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/*
* Copyright © 2018, VideoLAN and dav1d authors
* Copyright © 2018, Two Orioles, LLC
* Copyright © 2019, James Almer <jamrial@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef DAV1D_INPUT_PARSE_H
#define DAV1D_INPUT_PARSE_H
#include "dav1d/headers.h"
static int leb128(FILE *const f, size_t *const len) {
unsigned i = 0, more;
*len = 0;
do {
uint8_t byte;
if (fread(&byte, 1, 1, f) < 1)
return -1;
more = byte & 0x80;
const unsigned bits = byte & 0x7f;
if (i <= 3 || (i == 4 && bits < (1 << 4)))
*len |= bits << (i * 7);
else if (bits) return -1;
if (++i == 8 && more) return -1;
} while (more);
return i;
}
// these functions are based on an implementation from FFmpeg, and relicensed
// with author's permission
static int leb(const uint8_t *ptr, int sz, size_t *const len) {
unsigned i = 0, more;
*len = 0;
do {
if (!sz--) return -1;
const int byte = *ptr++;
more = byte & 0x80;
const unsigned bits = byte & 0x7f;
if (i <= 3 || (i == 4 && bits < (1 << 4)))
*len |= bits << (i * 7);
else if (bits) return -1;
if (++i == 8 && more) return -1;
} while (more);
return i;
}
static inline int parse_obu_header(const uint8_t *buf, int buf_size,
size_t *const obu_size,
enum Dav1dObuType *const type,
const int allow_implicit_size)
{
int ret, extension_flag, has_size_flag;
if (!buf_size)
return -1;
if (*buf & 0x80) // obu_forbidden_bit
return -1;
*type = (*buf & 0x78) >> 3;
extension_flag = (*buf & 0x4) >> 2;
has_size_flag = (*buf & 0x2) >> 1;
// ignore obu_reserved_1bit
buf++;
buf_size--;
if (extension_flag) {
buf++;
buf_size--;
// ignore fields
}
if (has_size_flag) {
ret = leb(buf, buf_size, obu_size);
if (ret < 0)
return -1;
return (int) *obu_size + ret + 1 + extension_flag;
} else if (!allow_implicit_size)
return -1;
*obu_size = buf_size;
return buf_size + 1 + extension_flag;
}
#endif /* DAV1D_INPUT_PARSE_H */
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