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- // Copyright 2016 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #ifndef MEDIA_BASE_SUBSAMPLE_ENTRY_H_
- #define MEDIA_BASE_SUBSAMPLE_ENTRY_H_
- #include <stddef.h>
- #include <stdint.h>
- #include <vector>
- #include "media/base/media_export.h"
- namespace media {
- // The Common Encryption spec provides for subsample encryption, where portions
- // of a sample are set in cleartext. A SubsampleEntry specifies the number of
- // clear and encrypted bytes in each subsample. For decryption, all of the
- // encrypted bytes in a sample should be considered a single logical stream,
- // regardless of how they are divided into subsamples, and the clear bytes
- // should not be considered as part of decryption. This is logically equivalent
- // to concatenating all 'cypher_bytes' portions of subsamples, decrypting that
- // result, and then copying each byte from the decrypted block over the
- // position of the corresponding encrypted byte.
- struct SubsampleEntry {
- SubsampleEntry() : clear_bytes(0), cypher_bytes(0) {}
- SubsampleEntry(uint32_t clear_bytes, uint32_t cypher_bytes)
- : clear_bytes(clear_bytes), cypher_bytes(cypher_bytes) {}
- uint32_t clear_bytes;
- uint32_t cypher_bytes;
- };
- // Verifies that |subsamples| correctly specifies a buffer of length
- // |input_size|. Returns false if the total of bytes specified in |subsamples|
- // does not match |input_size|.
- MEDIA_EXPORT bool VerifySubsamplesMatchSize(
- const std::vector<SubsampleEntry>& subsamples,
- size_t input_size);
- } // namespace media
- #endif // MEDIA_BASE_SUBSAMPLE_ENTRY_H_
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