chromium/third_party/ffmpeg/libavutil/encryption_info.h

/**
 * 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>

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.
 */
AVEncryptionInfo;

/**
 * This describes info used to initialize an encryption key system.
 *
 * The size of this struct is not part of the public ABI.
 */
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 iv_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 */