4K iTunes Movies


priitv8

macrumors 68040
Jan 13, 2011
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443
Estonia
There is no way to play Dolby Vision rips using software even from a 4k disc without re-encoding the audio as far as I know.
Why? iTunes/Netflix DV is directly playable on appleTV or Sony Bravia.
Its not the same as DV from uhd disc.
 

Audit13

macrumors 601
Apr 19, 2017
4,415
1,112
Toronto, Ontario, Canada
Why? iTunes/Netflix DV is directly playable on appleTV or Sony Bravia.
Its not the same as DV from uhd disc.
Do you have a source to explain the difference between DV encoding for UHD and DV encoding for iTunes, Vudu, or Netflix? I always thought both video sources contained the same DV metadata so video files didn't have to be encoded differently for streaming services.

An extremely popular media player is the nVidia Shield and it does not support DV playback from any file.
 

priitv8

macrumors 68040
Jan 13, 2011
3,533
443
Estonia
Do you have a source to explain the difference between DV encoding for UHD and DV encoding for iTunes, Vudu, or Netflix? I always thought both video sources contained the same DV metadata so video files didn't have to be encoded differently for streaming services.
Best source is the Dolby document Dolby VisionProfiles and levels
Long story short - UHD BD uses a very special DV encoding - profile 7. The only reason for it's existence is backward compatibility. It contains actually 2 video streams: one 2160p HDR10 stream that plays back on any UHD player. And then one 1080p track, encoded also in HDR10, that is used to "enhance" the base HDR10 image into 12-bit Dolby Vision image, dynamically:
(it is worth mentioning that to have 2 video streams in one file is in itself very unusual)
Screenshot 2019-03-17 at 20.00.29.png
The other, used in streaming, is a profile 5 encoding. It contains a single (usually 2160p, but is really resolution-agnostic) video track, encoded with special Dolby Vision flavor of HEVC 10-bit encoder - dvhe:
Screenshot 2019-03-17 at 20.03.21.png
The codec name dvhe.05.09 is actually nicely explained in Dolby's reference document, linked above.
 
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Audit13

macrumors 601
Apr 19, 2017
4,415
1,112
Toronto, Ontario, Canada
Unfortunately, I don't have a shield as I use my htpc to play audio and video files. I use an apple tv 4k for iTunes and Netflix, and the lg apps for Google movies and Vudu.