Support writing HLS using PyavOutput

There were just a couple of missing things:

1. We need to be able to pass in options such as hls_time etc.
2. Packets must correctly flag when they are keyframes.

You can make a PyavOutput write HLS using, for example:

options = {
    "hls_time": "5",
    "hls_list_size": "8",
    "hls_flags": "delete_segments+append_list+independent_segments"
}
output = PyavOutput("/dev/shm/cam_hls/live.m3u8", format='hls', options=options)

Signed-off-by: David Plowman <[email protected]>

Author: davidplowman

picamera2/outputs/pyavoutput.py

@@ -18,12 +18,13 @@ class PyavOutput(Output):
     back in.
     """
 
-    def __init__(self, output_name, format=None, pts=None):
+    def __init__(self, output_name, format=None, pts=None, options=None):
         super().__init__(pts=pts)
         self._output_name = output_name
         self._format = format
         self._streams = {}
         self._container = None
+        self._options = options
         # A user can set this to get notifications of failures.
         self.error_callback = None
 
@@ -40,7 +41,7 @@ def _add_stream(self, encoder_stream, codec_name, **kwargs):
 
     def start(self):
         """Start the PyavOutput."""
-        self._container = av.open(self._output_name, "w", format=self._format)
+        self._container = av.open(self._output_name, "w", format=self._format, options=self._options)
         super().start()
 
     def stop(self):
@@ -64,6 +65,7 @@ def outputframe(self, frame, keyframe=True, timestamp=None, packet=None, audio=F
                 packet.dts = timestamp
                 packet.pts = timestamp
                 packet.time_base = Fraction(1, 1000000)
+                packet.is_keyframe = keyframe
                 packet.stream = self._streams["video"]
             else:
                 # We can copy the packet we are given, updating the stream to be our version, and amending
@@ -75,6 +77,7 @@ def outputframe(self, frame, keyframe=True, timestamp=None, packet=None, audio=F
                 new_packet.dts = timestamp
                 new_packet.pts = timestamp
                 new_packet.time_base = Fraction(1, 1000000)
+                new_packet.is_keyframe = keyframe
                 packet = new_packet
 
             try: