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/*
* XBM image format
*
* Copyright (c) 2012 Paul B Mahol
*
* 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/reverse.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "decode.h"
static int get_nibble(uint8_t x)
{
#define TIMES256(idx) \
TIMES64(4 * (idx)) TIMES64(4 * (idx) + 1) TIMES64(4 * (idx) + 2) TIMES64(4 * (idx) + 3)
#define TIMES64(idx) \
TIMES16(4 * (idx)) TIMES16(4 * (idx) + 1) TIMES16(4 * (idx) + 2) TIMES16(4 * (idx) + 3)
#define TIMES16(idx) \
TIMES4(4 * (idx)) TIMES4(4 * (idx) + 1) TIMES4(4 * (idx) + 2) TIMES4(4 * (idx) + 3)
#define TIMES4(idx) \
ENTRY(4 * (idx)) ENTRY(4 * (idx) + 1) ENTRY(4 * (idx) + 2) ENTRY(4 * (idx) + 3)
#define ENTRY(x) [x] = ((x) >= 'a' && (x) <= 'f') ? (x) - ('a' - 10) : \
((x) >= 'A' && (x) <= 'F') ? (x) - ('A' - 10) : \
((x) >= '0' && (x) <= '9') ? (x) - '0' : 255,
static const uint8_t lut[] = {
TIMES256(0)
};
return lut[x];
}
static int parse_str_int(const uint8_t *p, const uint8_t *end, const uint8_t *key)
{
int keylen = strlen(key);
const uint8_t *e = end - keylen;
for(; p < e; p++) {
if (!memcmp(p, key, keylen))
break;
}
p += keylen;
if (p >= end)
return INT_MIN;
for(; p<end; p++) {
char *eptr;
int64_t ret = strtol(p, &eptr, 10);
if ((const uint8_t *)eptr != p)
return ret;
}
return INT_MIN;
}
static int xbm_decode_frame(AVCodecContext *avctx, AVFrame *p,
int *got_frame, AVPacket *avpkt)
{
int ret, linesize, i, j;
int width = 0;
int height = 0;
const uint8_t *end, *ptr = avpkt->data;
const uint8_t *next;
uint8_t *dst;
avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
end = avpkt->data + avpkt->size;
width = parse_str_int(avpkt->data, end, "_width");
height = parse_str_int(avpkt->data, end, "_height");
if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
return ret;
if (avctx->skip_frame >= AVDISCARD_ALL)
return avpkt->size;
if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
return ret;
// goto start of image data
next = memchr(ptr, '{', avpkt->size);
if (!next)
next = memchr(ptr, '(', avpkt->size);
if (!next)
return AVERROR_INVALIDDATA;
ptr = next + 1;
linesize = (avctx->width + 7) / 8;
for (i = 0; i < avctx->height; i++) {
dst = p->data[0] + i * p->linesize[0];
for (j = 0; j < linesize; j++) {
uint8_t nib, val;
while (ptr < end && *ptr != 'x' && *ptr != '$')
ptr++;
ptr ++;
if (ptr < end && (val = get_nibble(*ptr)) <= 15) {
ptr++;
if ((nib = get_nibble(*ptr)) <= 15) {
val = (val << 4) + nib;
ptr++;
}
*dst++ = ff_reverse[val];
if ((val = get_nibble(*ptr)) <= 15 && j+1 < linesize) {
j++;
ptr++;
if ((nib = get_nibble(*ptr)) <= 15) {
val = (val << 4) + nib;
ptr++;
}
*dst++ = ff_reverse[val];
}
} else {
av_log(avctx, AV_LOG_ERROR,
"Unexpected data at %.8s.\n", ptr);
return AVERROR_INVALIDDATA;
}
}
}
*got_frame = 1;
return avpkt->size;
}
const FFCodec ff_xbm_decoder = {
.p.name = "xbm",
CODEC_LONG_NAME("XBM (X BitMap) image"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_XBM,
.p.capabilities = AV_CODEC_CAP_DR1,
.caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
FF_CODEC_DECODE_CB(xbm_decode_frame),
};
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