michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef MOZILLA_MEDIASEGMENT_H_
michael@0: #define MOZILLA_MEDIASEGMENT_H_
michael@0: 
michael@0: #include "nsTArray.h"
michael@0: #ifdef MOZILLA_INTERNAL_API
michael@0: #include "mozilla/TimeStamp.h"
michael@0: #endif
michael@0: #include <algorithm>
michael@0: #include "Latency.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: /**
michael@0:  * We represent media times in 64-bit fixed point. So 1 MediaTime is
michael@0:  * 1/(2^MEDIA_TIME_FRAC_BITS) seconds.
michael@0:  */
michael@0: typedef int64_t MediaTime;
michael@0: const int64_t MEDIA_TIME_FRAC_BITS = 20;
michael@0: const int64_t MEDIA_TIME_MAX = INT64_MAX;
michael@0: 
michael@0: inline MediaTime MillisecondsToMediaTime(int32_t aMS)
michael@0: {
michael@0:   return (MediaTime(aMS) << MEDIA_TIME_FRAC_BITS)/1000;
michael@0: }
michael@0: 
michael@0: inline MediaTime SecondsToMediaTime(double aS)
michael@0: {
michael@0:   NS_ASSERTION(aS <= (MEDIA_TIME_MAX >> MEDIA_TIME_FRAC_BITS),
michael@0:                "Out of range");
michael@0:   return MediaTime(aS * (1 << MEDIA_TIME_FRAC_BITS));
michael@0: }
michael@0: 
michael@0: inline double MediaTimeToSeconds(MediaTime aTime)
michael@0: {
michael@0:   return aTime*(1.0/(1 << MEDIA_TIME_FRAC_BITS));
michael@0: }
michael@0: 
michael@0: inline int64_t MediaTimeToMicroseconds(MediaTime aTime)
michael@0: {
michael@0:   return aTime*(1000000.0/(1 << MEDIA_TIME_FRAC_BITS));
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * A number of ticks at a rate determined by some underlying track (e.g.
michael@0:  * audio sample rate). We want to make sure that multiplying TrackTicks by
michael@0:  * 2^MEDIA_TIME_FRAC_BITS doesn't overflow, so we set its max accordingly.
michael@0:  */
michael@0: typedef int64_t TrackTicks;
michael@0: const int64_t TRACK_TICKS_MAX = INT64_MAX >> MEDIA_TIME_FRAC_BITS;
michael@0: 
michael@0: /**
michael@0:  * A MediaSegment is a chunk of media data sequential in time. Different
michael@0:  * types of data have different subclasses of MediaSegment, all inheriting
michael@0:  * from MediaSegmentBase.
michael@0:  * All MediaSegment data is timed using TrackTicks. The actual tick rate
michael@0:  * is defined on a per-track basis. For some track types, this can be
michael@0:  * a fixed constant for all tracks of that type (e.g. 1MHz for video).
michael@0:  *
michael@0:  * Each media segment defines a concept of "null media data" (e.g. silence
michael@0:  * for audio or "no video frame" for video), which can be efficiently
michael@0:  * represented. This is used for padding.
michael@0:  */
michael@0: class MediaSegment {
michael@0: public:
michael@0:   virtual ~MediaSegment()
michael@0:   {
michael@0:     MOZ_COUNT_DTOR(MediaSegment);
michael@0:   }
michael@0: 
michael@0:   enum Type {
michael@0:     AUDIO,
michael@0:     VIDEO,
michael@0:     TYPE_COUNT
michael@0:   };
michael@0: 
michael@0:   /**
michael@0:    * Gets the total duration of the segment.
michael@0:    */
michael@0:   TrackTicks GetDuration() const { return mDuration; }
michael@0:   Type GetType() const { return mType; }
michael@0: 
michael@0:   /**
michael@0:    * Create a MediaSegment of the same type.
michael@0:    */
michael@0:   virtual MediaSegment* CreateEmptyClone() const = 0;
michael@0:   /**
michael@0:    * Moves contents of aSource to the end of this segment.
michael@0:    */
michael@0:   virtual void AppendFrom(MediaSegment* aSource) = 0;
michael@0:   /**
michael@0:    * Append a slice of aSource to this segment.
michael@0:    */
michael@0:   virtual void AppendSlice(const MediaSegment& aSource,
michael@0:                            TrackTicks aStart, TrackTicks aEnd) = 0;
michael@0:   /**
michael@0:    * Replace all contents up to aDuration with null data.
michael@0:    */
michael@0:   virtual void ForgetUpTo(TrackTicks aDuration) = 0;
michael@0:   /**
michael@0:    * Insert aDuration of null data at the start of the segment.
michael@0:    */
michael@0:   virtual void InsertNullDataAtStart(TrackTicks aDuration) = 0;
michael@0:   /**
michael@0:    * Insert aDuration of null data at the end of the segment.
michael@0:    */
michael@0:   virtual void AppendNullData(TrackTicks aDuration) = 0;
michael@0:   /**
michael@0:    * Replace contents with disabled data of the same duration
michael@0:    */
michael@0:   virtual void ReplaceWithDisabled() = 0;
michael@0:   /**
michael@0:    * Remove all contents, setting duration to 0.
michael@0:    */
michael@0:   virtual void Clear() = 0;
michael@0: 
michael@0:   virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const
michael@0:   {
michael@0:     return 0;
michael@0:   }
michael@0: 
michael@0:   virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
michael@0:   {
michael@0:     return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
michael@0:   }
michael@0: 
michael@0: protected:
michael@0:   MediaSegment(Type aType) : mDuration(0), mType(aType)
michael@0:   {
michael@0:     MOZ_COUNT_CTOR(MediaSegment);
michael@0:   }
michael@0: 
michael@0:   TrackTicks mDuration; // total of mDurations of all chunks
michael@0:   Type mType;
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * C is the implementation class subclassed from MediaSegmentBase.
michael@0:  * C must contain a Chunk class.
michael@0:  */
michael@0: template <class C, class Chunk> class MediaSegmentBase : public MediaSegment {
michael@0: public:
michael@0:   virtual MediaSegment* CreateEmptyClone() const
michael@0:   {
michael@0:     return new C();
michael@0:   }
michael@0:   virtual void AppendFrom(MediaSegment* aSource)
michael@0:   {
michael@0:     NS_ASSERTION(aSource->GetType() == C::StaticType(), "Wrong type");
michael@0:     AppendFromInternal(static_cast<C*>(aSource));
michael@0:   }
michael@0:   void AppendFrom(C* aSource)
michael@0:   {
michael@0:     AppendFromInternal(aSource);
michael@0:   }
michael@0:   virtual void AppendSlice(const MediaSegment& aSource,
michael@0:                            TrackTicks aStart, TrackTicks aEnd)
michael@0:   {
michael@0:     NS_ASSERTION(aSource.GetType() == C::StaticType(), "Wrong type");
michael@0:     AppendSliceInternal(static_cast<const C&>(aSource), aStart, aEnd);
michael@0:   }
michael@0:   void AppendSlice(const C& aOther, TrackTicks aStart, TrackTicks aEnd)
michael@0:   {
michael@0:     AppendSliceInternal(aOther, aStart, aEnd);
michael@0:   }
michael@0:   /**
michael@0:    * Replace the first aDuration ticks with null media data, because the data
michael@0:    * will not be required again.
michael@0:    */
michael@0:   virtual void ForgetUpTo(TrackTicks aDuration)
michael@0:   {
michael@0:     if (mChunks.IsEmpty() || aDuration <= 0) {
michael@0:       return;
michael@0:     }
michael@0:     if (mChunks[0].IsNull()) {
michael@0:       TrackTicks extraToForget = std::min(aDuration, mDuration) - mChunks[0].GetDuration();
michael@0:       if (extraToForget > 0) {
michael@0:         RemoveLeading(extraToForget, 1);
michael@0:         mChunks[0].mDuration += extraToForget;
michael@0:         mDuration += extraToForget;
michael@0:       }
michael@0:       return;
michael@0:     }
michael@0:     RemoveLeading(aDuration, 0);
michael@0:     mChunks.InsertElementAt(0)->SetNull(aDuration);
michael@0:     mDuration += aDuration;
michael@0:   }
michael@0:   virtual void InsertNullDataAtStart(TrackTicks aDuration)
michael@0:   {
michael@0:     if (aDuration <= 0) {
michael@0:       return;
michael@0:     }
michael@0:     if (!mChunks.IsEmpty() && mChunks[0].IsNull()) {
michael@0:       mChunks[0].mDuration += aDuration;
michael@0:     } else {
michael@0:       mChunks.InsertElementAt(0)->SetNull(aDuration);
michael@0:     }
michael@0: #ifdef MOZILLA_INTERNAL_API
michael@0:     mChunks[0].mTimeStamp = mozilla::TimeStamp::Now();
michael@0: #endif
michael@0:     mDuration += aDuration;
michael@0:   }
michael@0:   virtual void AppendNullData(TrackTicks aDuration)
michael@0:   {
michael@0:     if (aDuration <= 0) {
michael@0:       return;
michael@0:     }
michael@0:     if (!mChunks.IsEmpty() && mChunks[mChunks.Length() - 1].IsNull()) {
michael@0:       mChunks[mChunks.Length() - 1].mDuration += aDuration;
michael@0:     } else {
michael@0:       mChunks.AppendElement()->SetNull(aDuration);
michael@0:     }
michael@0:     mDuration += aDuration;
michael@0:   }
michael@0:   virtual void ReplaceWithDisabled()
michael@0:   {
michael@0:     if (GetType() != AUDIO) {
michael@0:       MOZ_CRASH("Disabling unknown segment type");
michael@0:     }
michael@0:     TrackTicks duration = GetDuration();
michael@0:     Clear();
michael@0:     AppendNullData(duration);
michael@0:   }
michael@0:   virtual void Clear()
michael@0:   {
michael@0:     mDuration = 0;
michael@0:     mChunks.Clear();
michael@0:   }
michael@0: 
michael@0:   class ChunkIterator {
michael@0:   public:
michael@0:     ChunkIterator(MediaSegmentBase<C, Chunk>& aSegment)
michael@0:       : mSegment(aSegment), mIndex(0) {}
michael@0:     bool IsEnded() { return mIndex >= mSegment.mChunks.Length(); }
michael@0:     void Next() { ++mIndex; }
michael@0:     Chunk& operator*() { return mSegment.mChunks[mIndex]; }
michael@0:     Chunk* operator->() { return &mSegment.mChunks[mIndex]; }
michael@0:   private:
michael@0:     MediaSegmentBase<C, Chunk>& mSegment;
michael@0:     uint32_t mIndex;
michael@0:   };
michael@0: 
michael@0:   void RemoveLeading(TrackTicks aDuration)
michael@0:   {
michael@0:     RemoveLeading(aDuration, 0);
michael@0:   }
michael@0: 
michael@0: #ifdef MOZILLA_INTERNAL_API
michael@0:   void GetStartTime(TimeStamp &aTime) {
michael@0:     aTime = mChunks[0].mTimeStamp;
michael@0:   }
michael@0: #endif
michael@0: 
michael@0:   virtual size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
michael@0:   {
michael@0:     size_t amount = mChunks.SizeOfExcludingThis(aMallocSizeOf);
michael@0:     for (size_t i = 0; i < mChunks.Length(); i++) {
michael@0:       amount += mChunks[i].SizeOfExcludingThisIfUnshared(aMallocSizeOf);
michael@0:     }
michael@0:     return amount;
michael@0:   }
michael@0: 
michael@0:   virtual size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const MOZ_OVERRIDE
michael@0:   {
michael@0:     return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
michael@0:   }
michael@0: 
michael@0: protected:
michael@0:   MediaSegmentBase(Type aType) : MediaSegment(aType) {}
michael@0: 
michael@0:   /**
michael@0:    * Appends the contents of aSource to this segment, clearing aSource.
michael@0:    */
michael@0:   void AppendFromInternal(MediaSegmentBase<C, Chunk>* aSource)
michael@0:   {
michael@0:     MOZ_ASSERT(aSource->mDuration >= 0);
michael@0:     mDuration += aSource->mDuration;
michael@0:     aSource->mDuration = 0;
michael@0:     if (!mChunks.IsEmpty() && !aSource->mChunks.IsEmpty() &&
michael@0:         mChunks[mChunks.Length() - 1].CanCombineWithFollowing(aSource->mChunks[0])) {
michael@0:       mChunks[mChunks.Length() - 1].mDuration += aSource->mChunks[0].mDuration;
michael@0:       aSource->mChunks.RemoveElementAt(0);
michael@0:     }
michael@0:     mChunks.MoveElementsFrom(aSource->mChunks);
michael@0:   }
michael@0: 
michael@0:   void AppendSliceInternal(const MediaSegmentBase<C, Chunk>& aSource,
michael@0:                            TrackTicks aStart, TrackTicks aEnd)
michael@0:   {
michael@0:     MOZ_ASSERT(aStart <= aEnd, "Endpoints inverted");
michael@0:     NS_WARN_IF_FALSE(aStart >= 0 && aEnd <= aSource.mDuration, "Slice out of range");
michael@0:     mDuration += aEnd - aStart;
michael@0:     TrackTicks offset = 0;
michael@0:     for (uint32_t i = 0; i < aSource.mChunks.Length() && offset < aEnd; ++i) {
michael@0:       const Chunk& c = aSource.mChunks[i];
michael@0:       TrackTicks start = std::max(aStart, offset);
michael@0:       TrackTicks nextOffset = offset + c.GetDuration();
michael@0:       TrackTicks end = std::min(aEnd, nextOffset);
michael@0:       if (start < end) {
michael@0:         mChunks.AppendElement(c)->SliceTo(start - offset, end - offset);
michael@0:       }
michael@0:       offset = nextOffset;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   Chunk* AppendChunk(TrackTicks aDuration)
michael@0:   {
michael@0:     MOZ_ASSERT(aDuration >= 0);
michael@0:     Chunk* c = mChunks.AppendElement();
michael@0:     c->mDuration = aDuration;
michael@0:     mDuration += aDuration;
michael@0:     return c;
michael@0:   }
michael@0: 
michael@0:   Chunk* FindChunkContaining(TrackTicks aOffset, TrackTicks* aStart = nullptr)
michael@0:   {
michael@0:     if (aOffset < 0) {
michael@0:       return nullptr;
michael@0:     }
michael@0:     TrackTicks offset = 0;
michael@0:     for (uint32_t i = 0; i < mChunks.Length(); ++i) {
michael@0:       Chunk& c = mChunks[i];
michael@0:       TrackTicks nextOffset = offset + c.GetDuration();
michael@0:       if (aOffset < nextOffset) {
michael@0:         if (aStart) {
michael@0:           *aStart = offset;
michael@0:         }
michael@0:         return &c;
michael@0:       }
michael@0:       offset = nextOffset;
michael@0:     }
michael@0:     return nullptr;
michael@0:   }
michael@0: 
michael@0:   Chunk* GetLastChunk()
michael@0:   {
michael@0:     if (mChunks.IsEmpty()) {
michael@0:       return nullptr;
michael@0:     }
michael@0:     return &mChunks[mChunks.Length() - 1];
michael@0:   }
michael@0: 
michael@0:   void RemoveLeading(TrackTicks aDuration, uint32_t aStartIndex)
michael@0:   {
michael@0:     NS_ASSERTION(aDuration >= 0, "Can't remove negative duration");
michael@0:     TrackTicks t = aDuration;
michael@0:     uint32_t chunksToRemove = 0;
michael@0:     for (uint32_t i = aStartIndex; i < mChunks.Length() && t > 0; ++i) {
michael@0:       Chunk* c = &mChunks[i];
michael@0:       if (c->GetDuration() > t) {
michael@0:         c->SliceTo(t, c->GetDuration());
michael@0:         t = 0;
michael@0:         break;
michael@0:       }
michael@0:       t -= c->GetDuration();
michael@0:       chunksToRemove = i + 1 - aStartIndex;
michael@0:     }
michael@0:     mChunks.RemoveElementsAt(aStartIndex, chunksToRemove);
michael@0:     mDuration -= aDuration - t;
michael@0:   }
michael@0: 
michael@0:   nsTArray<Chunk> mChunks;
michael@0: #ifdef MOZILLA_INTERNAL_API
michael@0:   mozilla::TimeStamp mTimeStamp;
michael@0: #endif
michael@0: };
michael@0: 
michael@0: }
michael@0: 
michael@0: #endif /* MOZILLA_MEDIASEGMENT_H_ */