Buildroot上的Python picamera？

Question

在buildroot生成的linux映像上，from picamera import PiCamera给出了python3.7中的以下错误。感谢关于如何修复的建议。谢谢！

/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

sudo apt-get update
sudo apt-get upgrade

sudo raspi-config

启用摄像头并重新启动

Answer 2

您需要选择rpi-userland包。在

我假设你在做覆盆子派，否则picamera不适合你。在

picamera试图打开诽谤罪共享库。rpi-userlandBuildroot包将下载、生成和安装此库。在

如果为python-picamera创建了Buildroot包，则应将select BR2_PACKAGE_RPI_USERLAND添加到其Config.in文件中，并复制rpi userland包的依赖项。在python-picamera.mk文件中，应该添加PYTHON_PICAMERA_DEPENDENCIES += rpi-userland。这将确保在启用picamera时始终选择并构建包。在

另外，如果您有一个正在工作的python-picamera包，请考虑将其发送到contribution guidelines之后的上游。在

如果没有为python-picamera生成Buildroot包，这可能是问题的根源。PyPI中的picamera包与libmmal的特定版本链接，该版本可能与Buildroot中的版本不同。这可能会导致导入模块时看到的错误。在

Answer 3

我最后只能用拉斯皮斯蒂尔。。。在

  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()