/**
  * 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 AVUTIL_ENCRYPTION_INFO_H
 #define AVUTIL_ENCRYPTION_INFO_H
 
 #include <stddef.h>
 #include <stdint.h>
 
 typedef struct AVSubsampleEncryptionInfo {
     /** The number of bytes that are clear. */
     unsigned int bytes_of_clear_data;
 
     /**
      * The number of bytes that are protected.  If using pattern encryption,
      * the pattern applies to only the protected bytes; if not using pattern
      * encryption, all these bytes are encrypted.
      */
     unsigned int bytes_of_protected_data;
 } AVSubsampleEncryptionInfo;
 
 /**
  * This describes encryption info for a packet.  This contains frame-specific
  * info for how to decrypt the packet before passing it to the decoder.
  *
  * The size of this struct is not part of the public ABI.
  */
 typedef struct AVEncryptionInfo {
     /** The fourcc encryption scheme. */
     uint32_t scheme;
 
     /**
      * Only used for pattern encryption.  This is the number of 16-byte blocks
      * that are encrypted.
      */
     uint32_t crypt_byte_block;
 
     /**
      * Only used for pattern encryption.  This is the number of 16-byte blocks
      * that are clear.
      */
     uint32_t skip_byte_block;
 
     /**
      * The ID of the key used to encrypt the packet.  This should always be
      * 16 bytes long, but may be changed in the future.
      */
     uint8_t *key_id;
     uint32_t key_id_size;
 
     /**
      * The initialization vector.  This may have been zero-filled to be the
      * correct block size.  This should always be 16 bytes long, but may be
      * changed in the future.
      */
     uint8_t *iv;
     uint32_t iv_size;
 
     /**
      * An array of subsample encryption info specifying how parts of the sample
      * are encrypted.  If there are no subsamples, then the whole sample is
      * encrypted.
      */
     AVSubsampleEncryptionInfo *subsamples;
     uint32_t subsample_count;
 } AVEncryptionInfo;
 
 /**
  * This describes info used to initialize an encryption key system.
  *
  * The size of this struct is not part of the public ABI.
  */
 typedef struct AVEncryptionInitInfo {
     /**
      * A unique identifier for the key system this is for, can be NULL if it
      * is not known.  This should always be 16 bytes, but may change in the
      * future.
      */
     uint8_t* system_id;
     uint32_t system_id_size;
 
     /**
      * An array of key IDs this initialization data is for.  All IDs are the
      * same length.  Can be NULL if there are no known key IDs.
      */
     uint8_t** key_ids;
     /** The number of key IDs. */
     uint32_t num_key_ids;
     /**
      * The number of bytes in each key ID.  This should always be 16, but may
      * change in the future.
      */
     uint32_t key_id_size;
 
     /**
      * Key-system specific initialization data.  This data is copied directly
      * from the file and the format depends on the specific key system.  This
      * can be NULL if there is no initialization data; in that case, there
      * will be at least one key ID.
      */
     uint8_t* data;
     uint32_t data_size;
 } AVEncryptionInitInfo;
 
 /**
  * Allocates an AVEncryptionInfo structure and sub-pointers to hold the given
  * number of subsamples.  This will allocate pointers for the key ID, IV,
  * and subsample entries, set the size members, and zero-initialize the rest.
  *
  * @param subsample_count The number of subsamples.
  * @param key_id_size The number of bytes in the key ID, should be 16.
  * @param key_id_size The number of bytes in the IV, should be 16.
  *
  * @return The new AVEncryptionInfo structure, or NULL on error.
  */
 AVEncryptionInfo *av_encryption_info_alloc(uint32_t subsample_count, uint32_t key_id_size, uint32_t iv_size);
 
 /**
  * Allocates an AVEncryptionInfo structure with a copy of the given data.
  * @return The new AVEncryptionInfo structure, or NULL on error.
  */
 AVEncryptionInfo *av_encryption_info_clone(const AVEncryptionInfo *info);
 
 /**
  * Frees the given encryption info object.  This MUST NOT be used to free the
  * side-data data pointer, that should use normal side-data methods.
  */
 void av_encryption_info_free(AVEncryptionInfo *info);
 
 /**
  * Creates a copy of the AVEncryptionInfo that is contained in the given side
  * data.  The resulting object should be passed to av_encryption_info_free()
  * when done.
  *
  * @return The new AVEncryptionInfo structure, or NULL on error.
  */
 AVEncryptionInfo *av_encryption_info_get_side_data(const uint8_t *side_data, size_t side_data_size);
 
 /**
  * Allocates and initializes side data that holds a copy of the given encryption
  * info.  The resulting pointer should be either freed using av_free or given
  * to av_packet_add_side_data().
  *
  * @return The new side-data pointer, or NULL.
  */
 uint8_t *av_encryption_info_add_side_data(
       const AVEncryptionInfo *info, size_t *side_data_size);
 
 
 /**
  * Allocates an AVEncryptionInitInfo structure and sub-pointers to hold the
  * given sizes.  This will allocate pointers and set all the fields.
  *
  * @return The new AVEncryptionInitInfo structure, or NULL on error.
  */
 AVEncryptionInitInfo *av_encryption_init_info_alloc(
     uint32_t system_id_size, uint32_t num_key_ids, uint32_t key_id_size, uint32_t data_size);
 
 /**
  * Frees the given encryption init info object.  This MUST NOT be used to free
  * the side-data data pointer, that should use normal side-data methods.
  */
 void av_encryption_init_info_free(AVEncryptionInitInfo* info);
 
 /**
  * Creates a copy of the AVEncryptionInitInfo that is contained in the given
  * side data.  The resulting object should be passed to
  * av_encryption_init_info_free() when done.
  *
  * @return The new AVEncryptionInitInfo structure, or NULL on error.
  */
 AVEncryptionInitInfo *av_encryption_init_info_get_side_data(
     const uint8_t* side_data, size_t side_data_size);
 
 /**
  * Allocates and initializes side data that holds a copy of the given encryption
  * init info.  The resulting pointer should be either freed using av_free or
  * given to av_packet_add_side_data().
  *
  * @return The new side-data pointer, or NULL.
  */
 uint8_t *av_encryption_init_info_add_side_data(
     const AVEncryptionInitInfo *info, size_t *side_data_size);
 
 #endif /* AVUTIL_ENCRYPTION_INFO_H */