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/*
* XBM parser
* Copyright (c) 2021 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
* XBM parser
*/
#include "libavutil/common.h"
#include "parser.h"
typedef struct XBMParseContext {
ParseContext pc;
uint16_t state16;
int count;
} XBMParseContext;
#define KEY (((uint64_t)'\n' << 56) | ((uint64_t)'#' << 48) | \
((uint64_t)'d' << 40) | ((uint64_t)'e' << 32) | \
((uint64_t)'f' << 24) | ('i' << 16) | ('n' << 8) | \
('e' << 0))
#define END ((';' << 8) | ('\n' << 0))
static int xbm_init(AVCodecParserContext *s)
{
XBMParseContext *bpc = s->priv_data;
bpc->count = 1;
return 0;
}
static int xbm_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
XBMParseContext *bpc = s->priv_data;
uint64_t state = bpc->pc.state64;
uint16_t state16 = bpc->state16;
int next = END_NOT_FOUND, i = 0;
s->pict_type = AV_PICTURE_TYPE_I;
s->key_frame = 1;
s->duration = 1;
*poutbuf_size = 0;
*poutbuf = NULL;
for (; i < buf_size; i++) {
state = (state << 8) | buf[i];
state16 = (state16 << 8) | buf[i];
if (state == KEY)
bpc->count++;
if ((state == KEY && bpc->count == 1)) {
next = i - 6;
break;
} else if (state16 == END) {
next = i + 1;
bpc->count = 0;
break;
}
}
bpc->pc.state64 = state;
bpc->state16 = state16;
if (ff_combine_frame(&bpc->pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
const AVCodecParser ff_xbm_parser = {
.codec_ids = { AV_CODEC_ID_XBM },
.priv_data_size = sizeof(XBMParseContext),
.parser_init = xbm_init,
.parser_parse = xbm_parse,
.parser_close = ff_parse_close,
};
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