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/*
* The Python Imaging Library.
* $Id$
*
* decoder for Autodesk Animator FLI/FLC animations
*
* history:
* 97-01-03 fl Created
* 97-01-17 fl Added SS2 support (FLC)
*
* Copyright (c) Fredrik Lundh 1997.
* Copyright (c) Secret Labs AB 1997.
*
* See the README file for information on usage and redistribution.
*/
#include "Imaging.h"
#define I16(ptr) ((ptr)[0] + ((ptr)[1] << 8))
#define I32(ptr) ((ptr)[0] + ((ptr)[1] << 8) + ((ptr)[2] << 16) + ((ptr)[3] << 24))
#define ERR_IF_DATA_OOB(offset) \
if ((data + (offset)) > ptr + bytes) { \
state->errcode = IMAGING_CODEC_OVERRUN; \
return -1; \
}
int
ImagingFliDecode(Imaging im, ImagingCodecState state, UINT8 *buf, Py_ssize_t bytes) {
UINT8 *ptr;
int framesize;
int c, chunks, advance;
int l, lines;
int i, j, x = 0, y, ymax;
/* If not even the chunk size is present, we'd better leave */
if (bytes < 4) {
return 0;
}
/* We don't decode anything unless we have a full chunk in the
input buffer */
ptr = buf;
framesize = I32(ptr);
// there can be one pad byte in the framesize
if (bytes + (bytes % 2) < framesize) {
return 0;
}
/* Make sure this is a frame chunk. The Python driver takes
case of other chunk types. */
if (bytes < 8) {
state->errcode = IMAGING_CODEC_OVERRUN;
return -1;
}
if (I16(ptr + 4) != 0xF1FA) {
state->errcode = IMAGING_CODEC_UNKNOWN;
return -1;
}
chunks = I16(ptr + 6);
ptr += 16;
bytes -= 16;
/* Process subchunks */
for (c = 0; c < chunks; c++) {
UINT8 *data;
if (bytes < 10) {
state->errcode = IMAGING_CODEC_OVERRUN;
return -1;
}
data = ptr + 6;
switch (I16(ptr + 4)) {
case 4:
case 11:
/* FLI COLOR chunk */
break; /* ignored; handled by Python code */
case 7:
/* FLI SS2 chunk (word delta) */
/* OOB ok, we've got 4 bytes min on entry */
lines = I16(data);
data += 2;
for (l = y = 0; l < lines && y < state->ysize; l++, y++) {
UINT8 *local_buf = (UINT8 *)im->image[y];
int p, packets;
ERR_IF_DATA_OOB(2)
packets = I16(data);
data += 2;
while (packets & 0x8000) {
/* flag word */
if (packets & 0x4000) {
y += 65536 - packets; /* skip lines */
if (y >= state->ysize) {
state->errcode = IMAGING_CODEC_OVERRUN;
return -1;
}
local_buf = (UINT8 *)im->image[y];
} else {
/* store last byte (used if line width is odd) */
local_buf[state->xsize - 1] = (UINT8)packets;
}
ERR_IF_DATA_OOB(2)
packets = I16(data);
data += 2;
}
for (p = x = 0; p < packets; p++) {
ERR_IF_DATA_OOB(2)
x += data[0]; /* pixel skip */
if (data[1] >= 128) {
ERR_IF_DATA_OOB(4)
i = 256 - data[1]; /* run */
if (x + i + i > state->xsize) {
break;
}
for (j = 0; j < i; j++) {
local_buf[x++] = data[2];
local_buf[x++] = data[3];
}
data += 2 + 2;
} else {
i = 2 * (int)data[1]; /* chunk */
if (x + i > state->xsize) {
break;
}
ERR_IF_DATA_OOB(2 + i)
memcpy(local_buf + x, data + 2, i);
data += 2 + i;
x += i;
}
}
if (p < packets) {
break; /* didn't process all packets */
}
}
if (l < lines) {
/* didn't process all lines */
state->errcode = IMAGING_CODEC_OVERRUN;
return -1;
}
break;
case 12:
/* FLI LC chunk (byte delta) */
/* OOB Check ok, we have 4 bytes min here */
y = I16(data);
ymax = y + I16(data + 2);
data += 4;
for (; y < ymax && y < state->ysize; y++) {
UINT8 *out = (UINT8 *)im->image[y];
ERR_IF_DATA_OOB(1)
int p, packets = *data++;
for (p = x = 0; p < packets; p++, x += i) {
ERR_IF_DATA_OOB(2)
x += data[0]; /* skip pixels */
if (data[1] & 0x80) {
i = 256 - data[1]; /* run */
if (x + i > state->xsize) {
break;
}
ERR_IF_DATA_OOB(3)
memset(out + x, data[2], i);
data += 3;
} else {
i = data[1]; /* chunk */
if (x + i > state->xsize) {
break;
}
ERR_IF_DATA_OOB(2 + i)
memcpy(out + x, data + 2, i);
data += i + 2;
}
}
if (p < packets) {
break; /* didn't process all packets */
}
}
if (y < ymax) {
/* didn't process all lines */
state->errcode = IMAGING_CODEC_OVERRUN;
return -1;
}
break;
case 13:
/* FLI BLACK chunk */
for (y = 0; y < state->ysize; y++) {
memset(im->image[y], 0, state->xsize);
}
break;
case 15:
/* FLI BRUN chunk */
/* OOB, ok, we've got 4 bytes min on entry */
for (y = 0; y < state->ysize; y++) {
UINT8 *out = (UINT8 *)im->image[y];
data += 1; /* ignore packetcount byte */
for (x = 0; x < state->xsize; x += i) {
ERR_IF_DATA_OOB(2)
if (data[0] & 0x80) {
i = 256 - data[0];
if (x + i > state->xsize) {
break; /* safety first */
}
ERR_IF_DATA_OOB(i + 1)
memcpy(out + x, data + 1, i);
data += i + 1;
} else {
i = data[0];
if (x + i > state->xsize) {
break; /* safety first */
}
memset(out + x, data[1], i);
data += 2;
}
}
if (x != state->xsize) {
/* didn't unpack whole line */
state->errcode = IMAGING_CODEC_OVERRUN;
return -1;
}
}
break;
case 16:
/* COPY chunk */
if (INT32_MAX / state->xsize < state->ysize) {
/* Integer overflow, bail */
state->errcode = IMAGING_CODEC_OVERRUN;
return -1;
}
/* Note, have to check Data + size, not just ptr + size) */
if (data + (state->xsize * state->ysize) > ptr + bytes) {
/* not enough data for frame */
/* UNDONE Unclear that we're actually going to leave the buffer at the right place. */
return ptr - buf; /* bytes consumed */
}
for (y = 0; y < state->ysize; y++) {
UINT8 *local_buf = (UINT8 *)im->image[y];
memcpy(local_buf, data, state->xsize);
data += state->xsize;
}
break;
case 18:
/* PSTAMP chunk */
break; /* ignored */
default:
/* unknown chunk */
/* printf("unknown FLI/FLC chunk: %d\n", I16(ptr+4)); */
state->errcode = IMAGING_CODEC_UNKNOWN;
return -1;
}
advance = I32(ptr);
if (advance == 0 ) {
// If there's no advance, we're in an infinite loop
state->errcode = IMAGING_CODEC_BROKEN;
return -1;
}
if (advance < 0 || advance > bytes) {
state->errcode = IMAGING_CODEC_OVERRUN;
return -1;
}
ptr += advance;
bytes -= advance;
}
return -1; /* end of frame */
}
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