/*
* MOV CENC (Common Encryption) writer
* Copyright (c) 2015 Eran Kornblau <erankor at gmail dot com>
*
* 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 AVFORMAT_MOVENCCENC_H
#define AVFORMAT_MOVENCCENC_H
#include "libavutil/aes_ctr.h"
#include "avformat.h"
#include "avio.h"
#define CENC_KID_SIZE (16)
struct MOVTrack;
typedef struct {
struct AVAESCTR* aes_ctr;
uint8_t* auxiliary_info;
size_t auxiliary_info_size;
size_t auxiliary_info_alloc_size;
uint32_t auxiliary_info_entries;
/* subsample support */
int use_subsamples;
uint16_t subsample_count;
size_t auxiliary_info_subsample_start;
uint8_t* auxiliary_info_sizes;
size_t auxiliary_info_sizes_alloc_size;
} MOVMuxCencContext;
/**
* Initialize a CENC context
* @param key encryption key, must have a length of AES_CTR_KEY_SIZE
* @param use_subsamples when enabled parts of a packet can be encrypted, otherwise the whole packet is encrypted
*/
int ff_mov_cenc_init(MOVMuxCencContext* ctx, uint8_t* encryption_key, int use_subsamples, int bitexact);
/**
* Free a CENC context
*/
void ff_mov_cenc_free(MOVMuxCencContext* ctx);
/**
* Write a fully encrypted packet
*/
int ff_mov_cenc_write_packet(MOVMuxCencContext* ctx, AVIOContext *pb, const uint8_t *buf_in, int size);
/**
* Parse AVC NAL units from annex B format, the nal size and type are written in the clear while the body is encrypted
*/
int ff_mov_cenc_avc_parse_nal_units(MOVMuxCencContext* ctx, AVIOContext *pb, const uint8_t *buf_in, int size);
/**
* Write AVC NAL units that are in MP4 format, the nal size and type are written in the clear while the body is encrypted
*/
int ff_mov_cenc_avc_write_nal_units(AVFormatContext *s, MOVMuxCencContext* ctx, int nal_length_size,
AVIOContext *pb, const uint8_t *buf_in, int size);
/**
* Write the cenc atoms that should reside inside stbl
*/
void ff_mov_cenc_write_stbl_atoms(MOVMuxCencContext* ctx, AVIOContext *pb);
/**
* Write the sinf atom, contained inside stsd
*/
int ff_mov_cenc_write_sinf_tag(struct MOVTrack* track, AVIOContext *pb, uint8_t* kid);
#endif /* AVFORMAT_MOVENCCENC_H */