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(MPNG) Create mpng_chunk

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This commit is contained in:
twinaphex 2015-02-17 04:36:19 +01:00
parent 58c2c959b5
commit b27871664a
1 changed files with 34 additions and 27 deletions
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61
libretro-sdk/formats/mpng/mpng_decode.c
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@ -45,17 +45,24 @@ struct mpng_ihdr
uint8_t interlace;
};
bool mpng_parse_ihdr(struct mpng_ihdr *ihdr, const uint8_t * chunk,
struct mpng_chunk
{
uint32_t size;
uint32_t type;
const uint8_t *data;
};
bool mpng_parse_ihdr(struct mpng_ihdr *ihdr, struct mpng_chunk *chunk,
enum video_format format, unsigned int *bpl,
uint8_t *pixels, uint8_t *pixelsat, uint8_t *pixelsend)
{
read32(ihdr->width, chunk);
read32(ihdr->height, chunk);
read8(ihdr->depth, chunk);
read8(ihdr->color_type, chunk);
read8(ihdr->compression, chunk);
read8(ihdr->filter, chunk);
read8(ihdr->interlace, chunk);
read32(ihdr->width, chunk->data);
read32(ihdr->height, chunk->data);
read8(ihdr->depth, chunk->data);
read8(ihdr->color_type, chunk->data);
read8(ihdr->compression, chunk->data);
read8(ihdr->filter, chunk->data);
read8(ihdr->interlace, chunk->data);
if (ihdr->width >= 0x80000000)
return false;
@ -127,6 +134,7 @@ bool mpng_parse_ihdr(struct mpng_ihdr *ihdr, const uint8_t * chunk,
return true;
}
bool png_decode(const void *userdata, size_t len,
struct mpng_image *img, enum video_format format)
{
@ -169,35 +177,34 @@ bool png_decode(const void *userdata, size_t len,
while (1)
{
unsigned int chunklen, chunktype;
unsigned int chunkchecksum;
unsigned int actualchunkchecksum;
const uint8_t * chunkdata = NULL;
struct mpng_chunk chunk = {0};
if ((data + 4 + 4) > data_end)
goto error;
chunklen = dword_be(data);
chunktype = dword_be(data+4);
chunk.size = dword_be(data);
chunk.type = dword_be(data+4);
if (chunklen>=0x80000000)
if (chunk.size >= 0x80000000)
goto error;
if ((data + 4 + chunklen + 4) > data_end)
if ((data + 4 + chunk.size + 4) > data_end)
goto error;
chunkchecksum = mz_crc32(mz_crc32(0, NULL, 0), (uint8_t*)data+4, 4 + chunklen);
chunkdata = data + 4 + 4;
actualchunkchecksum = dword_be(data + 4 + 4 + chunklen);
chunkchecksum = mz_crc32(mz_crc32(0, NULL, 0), (uint8_t*)data+4, 4 + chunk.size);
chunk.data = (const uint8_t*)(data + 4 + 4);
actualchunkchecksum = dword_be(data + 4 + 4 + chunk.size);
if (actualchunkchecksum != chunkchecksum)
goto error;
data += 4 + 4 + chunklen + 4;
data += 4 + 4 + chunk.size + 4;
switch (chunktype)
switch (chunk.type)
{
case MPNG_CHUNK_IHDR:
if (!mpng_parse_ihdr(&ihdr, chunkdata, format, &bpl, pixels,
if (!mpng_parse_ihdr(&ihdr, &chunk, format, &bpl, pixels,
pixelsat, pixelsend))
goto error;
break;
@ -207,7 +214,7 @@ bool png_decode(const void *userdata, size_t len,
if (!pixels || palette_len != 0)
goto error;
if (chunklen == 0 || chunklen % 3 || chunklen > 3 * 256)
if (chunk.size == 0 || chunk.size % 3 || chunk.size > 3 * 256)
goto error;
/* Palette on RGB is allowed but rare,
@ -215,11 +222,11 @@ bool png_decode(const void *userdata, size_t len,
if (ihdr.color_type != 3)
break;
palette_len = chunklen / 3;
palette_len = chunk.size / 3;
for (i = 0; i < palette_len; i++)
{
read24(palette[i], chunkdata);
read24(palette[i], chunk.data);
palette[i] |= 0xFF000000;
}
}
@ -252,12 +259,12 @@ bool png_decode(const void *userdata, size_t len,
if (!pixels || (ihdr.color_type == 3 && palette_len == 0))
goto error;
chunklen_copy = chunklen;
chunklen_copy = chunk.size;
byteshere = (pixelsend - pixelsat)+1;
#ifdef WANT_MINIZ
status = tinfl_decompress(&inflator,
(const mz_uint8 *)chunkdata,
(const mz_uint8 *)chunk.data,
&chunklen_copy, pixels,
pixelsat,
&byteshere,
@ -289,7 +296,7 @@ bool png_decode(const void *userdata, size_t len,
if (data != data_end)
goto error;
if (chunklen)
if (chunk.size)
goto error;
finalbytes = (pixelsend - pixelsat);
@ -552,7 +559,7 @@ bool png_decode(const void *userdata, size_t len,
}
break;
default:
if (!(chunktype & 0x20000000))
if (!(chunk.type & 0x20000000))
goto error;//unknown critical
//otherwise ignore
}