scratch-screen-share/notes.org at 5575db018e4486d83a6a1ef7356905591fe9fbb1

  (defmacro with-dbus-method-inovaction ((result-var method &rest args) &body body)
  (alexandria:with-gensyms (bus notifications-object)
    `(dbus:with-open-bus (,bus (dbus:session-server-addresses))
       (dbus:with-introspected-object (,notifications-object ,bus "/org/freedesktop/Notifications" "org.freedesktop.Notifications")
         (let ((,result-var (,notifications-object "org.freedesktop.Notifications" ,method ,@args)))
          ,@body)))))

example in cl-notify of working with signals

https://github.com/Lautaro-Garcia/cl-notify/blob/main/src/signals.lisp

they register single handler, and add callbacks dynamically & call them from the registered function

it's the one that's used to create multiplexer for communication i tried to figure out what it means to have event-loops

docs on dbus Screenshots portal

https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Screenshot.html

the methods and stuff

docs on dbus type system

https://dbus.freedesktop.org/doc/dbus-specification.html#type-system

i.e how to understand types of methods and properties

  CL-USER> (dbus:sigexp "xsaysas")
(:INT64 :STRING (:ARRAY :BYTE) :STRING (:ARRAY :STRING))

function signature explanation can show what should lisp types be https://github.com/death/dbus/issues/17#issuecomment-418920440

example of flameshot how they get Screenshot via dbus

https://github.com/flameshot-org/flameshot/blob/c1dac52231024174faa68a29577129ebca125dff/src/utils/screengrabber.cpp#L59

dbus methods for Notification

https://specifications.freedesktop.org/notification-spec/notification-spec-latest.html#signals

dbus methods of ScreenCast

https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.ScreenCast.html how to start them etc

dbus spec on Request & Response for the async methods

https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Request.html#org-freedesktop-portal-request

repo for xdg-portal for wayland

https://github.com/emersion/xdg-desktop-portal-wlr

the python snippet to check that ScreenCast via xdg-portal works

https://gitlab.gnome.org/-/snippets/19

[2024-07-20 Sat]

and now i want to try to get display of stuff into gtk window, i guess

doc about cl bindings to gtk3

https://www.crategus.com/books/cl-gtk/gtk-tutorial.html#example-window-simple-c

well, i guess i could go and try to read guide on pipewire with C examples

https://docs.pipewire.org/page_tutorial.html this is tutorial for the system

and here is example program that maybe does similar thing https://docs.pipewire.org/video-play_8c-example.html

[2024-07-28 Sun]

ok, now i'm trying to get frames from the pipewire 'out' node

and one option i'm exploring is gstreamer

which is a framework for creating applications that stream video / audio with some kind of ability to define \ declare pipeline and then start and then use api somehow

there's c api, and gobject accessibility layer so either c to common lisp, or gobject common lisp thingy maybe exist

reading docs

https://gstreamer.freedesktop.org/documentation/frequently-asked-questions/using.html?gi-language=c

added via gst_all_1.gstreamer

i guess i can try to go with the tutorials?

https://gstreamer.freedesktop.org/documentation/tutorials/index.html?gi-language=c

but with common lisp over gobject? i think i'm already using this in the gtk bindings playground? maybe not https://cl-gtk2.common-lisp.dev/doc/gobject/Creating-GObjects-classes-and-implementing-GInterfaces.html

GObject binding at the moment provides only limited scenarios of creating GObject classes.

and there's something

https://github.com/BohongHuang/cl-gobject-introspection-wrapper

which is based on older

https://github.com/andy128k/cl-gobject-introspection

https://search.nixos.org/packages?channel=unstable&from=0&size=50&sort=relevance&type=packages&query=gobject

they are packaged in nix, this is just unbelievable how much is done by humanity, omg

[2024-08-15 Thu]

getting back after a long while.

so, i was at the creating a window, not knowing how to stream video from pipewire out node so. what to do, huh i think gtk3 bindings library was separate from gobject and glib

but maybe it doesn't matter? or maybe i should figure out glib bindings and use gtk3 though it?

well, there's something simple with opening a window

gtk-playground.lisp::defun example-window-simple (

and something extra simple with gstreamer opening separate window for test video source

/efim/scratch-screen-share/src/commit/5575db018e4486d83a6a1ef7356905591fe9fbb1/gstreamer/tutorial-hello-world.lisp

maybe try to open gstreamer window with screen share?

ok, when i try example of pipewire window on screenshare source i get error that pipewiresrc is not found and that's right, i used system-wide gst-launch-1.0 and when i tried with one in flake shell - it also didn't work

so. tried removing all from shell env, then not found namespace Gst (defvar gstreamer (gir:require-namespace "Gst"))

so. yeah. maybe i need to install dev headers or something?

so. for moving the video around. chatgpt recommended something named 'videobox'

like i can declare it in the pipeline and then get reference to it and use to set video coordinates, huh? https://gstreamer.freedesktop.org/documentation/videobox/index.html?gi-language=python the thing exists but i have zero idea whether it's accessible in a way that's recommended

(defun for-screencast ()
  (gir:invoke (*gstreamer* 'init) '())
  (let* ((pipeline (gir:invoke (*gstreamer* 'parse-launch)
                                "pipewiresrc path=49 ! videoconvert ! videobox top=0 left=0 right=0 bottom=0 ! videoconvert ! autovideosink"
                                ))
         (videobox (gir:invoke (pipeline 'get-element-by-name) "videobox")))
    ;; Set the initial state to playing
    (gir:invoke (pipeline 'set-state) (gir:nget *gstreamer* "State" :playing))
    
    ;; Function to move the video
    (defun move-video (top left)
      (gir:invoke (videobox 'set-property) 'top top)
      (gir:invoke (videobox 'set-property) 'left left))

    ;; Example: Move the video 10 pixels down and 20 pixels to the right
    (move-video 10 20)))

and similar advice from claude, huh

(defun for-screencast ()
  (gir:invoke (*gstreamer* 'init) '())
  (let* ((pipeline (gir:invoke (*gstreamer* 'parse-launch)
                               "pipewiresrc path=49 ! videoconvert ! videobox name=move ! videoscale ! autovideosink"))
         (move-element (gir:invoke (pipeline 'get-by-name) "move")))
    (gir:invoke (pipeline 'set-state) (gir:nget *gstreamer* "State" :playing))
    (values pipeline move-element)))

(defun move-video (move-element left top)
  (gir:set-property move-element "left" left)
  (gir:set-property move-element "top" top))

;; Usage:
(multiple-value-bind (pipeline move-element) (for-screencast)
  ;; Move video 50 pixels to the right and 30 pixels down
  (move-video move-element 50 30)
  ;; Your main loop or other logic here
  )

let's try this out

[2024-08-16 Fri]

new day of the vacation

the experiment with moving the video, right?

could it be that both examples are fake? i don't seem to find both 'get-element things

trying to find anything about dynamism in gstreamer https://coaxion.net/blog/2014/01/gstreamer-dynamic-pipelines/ looks like this is about changing elements of the pipeline

and it's possible that parameters of the pipeline elements (pads?) are also static

options for transforming frames?

videotransform : A combination of scaling, 90-degree-step rotation,

https://github.com/Freescale/gstreamer-imx/blob/master/README.md horizontal/vertical flipping, and color space conversion operations. These elements are able to render video overlay compositions from GstVideoOverlayCompositionMeta data. They also implement the GstVideoDirection interface and have a "video-direction" property that handles rotation and flipping. Through this property, it is possible to configure these elements to auto-rotate images according to the information in image-orientation tags.

glimagesink

https://gstreamer.freedesktop.org/documentation/opengl/glimagesink.html?gi-language=python gst-launch-1.0 -v videotestsrc ! video/x-raw ! glimagesink has error ERROR: from element /GstPipeline:pipeline0/GstGLImageSinkBin:glimagesinkbin0/GstGLImageSink:sink: Failed to create EGLDisplay from native display Additional debug info: ../ext/gl/gstglimagesink.c(1136): _ensure_gl_setup (): /GstPipeline:pipeline0/GstGLImageSinkBin:glimagesinkbin0/GstGLImageSink:sink ERROR: pipeline doesn't want to preroll.

so maybe opengl is not available? how to check?

gltransformation

https://gstreamer.freedesktop.org/documentation/opengl/gltransformation.html?gi-language=python

here examples seem to be for images, not video and same error, let's figure out the opengl check

somewhat categorized things?

[2024-08-21 Wed]

visiting sister, returning back

last time i got stuck on video displaying frozen when i tried to add appsink

just re-checking my basic gstreamer pipeline and screencast start - thing works but i want to clean it up i guess, to allow for simpler retries?

so, for the appsnk there are signals

https://gstreamer.freedesktop.org/documentation/app/appsink.html?gi-language=python#appsink::new-sample

new-sample

def new_sample_callback (appsink, udata):
    #python callback for the 'new-sample' signal

Signal that a new sample is available.

but how do i connect to a callback from common lisp and gobject introspection https://github.com/andy128k/cl-gobject-introspection does the gitlab repo has info on callbacks?

can't seem to call method 'pull-sample' maybe article will help? https://gstreamer.freedesktop.org/documentation/application-development/advanced/pipeline-manipulation.html?gi-language=python#grabbing-data-with-appsink

well, this looks like method on gst namespace? "gst_app_sink_pull_sample()" https://gstreamer.freedesktop.org/documentation/applib/gstappsink.html?gi-language=python#gst_app_sink_pull_sample

there's article for python bindings https://lifestyletransfer.com/how-to-use-gstreamer-appsink-in-python/

[2024-08-22 Thu]

hey, i think this is progress

i am able to call appsink 'pull-sample after all (for some reason, i don't know what i was doing differently)

new error: >>> got to process sample with #<STRUCT-INSTANCE {10128D02F3}> but in the code for processing of the sample some type errors

Backtrace: 0: ((:METHOD GIR::THIS-OF (T)) T) [fast-method] 1: (GIR:PROPERTY T DATA) 2: (PROCESS-FRAME #<GIR::STRUCT-INSTANCE {100BCDAB73}>) 3: ((LAMBDA (APPSINK) :IN START-PROCESSING) #<GIR::OBJECT-INSTANCE {100BBE02D3}>)

ok, but when i have struct instance, how do i introspect it?

let's just go and read documentation for the type that's returned from pull-sample, sure

also there's that python code, right? doc 1: get sample on appsink https://people.freedesktop.org/~tsaunier/documentation/gst-plugins-base-app-1.0/gstappsink.html?gi-language=c#gst_app_sink_pull_sample doc 2: GstSample class https://people.freedesktop.org/~tsaunier/documentation/gstreamer-1.0/gstsample.html?gi-language=c#GstSample

so on GstSample everything is taken as results of funciton calls? let's try that

well, maybe i don't need get-info on sample, it returns null, maybe i need it on buffer? doc 3: get-buffer on sample https://people.freedesktop.org/~tsaunier/documentation/gstreamer-1.0/gstsample.html?gi-language=python#gst_sample_get_buffer doc 4: buffer class info https://people.freedesktop.org/~tsaunier/documentation/gstreamer-1.0/gstbuffer.html?gi-language=python#gst_buffer_peek_memory

i'm recommended to look into GstBuffer.map

https://people.freedesktop.org/~tsaunier/documentation/gstreamer-1.0/gstbuffer.html?gi-language=python#gst_buffer_map

it returns some https://people.freedesktop.org/~tsaunier/documentation/gstreamer-1.0/gstmemory.html?gi-language=python#GstMapInfo

struggling, searching for answers

https://github.com/andy128k/cl-gobject-introspection/issues/73#issuecomment-755316735 Examples of inspection of a repository can be found in test files.

https://github.com/andy128k/cl-gobject-introspection/blob/master/test/test1.lisp

and i mean it's possible that referencing members of a structure is not implemented?

so, huh using internal functions

(data (gir:fields-dict-of (gir:struct-class-of map-info)))

i see >>>> and data has size NIL and buf ((memory . #<FIELD-INFO {100FEB4083}>) (flags . #<FIELD-INFO {100FEB4153}>) (data . #<FIELD-INFO {100FEB4223}>) (size . #<FIELD-INFO {100FEB42F3}>) (maxsize . #<FIELD-INFO {100FEB43C3}>) (user_data . #<FIELD-INFO {100FEB4493}>) (_gst_reserved . #<FIELD-INFO {100FEB4563}>)) ; Evaluation aborted on T CAPTURING-FRAMES>

so. there are data and size fields.

15 KiB Raw Blame History

[2024-06-28 Fri]

well, i'm setting up sbcl and sly?

well, just flake shell and (use-package sly) is enough

[2024-06-29 Sat]

going through the dbus guide, sounds neat

now let's read about calling methods

the receiving of the signals

all the different tabs i had

overall freedesktop portal dbus api docs

searching github for 'get-managed-objects usage

searchin github for 'define-singlan-handler usage examples

example in cl-notify of calling a method 'with-introspected-object