From 0c32db00aa23dcd3bd8a48bbd838d4a55db75535 Mon Sep 17 00:00:00 2001 From: Theresa O'Connor Date: Tue, 2 May 2017 13:53:54 -0700 Subject: [PATCH] Add ISO Common Encryption 'cbcs' Protection Scheme. --- format-registry/stream/mp4.html | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/format-registry/stream/mp4.html b/format-registry/stream/mp4.html index 03d0d53e..0ac7ca0d 100644 --- a/format-registry/stream/mp4.html +++ b/format-registry/stream/mp4.html @@ -362,7 +362,7 @@ } } - ISO Common Encryption ('cenc') Protection Scheme for ISO Base Media File Format Stream Format + ISO Common Encryption ('cenc' and 'cbcs') Protection Schemes for ISO Base Media File Format Stream Format @@ -471,7 +471,7 @@

-

ISO Common Encryption ('cenc') Protection Scheme for ISO Base Media File Format Stream Format

+

ISO Common Encryption ('cenc' and 'cbcs') Protection Schemes for ISO Base Media File Format Stream Format

W3C Editor's Draft

This version:
@@ -515,10 +515,10 @@

Abstract

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This specification defines the stream format for using ISO Base Media File Format [ISOBMFF] content that uses the ISO Common Encryption ('cenc') protection scheme [CENC] with the Encrypted Media Extensions [ENCRYPTED-MEDIA].

+

This specification defines the stream format for using ISO Base Media File Format [ISOBMFF] content that uses ISO Common Encryption ('cenc' or 'cbcs') protection schemes [CENC] with the Encrypted Media Extensions [ENCRYPTED-MEDIA].

Note
-

Although the ISO Base Media File Format [ISOBMFF] associated with this format's MIME type/subtype strings supports multiple protection schemes, when used with Encrypted Media Extensions, these strings refer specifically to content encrypted and packaged using the 'cenc' protection scheme [CENC]. +

Although the ISO Base Media File Format [ISOBMFF] associated with this format's MIME type/subtype strings supports multiple protection schemes, when used with Encrypted Media Extensions, these strings refer specifically to content encrypted and packaged using either 'cenc' or 'cbcs' protection scheme [CENC].

@@ -575,15 +575,17 @@

1. Stream Format

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ISO Base Media File Format [ISOBMFF] content that is encrypted using the ISO Common Encryption ('cenc') protection scheme [CENC] SHALL be encrypted at the sample level with AES-128 CTR encryption (Section 9 of [CENC]). This protection method enables multiple Key Systems to decrypt the same media content.

+

ISO Base Media File Format [ISOBMFF] content that is encrypted using the ISO Common Encryption ('cenc') protection scheme [CENC] SHALL be encrypted at the sample level with AES-128 CTR (Section 9 of [CENC]).

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ISO Base Media File Format [ISOBMFF] content that is encrypted using the ISO Common Encryption ('cbcs') protection scheme [CENC] SHALL be encrypted at the sample level with AES-128 CBC (Section 10 of [CENC]).

+

These protection methods enable multiple Key Systems to decrypt the same media content.

Each key is identified by a key ID and each encrypted sample is associated with the key ID of the key needed to decrypt it. This association is signaled either through the specification of a default key ID in the track encryption box ('tenc') or by assigning the sample to a Sample Group, the definition of which specifies a key ID. Streams may contain a mixture of encrypted and unencrypted samples.

2. Detection

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For a stream determined to be in the ISO Base Media File Format [ISOBMFF], this ISO Common Encryption ('cenc') Protection Scheme may be detected as follows.

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Protection scheme signaling conforms with [ISOBMFF]. When protection has been applied, the stream type will be transformed to 'encv' for video or 'enca' for audio, with a Protection Scheme Information Box ('sinf') added to the sample entry in the Sample Description Box ('stsd'). The Protection Scheme Information Box ('sinf') will contain a Scheme Type Box ('schm') with a scheme_type field set to a value of 'cenc'. [CENC]

+

For a stream determined to be in the ISO Base Media File Format [ISOBMFF], these ISO Common Encryption ('cenc' or 'cbcs') Protection Schemes may be detected as follows.

+

Protection scheme signaling conforms with [ISOBMFF]. When protection has been applied, the stream type will be transformed to 'encv' for video or 'enca' for audio, with a Protection Scheme Information Box ('sinf') added to the sample entry in the Sample Description Box ('stsd'). The Protection Scheme Information Box ('sinf') will contain a Scheme Type Box ('schm') with a scheme_type field set to a value of 'cenc' or 'cbcs'. [CENC]