playback issue of HEVC content with CENC cbcs encryption in AVplayer

Question

jingke2000 OP

Created Feb ’20

Replies 1

Boosts 0

Participants 2

Hi,

We have 4K video conent encoded in HEVC packaged in HLS fmp4. The playback from the AVplayer in an iPad with iOS 13 is fine. However, after CENC cbcs encryption, the playback shows macroblocking issue every 1 or 2seonds. We used Shaka Packager to package or encrypt the 4K content in both cases. Here are the links to the sample conent:

Clear (playback is OK):

https://hls-demo-s3.s3.us-east-2.amazonaws.com/4k_cbcs_testing/3/video.m3u8

Encrypted (playback has macroblocking issue):

https://hls-demo-s3.s3.us-east-2.amazonaws.com/4k_cbcs_testing/4/video.m3u8

Can some one help to see what the problem could be?

Thanks.

Boost

Answer 1

witchfndrGeneral OP

Dec ’24

Hey jingke2000,

It's been a few years since you posted this, but I am also attempting to create a packager for HLS/Dash.

I saw in your other post you were referencing the ISO docs for encryption - which I also have a copy of.

I feel like I'm at a dead end or do not fully understand the spec - all outputs from Shaka/Bento4 and the similar seem to know something I don't - I am encrypting sub-samples in the 144/16 byte pattern (1:9), but just can't get a valid output. The outputs from the third party packagers seem to have completely arbitrary byte counts in their SENC boxes.

Did you in the end just use Shaka packager to encrypt your HLS material? Or do you have any suggestions for further reading for formatting cbcs HLS?

Many thanks

0