Hi Alex, Quoting Dave Stevenson (2022-11-01 18:20:47) > Hi Alexander > > On Tue, 1 Nov 2022 at 15:04, Alexander Stein > <alexander.stein@xxxxxxxxxxxxxxx> wrote: > > > > Hi Dave, > > > > thanks for the fast reply. > > > > Am Dienstag, 1. November 2022, 14:47:16 CET schrieb Dave Stevenson: > > > Hi Alexander > > > > > > On Tue, 1 Nov 2022 at 11:59, Alexander Stein > > > <snip> > > > > > > > > Using this series I was able to do some camera playback on LVDS display on > > > > imx8mm based platform (TQMa8MxML). My command was 'gst-launch-1.0 v4l2src > > > > device=/dev/video0 ! video/x- > > > > raw,format=GRAY8,bpp=8,width=1280,height=720,framerate=30/1 ! videoconvert > > > > ! waylandsink' > > > > But due to SW colorspace conversion this is awfully slow. > > > > Using a testsink I get about 72FPS on 1280x720 for GREY. Is this to be > > > > expected? > > > > I used 'gst-launch-1.0 v4l2src device=/dev/video0 ! video/x- > > > > raw,format=GRAY8,bpp=8,width=1280,height=720,framerate=30/1 ! > > > > fpsdisplaysink video-sink="testsink" text-overlay=false silent=false > > > > sync=false -v' for that. > > > AFAIK v4l2src doesn't map from a caps framerate=30/1 to the relevant > > > V4L2_CID_VBLANK and V4L2_CID_HBLANK controls used by raw sensors for > > > frame rate control (see docs at [1]). The sensor will therefore stream > > > at whatever rate the controls get left at. > > > > Yes I noticed the framerate caps has no effect. But I lack some kind of > > reference system to decide what should work and what not. > > As per the docs link, raw sensors will be using the HBLANK and VBLANK > controls, not VIDIOC_S_PARM. > I don't know whether the GStreamer folks wish to add support to > v4l2src to set those - libcamerasrc is going to be the more normal > user of these sensors, but that generally means needing an ISP of some > form. With just v4l2src you've got no AE / AGC control loops, so it is > only of use in controlled lighting conditions. > > I don't know the full details of the imx8 range, but believe the > libcamera folk were working with one of the imx8 platforms. We have the i.MX8MP working with the ISP available on that variant. I think we can also anticipate some support for other i.MX8 ranges with a GPU based 'ISP' in the (nearish) future, but I don't know what the timescales will be yet. -- Kieran
