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FFmpeg/libavcodec/pcx.c

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/*
* PC Paintbrush PCX (.pcx) image decoder
* Copyright (c) 2007, 2008 Ivo van Poorten
*
* This decoder does not support CGA palettes. I am unable to find samples
* and Netpbm cannot generate them.
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avcodec.h"
#include "bytestream.h"
#include "bitstream.h"
typedef struct PCXContext {
AVFrame picture;
} PCXContext;
static av_cold int pcx_init(AVCodecContext *avctx) {
PCXContext *s = avctx->priv_data;
avcodec_get_frame_defaults(&s->picture);
avctx->coded_frame= &s->picture;
return 0;
}
/**
* @return advanced src pointer
*/
static const uint8_t *pcx_rle_decode(const uint8_t *src, uint8_t *dst,
unsigned int bytes_per_scanline) {
unsigned int i = 0;
unsigned char run, value;
while (i<bytes_per_scanline) {
run = 1;
value = *src++;
if (value >= 0xc0) {
run = value & 0x3f;
value = *src++;
}
while (i<bytes_per_scanline && run--)
dst[i++] = value;
}
return src;
}
static void pcx_palette(const uint8_t **src, uint32_t *dst, unsigned int pallen) {
unsigned int i;
for (i=0; i<pallen; i++)
*dst++ = bytestream_get_be24(src);
memset(dst, 0, (256 - pallen) * sizeof(*dst));
}
static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
const uint8_t *buf, int buf_size) {
PCXContext * const s = avctx->priv_data;
AVFrame *picture = data;
AVFrame * const p = &s->picture;
int xmin, ymin, xmax, ymax;
unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
bytes_per_scanline;
uint8_t *ptr;
uint8_t const *bufstart = buf;
if (buf[0] != 0x0a || buf[1] > 5 || buf[1] == 1 || buf[2] != 1) {
av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
return -1;
}
xmin = AV_RL16(buf+ 4);
ymin = AV_RL16(buf+ 6);
xmax = AV_RL16(buf+ 8);
ymax = AV_RL16(buf+10);
if (xmax < xmin || ymax < ymin) {
av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
return -1;
}
w = xmax - xmin + 1;
h = ymax - ymin + 1;
bits_per_pixel = buf[3];
bytes_per_line = AV_RL16(buf+66);
nplanes = buf[65];
bytes_per_scanline = nplanes * bytes_per_line;
if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8) {
av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
return -1;
}
switch ((nplanes<<8) + bits_per_pixel) {
case 0x0308:
avctx->pix_fmt = PIX_FMT_RGB24;
break;
case 0x0108:
case 0x0104:
case 0x0102:
case 0x0101:
case 0x0401:
case 0x0301:
case 0x0201:
avctx->pix_fmt = PIX_FMT_PAL8;
break;
default:
av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
return -1;
}
buf += 128;
if (p->data[0])
avctx->release_buffer(avctx, p);
if (avcodec_check_dimensions(avctx, w, h))
return -1;
if (w != avctx->width || h != avctx->height)
avcodec_set_dimensions(avctx, w, h);
if (avctx->get_buffer(avctx, p) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return -1;
}
p->pict_type = FF_I_TYPE;
ptr = p->data[0];
stride = p->linesize[0];
if (nplanes == 3 && bits_per_pixel == 8) {
uint8_t scanline[bytes_per_scanline];
for (y=0; y<h; y++) {
buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
for (x=0; x<w; x++) {
ptr[3*x ] = scanline[x ];
ptr[3*x+1] = scanline[x+ bytes_per_line ];
ptr[3*x+2] = scanline[x+(bytes_per_line<<1)];
}
ptr += stride;
}
} else if (nplanes == 1 && bits_per_pixel == 8) {
uint8_t scanline[bytes_per_scanline];
const uint8_t *palstart = bufstart + buf_size - 769;
for (y=0; y<h; y++, ptr+=stride) {
buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
memcpy(ptr, scanline, w);
}
if (buf != palstart) {
av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
buf = palstart;
}
if (*buf++ != 12) {
av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
return -1;
}
} else if (nplanes == 1) { /* all packed formats, max. 16 colors */
uint8_t scanline[bytes_per_scanline];
GetBitContext s;
for (y=0; y<h; y++) {
init_get_bits(&s, scanline, bytes_per_scanline<<3);
buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
for (x=0; x<w; x++)
ptr[x] = get_bits(&s, bits_per_pixel);
ptr += stride;
}
} else { /* planar, 4, 8 or 16 colors */
uint8_t scanline[bytes_per_scanline];
int i;
for (y=0; y<h; y++) {
buf = pcx_rle_decode(buf, scanline, bytes_per_scanline);
for (x=0; x<w; x++) {
int m = 0x80 >> (x&7), v = 0;
for (i=nplanes - 1; i>=0; i--) {
v <<= 1;
v += !!(scanline[i*bytes_per_line + (x>>3)] & m);
}
ptr[x] = v;
}
ptr += stride;
}
}
if (nplanes == 1 && bits_per_pixel == 8) {
pcx_palette(&buf, (uint32_t *) p->data[1], 256);
} else if (bits_per_pixel < 8) {
const uint8_t *palette = bufstart+16;
pcx_palette(&palette, (uint32_t *) p->data[1], 16);
}
*picture = s->picture;
*data_size = sizeof(AVFrame);
return buf - bufstart;
}
static av_cold int pcx_end(AVCodecContext *avctx) {
PCXContext *s = avctx->priv_data;
if(s->picture.data[0])
avctx->release_buffer(avctx, &s->picture);
return 0;
}
AVCodec pcx_decoder = {
"pcx",
CODEC_TYPE_VIDEO,
CODEC_ID_PCX,
sizeof(PCXContext),
pcx_init,
NULL,
pcx_end,
pcx_decode_frame,
0,
NULL,
.long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
};