libmedia/VideoDecoder.h

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