Re: write once, run anywhere: bah

On 7/5/26 21:38, Eli the Bearded wrote:
> I have a piece of software, to drive a USB camera, that ran fine on
> Ubuntu 20.04 but is segfaulting on Debian 13. It's something to do with
> the "libuvc" library. Before I installed libuvc0
> (libuvc0_0.0.7-3_amd64.deb), it ran but with an all white window and an
> error message about libuvc to stdout. Now it crashes almost immediagely:
> 
> Stack: [0x00007fdf89d00000,0x00007fdf89e00000],  sp=0x00007fdf89dfe4a8, free space=1017k
> Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
> C  [libuvc.so.0+0xaa48]  uvc_get_format_descs+0x8
> C  [libHelloJni.so+0xb1b8]  Java_HelloJni_getResolutions+0x195
> j  HelloJni.getResolutions(LCamera;)[LResolution;+0
> j  Visualizer.init()V+7887
> j  Visualizer.main([Ljava/lang/String;)V+348
> v  ~StubRoutines::call_stub 0x00007fdf73d37cc6
> V  [libjvm.so+0x9377ca]  JavaCalls::call_helper(JavaValue*, methodHandle const&, JavaCallArguments*, JavaThread*)+0x2da V  [libjvm.so+0x9e3175]  jni_invoke_static(JNIEnv_*, JavaValue*, _jobject*, JNICallType, _jmethodID*, JNI_ArgumentPusher *, JavaThread*) [clone .constprop.1]+0x365
> V  [libjvm.so+0x9f5502]  jni_CallStaticVoidMethod+0x252
> C  [libjli.so+0x522b]  JavaMain+0xf4b
> C  [libjli.so+0x826d]  ThreadJavaMain+0xd
> Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
> j  HelloJni.getResolutions(LCamera;)[LResolution;+0
> j  Visualizer.init()V+7887
> j  Visualizer.main([Ljava/lang/String;)V+348
> v  ~StubRoutines::call_stub 0x00007fdf73d37cc6
>   
> siginfo: si_signo: 11 (SIGSEGV), si_code: 128 (SI_KERNEL), si_addr: 0x0000000000000000
> 
> So happy to have what I thought would be an upgrade proof piece of
> software fail so quickly.
> 
> When I purchased this, I thought the "works with Linux" meant it worked
> like a regular webcam, not "requires special software". I would not have
> bought it knowing it needed special software.
> 
> The company to avoid is Ipevo, and the camera to avoid is the V4K.


   Device drivers have always been the bane of
   computing - but there's really no way around
   the damned things. No such thing as a "universal
   device interface".

   Maybe could be, but WOW the complexity ! It'd
   also have to be built into every device - 500
   little boxes to fill in, so to speak.

   As for USB cameras - I have a lot of those. Never
   really had many issues. Most IP cams have a web
   interface built in and the rest are just kinda
   plug-n-play. V4L2 works pretty well for setting
   the usual video params afterwards.

   Oh, try running "cheese" and then try the cam
   again. Sometimes the /dev/video(x) may not 'take'
   until something like cheese uses it. This is SOP
   with software like 'motion'.