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 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /* vim:set ts=2 sw=2 sts=2 et cindent: */

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #if !defined(OggReader_h_)

 #define OggReader_h_

 #include <ogg/ogg.h>

 #include <theora/theoradec.h>

 #ifdef MOZ_TREMOR

 #include <tremor/ivorbiscodec.h>

 #else

 #include <vorbis/codec.h>

 #endif

 #include "MediaDecoderReader.h"

 #include "OggCodecState.h"

 #include "VideoUtils.h"

 #include "mozilla/Monitor.h"

 namespace mozilla {

 namespace dom {

 class TimeRanges;

 }

 }

 namespace mozilla {

 // Thread safe container to store the codec information and the serial for each

 // streams.

 class OggCodecStore

 {

   public:

     OggCodecStore();

     void Add(uint32_t serial, OggCodecState* codecState);

     bool Contains(uint32_t serial);

     OggCodecState* Get(uint32_t serial);

     bool IsKnownStream(uint32_t aSerial);

   private:

     // Maps Ogg serialnos to OggStreams.

     nsClassHashtable<nsUint32HashKey, OggCodecState> mCodecStates;

     // Protects the |mCodecStates| and the |mKnownStreams| members.

     Monitor mMonitor;

 };

 class OggReader : public MediaDecoderReader

 {

 public:

   OggReader(AbstractMediaDecoder* aDecoder);

   ~OggReader();

   virtual nsresult Init(MediaDecoderReader* aCloneDonor);

   virtual nsresult ResetDecode();

   virtual bool DecodeAudioData();

   // If the Theora granulepos has not been captured, it may read several packets

   // until one with a granulepos has been captured, to ensure that all packets

   // read have valid time info.

   virtual bool DecodeVideoFrame(bool &aKeyframeSkip,

                                   int64_t aTimeThreshold);

   virtual bool HasAudio() {

     return (mVorbisState != 0 && mVorbisState->mActive)

 #ifdef MOZ_OPUS

       || (mOpusState != 0 && mOpusState->mActive)

 #endif /* MOZ_OPUS */

       ;

   }

   virtual bool HasVideo() {

     return mTheoraState != 0 && mTheoraState->mActive;

   }

   virtual nsresult ReadMetadata(MediaInfo* aInfo,

                                 MetadataTags** aTags);

   virtual nsresult Seek(int64_t aTime, int64_t aStartTime, int64_t aEndTime, int64_t aCurrentTime);

   virtual nsresult GetBuffered(dom::TimeRanges* aBuffered, int64_t aStartTime);

 private:

   // This monitor should be taken when reading or writing to mIsChained.

   ReentrantMonitor mMonitor;

   // Specialized Reset() method to signal if the seek is

   // to the start of the stream.

   nsresult ResetDecode(bool start);

   bool HasSkeleton() {

     return mSkeletonState != 0 && mSkeletonState->mActive;

   }

   // Seeks to the keyframe preceeding the target time using available

   // keyframe indexes.

   enum IndexedSeekResult {

     SEEK_OK,          // Success.

     SEEK_INDEX_FAIL,  // Failure due to no index, or invalid index.

     SEEK_FATAL_ERROR  // Error returned by a stream operation.

   };

   IndexedSeekResult SeekToKeyframeUsingIndex(int64_t aTarget);

   // Rolls back a seek-using-index attempt, returning a failure error code.

   IndexedSeekResult RollbackIndexedSeek(int64_t aOffset);

   // Represents a section of contiguous media, with a start and end offset,

   // and the timestamps of the start and end of that range, that is cached.

   // Used to denote the extremities of a range in which we can seek quickly

   // (because it's cached).

   class SeekRange {

   public:

     SeekRange()

       : mOffsetStart(0),

         mOffsetEnd(0),

         mTimeStart(0),

         mTimeEnd(0)

     {}

     SeekRange(int64_t aOffsetStart,

               int64_t aOffsetEnd,

               int64_t aTimeStart,

               int64_t aTimeEnd)

       : mOffsetStart(aOffsetStart),

         mOffsetEnd(aOffsetEnd),

         mTimeStart(aTimeStart),

         mTimeEnd(aTimeEnd)

     {}

     bool IsNull() const {

       return mOffsetStart == 0 &&

              mOffsetEnd == 0 &&

              mTimeStart == 0 &&

              mTimeEnd == 0;

     }

     int64_t mOffsetStart, mOffsetEnd; // in bytes.

     int64_t mTimeStart, mTimeEnd; // in usecs.

   };

   // Seeks to aTarget usecs in the buffered range aRange using bisection search,

   // or to the keyframe prior to aTarget if we have video. aAdjustedTarget is

   // an adjusted version of the target used to account for Opus pre-roll, if

   // necessary. aStartTime must be the presentation time at the start of media,

   // and aEndTime the time at end of media. aRanges must be the time/byte ranges

   // buffered in the media cache as per GetSeekRanges().

   nsresult SeekInBufferedRange(int64_t aTarget,

                                int64_t aAdjustedTarget,

                                int64_t aStartTime,

                                int64_t aEndTime,

                                const nsTArray<SeekRange>& aRanges,

                                const SeekRange& aRange);

   // Seeks to before aTarget usecs in media using bisection search. If the media

   // has video, this will seek to before the keyframe required to render the

   // media at aTarget. Will use aRanges in order to narrow the bisection

   // search space. aStartTime must be the presentation time at the start of

   // media, and aEndTime the time at end of media. aRanges must be the time/byte

   // ranges buffered in the media cache as per GetSeekRanges().

   nsresult SeekInUnbuffered(int64_t aTarget,

                             int64_t aStartTime,

                             int64_t aEndTime,

                             const nsTArray<SeekRange>& aRanges);

   // Get the end time of aEndOffset. This is the playback position we'd reach

   // after playback finished at aEndOffset.

   int64_t RangeEndTime(int64_t aEndOffset);

   // Get the end time of aEndOffset, without reading before aStartOffset.

   // This is the playback position we'd reach after playback finished at

   // aEndOffset. If bool aCachedDataOnly is true, then we'll only read

   // from data which is cached in the media cached, otherwise we'll do

   // regular blocking reads from the media stream. If bool aCachedDataOnly

   // is true, this can safely be called on the main thread, otherwise it

   // must be called on the state machine thread.

   int64_t RangeEndTime(int64_t aStartOffset,

                        int64_t aEndOffset,

                        bool aCachedDataOnly);

   // Get the start time of the range beginning at aOffset. This is the start

   // time of the first frame and or audio sample we'd be able to play if we

   // started playback at aOffset.

   int64_t RangeStartTime(int64_t aOffset);

   // Performs a seek bisection to move the media stream's read cursor to the

   // last ogg page boundary which has end time before aTarget usecs on both the

   // Theora and Vorbis bitstreams. Limits its search to data inside aRange;

   // i.e. it will only read inside of the aRange's start and end offsets.

   // aFuzz is the number of usecs of leniency we'll allow; we'll terminate the

   // seek when we land in the range (aTime - aFuzz, aTime) usecs.

   nsresult SeekBisection(int64_t aTarget,

                          const SeekRange& aRange,

                          uint32_t aFuzz);

   // Returns true if the serial number is for a stream we encountered

   // while reading metadata. Call on the main thread only.

   bool IsKnownStream(uint32_t aSerial);

   // Fills aRanges with SeekRanges denoting the sections of the media which

   // have been downloaded and are stored in the media cache. The reader

   // monitor must must be held with exactly one lock count. The MediaResource

   // must be pinned while calling this.

   nsresult GetSeekRanges(nsTArray<SeekRange>& aRanges);

   // Returns the range in which you should perform a seek bisection if

   // you wish to seek to aTarget usecs, given the known (buffered) byte ranges

   // in aRanges. If aExact is true, we only return an exact copy of a

   // range in which aTarget lies, or a null range if aTarget isn't contained

   // in any of the (buffered) ranges. Otherwise, when aExact is false,

   // we'll construct the smallest possible range we can, based on the times

   // and byte offsets known in aRanges. We can then use this to minimize our

   // bisection's search space when the target isn't in a known buffered range.

   SeekRange SelectSeekRange(const nsTArray<SeekRange>& aRanges,

                             int64_t aTarget,

                             int64_t aStartTime,

                             int64_t aEndTime,

                             bool aExact);

 private:

   // Decodes a packet of Vorbis data, and inserts its samples into the

   // audio queue.

   nsresult DecodeVorbis(ogg_packet* aPacket);

   // Decodes a packet of Opus data, and inserts its samples into the

   // audio queue.

   nsresult DecodeOpus(ogg_packet* aPacket);

   // Decodes a packet of Theora data, and inserts its frame into the

   // video queue. May return NS_ERROR_OUT_OF_MEMORY. Caller must have obtained

   // the reader's monitor. aTimeThreshold is the current playback position

   // in media time in microseconds. Frames with an end time before this will

   // not be enqueued.

   nsresult DecodeTheora(ogg_packet* aPacket, int64_t aTimeThreshold);

   // Read a page of data from the Ogg file. Returns true if a page has been

   // read, false if the page read failed or end of file reached.

   bool ReadOggPage(ogg_page* aPage);

   // Reads and decodes header packets for aState, until either header decode

   // fails, or is complete. Initializes the codec state before returning.

   // Returns true if reading headers and initializtion of the stream

   // succeeds.

   bool ReadHeaders(OggCodecState* aState);

   // Reads the next link in the chain.

   bool ReadOggChain();

   // Set this media as being a chain and notifies the state machine that the

   // media is no longer seekable.

   void SetChained(bool aIsChained);

   // Returns the next Ogg packet for an bitstream/codec state. Returns a

   // pointer to an ogg_packet on success, or nullptr if the read failed.

   // The caller is responsible for deleting the packet and its |packet| field.

   ogg_packet* NextOggPacket(OggCodecState* aCodecState);

   // Fills aTracks with the serial numbers of each active stream, for use by

   // various SkeletonState functions.

   void BuildSerialList(nsTArray<uint32_t>& aTracks);

   OggCodecStore mCodecStore;

   // Decode state of the Theora bitstream we're decoding, if we have video.

   TheoraState* mTheoraState;

   // Decode state of the Vorbis bitstream we're decoding, if we have audio.

   VorbisState* mVorbisState;

 #ifdef MOZ_OPUS

   // Decode state of the Opus bitstream we're decoding, if we have one.

   OpusState *mOpusState;

   // Represents the user pref media.opus.enabled at the time our

   // contructor was called. We can't check it dynamically because

   // we're not on the main thread;

   bool mOpusEnabled;

 #endif /* MOZ_OPUS */

   // Decode state of the Skeleton bitstream.

   SkeletonState* mSkeletonState;

   // Ogg decoding state.

   ogg_sync_state mOggState;

   // Vorbis/Opus/Theora data used to compute timestamps. This is written on the

   // decoder thread and read on the main thread. All reading on the main

   // thread must be done after metadataloaded. We can't use the existing

   // data in the codec states due to threading issues. You must check the

   // associated mTheoraState or mVorbisState pointer is non-null before

   // using this codec data.

   uint32_t mVorbisSerial;

   uint32_t mOpusSerial;

   uint32_t mTheoraSerial;

   vorbis_info mVorbisInfo;

   int mOpusPreSkip;

   th_info mTheoraInfo;

   // The picture region inside Theora frame to be displayed, if we have

   // a Theora video track.

   nsIntRect mPicture;

   // True if we are decoding a chained ogg. Reading or writing to this member

   // should be done with |mMonitor| acquired.

   bool mIsChained;

   // Number of audio frames decoded so far.

   int64_t mDecodedAudioFrames;

 };

 } // namespace mozilla

 #endif