ref: b4f1c1c647d3e85ed3fe00f4fb1d1eb5623b69ab
dir: /tools/input/parse.h/
/* * Copyright © 2018, VideoLAN and dav1d authors * Copyright © 2018, Two Orioles, LLC * Copyright © 2019, James Almer <[email protected]> * 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 */