ffmpeg/libavcodec/xwd_parser.c

104 lines
3.0 KiB
C

/*
* XWD parser
* Copyright (c) 2022 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
*/
/**
* @file
* XWD parser
**/
#include "libavutil/intreadwrite.h"
#include "parser.h"
#include "xwd.h"
typedef struct XWDParseContext {
ParseContext pc;
int left;
int idx;
uint8_t hdr[XWD_HEADER_SIZE];
} XWDParseContext;
static int xwd_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
XWDParseContext *t = s->priv_data;
ParseContext *pc = &t->pc;
int next = END_NOT_FOUND;
s->pict_type = AV_PICTURE_TYPE_NONE;
*poutbuf = NULL;
*poutbuf_size = 0;
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
} else {
for (int i = 0; i < buf_size; i++) {
if (t->left > 0) {
t->left--;
if (t->left == 0) {
next = i;
break;
}
continue;
}
if (t->idx >= 100) {
t->idx = 99;
memmove(&t->hdr[0], &t->hdr[1], XWD_HEADER_SIZE-1);
}
t->hdr[t->idx++] = buf[i];
if (t->idx >= 100 && AV_RB32(t->hdr + 4) == XWD_VERSION) {
uint32_t header_size = AV_RB32(t->hdr + 0);
uint32_t height = AV_RB32(t->hdr + 20);
uint32_t lsize = AV_RB32(t->hdr + 48);
uint32_t ncolors = AV_RB32(t->hdr + 76);
uint32_t size = header_size + ncolors * XWD_CMAP_SIZE + height * lsize;
pc->frame_start_found = 1;
t->left = size - XWD_HEADER_SIZE + 1;
t->idx = 0;
memset(t->hdr, 0, sizeof(t->hdr));
}
}
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0)
return buf_size;
}
*poutbuf = buf;
*poutbuf_size = buf_size;
s->pict_type = AV_PICTURE_TYPE_I;
s->key_frame = 1;
s->duration = 1;
return next;
}
const AVCodecParser ff_xwd_parser = {
.codec_ids = { AV_CODEC_ID_XWD },
.priv_data_size = sizeof(XWDParseContext),
.parser_parse = xwd_parse,
.parser_close = ff_parse_close,
};