Transcode 3D to 2D

[Vidman 589]

Is this or will this be possible in the future... if a movie is flagged as 3dsbs or 3dtab can / will mb3 server transcode it to 2d for non 3d devices or to watch in 2d on 3d devices

Edited March 10, 2014 by Vidman

[Luke 37096]

Yes, once it moves up the priority list i don't think it will be a big problem.

[Vidman 589]

With the amount of progress in mb3 in the last 6 months I thought I'd give this request a bump

[Vidman 589]

...so not much interest in this obviously so I'm just wondering what other users do. ..do you all just manually transcode 3d movies to 2d and have two versions of the movie in your library?

[AxeMan 22]

3D in general is still niche, for home. Until we get to a point where we have glasses free 3d, i doubt it'll get much traction outside of a theatre setting.

 

If they put a poll on features - i'd would much much much rather see mobile sync added. With the cost of mobile bandwidth, i'm sure a lot more people would find that useful.

 

As for me - I don't have any 3D content - and will more than likely keep it that way for the time being.

[techywarrior 688]

I don't have any 3D movies so I'm not an expert about this at all but from reading the forums here it sounds like there are two things:

 

1. There is a 3D format that supports 2D and 3D. Perhaps if possible you should store your movies in that format.

2. There is support in MB for having a 2D and 3D version of the movie in the same folder if named correctly. (you may have to lookup the exact details tho). Of course this will require you to make the 2D version manually.

 

3D didn't catch on when they tried it in the 50s, 60s, 80s, or now. It has always been a fad and although the technology is much better now then it was in the past I still think it's a fad. Even manufacturers have basically given up on residential 3D. When was the last time you saw a commercial for a 3D TV? Now it's all 4K and silly curved displays (which also add nothing but detract from the experience).

[moddie 2]

sorry for bumping such an  old thread

 

This is a feature I'd love to see sometime, especially since I've switched my living room tv from 1080/3D to 4K non 3d so i no longer have the option to do 3D->2D "conversion" on the TV.

I stil use 3D on the living room projector and the bedroom TV, so I won't just convert and I'd rather save the diskspace than have 2 versions.

Is there any chance of seeing this feature in the future?

 

If conversion is your only option and you've stumbled upon this thread, the following ffmpeg commands seem to do the trick:

for HSBS:

ffmpeg -i i.robot.3d.hsbs.mkv -vf "crop=w=iw/2:h=ih:x=0:y=0,scale=w=2*iw:h=ih,setdar=2"  -map 0:v -map 0:a -y i.robot.mkv

for HTAB:

ffmpeg -i brave.3d.htab.mkv -vf "crop=w=iw:h=ih/2:x=0:y=0,scale=w=iw:h=2*ih,setdar=2"  -map 0:v -map 0:a -y brave.mkv

To anyone more knowledgeable I'd like to pose the following questions:

What does setdar=2 do in this instance? display aspect ratio?

Are there any faster/more efficient methods of doing this?

It's painfully slow on my Xeon E3-1265L V2 @ 3.1GHz, around x0.8 to x1.2 speed...

 

greetings

/moddie

[Waldonnis 148]

To anyone more knowledgeable I'd like to pose the following questions:

What does setdar=2 do in this instance? display aspect ratio?

Are there any faster/more efficient methods of doing this?

It's painfully slow on my Xeon E3-1265L V2 @ 3.1GHz, around x0.8 to x1.2 speed...

 

setdar does alter the display aspect ratio, although I don't use it enough to understand why the value of 2 is being chosen in this case.  I typically use an Avisynth script for resizing, though, so I don't know much about using ffmpeg arguments to do it.  I'm just used to Avisynth for that, and even then I don't typically have a need for this type of resizing (99% of my very infrequent resizing is just a downscale that maintains the aspect ratio or 4:3 crops).  If it works, though, it's probably not worth questioning unless you plan on modifying it 

 

There really aren't any faster ways to do it, though.  I have a few 3D movies and just do a fresh non-3D encode from the source, since almost all of them present the left-eye 2D frames if you ignore the MVC stream (in rare cases, you'll see right-eye first on some discs, but it often doesn't make a huge difference as the non-MVC stream is usually the preferred 2D presentation anyway).  I do this mostly for quality reasons, as the initial "half" scaling wiped out some info from the frames and I'm a stickler for quality/artifacts.  If this was FTAB, it would be better/slightly easier as the entire frame info for each eye was preserved and it's a straight crop without upscaling the height (or width in the case of HSBS).