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/*
* 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 <stddef.h>
#include <stdint.h>
#include "atsc_a53.h"
#include "get_bits.h"
int ff_parse_a53_cc(AVBufferRef **pbuf, const uint8_t *data, int size)
{
AVBufferRef *buf = *pbuf;
GetBitContext gb;
size_t new_size, old_size = buf ? buf->size : 0;
int ret, cc_count;
if (size < 3)
return AVERROR(EINVAL);
ret = init_get_bits8(&gb, data, size);
if (ret < 0)
return ret;
if (get_bits(&gb, 8) != 0x3) // user_data_type_code
return 0;
skip_bits(&gb, 1); // reserved
if (!get_bits(&gb, 1)) // process_cc_data_flag
return 0;
skip_bits(&gb, 1); // zero bit
cc_count = get_bits(&gb, 5);
if (!cc_count)
return 0;
skip_bits(&gb, 8); // reserved
/* 3 bytes per CC plus one byte marker_bits at the end */
if (cc_count * 3 >= (get_bits_left(&gb) >> 3))
return AVERROR(EINVAL);
new_size = (old_size + cc_count * 3);
if (new_size > INT_MAX)
return AVERROR(EINVAL);
/* Allow merging of the cc data from two fields. */
ret = av_buffer_realloc(pbuf, new_size);
if (ret < 0)
return ret;
buf = *pbuf;
/* Use of av_buffer_realloc assumes buffer is writeable */
for (int i = 0; i < cc_count; i++) {
buf->data[old_size++] = get_bits(&gb, 8);
buf->data[old_size++] = get_bits(&gb, 8);
buf->data[old_size++] = get_bits(&gb, 8);
}
return cc_count;
}
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