blob: 582bce9b0297af6df7bcbf6a06f4bca97b9da252 [file] [log] [blame]
// Copyright 2015 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.
#include <stdint.h>
#include <string>
#include <vector>
namespace chromecast {
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;
// Contains all metadata needed to decrypt a media sample.
class CastDecryptConfig {
virtual ~CastDecryptConfig() {}
// Returns the ID for this sample's decryption key.
virtual const std::string& key_id() const = 0;
// Returns the initialization vector as defined by the encryption format.
virtual const std::string& iv() const = 0;
// Returns the clear and encrypted portions of the sample as described above.
virtual const std::vector<SubsampleEntry>& subsamples() const = 0;
} // namespace media
} // namespace chromecast