(node);
}
static void *png_alloc_malloc(size_t size)
{
void *addr = malloc(size);
png_alloc_add_node(addr, size);
return addr;
}
static void *png_alloc_realloc(void *addr, size_t size)
{
void *new_addr;
if (!addr)
return png_alloc_malloc(size);
new_addr = realloc(addr, size);
if (new_addr != addr) {
png_alloc_node_t *old_node;
old_node = png_alloc_find_node(addr);
png_alloc_remove_node(old_node);
png_alloc_add_node(new_addr, size);
}
return new_addr;
}
static void png_alloc_free(void *addr)
{
png_alloc_node_t *node = png_alloc_find_node(addr);
if (!node)
return;
png_alloc_remove_node(node);
free(addr);
}
void png_alloc_free_all()
{
while (png_alloc_tail) {
void *addr = png_alloc_tail->addr;
png_alloc_remove_node(png_alloc_tail);
free(addr);
}
}
/*************************************************************************************************/
__maybe_unused static void vector32_cleanup(vector32_t *p)
{
p->size = p->allocsize = 0;
if (p->data)
png_alloc_free(p->data);
p->data = NULL;
}
static uint32_t vector32_resize(vector32_t *p, size_t size)
{ // returns 1 if success, 0 if failure ==> nothing done
if (size * sizeof (uint32_t) > p->allocsize) {
size_t newsize = size * sizeof (uint32_t) * 2;
void *data = png_alloc_realloc(p->data, newsize);
if (data) {
p->allocsize = newsize;
p->data = (uint32_t *) data;
p->size = size;
} else
return 0;
} else
p->size = size;
return 1;
}
static uint32_t vector32_resizev(vector32_t *p, size_t size, uint32_t value)
{ // resize and give all new elements the value
size_t oldsize = p->size, i;
if (!vector32_resize(p, size))
return 0;
for (i = oldsize; i < size; i++)
p->data[i] = value;
return 1;
}
static void vector32_init(vector32_t *p)
{
p->data = NULL;
p->size = p->allocsize = 0;
}
__maybe_unused static vector32_t *vector32_new(size_t size, uint32_t value)
{
vector32_t *p = png_alloc_malloc(sizeof (vector32_t));
vector32_init(p);
if (size && !vector32_resizev(p, size, value))
return NULL;
return p;
}
/*************************************************************************************************/
__maybe_unused static void vector8_cleanup(vector8_t *p)
{
p->size = p->allocsize = 0;
if (p->data)
png_alloc_free(p->data);
p->data = NULL;
}
static uint32_t vector8_resize(vector8_t *p, size_t size)
{ // returns 1 if success, 0 if failure ==> nothing done
// xxx: the use of sizeof uint32_t here seems like a bug (this descends from the lodepng vector
// compatibility functions which do the same). without this there is corruption in certain cases,
// so this was probably done to cover up allocation bug(s) in the original picopng code!
if (size * sizeof (uint32_t) > p->allocsize) {
size_t newsize = size * sizeof (uint32_t) * 2;
void *data = png_alloc_realloc(p->data, newsize);
if (data) {
p->allocsize = newsize;
p->data = (uint8_t *) data;
p->size = size;
} else
return 0; // error: not enough memory
} else
p->size = size;
return 1;
}
static uint32_t vector8_resizev(vector8_t *p, size_t size, uint8_t value)
{ // resize and give all new elements the value
size_t oldsize = p->size, i;
if (!vector8_resize(p, size))
return 0;
for (i = oldsize; i < size; i++)
p->data[i] = value;
return 1;
}
static void vector8_init(vector8_t *p)
{
p->data = NULL;
p->size = p->allocsize = 0;
}
static vector8_t *vector8_new(size_t size, uint8_t value)
{
vector8_t *p = png_alloc_malloc(sizeof (vector8_t));
vector8_init(p);
if (size && !vector8_resizev(p, size, value))
return NULL;
return p;
}
static vector8_t *vector8_copy(vector8_t *p)
{
vector8_t *q = vector8_new(p->size, 0);
uint32_t n;
for (n = 0; n < q->size; n++)
q->data[n] = p->data[n];
return q;
}
/*************************************************************************************************/
static int Zlib_decompress(vector8_t *out, const vector8_t *in) // returns error value
{
return picopng_zlib_decompress(out->data, out->size, in->data, in->size);
}
/*************************************************************************************************/
#define PNG_SIGNATURE 0x0a1a0a0d474e5089ull
#define CHUNK_IHDR 0x52444849
#define CHUNK_IDAT 0x54414449
#define CHUNK_IEND 0x444e4549
#define CHUNK_PLTE 0x45544c50
#define CHUNK_tRNS 0x534e5274
int PNG_error;
static uint32_t PNG_readBitFromReversedStream(size_t *bitp, const uint8_t *bits)
{
uint32_t result = (bits[*bitp >> 3] >> (7 - (*bitp & 0x7))) & 1;
(*bitp)++;
return result;
}
static uint32_t PNG_readBitsFromReversedStream(size_t *bitp, const uint8_t *bits, uint32_t nbits)
{
uint32_t i, result = 0;
for (i = nbits - 1; i < nbits; i--)
result += ((PNG_readBitFromReversedStream(bitp, bits)) << i);
return result;
}
static void PNG_setBitOfReversedStream(size_t *bitp, uint8_t *bits, uint32_t bit)
{
bits[*bitp >> 3] |= (bit << (7 - (*bitp & 0x7)));
(*bitp)++;
}
static uint32_t PNG_read32bitInt(const uint8_t *buffer)
{
return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
}
static int PNG_checkColorValidity(uint32_t colorType, uint32_t bd) // return type is a LodePNG error code
{
if ((colorType == 2 || colorType == 4 || colorType == 6)) {
if (!(bd == 8 || bd == 16))
return 37;
else
return 0;
} else if (colorType == 0) {
if (!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16))
return 37;
else
return 0;
} else if (colorType == 3) {
if (!(bd == 1 || bd == 2 || bd == 4 || bd == 8))
return 37;
else
return 0;
} else
return 31; // nonexistent color type
}
static uint32_t PNG_getBpp(const PNG_info_t *info)
{
uint32_t bitDepth, colorType;
bitDepth = info->bitDepth;
colorType = info->colorType;
if (colorType == 2)
return (3 * bitDepth);
else if (colorType >= 4)
return (colorType - 2) * bitDepth;
else
return bitDepth;
}
static void PNG_readPngHeader(PNG_info_t *info, const uint8_t *in, size_t inlength)
{ // read the information from the header and store it in the Info
if (inlength < 29) {
PNG_error = 27; // error: the data length is smaller than the length of the header
return;
}
if (*(uint64_t *) in != PNG_SIGNATURE) {
PNG_error = 28; // no PNG signature
return;
}
if (*(uint32_t *) &in[12] != CHUNK_IHDR) {
PNG_error = 29; // error: it doesn't start with a IHDR chunk!
return;
}
info->width = PNG_read32bitInt(&in[16]);
info->height = PNG_read32bitInt(&in[20]);
info->bitDepth = in[24];
info->colorType = in[25];
info->compressionMethod = in[26];
if (in[26] != 0) {
PNG_error = 32; // error: only compression method 0 is allowed in the specification
return;
}
info->filterMethod = in[27];
if (in[27] != 0) {
PNG_error = 33; // error: only filter method 0 is allowed in the specification
return;
}
info->interlaceMethod = in[28];
if (in[28] > 1) {
PNG_error = 34; // error: only interlace methods 0 and 1 exist in the specification
return;
}
PNG_error = PNG_checkColorValidity(info->colorType, info->bitDepth);
}
static int PNG_paethPredictor(int a, int b, int c) // Paeth predicter, used by PNG filter type 4
{
int p, pa, pb, pc;
p = a + b - c;
pa = p > a ? (p - a) : (a - p);
pb = p > b ? (p - b) : (b - p);
pc = p > c ? (p - c) : (c - p);
return (pa <= pb && pa <= pc) ? a : (pb <= pc ? b : c);
}
static void PNG_unFilterScanline(uint8_t *recon, const uint8_t *scanline, const uint8_t *precon,
size_t bytewidth, uint32_t filterType, size_t length)
{
size_t i;
switch (filterType) {
case 0:
for (i = 0; i < length; i++)
recon[i] = scanline[i];
break;
case 1:
for (i = 0; i < bytewidth; i++)
recon[i] = scanline[i];
for (i = bytewidth; i < length; i++)
recon[i] = scanline[i] + recon[i - bytewidth];
break;
case 2:
if (precon)
for (i = 0; i < length; i++)
recon[i] = scanline[i] + precon[i];
else
for (i = 0; i < length; i++)
recon[i] = scanline[i];
break;
case 3:
if (precon) {
for (i = 0; i < bytewidth; i++)
recon[i] = scanline[i] + precon[i] / 2;
for (i = bytewidth; i < length; i++)
recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2);
} else {
for (i = 0; i < bytewidth; i++)
recon[i] = scanline[i];
for (i = bytewidth; i < length; i++)
recon[i] = scanline[i] + recon[i - bytewidth] / 2;
}
break;
case 4:
if (precon) {
for (i = 0; i < bytewidth; i++)
recon[i] = (uint8_t) (scanline[i] + PNG_paethPredictor(0, precon[i], 0));
for (i = bytewidth; i < length; i++)
recon[i] = (uint8_t) (scanline[i] + PNG_paethPredictor(recon[i - bytewidth],
precon[i], precon[i - bytewidth]));
} else {
for (i = 0; i < bytewidth; i++)
recon[i] = scanline[i];
for (i = bytewidth; i < length; i++)
recon[i] = (uint8_t) (scanline[i] + PNG_paethPredictor(recon[i - bytewidth], 0, 0));
}
break;
default:
PNG_error = 36; // error: nonexistent filter type given
return;
}
}
static void PNG_adam7Pass(uint8_t *out, uint8_t *linen, uint8_t *lineo, const uint8_t *in, uint32_t w,
size_t passleft, size_t passtop, size_t spacex, size_t spacey, size_t passw, size_t passh,
uint32_t bpp)
{
size_t bytewidth, linelength;
uint32_t y;
uint8_t *temp;
// filter and reposition the pixels into the output when the image is Adam7 interlaced. This
// function can only do it after the full image is already decoded. The out buffer must have
// the correct allocated memory size already.
if (passw == 0)
return;
bytewidth = (bpp + 7) / 8;
linelength = 1 + ((bpp * passw + 7) / 8);
for (y = 0; y < passh; y++) {
size_t i, b;
uint8_t filterType = in[y * linelength], *prevline = (y == 0) ? 0 : lineo;
PNG_unFilterScanline(linen, &in[y * linelength + 1], prevline, bytewidth, filterType,
(w * bpp + 7) / 8);
if (PNG_error)
return;
if (bpp >= 8)
for (i = 0; i < passw; i++)
for (b = 0; b < bytewidth; b++) // b = current byte of this pixel
out[bytewidth * w * (passtop + spacey * y) + bytewidth *
(passleft + spacex * i) + b] = linen[bytewidth * i + b];
else
for (i = 0; i < passw; i++) {
size_t obp, bp;
obp = bpp * w * (passtop + spacey * y) + bpp * (passleft + spacex * i);
bp = i * bpp;
for (b = 0; b < bpp; b++)
PNG_setBitOfReversedStream(&obp, out, PNG_readBitFromReversedStream(&bp, linen));
}
temp = linen;
linen = lineo;
lineo = temp; // swap the two buffer pointers "line old" and "line new"
}
}
static int PNG_convert(const PNG_info_t *info, vector8_t *out, const uint8_t *in)
{ // converts from any color type to 32-bit. return value = LodePNG error code
size_t i, c;
uint32_t bitDepth, colorType;
size_t numpixels, bp;
uint8_t *out_data;
bitDepth = info->bitDepth;
colorType = info->colorType;
numpixels = info->width * info->height;
bp = 0;
vector8_resize(out, numpixels * 4);
out_data = out->size ? out->data : 0;
if (bitDepth == 8 && colorType == 0) // greyscale
for (i = 0; i < numpixels; i++) {
out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = in[i];
out_data[4 * i + 3] = (info->key_defined && (in[i] == info->key_r)) ? 0 : 255;
}
else if (bitDepth == 8 && colorType == 2) // RGB color
for (i = 0; i < numpixels; i++) {
for (c = 0; c < 3; c++)
out_data[4 * i + c] = in[3 * i + c];
out_data[4 * i + 3] = (info->key_defined && (in[3 * i + 0] == info->key_r) &&
(in[3 * i + 1] == info->key_g) && (in[3 * i + 2] == info->key_b)) ? 0 : 255;
}
else if (bitDepth == 8 && colorType == 3) // indexed color (palette)
for (i = 0; i < numpixels; i++) {
if (4U * in[i] >= info->palette->size)
return 46;
for (c = 0; c < 4; c++) // get rgb colors from the palette
out_data[4 * i + c] = info->palette->data[4 * in[i] + c];
}
else if (bitDepth == 8 && colorType == 4) // greyscale with alpha
for (i = 0; i < numpixels; i++) {
out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = in[2 * i + 0];
out_data[4 * i + 3] = in[2 * i + 1];
}
else if (bitDepth == 8 && colorType == 6)
for (i = 0; i < numpixels; i++)
for (c = 0; c < 4; c++)
out_data[4 * i + c] = in[4 * i + c]; // RGB with alpha
else if (bitDepth == 16 && colorType == 0) // greyscale
for (i = 0; i < numpixels; i++) {
out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = in[2 * i];
out_data[4 * i + 3] = (info->key_defined && (256U * in[i] + in[i + 1] == info->key_r))
? 0 : 255;
}
else if (bitDepth == 16 && colorType == 2) // RGB color
for (i = 0; i < numpixels; i++) {
for (c = 0; c < 3; c++)
out_data[4 * i + c] = in[6 * i + 2 * c];
out_data[4 * i + 3] = (info->key_defined &&
(256U * in[6 * i + 0] + in[6 * i + 1] == info->key_r) &&
(256U * in[6 * i + 2] + in[6 * i + 3] == info->key_g) &&
(256U * in[6 * i + 4] + in[6 * i + 5] == info->key_b)) ? 0 : 255;
}
else if (bitDepth == 16 && colorType == 4) // greyscale with alpha
for (i = 0; i < numpixels; i++) {
out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = in[4 * i]; // msb
out_data[4 * i + 3] = in[4 * i + 2];
}
else if (bitDepth == 16 && colorType == 6)
for (i = 0; i < numpixels; i++)
for (c = 0; c < 4; c++)
out_data[4 * i + c] = in[8 * i + 2 * c]; // RGB with alpha
else if (bitDepth < 8 && colorType == 0) // greyscale
for (i = 0; i < numpixels; i++) {
uint32_t value = (PNG_readBitsFromReversedStream(&bp, in, bitDepth) * 255) /
((1 << bitDepth) - 1); // scale value from 0 to 255
out_data[4 * i + 0] = out_data[4 * i + 1] = out_data[4 * i + 2] = (uint8_t) value;
out_data[4 * i + 3] = (info->key_defined && value &&
(((1U << bitDepth) - 1U) == info->key_r) && ((1U << bitDepth) - 1U)) ? 0 : 255;
}
else if (bitDepth < 8 && colorType == 3) // palette
for (i = 0; i < numpixels; i++) {
uint32_t value = PNG_readBitsFromReversedStream(&bp, in, bitDepth);
if (4 * value >= info->palette->size)
return 47;
for (c = 0; c < 4; c++) // get rgb colors from the palette
out_data[4 * i + c] = info->palette->data[4 * value + c];
}
return 0;
}
static PNG_info_t *PNG_info_new(void)
{
PNG_info_t *info = png_alloc_malloc(sizeof (PNG_info_t));
uint32_t i;
for (i = 0; i < sizeof (PNG_info_t); i++)
((uint8_t *) info)[i] = 0;
info->palette = vector8_new(0, 0);
info->image = vector8_new(0, 0);
return info;
}
PNG_info_t *PNG_decode(const uint8_t *in, uint32_t size)
{
PNG_info_t *info;
size_t pos;
vector8_t *idat;
bool IEND, known_type;
uint32_t bpp;
vector8_t *scanlines; // now the out buffer will be filled
size_t bytewidth, outlength;
uint8_t *out_data;
PNG_error = 0;
if (size == 0 || in == 0) {
PNG_error = 48; // the given data is empty
return NULL;
}
info = PNG_info_new();
PNG_readPngHeader(info, in, size);
if (PNG_error)
return NULL;
pos = 33; // first byte of the first chunk after the header
idat = NULL; // the data from idat chunks
IEND = false;
known_type = true;
info->key_defined = false;
// loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. IDAT data is
// put at the start of the in buffer
while (!IEND) {
size_t i, j;
size_t chunkLength;
uint32_t chunkType;
if (pos + 8 >= size) {
PNG_error = 30; // error: size of the in buffer too small to contain next chunk
return NULL;
}
chunkLength = PNG_read32bitInt(&in[pos]);
pos += 4;
if (chunkLength > 0x7fffffff) {
PNG_error = 63;
return NULL;
}
if (pos + chunkLength >= size) {
PNG_error = 35; // error: size of the in buffer too small to contain next chunk
return NULL;
}
chunkType = *(uint32_t *) &in[pos];
if (chunkType == CHUNK_IDAT) { // IDAT: compressed image data chunk
size_t offset = 0;
if (idat) {
offset = idat->size;
vector8_resize(idat, offset + chunkLength);
} else
idat = vector8_new(chunkLength, 0);
for (i = 0; i < chunkLength; i++)
idat->data[offset + i] = in[pos + 4 + i];
pos += (4 + chunkLength);
} else if (chunkType == CHUNK_IEND) { // IEND
pos += 4;
IEND = true;
} else if (chunkType == CHUNK_PLTE) { // PLTE: palette chunk
pos += 4; // go after the 4 letters
vector8_resize(info->palette, 4 * (chunkLength / 3));
if (info->palette->size > (4 * 256)) {
PNG_error = 38; // error: palette too big
return NULL;
}
for (i = 0; i < info->palette->size; i += 4) {
for (j = 0; j < 3; j++)
info->palette->data[i + j] = in[pos++]; // RGB
info->palette->data[i + 3] = 255; // alpha
}
} else if (chunkType == CHUNK_tRNS) { // tRNS: palette transparency chunk
pos += 4; // go after the 4 letters
if (info->colorType == 3) {
if (4 * chunkLength > info->palette->size) {
PNG_error = 39; // error: more alpha values given than there are palette entries
return NULL;
}
for (i = 0; i < chunkLength; i++)
info->palette->data[4 * i + 3] = in[pos++];
} else if (info->colorType == 0) {
if (chunkLength != 2) {
PNG_error = 40; // error: this chunk must be 2 bytes for greyscale image
return NULL;
}
info->key_defined = true;
info->key_r = info->key_g = info->key_b = 256 * in[pos] + in[pos + 1];
pos += 2;
} else if (info->colorType == 2) {
if (chunkLength != 6) {
PNG_error = 41; // error: this chunk must be 6 bytes for RGB image
return NULL;
}
info->key_defined = true;
info->key_r = 256 * in[pos] + in[pos + 1];
pos += 2;
info->key_g = 256 * in[pos] + in[pos + 1];
pos += 2;
info->key_b = 256 * in[pos] + in[pos + 1];
pos += 2;
} else {
PNG_error = 42; // error: tRNS chunk not allowed for other color models
return NULL;
}
} else { // it's not an implemented chunk type, so ignore it: skip over the data
if (!(in[pos + 0] & 32)) {
// error: unknown critical chunk (5th bit of first byte of chunk type is 0)
PNG_error = 69;
return NULL;
}
pos += (chunkLength + 4); // skip 4 letters and uninterpreted data of unimplemented chunk
known_type = false;
}
pos += 4; // step over CRC (which is ignored)
}
bpp = PNG_getBpp(info);
scanlines = vector8_new(((info->width * (info->height * bpp + 7)) / 8) + info->height, 0);
PNG_error = Zlib_decompress(scanlines, idat);
if (PNG_error)
return NULL; // stop if the zlib decompressor returned an error
bytewidth = (bpp + 7) / 8;
outlength = (info->height * info->width * bpp + 7) / 8;
vector8_resize(info->image, outlength); // time to fill the out buffer
out_data = outlength ? info->image->data : 0;
if (info->interlaceMethod == 0) { // no interlace, just filter
size_t y, obp, bp;
size_t linestart, linelength;
linestart = 0;
// length in bytes of a scanline, excluding the filtertype byte
linelength = (info->width * bpp + 7) / 8;
if (bpp >= 8) // byte per byte
for (y = 0; y < info->height; y++) {
uint32_t filterType = scanlines->data[linestart];
const uint8_t *prevline;
prevline = (y == 0) ? 0 : &out_data[(y - 1) * info->width * bytewidth];
PNG_unFilterScanline(&out_data[linestart - y], &scanlines->data[linestart + 1],
prevline, bytewidth, filterType, linelength);
if (PNG_error)
return NULL;
linestart += (1 + linelength); // go to start of next scanline
} else { // less than 8 bits per pixel, so fill it up bit per bit
vector8_t *templine; // only used if bpp < 8
templine = vector8_new((info->width * bpp + 7) >> 3, 0);
for (y = 0, obp = 0; y < info->height; y++) {
uint32_t filterType = scanlines->data[linestart];
const uint8_t *prevline;
prevline = (y == 0) ? 0 : &out_data[(y - 1) * info->width * bytewidth];
PNG_unFilterScanline(templine->data, &scanlines->data[linestart + 1], prevline,
bytewidth, filterType, linelength);
if (PNG_error)
return NULL;
for (bp = 0; bp < info->width * bpp;)
PNG_setBitOfReversedStream(&obp, out_data, PNG_readBitFromReversedStream(&bp,
templine->data));
linestart += (1 + linelength); // go to start of next scanline
}
}
} else { // interlaceMethod is 1 (Adam7)
int i;
vector8_t *scanlineo, *scanlinen; // "old" and "new" scanline
size_t passw[7] = {
(info->width + 7) / 8, (info->width + 3) / 8, (info->width + 3) / 4,
(info->width + 1) / 4, (info->width + 1) / 2, (info->width + 0) / 2,
(info->width + 0) / 1
};
size_t passh[7] = {
(info->height + 7) / 8, (info->height + 7) / 8, (info->height + 3) / 8,
(info->height + 3) / 4, (info->height + 1) / 4, (info->height + 1) / 2,
(info->height + 0) / 2
};
size_t passstart[7] = { 0 };
size_t pattern[28] = { 0, 4, 0, 2, 0, 1, 0, 0, 0, 4, 0, 2, 0, 1, 8, 8, 4, 4, 2, 2, 1, 8, 8,
8, 4, 4, 2, 2 }; // values for the adam7 passes
for (i = 0; i < 6; i++)
passstart[i + 1] = passstart[i] + passh[i] * ((passw[i] ? 1 : 0) + (passw[i] * bpp + 7) / 8);
scanlineo = vector8_new((info->width * bpp + 7) / 8, 0);
scanlinen = vector8_new((info->width * bpp + 7) / 8, 0);
for (i = 0; i < 7; i++)
PNG_adam7Pass(out_data, scanlinen->data, scanlineo->data, &scanlines->data[passstart[i]],
info->width, pattern[i], pattern[i + 7], pattern[i + 14], pattern[i + 21],
passw[i], passh[i], bpp);
}
if (info->colorType != 6 || info->bitDepth != 8) { // conversion needed
vector8_t *copy = vector8_copy(info->image); // xxx: is this copy necessary?
PNG_error = PNG_convert(info, info->image, copy->data);
}
return info;
}
/*************************************************************************************************/
#ifdef TEST
#include <stdio.h>
#include <sys/stat.h>
int main(int argc, char **argv)
{
char *fname = (argc > 1) ? argv[1] : "test.png";
PNG_info_t *info;
struct stat statbuf;
uint32_t insize, outsize;
FILE *infp, *outfp;
uint8_t *inbuf;
uint32_t n;
if (stat(fname, &statbuf) != 0) {
perror("stat");
return 1;
} else if (!statbuf.st_size) {
printf("file empty\n");
return 1;
}
insize = (uint32_t) statbuf.st_size;
inbuf = malloc(insize);
infp = fopen(fname, "rb");
if (!infp) {
perror("fopen");
free(inbuf);
return 1;
} else if (fread(inbuf, 1, insize, infp) != insize) {
perror("fread");
free(inbuf);
fclose(infp);
return 1;
}
fclose(infp);
printf("input file: %s (size: %d)\n", fname, insize);
info = PNG_decode(inbuf, insize);
free(inbuf);
printf("PNG_error: %d\n", PNG_error);
if (PNG_error != 0)
return 1;
printf("width: %d, height: %d\nfirst 16 bytes: ", info->width, info->height);
for (n = 0; n < 16; n++)
printf("%02x ", info->image->data[n]);
printf("\n");
outsize = info->width * info->height * 4;
printf("image size: %d\n", outsize);
if (outsize != info->image->size) {
printf("error: image size doesn't match dimensions\n");
return 1;
}
outfp = fopen("out.bin", "wb");
if (!outfp) {
perror("fopen");
return 1;
} else if (fwrite(info->image->data, 1, outsize, outfp) != outsize) {
perror("fwrite");
fclose(outfp);
return 1;
}
fclose(outfp);
#ifdef ALLOC_DEBUG
png_alloc_node_t *node;
for (node = png_alloc_head, n = 1; node; node = node->next, n++)
printf("node %d (%p) addr = %p, size = %zu\n", n, node, node->addr, node->size);
#endif
png_alloc_free_all(); // also frees info and image data from PNG_decode
return 0;
}
#endif
