[libcamera-devel] use of v4l2-compat.so

[Nicolas Dufresne]

Le lundi 15 juin 2020 à 23:38 +0530, naidu nama a écrit :
> Hi,
> What does this wrapper library mean?
> where can i find this API??

The API is V4L2 API, this library will catch calls to
open/close/ioctl/poll and when they match a V4L2 use cases, they will
be emulated on top of libcamera.

> 
> Thanks,
> naidu.
> 
> On Mon, Jun 15, 2020 at 9:32 PM Nicolas Dufresne <nicolas at ndufresne.ca> wrote:
> > Le lundi 15 juin 2020 à 11:52 -0400, Nicolas Dufresne a écrit :
> > > Le lundi 15 juin 2020 à 18:11 +0300, Laurent Pinchart a écrit :
> > > > On Mon, Jun 15, 2020 at 11:06:45AM -0400, Nicolas Dufresne wrote:
> > > > > Le lundi 15 juin 2020 à 18:52 +0530, naidu nama a écrit :
> > > > > > Hi,
> > > > > > I am able to build the v4l2 directory.I am getting a shared libary
> > > > > > v4l2-compat.so.How can i use this in my libcamera or how can i test
> > > > > > that v4l2-compat.so
> > > > > 
> > > > > One way is to make sure it's in your library path, and
> > > > > use LD_PRELOAD=v4l2-compat.so .  Last time I tried it was missing
> > > > > poll() emulation.
> > > > 
> > > > poll() support has been merged, along with several bug fixes. Paul is
> > > > working on additional fixes, they should hopefully land this week.
> > > 
> > > Great ! I confirm it works under GStreamer now:
> > > 
> > > LD_LIBRARY_PATH=$(pwd)/build/src/v4l2 LD_PRELOAD=v4l2-compat.so gst-launch-1.0 v4l2src ! glimagesink
> > > 
> > 
> > Well, it *minimally* works. It seems that it's impossible to pick
> > resolution different from 160x120, or select JPEG. As for other app,
> > libv4l2 wrapper don't seem handled, in firefox it does not get used and
> > it causes chrome to hang at start.
> > 
> > Nicolas
> >