ffmpeg/libavcodec/xbmdec.c

123 lines
3.8 KiB
C

/*
* XBM image format
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; 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 xbm_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame, AVPacket *avpkt)
{
AVFrame *p = data;
int ret, linesize, i;
int width = 0;
int height = 0;
const uint8_t *ptr = avpkt->data;
uint8_t *dst;
avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
while (!width || !height) {
ptr += strcspn(ptr, "#");
if (ptr >= avpkt->data + avpkt->size) {
av_log(avctx, AV_LOG_ERROR, "End of file reached.\n");
return AVERROR_INVALIDDATA;
}
if (strncmp(ptr, "#define", 7) != 0) {
av_log(avctx, AV_LOG_ERROR,
"Unexpected preprocessor directive.\n");
return AVERROR_INVALIDDATA;
}
// skip the name
ptr += strcspn(ptr, "_") + 1;
// get width or height
if (strncmp(ptr, "width", 5) == 0) {
ptr += strcspn(ptr, " ");
width = strtol(ptr, NULL, 10);
} else if (strncmp(ptr, "height", 6) == 0) {
ptr += strcspn(ptr, " ");
height = strtol(ptr, NULL, 10);
} else {
// skip offset and unknown variables
av_log(avctx, AV_LOG_VERBOSE,
"Ignoring preprocessor directive.\n");
}
}
if ((ret = ff_set_dimensions(avctx, width, height)) < 0)
return ret;
if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
return ret;
// go to start of image data
ptr += strcspn(ptr, "{");
linesize = (avctx->width + 7) / 8;
for (i = 0; i < avctx->height; i++) {
int eol = 0, e = 0;
dst = p->data[0] + i * p->linesize[0];
if (ptr >= avpkt->data + avpkt->size) {
av_log(avctx, AV_LOG_ERROR, "End of file reached.\n");
return AVERROR_INVALIDDATA;
}
do {
int val;
uint8_t *endptr;
ptr += strcspn(ptr, "x") - 1; // -1 to get 0x
val = strtol(ptr, (char **)&endptr, 16);
if (endptr - ptr == 4) {
// XBM X11 format
*dst++ = ff_reverse[val];
eol = linesize;
} else if (endptr - ptr == 6) {
// XBM X10 format
*dst++ = ff_reverse[val >> 8];
*dst++ = ff_reverse[val & 0xFF];
eol = linesize / 2; // 2 bytes read
} else {
av_log(avctx, AV_LOG_ERROR,
"Unexpected data at %.8s.\n", ptr);
return AVERROR_INVALIDDATA;
}
ptr = endptr;
} while (++e < eol);
}
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,
};