build/android/pylib/screenshot.py

   1 # Copyright 2013 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 import logging
   6 import os
   7 import tempfile
   8 import time
   9
  10 from devil.android import device_signal
  11 from devil.utils import cmd_helper
  12
  13
  14 class VideoRecorder(object):
  15   """Records a screen capture video from an Android Device (KitKat or newer).
  16
  17   Args:
  18     device: DeviceUtils instance.
  19     host_file: Path to the video file to store on the host.
  20     megabits_per_second: Video bitrate in megabits per second. Allowed range
  21                          from 0.1 to 100 mbps.
  22     size: Video frame size tuple (width, height) or None to use the device
  23           default.
  24     rotate: If True, the video will be rotated 90 degrees.
  25   """
  26   def __init__(self, device, megabits_per_second=4, size=None,
  27                rotate=False):
  28     self._device = device
  29     self._device_file = (
  30         '%s/screen-recording.mp4' % device.GetExternalStoragePath())
  31     self._recorder = None
  32     self._recorder_stdout = None
  33     self._is_started = False
  34
  35     self._args = ['adb']
  36     if str(self._device):
  37       self._args += ['-s', str(self._device)]
  38     self._args += ['shell', 'screenrecord', '--verbose']
  39     self._args += ['--bit-rate', str(megabits_per_second * 1000 * 1000)]
  40     if size:
  41       self._args += ['--size', '%dx%d' % size]
  42     if rotate:
  43       self._args += ['--rotate']
  44     self._args += [self._device_file]
  45
  46   def Start(self):
  47     """Start recording video."""
  48     self._recorder_stdout = tempfile.mkstemp()[1]
  49     self._recorder = cmd_helper.Popen(
  50         self._args, stdout=open(self._recorder_stdout, 'w'))
  51     if not self._device.GetPids('screenrecord'):
  52       raise RuntimeError('Recording failed. Is your device running Android '
  53                          'KitKat or later?')
  54
  55   def IsStarted(self):
  56     if not self._is_started:
  57       for line in open(self._recorder_stdout):
  58         self._is_started = line.startswith('Content area is ')
  59         if self._is_started:
  60           break
  61     return self._is_started
  62
  63   def Stop(self):
  64     """Stop recording video."""
  65     os.remove(self._recorder_stdout)
  66     self._is_started = False
  67     if not self._recorder:
  68       return
  69     if not self._device.KillAll('screenrecord', signum=device_signal.SIGINT,
  70                                 quiet=True):
  71       logging.warning('Nothing to kill: screenrecord was not running')
  72     self._recorder.wait()
  73
  74   def Pull(self, host_file=None):
  75     """Pull resulting video file from the device.
  76
  77     Args:
  78       host_file: Path to the video file to store on the host.
  79     Returns:
  80       Output video file name on the host.
  81     """
  82     # TODO(jbudorick): Merge filename generation with the logic for doing so in
  83     # DeviceUtils.
  84     host_file_name = (
  85         host_file
  86         or 'screen-recording-%s.mp4' % time.strftime('%Y%m%dT%H%M%S',
  87                                                      time.localtime()))
  88     host_file_name = os.path.abspath(host_file_name)
  89     self._device.PullFile(self._device_file, host_file_name)
  90     self._device.RunShellCommand('rm -f "%s"' % self._device_file)
  91     return host_file_name