On Tue, 2020-06-30 at 15:37 +0200, Martin Kepplinger wrote: > On 30.06.20 14:59, Ezequiel Garcia wrote: > > Hi Martin, > > > > On Tue, 2020-06-30 at 13:16 +0200, Martin Kepplinger wrote: > > > Hi Ezequiel, > > > > > > On the Librem 5 (imx8mq) I try to decode a (h264) full hd video file > > > using the VPU. > > > > > > I'm running the following tree that doesn't change much, but adds the > > > VPU dts description: > > > https://source.puri.sm/martin.kepplinger/linux-next/-/commits/5.8-rc3/librem5___vpu > > > (output of "v4l-ctl --all" at the bottom). > > > > > > > OK, this means the VPU is enabled with the Hantro driver, so far so good. > > > > > I now run your version of ffmpeg: > > > https://gitlab.collabora.com/ezequiel/ffmpeg/-/commits/stateless-mpeg2-vp8-h264-v4 > > > (with minor build fixes) but simply doing "ffplay <file>" seems like not > > > using /dev/video0 > > > > > > Is this supposed to work? If so, do I need to know anything about ffmpeg > > > to be able to test this? How do you verify that the v4l2 mem2mem device > > > (vpu) is being used? > > > > > > > Not sure what state the branch is on, and also IIRC you should use that together > > with mpv for proper zero-copy operation. > > > > I think the libre elec community can help you with that, as they maintain > > proper ffmpeg/mpv branches. > > thanks for the hint. > > > Do you need this to work with ffmpeg, or is GStreamer also OK? > > gstreamer would be equally fine (or easier as I've used that before) for > me. Last time I checked I think I'd have to build many more libraries > from source in order to test though. That's the only reason why I've > tried ffmpeg. > In my experience, using gst-build is not too hard; combined with meson, it's really fast to cross build. There are a couple articles: https://www.collabora.com/news-and-blog/blog/2020/03/19/getting-started-with-gstreamer-gst-build/ https://www.collabora.com/news-and-blog/blog/2020/05/15/cross-compiling-with-gst-build-and-gstreamer/ .. or tl;dr off the top of my head, hope it works: (host) cd whatever_your_nfs_rootfs_is/gst-build (host) meson --cross-file /home/user/meson-cross/arm64.txt build (host) ninja -C build (The second article explains how to generate a cross-file) Then on the target: (target) cd gst-build/ (target) ./gst-uninstalled.py Few examples that have worked out of the box. The GL ones might or might not work, depending on your support. gst-launch-1.0 filesrc location=/$1 ! parsebin ! decodebin3 ! fakevideosink gst-launch-1.0 -ev filesrc location=$1 ! decodebin3 ! videoconvert ! video/x-raw,format=YUY2 ! glupload ! glfiltercube ! glimagesink gst-launch-1.0 -ev filesrc location=$1 ! decodebin3 ! videoconvert ! video/x-raw,format=NV12 ! kmssink You'll have VPU interrupts and should see nice CPU usage. The GStreamer filter element that decodebin3 should pick up is "v4l2slh264dec". Let us know if it works :-) Thanks, Ezequiel
