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jacksonliam / mjpg-streamer

Fork of http://sourceforge.net/projects/mjpg-streamer/
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ptp2 plugin doesn't work #173

Open plfort opened 5 years ago

plfort commented 5 years ago

Hello, Is it possible to process stdin with mjpg-streamer ? I would like to do : gphoto2 --capture-movie --stdout | mjpg-streamer ...

I saw the plugin input_ptp2 but I can't make it work, I get this error : mjpg_streamer: symbol lookup error: /usr/local/lib/mjpg-streamer/input_ptp2.so: undefined symbol: gp_context_new

jacksonliam commented 5 years ago

Hey, we don't support input from stdin, However, I did fix the link error for input_ptp2 - I guess no-one has tried to use it in years!

Do a 

make distclean
git pull
make

And it should fix the undefined symbol: gp_context_new error

plfort commented 5 years ago

Thank you ! It is better : the camera is detected and the capture seems to start (mirror is raised) but finish with a Segmentation fault. I'm not a C developer but I can try ... I'll make a PR if I can solve the problem.

jacksonliam commented 5 years ago

Ah that's a shame.

I don't have a compatible camera to fix it myself but if you can't find the bug then do a debug build (see below), run it and send me the corefile from the crash I might be able to work it out.

make distclean
make CMAKE_BUILD_TYPE=Debug
jacksonliam commented 5 years ago

As a stab in the dark, there is no buffer overrun protection and whoever wrote the plugin assumed the camera wouldn't send frames above 256KB...

As a test, modify the 256 on this line to something more than big enough to hold what your camera can send, e.g. 10000. https://github.com/jacksonliam/mjpg-streamer/blob/master/mjpg-streamer-experimental/plugins/input_ptp2/input_ptp2.c#L134

plfort commented 5 years ago

Hey! I stopped there yesterday after I raised it to 512, and it worked ! But I was thinking of making a better fix : maybe usining realloc to fit xsize ?

jacksonliam commented 5 years ago

Good news! Yes that would be the better fix.

If the buffer is too small realloc to something bigger than xsize plus some margin (10% ?), exiting gracefully if the realloc fails.