MFSampleExtension_Encryption_CryptByteBlock attribute

Specifies the encrypted byte block size for sample-based pattern encryption.

Data type

UINT32

Remarks

The number of clear (non-encrypted) bytes in the subsample mapping block are specified in the MFSampleExtension_Encryption_SkipByteBlock attribute. If either of these attributes are not present or have a value of 0, it means that the sample is either 'cenc' or 'cbc1' depending on value of MFSampleExtension_Encryption_ProtectionScheme attribute.

In cases where the Source is MP4-based, the value is set based off the values of default_crypt_byte_block within the track encryption box (‘tenc’) in the MP4 header. For more information, see MFSampleExtension_Encryption_ProtectionScheme.

Requirements