Buildroot上的Python picamera？

Question

from picamera import PiCamera在buildroot生成的linux映像上的from picamera import PiCamera給出以下錯誤。 贊賞有關如何修復的建議。 謝謝！

/usr/bin/python3.7: symbol 'mmal_port_pool_create': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_list_push_front': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_list_destroy': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_rational_to_fixed_16_16': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_status_to_string': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_list_push_back': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_list_create': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_list_insert': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_rational_equal': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_list_pop_front': can't resolve symbol
/usr/bin/python3.7: symbol 'mmal_port_type_to_string': can't resolve symbol
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.7/site-packages/picamera/__init__.py", line 72, in <module>
    from picamera.exc import (
  File "/usr/lib/python3.7/site-packages/picamera/exc.py", line 41, in <module>
    import picamera.mmal as mmal
  File "/usr/lib/python3.7/site-packages/picamera/mmal.py", line 49, in <module>
    _lib = ct.CDLL('libmmal.so')
  File "/usr/lib/python3.7/ctypes/__init__.py", line 356, in __init__
    self._handle = _dlopen(self._name, mode)
OSError: dlopen() error

Answer 1

您需要選擇rpi-userland軟件包。

我假設您在Raspberry Pi上工作，否則picamera不適合您開始。

picamera嘗試打開libmmal.so共享庫。 rpi-userland Buildroot軟件包將下載，構建和安裝該庫。

如果為python-picamera軟件包，則應將select BR2_PACKAGE_RPI_USERLAND添加到其Config.in文件中，並復制rpi-userland軟件包的依賴項。 在python-picamera.mk文件中，您應該添加PYTHON_PICAMERA_DEPENDENCIES += rpi-userland 。 這樣可以確保在啟用picamera時始終選擇並構建該程序包。

另外，如果您有可用的python-picamera軟件包，請考慮按照貢獻准則將其發送到上游。

如果您沒有為python-picamera軟件包，則可能是問題的根源。 PyPI的picamera軟件包與libmmal的特定版本鏈接，該版本可能與Buildroot中的版本不同。 這可能會導致導入模塊時看到的錯誤。

Answer 2

FWIW我最終只是使用raspistill ...

  raspistill_params = (' -n'
  + ' -ISO ' + str(iso)
  + ' -ss ' + str(shutter_speed)
  + ' -mm ' + meter_mode
  + ' -ex ' + exposure_mode
  + ' --ev ' + str(exposure_compensation)
  + ' -awb ' + awb_mode
  + ' -br ' + str(brightness)
  + ' -co ' + str(contrast)
  + ' -sa ' + str(saturation)
  + ' -sh ' + str(sharpness)
  + ' -drc ' + drc_strength
  + ' -rot ' + str(rotation) 
  + ' -q ' + str(quality) 
  + ' -w ' + str(width) 
  + ' -h ' + str(height) 
  + ' -ae ' + str(annotate_text_size) + ',0xff,0x808000 '
  + ' -a "' + annotate_text + '"'
  + ' -x GPS.GPSLatitudeRef=' + exif_lat_ref(latitude)  
  + ' -x GPS.GPSLatitude=' + exif_latlong(latitude)  
  + ' -x GPS.GPSLongitudeRef=' + exif_long_ref(longitude)  
  + ' -x GPS.GPSLongitude=' + exif_latlong(longitude) 
  + ' -o ' + filename
  )

  proc = subprocess.Popen("raspistill " + raspistill_params, shell=True, stdout=subprocess.PIPE)
  ret_val = proc.communicate() 

Answer 3

sudo apt-get update
sudo apt-get upgrade

sudo raspi-config

啟用相機並重啟