mirror of
https://code.videolan.org/videolan/dav1d
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112 lines
3.5 KiB
C
112 lines
3.5 KiB
C
/*
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* Copyright © 2018, VideoLAN and dav1d authors
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* Copyright © 2018, Two Orioles, LLC
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* Copyright © 2019, James Almer <jamrial@gmail.com>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
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* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef DAV1D_INPUT_PARSE_H
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#define DAV1D_INPUT_PARSE_H
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#include <limits.h>
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#include "dav1d/headers.h"
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static int leb128(FILE *const f, size_t *const len) {
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uint64_t val = 0;
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unsigned i = 0, more;
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do {
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uint8_t v;
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if (fread(&v, 1, 1, f) < 1)
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return -1;
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more = v & 0x80;
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val |= ((uint64_t) (v & 0x7F)) << (i * 7);
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i++;
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} while (more && i < 8);
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if (val > UINT_MAX || more)
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return -1;
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*len = (size_t) val;
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return i;
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}
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// these functions are based on an implementation from FFmpeg, and relicensed
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// with author's permission
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static int leb(const uint8_t *ptr, int sz, size_t *const len) {
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uint64_t val = 0;
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unsigned i = 0, more;
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do {
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if (!sz--) return -1;
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const int v = *ptr++;
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more = v & 0x80;
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val |= ((uint64_t) (v & 0x7F)) << (i * 7);
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i++;
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} while (more && i < 8);
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if (val > UINT_MAX || more)
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return -1;
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*len = (size_t) val;
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return i;
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}
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static inline int parse_obu_header(const uint8_t *buf, int buf_size,
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size_t *const obu_size,
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enum Dav1dObuType *const type,
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const int allow_implicit_size)
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{
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int ret, extension_flag, has_size_flag;
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if (!buf_size)
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return -1;
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if (*buf & 0x80) // obu_forbidden_bit
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return -1;
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*type = (*buf & 0x78) >> 3;
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extension_flag = (*buf & 0x4) >> 2;
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has_size_flag = (*buf & 0x2) >> 1;
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// ignore obu_reserved_1bit
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buf++;
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buf_size--;
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if (extension_flag) {
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if (!buf_size)
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return -1;
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buf++;
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buf_size--;
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// ignore fields
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}
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if (has_size_flag) {
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ret = leb(buf, buf_size, obu_size);
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if (ret < 0)
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return -1;
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return (int) *obu_size + ret + 1 + extension_flag;
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} else if (!allow_implicit_size)
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return -1;
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*obu_size = buf_size;
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return buf_size + 1 + extension_flag;
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}
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#endif /* DAV1D_INPUT_PARSE_H */
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