content/media/video/public/nsVideoDecoder.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   3 /* ***** BEGIN LICENSE BLOCK *****
   4  * Version: ML 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
  10  *
  11  * Software distributed under the License is distributed on an "AS IS" basis,
  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is Mozilla code.
  17  *
  18  * The Initial Developer of the Original Code is the Mozilla Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 2007
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *  Chris Double <chris.double@double.co.nz>
  24  *
  25  * Alternatively, the contents of this file may be used under the terms of
  26  * either the GNU General Public License Version 2 or later (the "GPL"), or
  27  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  28  * in which case the provisions of the GPL or the LGPL are applicable instead
  29  * of those above. If you wish to allow use of your version of this file only
  30  * under the terms of either the GPL or the LGPL, and not to allow others to
  31  * use your version of this file under the terms of the MPL, indicate your
  32  * decision by deleting the provisions above and replace them with the notice
  33  * and other provisions required by the GPL or the LGPL. If you do not delete
  34  * the provisions above, a recipient may use your version of this file under
  35  * the terms of any one of the MPL, the GPL or the LGPL.
  36  *
  37  * ***** END LICENSE BLOCK ***** */
  38 #if !defined(nsVideoDecoder_h___)
  39 #define nsVideoDecoder_h___
  40
  41 #include "nsIObserver.h"
  42 #include "nsSize.h"
  43 #include "prlog.h"
  44 #include "gfxContext.h"
  45 #include "gfxRect.h"
  46 #include "nsITimer.h"
  47
  48 #ifdef PR_LOGGING
  49 extern PRLogModuleInfo* gVideoDecoderLog;
  50 #define LOG(type, msg) PR_LOG(gVideoDecoderLog, type, msg)
  51 #else
  52 #define LOG(type, msg)
  53 #endif
  54
  55 class nsHTMLMediaElement;
  56
  57 // All methods of nsVideoDecoder must be called from the main thread only
  58 // with the exception of SetRGBData. The latter can be called from any thread.
  59 class nsVideoDecoder : public nsIObserver
  60 {
  61  public:
  62   nsVideoDecoder();
  63   virtual ~nsVideoDecoder() { }
  64
  65   // Initialize the logging object
  66   static nsresult InitLogger();
  67
  68   // Perform any initialization required for the decoder.
  69   // Return PR_TRUE on successful initialisation, PR_FALSE
  70   // on failure.
  71   virtual PRBool Init();
  72
  73
  74   // Return the current URI being played or downloaded.
  75   virtual void GetCurrentURI(nsIURI** aURI) = 0;
  76
  77   // Return the time position in the video stream being
  78   // played measured in seconds.
  79   virtual float GetCurrentTime() = 0;
  80
  81   // Seek to the time position in (seconds) from the start of the video.
  82   virtual nsresult Seek(float time) = 0;
  83
  84   // Called by the element when the playback rate has been changed.
  85   // Adjust the speed of the playback, optionally with pitch correction,
  86   // when this is called.
  87   virtual nsresult PlaybackRateChanged() = 0;
  88
  89   // Return the duration of the video in seconds.
  90   virtual float GetDuration() = 0;
  91
  92   // Pause video playback.
  93   virtual void Pause() = 0;
  94
  95   // Return the current audio volume that the video plays at.
  96   // This is a value form 0 through to 1.0.
  97   virtual float GetVolume() = 0;
  98
  99   // Set the audio volume. It should be a value from 0 to 1.0.
 100   virtual void SetVolume(float volume) = 0;
 101
 102   // Returns the current video frame width and height.
 103   // If there is no video frame, returns the given default size.
 104   virtual nsIntSize GetVideoSize(nsIntSize defaultSize) = 0;
 105
 106   // Return the current framerate of the video, in frames per second.
 107   virtual double GetVideoFramerate() = 0;
 108
 109   // Start playback of a video. 'Load' must have previously been
 110   // called.
 111   virtual nsresult Play() = 0;
 112
 113   // Stop playback of a video, and stop download of video stream.
 114   virtual void Stop() = 0;
 115
 116   // Start downloading the video at the given URI. Decode
 117   // the downloaded data up to the point of the first frame
 118   // of data.
 119   virtual nsresult Load(nsIURI* aURI) = 0;
 120
 121   // Draw the latest video data. This is done
 122   // here instead of in nsVideoFrame so that the lock around the
 123   // RGB buffer doesn't have to be exposed publically.
 124   // The current video frame is drawn to fill aRect.
 125   // Called in the main thread only.
 126   virtual void Paint(gfxContext* aContext, const gfxRect& aRect);
 127
 128   // Called when the video file has completed downloading.
 129   virtual void ResourceLoaded() = 0;
 130
 131   // Return the current number of bytes loaded from the video file.
 132   // This is used for progress events.
 133   virtual PRUint32 GetBytesLoaded() = 0;
 134
 135   // Return the size of the video file in bytes.
 136   // This is used for progress events.
 137   virtual PRUint32 GetTotalBytes() = 0;
 138
 139   // Called when the HTML DOM element is bound.
 140   virtual void ElementAvailable(nsHTMLMediaElement* anElement);
 141
 142   // Called when the HTML DOM element is unbound.
 143   virtual void ElementUnavailable();
 144
 145   // Invalidate the frame.
 146   virtual void Invalidate();
 147
 148   // Update progress information.
 149   virtual void Progress();
 150
 151 protected:
 152   // Cleanup internal data structures
 153   virtual void Shutdown();
 154
 155   // Start invalidating the video frame at the interval required
 156   // by the specificed framerate (in frames per second).
 157   nsresult StartInvalidating(double aFramerate);
 158
 159   // Stop invalidating the video frame
 160   void StopInvalidating();
 161
 162   // Start timer to update download progress information.
 163   nsresult StartProgress();
 164
 165   // Stop progress information timer.
 166   nsresult StopProgress();
 167
 168   // Set the RGB width, height and framerate. The passed RGB buffer is
 169   // copied to the mRGB buffer. This also allocates the mRGB buffer if
 170   // needed.
 171   // This is the only nsVideoDecoder method that may be called
 172   // from threads other than the main thread.
 173   void SetRGBData(PRInt32 aWidth,
 174                   PRInt32 aHeight,
 175                   double aFramerate,
 176                   unsigned char* aRGBBuffer);
 177
 178 protected:
 179   // Timer used for invalidating the video
 180   nsCOMPtr<nsITimer> mInvalidateTimer;
 181
 182   // Timer used for updating progress events
 183   nsCOMPtr<nsITimer> mProgressTimer;
 184
 185   // The element is not reference counted. Instead the decoder is
 186   // notified when it is able to be used. It should only ever be
 187   // accessed from the main thread.
 188   nsHTMLMediaElement* mElement;
 189
 190   // RGB data for last decoded frame of video data.
 191   // The size of the buffer is mRGBWidth*mRGBHeight*4 bytes and
 192   // contains bytes in RGBA format.
 193   nsAutoArrayPtr<unsigned char> mRGB;
 194
 195   PRInt32 mRGBWidth;
 196   PRInt32 mRGBHeight;
 197
 198   // Has our size changed since the last repaint?
 199   PRPackedBool mSizeChanged;
 200
 201   // Lock around the video RGB, width and size data. This
 202   // is used in the decoder backend threads and the main thread
 203   // to ensure that repainting the video does not use these
 204   // values while they are out of sync (width changed but
 205   // not height yet, etc).
 206   // Backends that are updating the height, width or writing
 207   // to the RGB buffer must obtain this lock first to ensure that
 208   // the video element does not use video data or sizes that are
 209   // in the midst of being changed.
 210   PRLock* mVideoUpdateLock;
 211
 212   // Framerate of video being displayed in the element
 213   // expressed in numbers of frames per second.
 214   double mFramerate;
 215 };
 216
 217 #endif