Tomi ValkeinenandLaurent Pinchart
9e4388cca5
Move MappedFrameBuffer to libcamera.utils, instead of extending FrameBuffer class with a new mmap() method. This keeps us more aligned to the C++ API. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
75 lines
1.9 KiB
Python
75 lines
1.9 KiB
Python
# SPDX-License-Identifier: LGPL-2.1-or-later
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# Copyright (C) 2022, Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
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class MappedFrameBuffer:
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def __init__(self, fb):
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self.__fb = fb
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def __enter__(self):
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import os
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import mmap
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fb = self.__fb
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# Collect information about the buffers
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bufinfos = {}
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for i in range(fb.num_planes):
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fd = fb.fd(i)
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if fd not in bufinfos:
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buflen = os.lseek(fd, 0, os.SEEK_END)
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bufinfos[fd] = {'maplen': 0, 'buflen': buflen}
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else:
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buflen = bufinfos[fd]['buflen']
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if fb.offset(i) > buflen or fb.offset(i) + fb.length(i) > buflen:
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raise RuntimeError(f'plane is out of buffer: buffer length={buflen}, ' +
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f'plane offset={fb.offset(i)}, plane length={fb.length(i)}')
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bufinfos[fd]['maplen'] = max(bufinfos[fd]['maplen'], fb.offset(i) + fb.length(i))
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# mmap the buffers
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maps = []
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for fd, info in bufinfos.items():
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map = mmap.mmap(fd, info['maplen'], mmap.MAP_SHARED, mmap.PROT_READ | mmap.PROT_WRITE)
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info['map'] = map
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maps.append(map)
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self.__maps = tuple(maps)
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# Create memoryviews for the planes
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planes = []
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for i in range(fb.num_planes):
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fd = fb.fd(i)
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info = bufinfos[fd]
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mv = memoryview(info['map'])
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start = fb.offset(i)
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end = fb.offset(i) + fb.length(i)
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mv = mv[start:end]
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planes.append(mv)
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self.__planes = tuple(planes)
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return self
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def __exit__(self, exc_type, exc_value, exc_traceback):
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for p in self.__planes:
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p.release()
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for mm in self.__maps:
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mm.close()
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@property
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def planes(self):
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return self.__planes
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