Vout plugin ?

[Undead Pixel]

Hello,

I would like to use VLC output videos as textures on objects (3D world), wherever they come from (webcam, DVD, mpeg, etc.).

I first guessed I had to write a new VLC vout plugin but can't succeed at making it work (compilation is ok, it crashes at launch because plugin p_module symbols are not initialized). I have not more hairs to remove on my head!

Am I on the good way (right method)? Are there other solutions I didn't see?

Thank you!

[Guest]

What is the form you need to work with?

Will jpeg work for you?

[Undear Pixel]

Actually texturing will be done by an independant application which will share a buffer for RGB images. My idea was to write in this buffer from VLC through the vout plugin.

Jpeg could be ok but might cost a compression process (then CPU time plus maybe file access time if not done in memory).

[Guest]

Originally I was asking because VLC does offer a snapshot function in PNG or JPG formats. I did expect that you were feeding this to another application for processing. It sounds (from your response) like raw video capture is more what you are looking for. If that's the case what would be the perfered croma format? I am still assuming a snapshot like function. I hope that's correct? Be aware that VLC can not do frame by frame as it is a packet based player.

[Undead Pixel]

I assumed that vout plugins could deal with a frame by frame reception of videos, as shown in several examples in VLC source code (OpenGL vout plugin for example).
YUV format should be ok even if I would prefer full RGB.
And you are right, the philosophy of it is close to a snapshot function, but without a transfer via a filesystem.

[Guest]

It's not the plug-ins, it's the player. VLC is packet based, as such it would be a major overhaul to do frame by frame and it is doubtful the developers will ever do this to satisfy one function that is seldom used by the majority of users.

By the way, I believe these are all of the Croma formats:

I420
I411
I422
YUYV
UYVY
RV24
RV32
I42N
I41N
GRAW

RV24 and RV32 seem to be common for raw video.

You may want to check what your program will import. If it will do PNG or JPG I would try using it and see if it is satisfactory, before spending lots of time in a redesign.

[Undead Pixel]

Actually the input format of the "display" application is not an issue, since we want to develop it by ourselves.
What you propose is to use VLC vout snapshot plugin in order to save PNG pictures, isn't it ? Is there a way to do it through a buffer shared by this plugin and our "display" application?
I think the real issue is that I can't manage to compile a bug-free vout plugin by myself. I mean, the code is ok, it is meant to exchange video frames between VLC and the "display" application. It even compiles but it crashes when I run VLC and my debug sessions have been showing that the plugin do not receive pointers to "common" plugin functions from VLC when loading the plugin dll. I'm using version 0.8.5 and seriously I can't understand why other plugin are working fine, since I based interfaces of mine on examples from VLC sources (simple copy/paste).

[DJ]

Perhaps you should try the IRC and ask these questions. I try to avoid programing and compiling issues because most don't understand the unique concepts of a single source code used for multiple operating systems or the idiosyncrasies of using the compiler or some of the unique features of VLC's group programing for daily updates. This is just way to long to go into here. Specially with how so many people verbalize there problems. All of these thing say nothing about understanding the specifications of formats and or containers.

[Zmenice]

Hey

I'm trying to do a similar thing. I need to do image processing for visual obstacle avoidance so I need RGB frames as fast as possible, I'm tring to do it in VB with the medicontrol.h API but im not sure how to implement this. it has a snapshot to RGB procedure but I dont know how to use it.

Maybe you can figure it out
If you get anywhere please would you let me know

Appreciate it