Two virtual cameras

[srec] / srec.py

diff --git a/srec.py b/srec.py
index 01b5a8ca7ec1200aff08d41fe85e718f224f5341..7421c74cc764f8642c3d4a5766c890ade5e044d6 100644 (file)
--- a/srec.py
+++ b/srec.py
@@ -4,10 +4,14 @@
 # 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 sys
+import time
 from typing import Any, Callable
 
 import gi
@@ -19,12 +23,27 @@ from gi.repository import GLib  # nopep8 pylint: disable=wrong-import-position
 
 
 @dataclass
-class Recording:
-    filename: str
+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: Recording | None = None
+recording: Stream | None = None
+sharing: Stream | None = None
 
 
 def make_filename() -> str:
@@ -39,9 +58,18 @@ def make_filename() -> str:
 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
+
+
 def find_size_display(stack: Gtk.Stack) -> Gtk.Label:
     return stack.get_child_by_name(
         'recording').get_first_child().get_next_sibling()
@@ -57,40 +85,50 @@ def summarize_size(n: int) -> str:
     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:
-    global recording  # pylint: disable=global-statement
+    global recording, sharing  # pylint: disable=global-statement
     assert recording is None
+    assert sharing is None
 
     filename = make_filename()
-    size_display = find_size_display(stack)
-
-    def update_size_display() -> Any:
-        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 recording is None else GLib.SOURCE_CONTINUE
-    GLib.timeout_add_seconds(1, update_size_display)
+    begin_monitoring_file_size(find_size_display(stack), filename)
 
-    command = (['ffmpeg', '-framerate', '25'] + video_source(stack) +
-               ['-f', 'pulse', '-ac', '2', '-i', 'default', filename])
-    # pylint: disable=consider-using-with
-    recording = Recording(
-        filename=filename,
-        process=subprocess.Popen(command, stdin=subprocess.PIPE))
     stack.set_visible_child_name("recording")
 
+    if is_sharing_enabled(stack):
+        sharing = Stream.start(
+            ['ffmpeg', '-i', '/dev/video0', '-f', 'v4l2', '-framerate', '25',
+             '-codec:v', 'rawvideo', '-pix_fmt', 'yuv420p', '/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:
-    global recording  # pylint: disable=global-statement
+    global recording, sharing  # pylint: disable=global-statement
     assert recording is not None
-    stdin = recording.process.stdin
-    assert stdin is not None
-    stdin.write(b'q')
-    stdin.flush()
-    recording.process.wait()
+    recording.stop()
     recording = None
+    if sharing is not None:
+        sharing.stop()
+        sharing = None
     stack.set_visible_child_name("not_recording")