libmedia/VideoDecoder.h

   1 // VideoDecoder.h: Video decoding base class.
   2 //
   3 //   Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012
   4 //   Free Software Foundation, Inc.
   5 //
   6 // This program is free software; you can redistribute it and/or modify
   7 // it under the terms of the GNU General Public License as published by
   8 // the Free Software Foundation; either version 3 of the License, or
   9 // (at your option) any later version.
  10 //
  11 // This program is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with this program; if not, write to the Free Software
  18 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19
  20
  21 #ifndef GNASH_VIDEODECODER_H
  22 #define GNASH_VIDEODECODER_H
  23
  24 #include "GnashImage.h"
  25
  26 #include <boost/noncopyable.hpp>
  27
  28 // Forward declarations
  29 namespace gnash {
  30         namespace media {
  31                 class EncodedVideoFrame;
  32         }
  33 }
  34
  35 namespace gnash {
  36 namespace media {
  37
  38 /// Abstract base class for embedded video decoders.
  39 //
  40 /// This very simple design allows, but does not require,
  41 /// the use of threads in an implementation. A user of this class push a frame
  42 /// into the decoder and can subsequently pop a decoded frame. Since the pop()
  43 /// call may block, it is advisable to first call peek() to see if there is a
  44 /// frame ready to be popped.
  45 ///
  46 class VideoDecoder : public boost::noncopyable {
  47
  48 public:
  49   virtual ~VideoDecoder()
  50   {
  51   }
  52
  53   /// Push an encoded video frame into the decoder
  54   //
  55   /// @param buffer the video frame to decode
  56   ///
  57   virtual void push(const EncodedVideoFrame& buffer) = 0;
  58
  59   /// Pop a decoded frame from the decoder. THIS METHOD MAY BLOCK.
  60   //
  61   /// @return The decoded video frame, or a NULL-containing unique_ptr if an
  62   ///         error occurred.
  63   virtual std::unique_ptr<image::GnashImage> pop() = 0;
  64
  65   /// \brief
  66   /// Check whether a decoded frame is ready to be popped.
  67   //
  68   /// This method will never block.
  69   ///
  70   /// @return true if there is a frame ready to be popped.
  71   ///
  72   virtual bool peek() = 0;
  73
  74   /// Get the width in pixels of the Video
  75   //
  76   /// @return   The width of a video frame, or 0 until this is known.
  77   ///           This is used ultimately for the AS Video.width property.
  78   virtual int width() const = 0;
  79
  80   /// Get the height in pixels of the Video
  81   //
  82   /// @return   The height of a video frame, or 0 until this is known.
  83   ///           This is used ultimately for the AS Video.height property.
  84   virtual int height() const = 0;
  85
  86 };
  87
  88
  89 } // gnash.media namespace
  90 } // gnash namespace
  91
  92 #endif // __VIDEODECODER_H__