gecko/content/media/ogg/nsOggCodecState.h

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/* ***** BEGIN LICENSE BLOCK *****
 * Version: ML 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla code.
 *
 * The Initial Developer of the Original Code is the Mozilla Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *  Chris Double <chris.double@double.co.nz>
 *  Chris Pearce <chris@pearce.org.nz>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * ***** END LICENSE BLOCK ***** */
#if !defined(nsOggCodecState_h_)
#define nsOggCodecState_h_

#include <ogg/ogg.h>
#include <theora/theoradec.h>
#include <vorbis/codec.h>
#include <nsDeque.h>
#include <nsTArray.h>
#include <nsClassHashtable.h>
#include "VideoUtils.h"

class OggPageDeallocator : public nsDequeFunctor {
  virtual void* operator() (void* aPage) {
    ogg_page* p = static_cast<ogg_page*>(aPage);
    delete p->header;
    delete p;
    return nsnull;
  }
};

// A queue of ogg_pages. When we read a page, and it's not from the bitstream
// which we're looking for a page for, we buffer the page in the nsOggCodecState,
// rather than pushing it immediately into the ogg_stream_state object. This
// is because if we're skipping up to the next keyframe in very large frame
// sized videos, there may be several megabytes of data between keyframes,
// and the ogg_stream_state would end up resizing its buffer every time we
// added a new 4K page to the bitstream, which kills performance on Windows.
class nsPageQueue : private nsDeque {
public:
  nsPageQueue() : nsDeque(new OggPageDeallocator()) {}
  ~nsPageQueue() { Erase(); }
  PRBool IsEmpty() { return nsDeque::GetSize() == 0; }
  void Append(ogg_page* aPage);
  ogg_page* PopFront() { return static_cast<ogg_page*>(nsDeque::PopFront()); }
  ogg_page* PeekFront() { return static_cast<ogg_page*>(nsDeque::PeekFront()); }
  void Erase() { nsDeque::Erase(); }
};

// Encapsulates the data required for decoding an ogg bitstream and for
// converting granulepos to timestamps.
class nsOggCodecState {
 public:
  // Ogg types we know about
  enum CodecType {
    TYPE_VORBIS=0,
    TYPE_THEORA=1,
    TYPE_SKELETON=2,
    TYPE_UNKNOWN=3
  };

 public:
  nsOggCodecState(ogg_page* aBosPage);
  virtual ~nsOggCodecState();
  
  // Factory for creating nsCodecStates.
  static nsOggCodecState* Create(ogg_page* aPage);
  
  virtual CodecType GetType() { return TYPE_UNKNOWN; }
  
  // Reads a header packet. Returns PR_TRUE when last header has been read.
  virtual PRBool DecodeHeader(ogg_packet* aPacket) {
    return (mDoneReadingHeaders = PR_TRUE);
  }

  // Returns the end time that a granulepos represents.
  virtual PRInt64 Time(PRInt64 granulepos) { return -1; }

  // Returns the start time that a granulepos represents.
  virtual PRInt64 StartTime(PRInt64 granulepos) { return -1; }

  // Initializes the codec state.
  virtual PRBool Init();

  // Returns PR_TRUE when this bitstream has finished reading all its
  // header packets.
  PRBool DoneReadingHeaders() { return mDoneReadingHeaders; }

  // Deactivates the bitstream. Only the primary video and audio bitstreams
  // should be active.
  void Deactivate() { mActive = PR_FALSE; }

  // Resets decoding state.
  virtual nsresult Reset();

  // Clones a page and adds it to our buffer of pages which we'll insert to
  // the bitstream at a later time (using PageInFromBuffer()). Memory stored in
  // cloned pages is freed when Reset() or PageInFromBuffer() are called.
  inline void AddToBuffer(ogg_page* aPage) { mBuffer.Append(aPage); }

  // Returns PR_TRUE if we had a buffered page and we successfully inserted it
  // into the bitstream.
  PRBool PageInFromBuffer();

  // Number of packets read.  
  PRUint64 mPacketCount;

  // Serial number of the bitstream.
  PRUint32 mSerial;

  // Ogg specific state.
  ogg_stream_state mState;

  // Buffer of pages which we've not yet inserted into the ogg_stream_state.
  nsPageQueue mBuffer;

  // Is the bitstream active; whether we're decoding and playing this bitstream.
  PRPackedBool mActive;
  
  // PR_TRUE when all headers packets have been read.
  PRPackedBool mDoneReadingHeaders;
};

class nsVorbisState : public nsOggCodecState {
public:
  nsVorbisState(ogg_page* aBosPage);
  virtual ~nsVorbisState();

  virtual CodecType GetType() { return TYPE_VORBIS; }
  virtual PRBool DecodeHeader(ogg_packet* aPacket);
  virtual PRInt64 Time(PRInt64 granulepos);
  virtual PRBool Init();
  virtual nsresult Reset();

  vorbis_info mInfo;
  vorbis_comment mComment;
  vorbis_dsp_state mDsp;
  vorbis_block mBlock;
};

class nsTheoraState : public nsOggCodecState {
public:
  nsTheoraState(ogg_page* aBosPage);
  virtual ~nsTheoraState();

  virtual CodecType GetType() { return TYPE_THEORA; }
  virtual PRBool DecodeHeader(ogg_packet* aPacket);
  virtual PRInt64 Time(PRInt64 granulepos);
  virtual PRInt64 StartTime(PRInt64 granulepos);
  virtual PRBool Init();

  // Returns the maximum number of milliseconds which a keyframe can be offset
  // from any given interframe.
  PRInt64 MaxKeyframeOffset();

  th_info mInfo;
  th_comment mComment;
  th_setup_info *mSetup;
  th_dec_ctx* mCtx;

  // Frame duration in ms.
  PRUint32 mFrameDuration;

  // Number of frames per second.
  float mFrameRate;

  float mPixelAspectRatio;
};

// Constructs a 32bit version number out of two 16 bit major,minor
// version numbers.
#define SKELETON_VERSION(major, minor) (((major)<<16)|(minor))

class nsSkeletonState : public nsOggCodecState {
public:
  nsSkeletonState(ogg_page* aBosPage);
  virtual ~nsSkeletonState();
  virtual CodecType GetType() { return TYPE_SKELETON; }
  virtual PRBool DecodeHeader(ogg_packet* aPacket);
  virtual PRInt64 Time(PRInt64 granulepos) { return -1; }
  virtual PRBool Init() { return PR_TRUE; }


  // Stores the offset of the page on which a keyframe starts,
  // and its presentation time.
  class nsKeyPoint {
  public:
    nsKeyPoint()
      : mOffset(PR_INT64_MAX),
        mTime(PR_INT64_MAX) {}

    nsKeyPoint(PRInt64 aOffset, PRInt64 aTime)
      : mOffset(aOffset),
        mTime(aTime) {}

    // Offset from start of segment/link-in-the-chain in bytes.
    PRInt64 mOffset;

    // Presentation time in ms.
    PRInt64 mTime;

    PRBool IsNull() {
      return mOffset == PR_INT64_MAX &&
             mTime == PR_INT64_MAX;
    }
  };

  // Stores a keyframe's byte-offset, presentation time and the serialno
  // of the stream it belongs to.
  class nsSeekTarget {
  public:
    nsSeekTarget() : mSerial(0) {}
    nsKeyPoint mKeyPoint;
    PRUint32 mSerial;
    PRBool IsNull() {
      return mKeyPoint.IsNull() &&
             mSerial == 0;
    }
  };

  // Determines from the seek index the keyframe which you must seek back to
  // in order to get all keyframes required to render all streams with
  // serialnos in aTracks, at time aTarget.
  nsresult IndexedSeekTarget(PRInt64 aTarget,
                             nsTArray<PRUint32>& aTracks,
                             nsSeekTarget& aResult);

  PRBool HasIndex() const {
    return mIndex.Count() > 0;
  }

  // Returns the duration of the active tracks in the media, if we have
  // an index. aTracks must be filled with the serialnos of the active tracks.
  // The duration is calculated as the greatest end time of all active tracks,
  // minus the smalled start time of all the active tracks.
  nsresult GetDuration(const nsTArray<PRUint32>& aTracks, PRInt64& aDuration);

private:

  // Decodes an index packet. Returns PR_FALSE on failure.
  PRBool DecodeIndex(ogg_packet* aPacket);

  // Gets the keypoint you must seek to in order to get the keyframe required
  // to render the stream at time aTarget on stream with serial aSerialno.
  nsresult IndexedSeekTargetForTrack(PRUint32 aSerialno,
                                     PRInt64 aTarget,
                                     nsKeyPoint& aResult);

  // Version of the decoded skeleton track, as per the SKELETON_VERSION macro.
  PRUint32 mVersion;

  // Length of the resource in bytes.
  PRInt64 mLength;

  // Stores the keyframe index and duration information for a particular
  // stream.
  class nsKeyFrameIndex {
  public:

    nsKeyFrameIndex(PRInt64 aStartTime, PRInt64 aEndTime) 
      : mStartTime(aStartTime),
        mEndTime(aEndTime)
    {
      MOZ_COUNT_CTOR(nsKeyFrameIndex);
    }

    ~nsKeyFrameIndex() {
      MOZ_COUNT_DTOR(nsKeyFrameIndex);
    }

    void Add(PRInt64 aOffset, PRInt64 aTimeMs) {
      mKeyPoints.AppendElement(nsKeyPoint(aOffset, aTimeMs));
    }

    const nsKeyPoint& Get(PRUint32 aIndex) const {
      return mKeyPoints[aIndex];
    }

    PRUint32 Length() const {
      return mKeyPoints.Length();
    }

    // Presentation time of the first sample in this stream in ms.
    const PRInt64 mStartTime;

    // End time of the last sample in this stream in ms.
    const PRInt64 mEndTime;

  private:
    nsTArray<nsKeyPoint> mKeyPoints;
  };

  // Maps Ogg serialnos to the index-keypoint list.
  nsClassHashtable<nsUint32HashKey, nsKeyFrameIndex> mIndex;
};

#endif