Recherche avancée

Sur d’autres sites (8054)

• FFMPEG crop video output is black screen, sound is good [on hold]

  11 janvier 2016, par Oum Alaa

  I cropped a video using ffmpeg command line, the output is black screen, the sound is clear and good :

  ffmpeg -i Original.mp4 -t 00:00:29 -vf "crop=634:300:0:60" Done.mp4

  ffmpeg version :

  ffmpeg version 0.8.17-4:0.8.17-0ubuntu0.12.04.1, Copyright (c) 2000-2014 the Libav developers

  built on Mar 16 2015 13:26:50 with gcc 4.6.3

  video information :

  mediainfo '--Inform=Video;%Width%x%Height%' Original.mp4
  
  634x360

  Thanks in advance

• Revision 90c9ede8e6 : Limit cyclic refresh revisitng blocks at the same quantizer. For screen content

  19 juin 2015, par Alex Converse

  Changed Paths :
   Modify /vp9/encoder/vp9_aq_cyclicrefresh.c

  
  
  Limit cyclic refresh revisitng blocks at the same quantizer.

  For screen content don’t refresh a block at a quantizer higher than
  it was last coded at. PReviosuly at realtime speeds the encoder had a
  tendency to recode a block from GOLDEN with a higher Q than it was last
  coded at.

  Change-Id : Iacd561806c769dcce1a81b9827ffc70090f5ba18

• How to select a rectangle of the screen to capture by dragging mouse on transparent background with wxPython ?

  4 août 2019, par makrottk

  I’m working on building an application to capture screen with ffmpeg and would like to determine the portion of the screen to capture by dragging the mouse, drawing a rectangle and passing the arguments to the ffmpeg call.

  I’m using wxPython to build a simple GUI for the application. I’ve gotten to the point where I can draw the rectangle and get the coordinates that I want : offset and size of the selected area.

  import wx
  
  
  
  global selectionOffset, selectionSize
  
  
  
  selectionOffset = ""
  
  selectionSize = ""
  
  
  
  class SelectableFrame(wx.Frame):
  
  
  
      c1 = None
  
      c2 = None
  
  
  
      def __init__(self, parent=None, id=wx.ID_ANY, title=""):
  
          wx.Frame.__init__(self, parent, id, title, size=wx.DisplaySize(), style=wx.TRANSPARENT_WINDOW)
  
  
  
          self.Bind(wx.EVT_MOTION, self.OnMouseMove)
  
          self.Bind(wx.EVT_LEFT_DOWN, self.OnMouseDown)
  
          self.Bind(wx.EVT_LEFT_UP, self.OnMouseUp)
  
          self.Bind(wx.EVT_PAINT, self.OnPaint)
  
  
  
          self.SetCursor(wx.Cursor(wx.CURSOR_CROSS))
  
  
  
      def OnMouseMove(self, event):
  
          if event.Dragging() and event.LeftIsDown():
  
              self.c2 = event.GetPosition()
  
              self.Refresh()
  
  
  
      def OnMouseDown(self, event):
  
          self.c1 = event.GetPosition()
  
  
  
      def OnMouseUp(self, event):
  
          self.SetCursor(wx.Cursor(wx.CURSOR_ARROW))
  
          self.Destroy()
  
  
  
      def OnPaint(self, event):
  
          global selectionOffset, selectionSize
  
          if self.c1 is None or self.c2 is None: return
  
  
  
          dc = wx.PaintDC(self)
  
          dc.SetPen(wx.Pen('red', 1))
  
          dc.SetBrush(wx.Brush(wx.Colour(0, 0, 0), wx.TRANSPARENT))
  
  
  
          dc.DrawRectangle(self.c1.x, self.c1.y, self.c2.x - self.c1.x, self.c2.y - self.c1.y)
  
          selectionOffset = str(self.c1.x) + "x" + str(self.c1.y)
  
          selectionSize = str(abs(self.c2.x - self.c1.x)) + "x" + str(abs(self.c2.y - self.c1.y))
  
      def PrintPosition(self, pos):
  
          return str(pos.x) + "x" + str(pos.y)
  
  
  
  
  
  class MyApp(wx.App):
  
  
  
      def OnInit(self):
  
          frame = SelectableFrame()
  
          frame.Show(True)
  
          self.SetTopWindow(frame)
  
  
  
          return True
  
  
  
  
  
  app = MyApp(redirect=False)
  
  app.MainLoop()
  
  print("offset: " + selectionOffset + ". Screen selection size: " + selectionSize)

  The problem is I can’t get the "background" to be transparent so I can see which portion of the screen I’m really grabbing. How can I do that with wxPython ? If there’s an easier way with another GUI tool or python module I’m open to suggestions. Thanks !