Screenshot of video element using phantomjs

问题:

I am trying to take a screenshot of page with a video element using phantomjs. Currently, i set the time of the video ahead to some desired seconds (i.e. 60). Then I use page.render(output). However, the screenshot created is always black. Can anyone see the problem or verify if what Im trying to do is possible?

回答1:

Running the features.js example (using modernizr.js), you will see

>phantomjs.exe examples\features.js
Detected features (using Modernizr 2.0.6):

Supported:
  touch
  generatedcontent
  fontface
  flexbox
  canvas
  canvastext
  postmessage
  websqldatabase
  hashchange
  history
  draganddrop
  websockets
  rgba
  hsla
  multiplebgs
  backgroundsize
  borderimage
  borderradius
  boxshadow
  textshadow
  opacity
  cssanimations
  csscolumns
  cssgradients
  cssreflections
  csstransforms
  csstransitions
  localstorage
  sessionstorage
  webworkers
  applicationcache
  svg
  inlinesvg
  smil
  svgclippaths

Not supported:
  csstransforms3d
  webgl
  geolocation
  indexeddb
  video
  audio

So, yes, video is not supported.

回答2:

Analogous to Cybermaxs' answer, here are the features of PhantomJS 2:

Detected features (using Modernizr 2.8.3):

Supported:
  flexbox
  flexboxlegacy
  canvas
  canvastext
  touch
  postmessage
  websqldatabase
  indexeddb
  hashchange
  history
  draganddrop
  websockets
  rgba
  hsla
  multiplebgs
  backgroundsize
  borderimage
  borderradius
  boxshadow
  textshadow
  opacity
  cssanimations
  csscolumns
  cssgradients
  cssreflections
  csstransforms
  csstransitions
  fontface
  generatedcontent
  localstorage
  sessionstorage
  webworkers
  applicationcache
  svg
  inlinesvg
  smil
  svgclippaths

Not supported:
  webgl
  geolocation
  csstransforms3d
  video
  audio