Re: [Flightgear-devel] --jpg-httpd command line option
On Tuesday, September 17, 2013 20:52:16 Curtis Olson wrote: If someone decides to jump into this, another feature that would be cool would be to stream the display out as a video stream which could then be played by any number of video players on a remote computer (like mplayer.) ffmpeg probably would provide library support to make this pretty straightforward, but I haven't had a chance to dive in and see how easy/hard it would be. One area where this feature could be useful is in UAV research and simulation where you'd like to emulate a live video feed back to a ground station. It could also be fun for sharing/broadcasting your simulator session and probably could be made to work with a web video server. In my own experimentation I've been able to sort of do this by using ffmpeg to capture an area of the screen, encode it as h.264 and send it off to a remote destination as a udp video stream, for example: ffmpeg -f x11grab -s vga -r 15 -b 100k -preset ultrafast -tune zerolatency -maxrate 100k -i :0.0+1,58 -f mpegts -vcodec h.264 udp:// remote.host.name.org:1234 But this requires careful manual sizing and placement of my flightgear window and it would be cool to have this built right in... I've seen other apps that can do this so I know it's technically possible, and I imagine not too much coding once you figure out the magic to make it happen. Curt. Hi, there, VLC does this better than ffmpeg, so it's probably a good idea to study it's codebase for streaming code. Also, MJPEG is nice, but as a container I'd choose Ogg/Theora instead of H264 since they're entirely open. Cheers, Adrian -- LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151iu=/4140/ostg.clktrk ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] --jpg-httpd command line option
On 17 Sep 2013, at 19:47, Rick Armstrong rick.armstr...@urbanrobotics.net
wrote:
Indeed, PNG would be ideal!
- if you have any interested in
doing this, I can point you at examples since the screenshot code was
converted to do the same thing recently -it's probably a couple of hours
hacking at most)
I'd be happy to take a crack at it. This would be my first foray into the
FlightGear source tree, so a pointer to some sample code would be great.
Okay, various pieces:
gui_funcs.cxx has the screenshot dumping code, especially the logic to
run things safely via an OSG GraphicsContextOperation. Its run() virtual
contains a call to: sg_glDumpWindow
which is defined in SimGear and does the actual reading of the frame-buffer and
writing via:
// dump the screen buffer to a png file, returns true on success
bool sg_glDumpWindow(const char *filename, int win_width, int
win_height)
{
osg::ref_ptrosg::Image img(new osg::Image);
img-readPixels(0,0, win_width, win_height, GL_RGB,
GL_UNSIGNED_BYTE);
return osgDB::writeImageFile(*img, filename);
}
The trick will be to interface this with the jpg-httpd infrastructure. There's
a problem I can see here - the osgDB API is very file orientated, but I assume
you need the image data in memory to send down the HTTP socket. We might need
to ask on the OSG mailing list if this can be done, otherwise you'd have to
read the file back after writing it. This is little ugly but the file should be
in the cache so probably no actual disk access happens.
Most of jpgfactory.cxx is irrelevant, I'd ignore it completely since it only
deals with the tile-rendering (not needed these days since we can render big GL
viewports natively) and the mechanics of running the image compressor. If you
can plug the stuff you need into line 227 of jpg-httpd, I think you're good.
That's a very rough sketch based on ten minutes reading of course.
Note if you want actual good performance from this system, there's much smarter
things that could be done, such as grabbing the frame buffer each normal
rendering frame, instead of re-rendering the scene each time an HTTP get is
received. That would need much more drastic changes to the system however.
As ever, any further questions, just ask.
Regards,
James
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[Flightgear-devel] --jpg-httpd command line option
Hello all, I'm a developer using FlightGear in a simulation project for work, and I'm currently getting imagery from FlightGear by triggering screenshots from my application and loading the screen captures from disk. It's kinda Rube Goldberg, but works well enough for a first draft. What I'd /really/ like to do is stream the imagery directly to my application. Googling around, I notice that there's a command-line option to do exactly this! It's not enabled in v2.10, but some more searching and I see that it can be enabled by setting -DJPEG_FACTORY:BOOL=ON in CMake. My question: before I go down that road, does anyone know if the JPG HTTPD functionality works? If yes, does it work well? The fact that it's turned-off by default makes me think that it might not be ready for prime-time. Any advice is greatly appreciated. Regards, Rick Armstrong Portland, OR, USA P.S. We're using Windows 7 VS 2010 and would be looking to build 64-bit binaries. -- LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151iu=/4140/ostg.clktrk___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] --jpg-httpd command line option
On 17 Sep 2013, at 10:41, Rick Armstrong waitingfortheelectric...@gmail.com wrote: -DJPEG_FACTORY:BOOL=ON in CMake. My question: before I go down that road, does anyone know if the JPG HTTPD functionality works? If yes, does it work well? The fact that it's turned-off by default makes me think that it might not be ready for prime-time. Any advice is greatly appreciated. It's turned off for build reasons, not because it's new or untested. I believe many people have used it exactly the way you describe. If you encounter problems, they should be easy to fix and patches are welcome! (The build reasons could actually be solved by using OSGDB to write out the files instead of using libjpeg directly - this would mean the feature could be enabled all the time, i.e removed from CMake, and also we could write out PNGs instead of JPEGs if desired - if you have any interested in doing this, I can point you at examples since the screenshot code was converted to do the same thing recently -it's probably a couple of hours hacking at most) Kind regards, James -- LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151iu=/4140/ostg.clktrk___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] --jpg-httpd command line option
If someone decides to jump into this, another feature that would be cool would be to stream the display out as a video stream which could then be played by any number of video players on a remote computer (like mplayer.) ffmpeg probably would provide library support to make this pretty straightforward, but I haven't had a chance to dive in and see how easy/hard it would be. One area where this feature could be useful is in UAV research and simulation where you'd like to emulate a live video feed back to a ground station. It could also be fun for sharing/broadcasting your simulator session and probably could be made to work with a web video server. In my own experimentation I've been able to sort of do this by using ffmpeg to capture an area of the screen, encode it as h.264 and send it off to a remote destination as a udp video stream, for example: ffmpeg -f x11grab -s vga -r 15 -b 100k -preset ultrafast -tune zerolatency -maxrate 100k -i :0.0+1,58 -f mpegts -vcodec h.264 udp:// remote.host.name.org:1234 But this requires careful manual sizing and placement of my flightgear window and it would be cool to have this built right in... I've seen other apps that can do this so I know it's technically possible, and I imagine not too much coding once you figure out the magic to make it happen. Curt. On Tue, Sep 17, 2013 at 6:16 AM, James Turner zakal...@mac.com wrote: On 17 Sep 2013, at 10:41, Rick Armstrong waitingfortheelectric...@gmail.com wrote: -DJPEG_FACTORY:BOOL=ON in CMake. My question: before I go down that road, does anyone know if the JPG HTTPD functionality works? If yes, does it work well? The fact that it's turned-off by default makes me think that it might not be ready for prime-time. Any advice is greatly appreciated. It's turned off for build reasons, not because it's new or untested. I believe many people have used it exactly the way you describe. If you encounter problems, they should be easy to fix and patches are welcome! (The build reasons could actually be solved by using OSGDB to write out the files instead of using libjpeg directly - this would mean the feature could be enabled all the time, i.e removed from CMake, and also we could write out PNGs instead of JPEGs if desired - if you have any interested in doing this, I can point you at examples since the screenshot code was converted to do the same thing recently -it's probably a couple of hours hacking at most) Kind regards, James -- LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151iu=/4140/ostg.clktrk ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- Curtis Olson: http://www.atiak.com - http://aem.umn.edu/~uav/ http://www.flightgear.org - http://gallinazo.flightgear.org -- LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151iu=/4140/ostg.clktrk___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] --jpg-httpd command line option
On Tue, Sep 17, 2013 at 6:16 AM, James Turner zakalawe@... wrote: ... It's turned off for build reasons, not because it's new or untested. I believe many people have used it exactly the way you describe. If you encounter problems, they should be easy to fix and patches are welcome! (The build reasons could actually be solved by using OSGDB to write out the files instead of using libjpeg directly - this would mean the feature could be enabled all the time, i.e removed from CMake, and also we could write out PNGs instead of JPEGs if desired Indeed, PNG would be ideal! - if you have any interested in doing this, I can point you at examples since the screenshot code was converted to do the same thing recently -it's probably a couple of hours hacking at most) I'd be happy to take a crack at it. This would be my first foray into the FlightGear source tree, so a pointer to some sample code would be great. Thanks, Rick -- *Information contained herein is subject to the Code of Federal Regulations Chapter 22 International Traffic in Arms Regulations. This data may not be resold, diverted, transferred, transshipped, made available to a foreign national within the United States, or otherwise disposed of in any other country outside of its intended destination, either in original form or after being incorporated through an intermediate process into other data without the prior written approval of the US Department of State. **Penalties for violation include bans on defense and military work, fines and imprisonment.* -- LIMITED TIME SALE - Full Year of Microsoft Training For Just $49.99! 1,500+ hours of tutorials including VisualStudio 2012, Windows 8, SharePoint 2013, SQL 2012, MVC 4, more. BEST VALUE: New Multi-Library Power Pack includes Mobile, Cloud, Java, and UX Design. Lowest price ever! Ends 9/20/13. http://pubads.g.doubleclick.net/gampad/clk?id=58041151iu=/4140/ostg.clktrk___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
