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authorTomi Valkeinen <tomi.valkeinen@ideasonboard.com>2022-06-08 10:24:16 +0300
committerLaurent Pinchart <laurent.pinchart@ideasonboard.com>2022-06-08 20:16:19 +0300
commitab21acb9c0efa4bef944c17ef3ac3ed8550a81d1 (patch)
treed8ce2104e431c5deb9d0f9626922f455fb56eacc /src/py/examples/simple-capture.py
parentd0b310b465a625f95491078011086728000f427f (diff)
py: examples: Add simple-capture.py
Add an example to showcase the more-or-less minimal capture case. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Reviewed-by: Jacopo Mondi <jacopo@jmondi.org> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
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+#!/usr/bin/env python3
+
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
+
+# A simple capture example showing:
+# - How to setup the camera
+# - Capture certain number of frames in a blocking manner
+# - How to stop the camera
+#
+# This simple example is, in many ways, too simple. The purpose of the example
+# is to introduce the concepts. A more realistic example is given in
+# simple-continuous-capture.py.
+
+import argparse
+import libcamera as libcam
+import sys
+
+# Number of frames to capture
+TOTAL_FRAMES = 30
+
+
+def main():
+ parser = argparse.ArgumentParser()
+ parser.add_argument('-c', '--camera', type=str, default='1',
+ help='Camera index number (starting from 1) or part of the name')
+ parser.add_argument('-f', '--format', type=str, help='Pixel format')
+ parser.add_argument('-s', '--size', type=str, help='Size ("WxH")')
+ args = parser.parse_args()
+
+ cm = libcam.CameraManager.singleton()
+
+ try:
+ if args.camera.isnumeric():
+ cam_idx = int(args.camera)
+ cam = next((cam for i, cam in enumerate(cm.cameras) if i + 1 == cam_idx))
+ else:
+ cam = next((cam for cam in cm.cameras if args.camera in cam.id))
+ except Exception:
+ print(f'Failed to find camera "{args.camera}"')
+ return -1
+
+ # Acquire the camera for our use
+
+ ret = cam.acquire()
+ assert ret == 0
+
+ # Configure the camera
+
+ cam_config = cam.generate_configuration([libcam.StreamRole.Viewfinder])
+
+ stream_config = cam_config.at(0)
+
+ if args.format:
+ fmt = libcam.PixelFormat(args.format)
+ stream_config.pixel_format = fmt
+
+ if args.size:
+ w, h = [int(v) for v in args.size.split('x')]
+ stream_config.size = libcam.Size(w, h)
+
+ ret = cam.configure(cam_config)
+ assert ret == 0
+
+ print(f'Capturing {TOTAL_FRAMES} frames with {stream_config}')
+
+ stream = stream_config.stream
+
+ # Allocate the buffers for capture
+
+ allocator = libcam.FrameBufferAllocator(cam)
+ ret = allocator.allocate(stream)
+ assert ret > 0
+
+ num_bufs = len(allocator.buffers(stream))
+
+ # Create the requests and assign a buffer for each request
+
+ reqs = []
+ for i in range(num_bufs):
+ # Use the buffer index as the cookie
+ req = cam.create_request(i)
+
+ buffer = allocator.buffers(stream)[i]
+ ret = req.add_buffer(stream, buffer)
+ assert ret == 0
+
+ reqs.append(req)
+
+ # Start the camera
+
+ ret = cam.start()
+ assert ret == 0
+
+ # frames_queued and frames_done track the number of frames queued and done
+
+ frames_queued = 0
+ frames_done = 0
+
+ # Queue the requests to the camera
+
+ for req in reqs:
+ ret = cam.queue_request(req)
+ assert ret == 0
+ frames_queued += 1
+
+ # The main loop. Wait for the queued Requests to complete, process them,
+ # and re-queue them again.
+
+ while frames_done < TOTAL_FRAMES:
+ # cm.get_ready_requests() blocks until there is an event and returns
+ # all the ready requests. Here we should almost always get a single
+ # Request, but in some cases there could be multiple or none.
+
+ reqs = cm.get_ready_requests()
+
+ for req in reqs:
+ frames_done += 1
+
+ buffers = req.buffers
+
+ # A ready Request could contain multiple buffers if multiple streams
+ # were being used. Here we know we only have a single stream,
+ # and we use next(iter()) to get the first and only buffer.
+
+ assert len(buffers) == 1
+
+ stream, fb = next(iter(buffers.items()))
+
+ # Here we could process the received buffer. In this example we only
+ # print a few details below.
+
+ meta = fb.metadata
+
+ print("seq {:3}, bytes {}, frames queued/done {:3}/{:<3}"
+ .format(meta.sequence,
+ '/'.join([str(p.bytes_used) for p in meta.planes]),
+ frames_queued, frames_done))
+
+ # If we want to capture more frames we need to queue more Requests.
+ # We could create a totally new Request, but it is more efficient
+ # to reuse the existing one that we just received.
+ if frames_queued < TOTAL_FRAMES:
+ req.reuse()
+ cam.queue_request(req)
+ frames_queued += 1
+
+ # Stop the camera
+
+ ret = cam.stop()
+ assert ret == 0
+
+ # Release the camera
+
+ ret = cam.release()
+ assert ret == 0
+
+ return 0
+
+
+if __name__ == '__main__':
+ sys.exit(main())