/* * AV1 common parsing code * * 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 */ #ifndef AVCODEC_AV1_PARSE_H#define AVCODEC_AV1_PARSE_H #include <stdint.h> #include "av1.h"#include "avcodec.h"#include "get_bits.h" typedef struct AV1OBU {    /** Size of payload */    int size;    const uint8_t *data;     /**     * Size, in bits, of just the data, excluding the trailing_one_bit and     * any trailing padding.     */    int size_bits;     /** Size of entire OBU, including header */    int raw_size;    const uint8_t *raw_data;     /** GetBitContext initialized to the start of the payload */    GetBitContext gb;     int type;     int temporal_id;    int spatial_id;} AV1OBU; /** An input packet split into OBUs */typedef struct AV1Packet {    AV1OBU *obus;    int nb_obus;    int obus_allocated;    unsigned obus_allocated_size;} AV1Packet; /** * Extract an OBU from a raw bitstream. * * @note This function does not copy or store any bitstream data. All *       the pointers in the AV1OBU structure will be valid as long *       as the input buffer also is. */int ff_av1_extract_obu(AV1OBU *obu, const uint8_t *buf, int length,                       void *logctx); /** * Split an input packet into OBUs. * * @note This function does not copy or store any bitstream data. All *       the pointers in the AV1Packet structure will be valid as *       long as the input buffer also is. */int ff_av1_packet_split(AV1Packet *pkt, const uint8_t *buf, int length,                        void *logctx); /** * Free all the allocated memory in the packet. */void ff_av1_packet_uninit(AV1Packet *pkt); static inline int64_t leb128(GetBitContext *gb) {    int64_t ret = 0;    int i;     for (i = 0; i < 8; i++) {        int byte = get_bits(gb, 8);        ret |= (int64_t)(byte & 0x7f) << (i * 7);        if (!(byte & 0x80))            break;    }    return ret;} static inline int parse_obu_header(const uint8_t *buf, int buf_size,                                   int64_t *obu_size, int *start_pos, int *type,                                   int *temporal_id, int *spatial_id){    GetBitContext gb;    int ret, extension_flag, has_size_flag;    int64_t size;     ret = init_get_bits8(&gb, buf, FFMIN(buf_size, 2 + 8)); // OBU header fields + max leb128 length    if (ret < 0)        return ret;     if (get_bits1(&gb) != 0) // obu_forbidden_bit        return AVERROR_INVALIDDATA;     *type      = get_bits(&gb, 4);    extension_flag = get_bits1(&gb);    has_size_flag  = get_bits1(&gb);    skip_bits1(&gb); // obu_reserved_1bit     if (extension_flag) {        *temporal_id = get_bits(&gb, 3);        *spatial_id  = get_bits(&gb, 2);        skip_bits(&gb, 3); // extension_header_reserved_3bits    } else {        *temporal_id = *spatial_id = 0;    }     *obu_size  = has_size_flag ? leb128(&gb)                               : buf_size - 1 - extension_flag;     if (get_bits_left(&gb) < 0)        return AVERROR_INVALIDDATA;     *start_pos = get_bits_count(&gb) / 8;     size = *obu_size + *start_pos;     if (size > buf_size)        return AVERROR_INVALIDDATA;     return size;} static inline int get_obu_bit_length(const uint8_t *buf, int size, int type){    int v;     /* There are no trailing bits on these */    if (type == AV1_OBU_TILE_GROUP ||        type == AV1_OBU_TILE_LIST ||        type == AV1_OBU_FRAME) {        if (size > INT_MAX / 8)            return AVERROR(ERANGE);        else            return size * 8;    }     while (size > 0 && buf[size - 1] == 0)        size--;     if (!size)        return 0;     v = buf[size - 1];     if (size > INT_MAX / 8)        return AVERROR(ERANGE);    size *= 8;     /* Remove the trailing_one_bit and following trailing zeros */    if (v)        size -= ff_ctz(v) + 1;     return size;} #endif /* AVCODEC_AV1_PARSE_H */