The Tor Browser: content/media/ogg/OggCodecState.h@8bccb770b82d (annotated)

content/media/ogg/OggCodecState.h@8bccb770b82d (annotated)

content/media/ogg/OggCodecState.h

Wed, 31 Dec 2014 13:27:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 13:27:57 +0100
branch: TOR_BUG_3246
changeset 6: 8bccb770b82d
permissions: -rw-r--r--

Ignore runtime configuration files generated during quality assurance.

 /* -*- 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(OggCodecState_h_)
 #define OggCodecState_h_
 #include <ogg/ogg.h>
 #include <theora/theoradec.h>
 #ifdef MOZ_TREMOR
 #include <tremor/ivorbiscodec.h>
 #else
 #include <vorbis/codec.h>
 #endif
 #ifdef MOZ_OPUS
 #include <opus/opus.h>
 #include "opus/opus_multistream.h"
 // For MOZ_SAMPLE_TYPE_*
 #include "mozilla/dom/HTMLMediaElement.h"
 #include "MediaDecoderStateMachine.h"
 #include "MediaDecoderReader.h"
 #endif
 #include <nsAutoRef.h>
 #include <nsDeque.h>
 #include <nsTArray.h>
 #include <nsClassHashtable.h>
 #include "VideoUtils.h"
 #include <stdint.h>
 // Uncomment the following to validate that we're predicting the number
 // of Vorbis samples in each packet correctly.
 #define VALIDATE_VORBIS_SAMPLE_CALCULATION
 #ifdef  VALIDATE_VORBIS_SAMPLE_CALCULATION
 #include <map>
 #endif
 #include "OpusParser.h"
 namespace mozilla {
 // Deallocates a packet, used in OggPacketQueue below.
 class OggPacketDeallocator : public nsDequeFunctor {
   virtual void* operator() (void* aPacket) {
     ogg_packet* p = static_cast<ogg_packet*>(aPacket);
     delete [] p->packet;
     delete p;
     return nullptr;
   }
 };
 // A queue of ogg_packets. When we read a page, we extract the page's packets
 // and buffer them in the owning stream's OggCodecState. 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 4KB page to the bitstream, which kills performance on Windows. This
 // also gives us the option to timestamp packets rather than decoded
 // frames/samples, reducing the amount of frames/samples we must decode to
 // determine start-time at a particular offset, and gives us finer control
 // over memory usage.
 class OggPacketQueue : private nsDeque {
 public:
   OggPacketQueue() : nsDeque(new OggPacketDeallocator()) {}
   ~OggPacketQueue() { Erase(); }
   bool IsEmpty() { return nsDeque::GetSize() == 0; }
   void Append(ogg_packet* aPacket);
   ogg_packet* PopFront() { return static_cast<ogg_packet*>(nsDeque::PopFront()); }
   ogg_packet* PeekFront() { return static_cast<ogg_packet*>(nsDeque::PeekFront()); }
   void PushFront(ogg_packet* aPacket) { nsDeque::PushFront(aPacket); }
   void PushBack(ogg_packet* aPacket) { nsDeque::PushFront(aPacket); }
   void Erase() { nsDeque::Erase(); }
 };
 // Encapsulates the data required for decoding an ogg bitstream and for
 // converting granulepos to timestamps.
 class OggCodecState {
 public:
   typedef mozilla::MetadataTags MetadataTags;
   // Ogg types we know about
   enum CodecType {
     TYPE_VORBIS=0,
     TYPE_THEORA=1,
     TYPE_OPUS=2,
     TYPE_SKELETON=3,
     TYPE_UNKNOWN=4
   };
   virtual ~OggCodecState();
   // Factory for creating nsCodecStates. Use instead of constructor.
   // aPage should be a beginning-of-stream page.
   static OggCodecState* Create(ogg_page* aPage);
   virtual CodecType GetType() { return TYPE_UNKNOWN; }
   // Reads a header packet. Returns false if an error was encountered
   // while reading header packets. Callers should check DoneReadingHeaders()
   // to determine if the last header has been read.
   // This function takes ownership of the packet and is responsible for
   // releasing it or queuing it for later processing.
   virtual bool DecodeHeader(ogg_packet* aPacket) {
     return (mDoneReadingHeaders = true);
   }
   // Build a hash table with tag metadata parsed from the stream.
   virtual MetadataTags* GetTags() {
     return nullptr;
   }
   // Returns the end time that a granulepos represents.
   virtual int64_t Time(int64_t granulepos) { return -1; }
   // Returns the start time that a granulepos represents.
   virtual int64_t StartTime(int64_t granulepos) { return -1; }
   // Initializes the codec state.
   virtual bool Init();
   // Returns true when this bitstream has finished reading all its
   // header packets.
   bool DoneReadingHeaders() { return mDoneReadingHeaders; }
   // Deactivates the bitstream. Only the primary video and audio bitstreams
   // should be active.
   void Deactivate() {
     mActive = false;
     mDoneReadingHeaders = true;
     Reset();
   }
   // Resets decoding state.
   virtual nsresult Reset();
   // Returns true if the OggCodecState thinks this packet is a header
   // packet. Note this does not verify the validity of the header packet,
   // it just guarantees that the packet is marked as a header packet (i.e.
   // it is definintely not a data packet). Do not use this to identify
   // streams, use it to filter header packets from data packets while
   // decoding.
   virtual bool IsHeader(ogg_packet* aPacket) { return false; }
   // Returns the next packet in the stream, or nullptr if there are no more
   // packets buffered in the packet queue. More packets can be buffered by
   // inserting one or more pages into the stream by calling PageIn(). The
   // caller is responsible for deleting returned packet's using
   // OggCodecState::ReleasePacket(). The packet will have a valid granulepos.
   ogg_packet* PacketOut();
   // Releases the memory used by a cloned packet. Every packet returned by
   // PacketOut() must be free'd using this function.
   static void ReleasePacket(ogg_packet* aPacket);
   // Extracts all packets from the page, and inserts them into the packet
   // queue. They can be extracted by calling PacketOut(). Packets from an
   // inactive stream are not buffered, i.e. this call has no effect for
   // inactive streams. Multiple pages may need to be inserted before
   // PacketOut() starts to return packets, as granulepos may need to be
   // captured.
   virtual nsresult PageIn(ogg_page* aPage);
   // Number of packets read.
   uint64_t mPacketCount;
   // Serial number of the bitstream.
   uint32_t mSerial;
   // Ogg specific state.
   ogg_stream_state mState;
   // Queue of as yet undecoded packets. Packets are guaranteed to have
   // a valid granulepos.
   OggPacketQueue mPackets;
   // Is the bitstream active; whether we're decoding and playing this bitstream.
   bool mActive;
   // True when all headers packets have been read.
   bool mDoneReadingHeaders;
 protected:
   // Constructs a new OggCodecState. aActive denotes whether the stream is
   // active. For streams of unsupported or unknown types, aActive should be
   // false.
   OggCodecState(ogg_page* aBosPage, bool aActive);
   // Deallocates all packets stored in mUnstamped, and clears the array.
   void ClearUnstamped();
   // Extracts packets out of mState until a data packet with a non -1
   // granulepos is encountered, or no more packets are readable. Header
   // packets are pushed into the packet queue immediately, and data packets
   // are buffered in mUnstamped. Once a non -1 granulepos packet is read
   // the granulepos of the packets in mUnstamped can be inferred, and they
   // can be pushed over to mPackets. Used by PageIn() implementations in
   // subclasses.
   nsresult PacketOutUntilGranulepos(bool& aFoundGranulepos);
   // Temporary buffer in which to store packets while we're reading packets
   // in order to capture granulepos.
   nsTArray<ogg_packet*> mUnstamped;
   // Validation utility for vorbis-style tag names.
   static bool IsValidVorbisTagName(nsCString& aName);
   // Utility method to parse and add a vorbis-style comment
   // to a metadata hash table. Most Ogg-encapsulated codecs
   // use the vorbis comment format for metadata.
   static bool AddVorbisComment(MetadataTags* aTags,
                         const char* aComment,
                         uint32_t aLength);
 };
 class VorbisState : public OggCodecState {
 public:
   VorbisState(ogg_page* aBosPage);
   virtual ~VorbisState();
   CodecType GetType() { return TYPE_VORBIS; }
   bool DecodeHeader(ogg_packet* aPacket);
   int64_t Time(int64_t granulepos);
   bool Init();
   nsresult Reset();
   bool IsHeader(ogg_packet* aPacket);
   nsresult PageIn(ogg_page* aPage);
   // Return a hash table with tag metadata.
   MetadataTags* GetTags();
   // Returns the end time that a granulepos represents.
   static int64_t Time(vorbis_info* aInfo, int64_t aGranulePos);
   vorbis_info mInfo;
   vorbis_comment mComment;
   vorbis_dsp_state mDsp;
   vorbis_block mBlock;
 private:
   // Reconstructs the granulepos of Vorbis packets stored in the mUnstamped
   // array.
   nsresult ReconstructVorbisGranulepos();
   // The "block size" of the previously decoded Vorbis packet, or 0 if we've
   // not yet decoded anything. This is used to calculate the number of samples
   // in a Vorbis packet, since each Vorbis packet depends on the previous
   // packet while being decoded.
   long mPrevVorbisBlockSize;
   // Granulepos (end sample) of the last decoded Vorbis packet. This is used
   // to calculate the Vorbis granulepos when we don't find a granulepos to
   // back-propagate from.
   int64_t mGranulepos;
 #ifdef VALIDATE_VORBIS_SAMPLE_CALCULATION
   // When validating that we've correctly predicted Vorbis packets' number
   // of samples, we store each packet's predicted number of samples in this
   // map, and verify we decode the predicted number of samples.
   std::map<ogg_packet*, long> mVorbisPacketSamples;
 #endif
   // Records that aPacket is predicted to have aSamples samples.
   // This function has no effect if VALIDATE_VORBIS_SAMPLE_CALCULATION
   // is not defined.
   void RecordVorbisPacketSamples(ogg_packet* aPacket, long aSamples);
   // Verifies that aPacket has had its number of samples predicted.
   // This function has no effect if VALIDATE_VORBIS_SAMPLE_CALCULATION
   // is not defined.
   void AssertHasRecordedPacketSamples(ogg_packet* aPacket);
 public:
   // Asserts that the number of samples predicted for aPacket is aSamples.
   // This function has no effect if VALIDATE_VORBIS_SAMPLE_CALCULATION
   // is not defined.
   void ValidateVorbisPacketSamples(ogg_packet* aPacket, long aSamples);
 };
 // Returns 1 if the Theora info struct is decoding a media of Theora
 // version (maj,min,sub) or later, otherwise returns 0.
 int TheoraVersion(th_info* info,
                   unsigned char maj,
                   unsigned char min,
                   unsigned char sub);
 class TheoraState : public OggCodecState {
 public:
   TheoraState(ogg_page* aBosPage);
   virtual ~TheoraState();
   CodecType GetType() { return TYPE_THEORA; }
   bool DecodeHeader(ogg_packet* aPacket);
   int64_t Time(int64_t granulepos);
   int64_t StartTime(int64_t granulepos);
   bool Init();
   bool IsHeader(ogg_packet* aPacket);
   nsresult PageIn(ogg_page* aPage);
   // Returns the maximum number of microseconds which a keyframe can be offset
   // from any given interframe.
   int64_t MaxKeyframeOffset();
   // Returns the end time that a granulepos represents.
   static int64_t Time(th_info* aInfo, int64_t aGranulePos);
   th_info mInfo;
   th_comment mComment;
   th_setup_info *mSetup;
   th_dec_ctx* mCtx;
   float mPixelAspectRatio;
 private:
   // Reconstructs the granulepos of Theora packets stored in the
   // mUnstamped array. mUnstamped must be filled with consecutive packets from
   // the stream, with the last packet having a known granulepos. Using this
   // known granulepos, and the known frame numbers, we recover the granulepos
   // of all frames in the array. This enables us to determine their timestamps.
   void ReconstructTheoraGranulepos();
 };
 class OpusState : public OggCodecState {
 #ifdef MOZ_OPUS
 public:
   OpusState(ogg_page* aBosPage);
   virtual ~OpusState();
   CodecType GetType() { return TYPE_OPUS; }
   bool DecodeHeader(ogg_packet* aPacket);
   int64_t Time(int64_t aGranulepos);
   bool Init();
   nsresult Reset();
   nsresult Reset(bool aStart);
   bool IsHeader(ogg_packet* aPacket);
   nsresult PageIn(ogg_page* aPage);
   // Returns the end time that a granulepos represents.
   static int64_t Time(int aPreSkip, int64_t aGranulepos);
   // Various fields from the Ogg Opus header.
   int mRate;        // Sample rate the decoder uses (always 48 kHz).
   int mChannels;    // Number of channels the stream encodes.
   uint16_t mPreSkip; // Number of samples to strip after decoder reset.
 #ifdef MOZ_SAMPLE_TYPE_FLOAT32
   float mGain;      // Gain to apply to decoder output.
 #else
   int32_t mGain_Q16; // Gain to apply to the decoder output.
 #endif
   nsAutoPtr<OpusParser> mParser;
   OpusMSDecoder *mDecoder;
   int mSkip;        // Number of samples left to trim before playback.
   // Granule position (end sample) of the last decoded Opus packet. This is
   // used to calculate the amount we should trim from the last packet.
   int64_t mPrevPacketGranulepos;
   // Construct and return a table of tags from the metadata header.
   MetadataTags* GetTags();
 private:
   // Reconstructs the granulepos of Opus packets stored in the
   // mUnstamped array. mUnstamped must be filled with consecutive packets from
   // the stream, with the last packet having a known granulepos. Using this
   // known granulepos, and the known frame numbers, we recover the granulepos
   // of all frames in the array. This enables us to determine their timestamps.
   bool ReconstructOpusGranulepos();
   // Granule position (end sample) of the last decoded Opus page. This is
   // used to calculate the Opus per-packet granule positions on the last page,
   // where we may need to trim some samples from the end.
   int64_t mPrevPageGranulepos;
 #endif /* MOZ_OPUS */
 };
 // Constructs a 32bit version number out of two 16 bit major,minor
 // version numbers.
 #define SKELETON_VERSION(major, minor) (((major)<<16)|(minor))
 class SkeletonState : public OggCodecState {
 public:
   SkeletonState(ogg_page* aBosPage);
   ~SkeletonState();
   CodecType GetType() { return TYPE_SKELETON; }
   bool DecodeHeader(ogg_packet* aPacket);
   int64_t Time(int64_t granulepos) { return -1; }
   bool Init() { return true; }
   bool IsHeader(ogg_packet* aPacket) { return true; }
   // Return true if the given time (in milliseconds) is within
   // the presentation time defined in the skeleton track.
   bool IsPresentable(int64_t aTime) { return aTime >= mPresentationTime; }
   // Stores the offset of the page on which a keyframe starts,
   // and its presentation time.
   class nsKeyPoint {
   public:
     nsKeyPoint()
       : mOffset(INT64_MAX),
         mTime(INT64_MAX) {}
     nsKeyPoint(int64_t aOffset, int64_t aTime)
       : mOffset(aOffset),
         mTime(aTime) {}
     // Offset from start of segment/link-in-the-chain in bytes.
     int64_t mOffset;
     // Presentation time in usecs.
     int64_t mTime;
     bool IsNull() {
       return mOffset == INT64_MAX &&
              mTime == 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;
     uint32_t mSerial;
     bool 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(int64_t aTarget,
                              nsTArray<uint32_t>& aTracks,
                              nsSeekTarget& aResult);
   bool 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<uint32_t>& aTracks, int64_t& aDuration);
 private:
   // Decodes an index packet. Returns false on failure.
   bool 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(uint32_t aSerialno,
                                      int64_t aTarget,
                                      nsKeyPoint& aResult);
   // Version of the decoded skeleton track, as per the SKELETON_VERSION macro.
   uint32_t mVersion;
   // Presentation time of the resource in milliseconds
   int64_t mPresentationTime;
   // Length of the resource in bytes.
   int64_t mLength;
   // Stores the keyframe index and duration information for a particular
   // stream.
   class nsKeyFrameIndex {
   public:
     nsKeyFrameIndex(int64_t aStartTime, int64_t aEndTime)
       : mStartTime(aStartTime),
         mEndTime(aEndTime)
     {
       MOZ_COUNT_CTOR(nsKeyFrameIndex);
     }
     ~nsKeyFrameIndex() {
       MOZ_COUNT_DTOR(nsKeyFrameIndex);
     }
     void Add(int64_t aOffset, int64_t aTimeMs) {
       mKeyPoints.AppendElement(nsKeyPoint(aOffset, aTimeMs));
     }
     const nsKeyPoint& Get(uint32_t aIndex) const {
       return mKeyPoints[aIndex];
     }
     uint32_t Length() const {
       return mKeyPoints.Length();
     }
     // Presentation time of the first sample in this stream in usecs.
     const int64_t mStartTime;
     // End time of the last sample in this stream in usecs.
     const int64_t mEndTime;
   private:
     nsTArray<nsKeyPoint> mKeyPoints;
   };
   // Maps Ogg serialnos to the index-keypoint list.
   nsClassHashtable<nsUint32HashKey, nsKeyFrameIndex> mIndex;
 };
 } // namespace mozilla
 // This allows the use of nsAutoRefs for an ogg_packet that properly free the
 // contents of the packet.
 template <>
 class nsAutoRefTraits<ogg_packet> : public nsPointerRefTraits<ogg_packet>
 {
 public:
   static void Release(ogg_packet* aPacket) {
     mozilla::OggCodecState::ReleasePacket(aPacket);
   }
 };
 #endif

The Tor Browser / annotate

content/media/ogg/OggCodecState.h@8bccb770b82d (annotated)

content/media/ogg/OggCodecState.h