Live Streams Component (#21473)

* initial commit of streams

* refactor stream component

* refactor so stream formats are not considered a platform

* initial test and minor refactor

* fix linting

* update requirements

* need av in tests as well

* fix import in class def vs method

* fix travis and docker builds

* address code review comments

* fix logger, add stream start/stop logs, listen to HASS stop

* address additional code review comments

* beef up tests

* fix tests

* fix lint

* add stream_source to onvif camera

* address pr comments

* add keepalive to camera play_stream service

* remove keepalive and move import

* implement registry and have output provider remove itself from stream after idle, set libav log level to error

tests/components/stream/common.py

@@ -0,0 +1,63 @@
+"""Collection of test helpers."""
+import io
+
+from homeassistant.components.stream import Stream
+from homeassistant.components.stream.const import (
+    DOMAIN, ATTR_STREAMS)
+
+
+def generate_h264_video():
+    """
+    Generate a test video.
+
+    See: http://docs.mikeboers.com/pyav/develop/cookbook/numpy.html
+    """
+    import numpy as np
+    import av
+
+    duration = 5
+    fps = 24
+    total_frames = duration * fps
+
+    output = io.BytesIO()
+    output.name = 'test.ts'
+    container = av.open(output, mode='w')
+
+    stream = container.add_stream('libx264', rate=fps)
+    stream.width = 480
+    stream.height = 320
+    stream.pix_fmt = 'yuv420p'
+
+    for frame_i in range(total_frames):
+
+        img = np.empty((480, 320, 3))
+        img[:, :, 0] = 0.5 + 0.5 * np.sin(
+            2 * np.pi * (0 / 3 + frame_i / total_frames))
+        img[:, :, 1] = 0.5 + 0.5 * np.sin(
+            2 * np.pi * (1 / 3 + frame_i / total_frames))
+        img[:, :, 2] = 0.5 + 0.5 * np.sin(
+            2 * np.pi * (2 / 3 + frame_i / total_frames))
+
+        img = np.round(255 * img).astype(np.uint8)
+        img = np.clip(img, 0, 255)
+
+        frame = av.VideoFrame.from_ndarray(img, format='rgb24')
+        for packet in stream.encode(frame):
+            container.mux(packet)
+
+    # Flush stream
+    for packet in stream.encode():
+        container.mux(packet)
+
+    # Close the file
+    container.close()
+    output.seek(0)
+
+    return output
+
+
+def preload_stream(hass, stream_source):
+    """Preload a stream for use in tests."""
+    stream = Stream(hass, stream_source)
+    hass.data[DOMAIN][ATTR_STREAMS][stream_source] = stream
+    return stream