小编Sof*_*ent的帖子

我将在 javascript 中从视频 url 生成视频缩略图。我需要通过ajax来完成。所以我遵循了这个方法。

var src = thumbnail; ///video url not youtube or vimeo,just video on server
var video = document.createElement('video');

video.src = src;

video.width = 360;
video.height = 240;

var canvas = document.createElement('canvas');
canvas.width = 360; 
canvas.height = 240;
var context = canvas.getContext('2d');

context.drawImage(video, 0, 0, canvas.width, canvas.height);
var dataURI = canvas.toDataURL('image/jpeg');
html += '<figure>';
html += '<img src="' + dataURI + '' + '" alt="' + item.description + '" />';
html += '<figurecaption>'+item.description+'</figurecaption>'
html += '</figure>';

但我得到的只是黑色图像。我猜是因为负载问题，但找不到解决方案。期待您的回音。 …

我正在尝试使用此命令运行django项目.

python manage.py runserver 8080

但每次我试图跑,我都面临着这样的错误.

Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "/Users/admin/.virtualenvs/myprojectname/lib/python2.7/site-packages/django/core/management/__init__.py", line 353, in execute_from_command_line
utility.execute()
File "/Users/admin/.virtualenvs/myprojectname/lib/python2.7/site-packages/django/core/management/__init__.py", line 327, in execute
django.setup()
File "/Users/admin/.virtualenvs/myprojectname/lib/python2.7/site-packages/django/__init__.py", line 18, in setup
apps.populate(settings.INSTALLED_APPS)
File "/Users/admin/.virtualenvs/myprojectname/lib/python2.7/site-packages/django/apps/registry.py", line 108, in populate
app_config.import_models(all_models)
File "/Users/admin/.virtualenvs/myprojectname/lib/python2.7/site-packages/django/apps/config.py", line 202, in import_models
self.models_module = import_module(models_module_name)
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py", line 37, in    import_module
__import__(name)
File "/Users/admin/.virtualenvs/myprojectname/lib/python2.7/site-packages/django/contrib/auth/models.py", line 4, in <module>
from django.contrib.auth.base_user import AbstractBaseUser, BaseUserManager
File "/Users/admin/.virtualenvs/myprojectname/lib/python2.7/site-packages/django/contrib/auth/base_user.py", line 49, in <module>
class …