blob: 6f9e70e9056c22f4c3624d16bc1e4b995268bffb
| 1 | /* |
| 2 | * MOV CENC (Common Encryption) writer |
| 3 | * Copyright (c) 2015 Eran Kornblau <erankor at gmail dot com> |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | #ifndef AVFORMAT_MOVENCCENC_H |
| 23 | #define AVFORMAT_MOVENCCENC_H |
| 24 | |
| 25 | #include "libavutil/aes_ctr.h" |
| 26 | #include "avformat.h" |
| 27 | #include "avio.h" |
| 28 | |
| 29 | #define CENC_KID_SIZE (16) |
| 30 | |
| 31 | struct MOVTrack; |
| 32 | |
| 33 | typedef struct { |
| 34 | struct AVAESCTR* aes_ctr; |
| 35 | uint8_t* auxiliary_info; |
| 36 | size_t auxiliary_info_size; |
| 37 | size_t auxiliary_info_alloc_size; |
| 38 | uint32_t auxiliary_info_entries; |
| 39 | |
| 40 | /* subsample support */ |
| 41 | int use_subsamples; |
| 42 | uint16_t subsample_count; |
| 43 | size_t auxiliary_info_subsample_start; |
| 44 | uint8_t* auxiliary_info_sizes; |
| 45 | size_t auxiliary_info_sizes_alloc_size; |
| 46 | } MOVMuxCencContext; |
| 47 | |
| 48 | /** |
| 49 | * Initialize a CENC context |
| 50 | * @param key encryption key, must have a length of AES_CTR_KEY_SIZE |
| 51 | * @param use_subsamples when enabled parts of a packet can be encrypted, otherwise the whole packet is encrypted |
| 52 | */ |
| 53 | int ff_mov_cenc_init(MOVMuxCencContext* ctx, uint8_t* encryption_key, int use_subsamples, int bitexact); |
| 54 | |
| 55 | /** |
| 56 | * Free a CENC context |
| 57 | */ |
| 58 | void ff_mov_cenc_free(MOVMuxCencContext* ctx); |
| 59 | |
| 60 | /** |
| 61 | * Write a fully encrypted packet |
| 62 | */ |
| 63 | int ff_mov_cenc_write_packet(MOVMuxCencContext* ctx, AVIOContext *pb, const uint8_t *buf_in, int size); |
| 64 | |
| 65 | /** |
| 66 | * Parse AVC NAL units from annex B format, the nal size and type are written in the clear while the body is encrypted |
| 67 | */ |
| 68 | int ff_mov_cenc_avc_parse_nal_units(MOVMuxCencContext* ctx, AVIOContext *pb, const uint8_t *buf_in, int size); |
| 69 | |
| 70 | /** |
| 71 | * Write AVC NAL units that are in MP4 format, the nal size and type are written in the clear while the body is encrypted |
| 72 | */ |
| 73 | int ff_mov_cenc_avc_write_nal_units(AVFormatContext *s, MOVMuxCencContext* ctx, int nal_length_size, |
| 74 | AVIOContext *pb, const uint8_t *buf_in, int size); |
| 75 | |
| 76 | /** |
| 77 | * Write the cenc atoms that should reside inside stbl |
| 78 | */ |
| 79 | void ff_mov_cenc_write_stbl_atoms(MOVMuxCencContext* ctx, AVIOContext *pb); |
| 80 | |
| 81 | /** |
| 82 | * Write the sinf atom, contained inside stsd |
| 83 | */ |
| 84 | int ff_mov_cenc_write_sinf_tag(struct MOVTrack* track, AVIOContext *pb, uint8_t* kid); |
| 85 | |
| 86 | #endif /* AVFORMAT_MOVENCCENC_H */ |
| 87 |