/*
  * 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 */