Hi Guennadi, On Monday 13 Jun 2016 17:33:01 Guennadi Liakhovetski wrote: > On Thu, 12 May 2016, Laurent Pinchart wrote: > > The HGO is a Histogram Generator One-Dimension. It computes per-channel > > histograms over a configurable region of the image with optional > > subsampling. > > > > Signed-off-by: Laurent Pinchart > > <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx> > > [snip] > > Do I understand this correctly, that with this if such a metadata device > is opened, while no video data is streaming, all calls will succeed, but > no buffers will be dequeued, i.e. the user-space application will hang in > DQBUF or poll() / select() indefinitely? That's correct. Same as with a mem-to-mem device, if you open the capture node, queue buffers and start streaming, DQBUF will wait until you start supplying buffers on the node at the other end of the pipeline. -- Regards, Laurent Pinchart
