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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 "libavutil/imgutils.h"
#include "avcodec.h"
#include "bytestream.h"
#include "get_bits.h"
#include "internal.h"
#define PCX_HEADER_SIZE 128
static int pcx_rle_decode(GetByteContext *gb,
uint8_t *dst,
unsigned int bytes_per_scanline,
int compressed)
{
unsigned int i = 0;
unsigned char run, value;
if (bytestream2_get_bytes_left(gb) < 1)
return AVERROR_INVALIDDATA;
if (compressed) {
while (i < bytes_per_scanline && bytestream2_get_bytes_left(gb)>0) {
run = 1;
value = bytestream2_get_byte(gb);
if (value >= 0xc0 && bytestream2_get_bytes_left(gb)>0) {
run = value & 0x3f;
value = bytestream2_get_byte(gb);
}
while (i < bytes_per_scanline && run--)
dst[i++] = value;
}
} else {
bytestream2_get_buffer(gb, dst, bytes_per_scanline);
}
return 0;
}
static void pcx_palette(GetByteContext *gb, uint32_t *dst, int pallen)
{
int i;
pallen = FFMIN(pallen, bytestream2_get_bytes_left(gb) / 3);
for (i = 0; i < pallen; i++)
*dst++ = 0xFF000000 | bytestream2_get_be24u(gb);
if (pallen < 256)
memset(dst, 0, (256 - pallen) * sizeof(*dst));
}
static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
AVPacket *avpkt)
{
GetByteContext gb;
AVFrame * const p = data;
int compressed, xmin, ymin, xmax, ymax;
int ret;
unsigned int w, h, bits_per_pixel, bytes_per_line, nplanes, stride, y, x,
bytes_per_scanline;
uint8_t *ptr, *scanline;
if (avpkt->size < PCX_HEADER_SIZE) {
av_log(avctx, AV_LOG_ERROR, "Packet too small\n");
return AVERROR_INVALIDDATA;
}
bytestream2_init(&gb, avpkt->data, avpkt->size);
if (bytestream2_get_byteu(&gb) != 0x0a || bytestream2_get_byteu(&gb) > 5) {
av_log(avctx, AV_LOG_ERROR, "this is not PCX encoded data\n");
return AVERROR_INVALIDDATA;
}
compressed = bytestream2_get_byteu(&gb);
bits_per_pixel = bytestream2_get_byteu(&gb);
xmin = bytestream2_get_le16u(&gb);
ymin = bytestream2_get_le16u(&gb);
xmax = bytestream2_get_le16u(&gb);
ymax = bytestream2_get_le16u(&gb);
avctx->sample_aspect_ratio.num = bytestream2_get_le16u(&gb);
avctx->sample_aspect_ratio.den = bytestream2_get_le16u(&gb);
if (xmax < xmin || ymax < ymin) {
av_log(avctx, AV_LOG_ERROR, "invalid image dimensions\n");
return AVERROR_INVALIDDATA;
}
w = xmax - xmin + 1;
h = ymax - ymin + 1;
bytestream2_skipu(&gb, 49);
nplanes = bytestream2_get_byteu(&gb);
bytes_per_line = bytestream2_get_le16u(&gb);
bytes_per_scanline = nplanes * bytes_per_line;
if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 ||
(!compressed && bytes_per_scanline > bytestream2_get_bytes_left(&gb) / h)) {
av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
return AVERROR_INVALIDDATA;
}
switch ((nplanes << 8) + bits_per_pixel) {
case 0x0308:
avctx->pix_fmt = AV_PIX_FMT_RGB24;
break;
case 0x0108:
case 0x0104:
case 0x0102:
case 0x0101:
case 0x0401:
case 0x0301:
case 0x0201:
avctx->pix_fmt = AV_PIX_FMT_PAL8;
break;
default:
av_log(avctx, AV_LOG_ERROR, "invalid PCX file\n");
return AVERROR_INVALIDDATA;
}
bytestream2_skipu(&gb, 60);
if ((ret = ff_set_dimensions(avctx, w, h)) < 0)
return ret;
if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
return ret;
p->pict_type = AV_PICTURE_TYPE_I;
ptr = p->data[0];
stride = p->linesize[0];
scanline = av_malloc(bytes_per_scanline + AV_INPUT_BUFFER_PADDING_SIZE);
if (!scanline)
return AVERROR(ENOMEM);
if (nplanes == 3 && bits_per_pixel == 8) {
for (y = 0; y < h; y++) {
ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
if (ret < 0)
goto end;
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) {
int palstart = avpkt->size - 769;
if (avpkt->size < 769) {
av_log(avctx, AV_LOG_ERROR, "File is too short\n");
ret = avctx->err_recognition & AV_EF_EXPLODE ?
AVERROR_INVALIDDATA : avpkt->size;
goto end;
}
for (y = 0; y < h; y++, ptr += stride) {
ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
if (ret < 0)
goto end;
memcpy(ptr, scanline, w);
}
if (bytestream2_tell(&gb) != palstart) {
av_log(avctx, AV_LOG_WARNING, "image data possibly corrupted\n");
bytestream2_seek(&gb, palstart, SEEK_SET);
}
if (bytestream2_get_byte(&gb) != 12) {
av_log(avctx, AV_LOG_ERROR, "expected palette after image data\n");
ret = avctx->err_recognition & AV_EF_EXPLODE ?
AVERROR_INVALIDDATA : avpkt->size;
goto end;
}
} else if (nplanes == 1) { /* all packed formats, max. 16 colors */
GetBitContext s;
for (y = 0; y < h; y++) {
init_get_bits8(&s, scanline, bytes_per_scanline);
ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
if (ret < 0)
goto end;
for (x = 0; x < w; x++)
ptr[x] = get_bits(&s, bits_per_pixel);
ptr += stride;
}
} else { /* planar, 4, 8 or 16 colors */
int i;
for (y = 0; y < h; y++) {
ret = pcx_rle_decode(&gb, scanline, bytes_per_scanline, compressed);
if (ret < 0)
goto end;
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;
}
}
ret = bytestream2_tell(&gb);
if (nplanes == 1 && bits_per_pixel == 8) {
pcx_palette(&gb, (uint32_t *)p->data[1], 256);
ret += 256 * 3;
} else if (bits_per_pixel * nplanes == 1) {
AV_WN32A(p->data[1] , 0xFF000000);
AV_WN32A(p->data[1]+4, 0xFFFFFFFF);
} else if (bits_per_pixel < 8) {
bytestream2_seek(&gb, 16, SEEK_SET);
pcx_palette(&gb, (uint32_t *)p->data[1], 16);
}
*got_frame = 1;
end:
av_free(scanline);
return ret;
}
const AVCodec ff_pcx_decoder = {
.name = "pcx",
.long_name = NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_PCX,
.decode = pcx_decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
};
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