Circular Buffer file save ...

[lmitcham]

I have a Raspberry Pi Zero 2W running the Bullseye OS and using the HQ camera running at 15 fps. I am attempting to emulate the basic CircularOutput example from the Picamera2 manual on page 43.

My understanding is that the example will start a circular buffer and can run for a period of time while filling the buffer with the most recent 5 seconds of video. At some point in time, the fileoutput is given a filename to write to and the most recent 5 seconds of video is saved to that file and the file is appended with video for a period of time until a stop is issued. The resulting video will be the buffered 5 seconds plus the video that was saved between the time the filename was created and the stop command.

In practice, I am seeing only the most recent 5 seconds of video saved, from when the stop was issued.

Relevant code snippet follows:

RECORD_FOR_SECONDS  = 5
RECORD_FPS = 15

CAMERA = Picamera2()
config = CAMERA.create_video_configuration(main={"size":(2028, 1080)}, 
                                            raw={"size":(2028, 1080)})
config["transform"] = libcamera.Transform(hflip=0, vflip=1)
CAMERA.configure(config)
encoder = H264Encoder(bitrate=10000000, iperiod=15)
OUTPUT = CircularOutput(buffersize=int(RECORD_FOR_SECONDS * RECORD_FPS), outputtofile=False)
CAMERA.start_recording(encoder, OUTPUT)

A period of time > 5 seconds passes ...

VIDEO_CLIP_FILENAME = str( GUN_SERIAL_NUMBER ) + "_" + dt.datetime.now().strftime('%Y%m%d_%H%M%S')
OUTPUT.fileoutput = RAM_DISK + VIDEO_CLIP_FILENAME + FILE_TYPE_H264   # Start the LIVE recording NOW
OUTPUT.start()

Another period of time > 5 seconds passes ...

OUTPUT.stop()
CAMERA.stop_recording()

I hope that I am just missing something simple.