installing, upgrading and etc

How to detect your device

install the recommendation (470 in this case)

useful to sort automatically as you insert elements

Custome comparator

A summary note of ISO/IEC 23001–7:2016

What is “Common Encryption”?

Common Encryption specifies standard encryption and key mapping methods that can be utilized to enable decryption of the same file using different DRM and key management systems.


  • define encryption algorithms and encryption-related metadata

Don’t do

  • rights mapping, key acquisition, and storage, DRM content protection compliance rules → are done by the DRM system


  • DRM specific information such as licenses, rights, and license acquisition information can be stored in PSSH

Protection Scheme

Protection Scheme Type

  • cenc AES-CTR mode full sample and video NAL subsample encryption
  • cbc1 AES-CBC mode full sample and video NAL subsample encryption
  • cens AES-CTR mode partial video NAL pattern


Example 1:

Example 2:

Example 3:


Example 1:

Input: s = “aba”
Output: true
Example 2:

Input: s = “abca”
Output: true
Explanation: You could delete the character ‘c’.
Example 3:

Input: s = “abc”

# of reference frames in various video codecs


AVC allows up to 16 reference frames to be used, but in practice, it
is rare to use more than 5.


From x265 manual

— ref <1..16>
Max number of L0 references to be allowed. This number has a linear multiplier effect on the amount of work performed in motion search, but will generally have a beneficial affect on compression and distortion.

Note that x265 allows up to 16 L0 references but the HEVC specification only allows a maximum of 8 total reference frames.
- if you have B frames…


Example 1:

Example 2:

Example 3:

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