[gst-devel] Video 3D support

[Stefan Kost]

On 24.05.2010 01:52, Martin Bisson wrote:
> David Schleef wrote:
>   
>> I recommend using a new caps type, perhaps video/x-raw-yuv-stereo
>> or some such, instead of using video/x-raw-yuv,stereo=true.  Using
>> video/x-raw-yuv leads to endless compatibility problems: elements
>> that currently handle video/x-raw-yuv would silently do the wrong
>> thing with stereo video.  Using x-raw-yuv would mean width/height
>> in the caps would be double the *actual* width/height of the mono
>> video, which is hacky.  Also, converting from stereo to mono in
>> many cases would require copying.
>>
>> Defining new fourccs:  This has the obvious disadvantage that
>> we'd either need to keep these internal to GStreamer, or make them
>> well-known enough for other people to use them.  Integrating with
>> existing elements (and libgstvideo) is straightfoward.  Adding
>> new layouts (side-by-side, top-bottom, memory consecutive, etc.)
>> is simple, although adds *lots* more fourccs.
>>   
>>     
> This means that we would have something like :
> - video/x-raw-yuv-stereo-side-by-side
> - video/x-raw-yuv-stereo-top-bottom
> - video/x-raw-yuv-stereo-row-interleaved
>   

Lets see what david replies. I think he rather meant

video/x-raw-yuv-stereo, format={"I420", "UVYV" ,..}, layout={"side-by-side", "over-under", ...}, ...

> And the same thing for different layouts like yuy2 and uyvy?  Planar 
> layouts like I420 might be problematic for row interleaving though, 
> because the u and v values spread to 2 lines...
>
> So these caps would describe 3D streams that carry the 2 images.  But 
> what about streams that actually are combinations of the 2 images, like 
> red/cyan streams?  I guess since these would be displayed on normal 
> devices, they could just be normal streams, i.e. a 
> video/x-raw-yuv-stereo-side-by-side stream could be converted to 
> red/cyan stream with caps video/x-raw-yuv.
>   
Reprendered Red/cyan is not really detectable and normaly we would just
render it as it is. I one would want to convert read/cyan into grayscale
over under one can use a hand-crafted pipeline. Also the red/cyan output
from the 3dmuxer would not show any sign of being 3d on its caps anymore.

Stefan

> I think this caps approach sounds like a good, simple approach that 
> would carry the information we need.  I'm not sure how I would deal with 
> interlaced frames yet, I'll have to look into that.
>
> Thanks for your reply,
>
> Martin
>
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