Sebastian Krzyszkowiak @dos@librem.one

@pavel Passing the right buffer size to gst_dmabuf_allocator_alloc helps it to not crash and not have garbage at the end of the frame 😂

@pavel For GTK: either https://docs.gtk.org/gdk4/class.DmabufTextureBuilder.html or https://gstreamer.freedesktop.org/documentation/gtk4/index.html

For SDL with GL: just import it the same way V4L buffers are imported.

Frankly, it's flexible enough that your choice of toolkit should only depend on other factors.

@pavel That one line is the only thing that runs from another thread and it's neither scary nor requires any locking 😁

But there are several other smelly things in this code and lots of missing error handling, so I'd rather start with that when looking for suspects.

@pavel Not sure what you mean. GStreamer is internally multi-threaded, but its API is thread-safe and there's only one thread in this code. Of course any kind of production-quality code will use some mainloop and enqueue buffers based on callbacks rather than while(!processed){} loop, but it's not exactly rocket science.

@pavel You've got a dma-buf handle, already mapped buffer and even GStreamer with all its sinks available, so... however you want? Pretty much anything will be able to consume it easily.

@pavel I'm playing with GStreamer now (which is new for me) and it seems like most of this code could be replaced with GStreamer elements, and the rest should neatly plug in as custom elements 😂

@pavel Yes, of course.

BTW. Turns out that streaming to YouTube instead of a local file is just a matter of using rtmpsink instead of filesink 😁

@pavel Pretty sure it will just work fine once it's rewritten cleanly and does such arcane magic as releasing the buffers at the right time etc. :)

@pavel When I lie to GStreamer and tell it that its input is in YUY2, it gets faster - perhaps even fast enough to encode at 1052x780. That's another opportunity for improvement.

(and there's nothing magic about fences, it's just a simple synchronization primitive 😛)

@pavel Toggling the killswitch makes it appear though.

IIRC PDAF was also usable at half-res.

RAW10 is just a matter of setting up clocks for higher bandwidth and more lanes. Switching data format is then just a single register away.

@pavel There's a question whether it will be worth elevated power consumption though. I've also stumbled upon csi erroring out with "Rx fifo overflow" requiring a reboot to recover that I haven't seen at lower resolutions, but haven't looked closer.

@pavel LDLIBS = -lEGL -lGLESv2 -lm -ldrm -I/usr/include/libdrm -lgbm -lgstvideo-1.0 -lgstapp-1.0 -lgstallocators-1.0 -lgstreamer-1.0 -lgobject-2.0 -lglib-2.0 -I/usr/include/gstreamer-1.0 -I/usr/include/glib-2.0 -I/usr/lib/aarch64-linux-gnu/glib-2.0/include

@pavel There's plenty of low-hanging fruits in there. Higher frame rates and 10-bit output are also likely some debugging session or two away 😜