Dolby Vision now possible through MP4 Mux.

[ArArdin]

Tonight I resumed the movie with the MA DV WEB-DL which as stated just above, has incorrect L5 metadata. It is set to 0 when it should be 276,276 (or 275,276 like hbo).

I noticed right away the black bars were not perfectly black like they were last night so I demuxed the rpu, edited L5 properly, injected it back, and voila, black bars are black again.
So this shows how important doing L5 properly is when doing the hybrid remux, especially if you play the movies on your TV internal player.

I haven't the Dolby Vision versions (yet), but the Batman films show different aspect ratios in one movie.
I understand setting L5 to 276 would be beneficial to the black bars. But wouldn't it also negatively affect DV playback on where normally the black bars would be, so when video is full frame?
Or is L5 also dynamic, and be adjustable for every scene/frame? If so, forgive my ignorance. I haven't done other with L5 than setting it to zero a couple of times.

[RESET_9999]

Or is L5 also dynamic, and be adjustable for every scene/frame? If so, forgive my ignorance. I haven't done other with L5 than setting it to zero a couple of times.

yes L5 is dynamic.

[chros]

Nice summary, thanks! I took a quick look at hmax version, but I wasn't blown away by the image quality

[quietvoid]

Itunes RPU is much larger even without L5 and L4. @Quietvoid, any idea why?

The iTunes stream has extra chroma reshaping, which makes reds slightly brighter.
https://slow.pics/c/Oa5JZnp6

So the reshaping params take a lot more bytes:

Code: Select all

"num_pivots_minus_2": [
      7,
      3,
      3
]

[RESET_9999]

interesting. thanks

but are you sure this is what's causing the difference in colors because I see kind of the same difference when I compare HDR10 MA with HDR10 HBO. https://slow.pics/c/axsHELui
MA looks closer to the SDR grade.

[quietvoid]

interesting. thanks

but are you sure this is what's causing the difference in colors because I see kind of the same difference when I compare HDR10 MA with HDR10 HBO. https://slow.pics/c/axsHELui
MA looks closer to the SDR grade.

I didn't check HDR10, only Dolby Vision profile 5 for iTunes and HBO Max.

[RESET_9999]

I didn't check HDR10, only Dolby Vision profile 5 for iTunes and HBO Max.

yes, you're right. I've compared the 3 streaming services P5 web-dl tonemapped to SDR and on itunes, the red looks more orange/brighter. I prefer how it looks on MA and HBO... https://slow.pics/c/MrSz6BQ4
So iTunes does something different in their RPU( i wonder why) and it explains why we couldn't get a match with @manix Atomos Shogun appleTV samples here viewtopic.php?p=111073#p111073

The HDR10 color mismatch from MA and HBO is something else.

[staknhalo]

So iTunes does something different in their RPU( i wonder why)

I'd guess just 'artistic intent' for whoever authored the DV grade for iTunes encode

Just like they're responsible for their own encode/bitrate level output from what they receive from the studios, places just do what they want with the DV grading too so to speak I suppose

[RESET_9999]

I'd guess just 'artistic intent' for whoever authored the DV grade for iTunes encode

Would be true if only this movie had this special re-shapping but its not case, they do that for all the appleTV content as shown here viewtopic.php?p=111073#p111073

Also, a while ago, the ATV4k(itunes) used to tone map DV to HDR10 instead of streaming the HDR10 encode and I always wondered why the red always looked more orange than the other sources. Now i know why.

[staknhalo]

I'd guess just 'artistic intent' for whoever authored the DV grade for iTunes encode

Would be true if only this movie had this special re-shapping but its not case, they do that for all the appleTV content as shown here viewtopic.php?p=111073#p111073

Also, a while ago, the ATV4k(itunes) used to tone map DV to HDR10 instead of streaming the HDR10 encode and I always wondered why the red always looked more orange than the other sources. Now i know why.

is it just 'artistic intent' across all apple stuff by whoevers authoring it there, title by title; or is it the same exact red push only, same exact metadata values each time, across all their content?

[RESET_9999]

is it just 'artistic intent' across all apple stuff by whoevers authoring it there, title by title; or is it the same exact red push only, same exact metadata values each time, across all their content?

I didnt check the metadata but yes it is the same red shift on every movie/show. That's why I don't see it as an artistic intent.
But I'll take a look at the metadata now that @quietvoid pointed out where to look.

[quietvoid]

Yes, it looks static for all Apple TV content I've tested.
Usually the pivots are 7, 3, 3 (or really 9, 5, 5), and the value for chroma components is always 0, 288, 224, 224, 287 (pred_pivot_value).
The coefficients for all components also appears to be the same all the time, so Apple might just be doing a static reshape for all their content.

This is also why the non decoded image looks very different to other services.

[RESET_9999]

thanks, @quietvoid for confirming, that is what I expected.

IMO it is better to convert any itunes/appletv profile 5 DV to profile 8 .

[staknhalo]

yeah i wonder why they're doing it then if intentional or if they even know they are

[drew_nickel]

@reset_9999

I'm sure you have already covered this, but whats the benefit of converting to profile 8?