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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/avstring.h"
#include "avcodec.h"
#include "internal.h"
#include "mathops.h"
static int convert(uint8_t x)
{
if (x >= 'a')
x -= 87;
else if (x >= 'A')
x -= 55;
else
x -= '0';
return x;
}
static int parse_str_int(const uint8_t *p, int len, const uint8_t *key)
{
const uint8_t *end = p + len;
for(; p<end - strlen(key); p++) {
if (!memcmp(p, key, strlen(key)))
break;
}
p += strlen(key);
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, void *data,
int *got_frame, AVPacket *avpkt)
{
AVFrame *p = data;
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, avpkt->size, "_width");
height = parse_str_int(avpkt->data, avpkt->size, "_height");
if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
return ret;
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 val;
while (ptr < end && *ptr != 'x' && *ptr != '$')
ptr++;
ptr ++;
if (ptr < end && av_isxdigit(*ptr)) {
val = convert(*ptr++);
if (av_isxdigit(*ptr))
val = (val << 4) + convert(*ptr++);
*dst++ = ff_reverse[val];
if (av_isxdigit(*ptr) && j+1 < linesize) {
j++;
val = convert(*ptr++);
if (av_isxdigit(*ptr))
val = (val << 4) + convert(*ptr++);
*dst++ = ff_reverse[val];
}
} else {
av_log(avctx, AV_LOG_ERROR,
"Unexpected data at %.8s.\n", ptr);
return AVERROR_INVALIDDATA;
}
}
}
p->key_frame = 1;
p->pict_type = AV_PICTURE_TYPE_I;
*got_frame = 1;
return avpkt->size;
}
AVCodec ff_xbm_decoder = {
.name = "xbm",
.long_name = NULL_IF_CONFIG_SMALL("XBM (X BitMap) image"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_XBM,
.decode = xbm_decode_frame,
.capabilities = AV_CODEC_CAP_DR1,
};
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