Topic: SVPcode - Stereoscopic 3D Detection Limitations

With most videos SVPcode will activate stereoscopic processing mode if the filename has some kind of 3D format in it.

Here is an example of when I append "SBS" to a video's filename.  stereo_type is correctly set to "1" (side by side processing)

# This script was generated by SVP 4 Manager.
# Check for more details.

import vapoursynth as vs
core = vs.get_core(threads=3)

if not hasattr(core,'svp1'):
    core.std.LoadPlugin("C:\\Program Files (x86)\\SVP 4\\plugins64\\svpflow1_vs.dll")
if not hasattr(core,'svp2'):
    core.std.LoadPlugin("C:\\Program Files (x86)\\SVP 4\\plugins64\\svpflow2_vs.dll")

clip = video_in

super_params     = "{scale:{up:0},gpu:1,rc:true}"
analyse_params   = "{block:{w:8,overlap:0},main:{search:{coarse:{distance:-8,bad:{sad:2000},width:530},type:2}},refine:[{thsad:250}]}"
smoothfps_params = "{gpuid:11,gpu_qn:1,rate:{num:11,den:5},algo:23,mask:{area:100,cover:80},scene:{mode:0}}"

src_fps     = 27.117
demo_mode   = 0
stereo_type = 1
nvof = 0
rife = 0

But for some videos with a stereoscopic format in the filename, SVPcode doesn't activate stereo mode.

I did some tests to try and find out when this works, and when it doesn't.  I suspect it has something to do with the resolution, so I created test videos of various frame sizes.  I added "SBS" to all of them and opened them in SVPcode to see whether stereo 3D mode was enabled.

It seems that above a certain frame area the detection fails.  Detection doesn't work for most of the common resolutions for high quality virtual reality videos.  Trying to transcode VR videos to 60 FPS is how I first noticed this problem.

I haven't learned how to manually use the newer version of SVPflow with AVISynth and VirtualDub like I did in the days before SVP 4 with InterFrame2.  SVPcode has been reliable and customizable enough to do what I want in most situations.  But recently I've run into some limitations with using it for very high resolution virtual reality videos, and this stereo detection issue is one that's probably a fixable bug.

Re: SVPcode - Stereoscopic 3D Detection Limitations

Thank you for information.
3D stereo detection must work for every video with OU, HOU and SBS tags in file name. … s_function

We will check why it not works for resolutions you pointed.

Re: SVPcode - Stereoscopic 3D Detection Limitations

Actually it is a hard-coded limit because it was discovered that "3d mode" (specifically "StackHorizontal" function) is very slow for large frames at least in Avisynth/ffdshow environment. And I can't see how we could fix this.
For the real-time VR playback it's much better to play it in "2d" mode even if it gives additional artifacts on the center line.
But I agree that we should remove this limit in the encoder mode.

Re: SVPcode - Stereoscopic 3D Detection Limitations

Chainik wrote:

Actually it is a hard-coded limit [...]

Ah, okay.  I avoided titling this thread as a "bug" because the way 3D detection in SPVcode stops working above a certain frame size made me suspect this behavior might be intentional.

I have a video profile for real-time frame-rate conversion with VR videos, but my hardware is too old to run it with good quality.  I prefer to do FRC offline for VR videos, so it would be useful for SVPcode to allow stereo mode on these very high resolution videos - even if it's slow.

Thanks for looking at this issue.