Tee webcam video to two virtual cameras

[srec] / srec.py

diff --git a/srec.py b/srec.py
index 36000c92019c20a196cd7853d412a12633c66876..962c147045b95ecbf76a0bca5dfca2b66e4cf5be 100644 (file)
--- a/srec.py
+++ b/srec.py
@@ -4,42 +4,136 @@
 # under the terms of the GNU General Public License as published by the
 # Free Software Foundation, version 3.
 
 # under the terms of the GNU General Public License as published by the
 # Free Software Foundation, version 3.
 

+from __future__ import annotations
+
+from dataclasses import dataclass
+from datetime import datetime
+import os

 import subprocess
 import subprocess

-from typing import Callable
+import sys
+import time
+from typing import Any, Callable

 
 import gi
 gi.require_version("Gtk", "4.0")
 
 import gi
 gi.require_version("Gtk", "4.0")

-from gi.repository import Gtk  # nopep8 pylint: disable=wrong-import-position
+gi.require_version("GLib", "2.0")
+
+from gi.repository import Gtk   # nopep8 pylint: disable=wrong-import-position
+from gi.repository import GLib  # nopep8 pylint: disable=wrong-import-position
+
+
+@dataclass
+class Stream:
+    process: subprocess.Popen[bytes]
+
+    @staticmethod
+    def start(command: list[str]) -> Stream:
+        # pylint: disable=consider-using-with
+        return Stream(process=subprocess.Popen(command, stdin=subprocess.PIPE))
+
+    def stop(self) -> None:
+        stdin = self.process.stdin
+        assert stdin is not None
+        try:
+            stdin.write(b'q')
+            stdin.flush()
+        except BrokenPipeError:
+            print("Stream already stopped?", file=sys.stderr)
+        self.process.wait()
+
+
+recording: Stream | None = None
+sharing: Stream | None = None
+
+
+def make_filename() -> str:
+    directory = os.environ.get(
+        'XDG_VIDEOS_DIR',
+        os.path.expanduser('~/Videos/SRec'))
+    os.makedirs(directory, exist_ok=True)
+    timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
+    return os.path.join(directory, f'srec {timestamp}.mkv')
+
+
+def video_source(stack: Gtk.Stack) -> list[str]:
+    if stack.get_child_by_name('not_recording').get_first_child().get_active():
+        return ['-f', 'x11grab', '-i', ':0.0+0,0']
+    if is_sharing_enabled(stack):
+        return ['-f', 'v4l2', '-i', '/dev/video9']
+    return ['-f', 'v4l2', '-i', '/dev/video0']
+

 
 

+def is_sharing_enabled(stack: Gtk.Stack) -> bool:
+    enabled = stack.get_child_by_name('not_recording').get_first_child(
+    ).get_next_sibling().get_next_sibling().get_active()
+    assert isinstance(enabled, bool)
+    return enabled

 
 

-recording = None
+
+def find_size_display(stack: Gtk.Stack) -> Gtk.Label:
+    return stack.get_child_by_name(
+        'recording').get_first_child().get_next_sibling()
+
+
+def summarize_size(n: int) -> str:
+    if n > 100_000_000:
+        m = int(n / (1024 * 1024))
+        return f'{m}M'
+    if n > 100_000:
+        k = int(n / 1024)
+        return f'{k}K'
+    return str(n)
+
+
+def begin_monitoring_file_size(size_display: Gtk.Label, filename: str) -> None:
+    def update_size_display() -> Any:
+        done = recording is None
+        if done:
+            size_display.set_label('')
+        else:
+            try:
+                size = summarize_size(os.stat(filename).st_size)
+            except FileNotFoundError:
+                size = '--'
+            size_display.set_label(f'<big>{size}</big>')
+        return GLib.SOURCE_REMOVE if done else GLib.SOURCE_CONTINUE
+    GLib.timeout_add_seconds(1, update_size_display)

 
 
 def on_start_recording(_: Gtk.Button, stack: Gtk.Stack) -> None:
 
 
 def on_start_recording(_: Gtk.Button, stack: Gtk.Stack) -> None:

-    global recording  # pylint: disable=global-statement
+    global recording, sharing  # pylint: disable=global-statement

     assert recording is None
     assert recording is None

-    screen_size = '1366x768'  # TODO
-    command = [
-            'ffmpeg',
-            '-video_size', screen_size,
-            '-framerate', '25',
-            '-f', 'x11grab', '-i', ':0.0+0,0',
-            '-f', 'pulse', '-ac', '2', '-i', 'default',
-            'screen-recording.mkv']  # nopep8
-    # pylint: disable=consider-using-with
-    recording = subprocess.Popen(command, stdin=subprocess.PIPE)
+    assert sharing is None
+
+    filename = make_filename()
+    begin_monitoring_file_size(find_size_display(stack), filename)
+

     stack.set_visible_child_name("recording")
 
     stack.set_visible_child_name("recording")
 

+    if is_sharing_enabled(stack):
+        out_opts = [
+            '-f', 'v4l2', '-framerate', '25', '-codec:v', 'rawvideo',
+            '-pix_fmt', 'yuv420p',
+        ]
+        sharing = Stream.start(
+            ['ffmpeg', '-i', '/dev/video0']
+            + out_opts + ['/dev/video8']
+            + out_opts + ['/dev/video9'])
+        time.sleep(3)  # Bad!!  We should not be sleeping in this thread!
+
+    recording = Stream.start(
+        ['ffmpeg', '-framerate', '25'] + video_source(stack) +
+        ['-f', 'pulse', '-ac', '2', '-i', 'default', filename])
+

 
 def on_stop_recording(_: Gtk.Button, stack: Gtk.Stack) -> None:
 
 def on_stop_recording(_: Gtk.Button, stack: Gtk.Stack) -> None:

-    global recording  # pylint: disable=global-statement
+    global recording, sharing  # pylint: disable=global-statement

     assert recording is not None
     assert recording is not None

-    stdin = recording.stdin
-    assert stdin is not None
-    stdin.write(b'q')
-    stdin.flush()
-    recording.wait()
+    recording.stop()

     recording = None
     recording = None

+    if sharing is not None:
+        sharing.stop()
+        sharing = None

     stack.set_visible_child_name("not_recording")
 
 
     stack.set_visible_child_name("not_recording")
 
 


@@ -54,19 +148,35 @@ def make_button(label: str, action: Callable[[
     return button
 
 
     return button
 
 

+def make_share_control() -> Gtk.CheckButton:
+    can_share = os.path.exists('/sys/module/v4l2loopback')
+    control = Gtk.CheckButton(
+        label='Share Webcam', sensitive=can_share, active=can_share)
+    control.set_margin_start(20)
+    return control
+
+

 def on_activate(app: Gtk.Application) -> None:
     win = Gtk.ApplicationWindow(application=app)
     win.set_title('SRec')
 def on_activate(app: Gtk.Application) -> None:
     win = Gtk.ApplicationWindow(application=app)
     win.set_title('SRec')

-    stack = Gtk.Stack()
+    win.set_icon_name('srec')

 
 

-    start_recording = make_button("Start Recording", on_start_recording, stack)
-    stack.add_named(start_recording, "not_recording")
+    stack = Gtk.Stack()

 
 

-    box = Gtk.Box()
-    box.set_orientation(Gtk.Orientation.VERTICAL)
-    stop_recording = make_button("Stop Recording", on_stop_recording, stack)
-    box.append(stop_recording)
-    stack.add_named(box, "recording")
+    nr_box = Gtk.Box()
+    nr_box.set_orientation(Gtk.Orientation.VERTICAL)
+    screen = Gtk.CheckButton(label='Screen')
+    nr_box.append(screen)
+    nr_box.append(Gtk.CheckButton(label='Webcam', active=True, group=screen))
+    nr_box.append(make_share_control())
+    nr_box.append(make_button("Start Recording", on_start_recording, stack))
+    stack.add_named(nr_box, "not_recording")
+
+    r_box = Gtk.Box()
+    r_box.set_orientation(Gtk.Orientation.VERTICAL)
+    r_box.append(make_button("Stop Recording", on_stop_recording, stack))
+    r_box.append(Gtk.Label(use_markup=True, justify=Gtk.Justification.CENTER))
+    stack.add_named(r_box, "recording")

 
     win.set_child(stack)
     win.present()
 
     win.set_child(stack)
     win.present()