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

 /* 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/. */

 #include "EbmlComposer.h"

 #include "libmkv/EbmlIDs.h"

 #include "libmkv/EbmlWriter.h"

 #include "libmkv/WebMElement.h"

 #include "prtime.h"

 namespace mozilla {

 // Timecode scale in nanoseconds

 static const unsigned long TIME_CODE_SCALE = 1000000;

 // The WebM header size without audio CodecPrivateData

 static const int32_t DEFAULT_HEADER_SIZE = 1024;

 void EbmlComposer::GenerateHeader()

 {

   // Write the EBML header.

   EbmlGlobal ebml;

   // The WEbM header default size usually smaller than 1k.

   nsAutoArrayPtr<uint8_t> buffer(new uint8_t[DEFAULT_HEADER_SIZE +

                                              mCodecPrivateData.Length()]);

   ebml.buf = buffer.get();

   ebml.offset = 0;

   writeHeader(&ebml);

   {

     EbmlLoc segEbmlLoc, ebmlLocseg, ebmlLoc;

     Ebml_StartSubElement(&ebml, &segEbmlLoc, Segment);

     {

       Ebml_StartSubElement(&ebml, &ebmlLocseg, SeekHead);

       // Todo: We don't know the exact sizes of encoded data and

       // ignore this section.

       Ebml_EndSubElement(&ebml, &ebmlLocseg);

       writeSegmentInformation(&ebml, &ebmlLoc, TIME_CODE_SCALE, 0);

       {

         EbmlLoc trackLoc;

         Ebml_StartSubElement(&ebml, &trackLoc, Tracks);

         {

           // Video

           if (mWidth > 0 && mHeight > 0) {

             writeVideoTrack(&ebml, 0x1, 0, "V_VP8",

                             mWidth, mHeight,

                             mDisplayWidth, mDisplayHeight, mFrameRate);

           }

           // Audio

           if (mCodecPrivateData.Length() > 0) {

             writeAudioTrack(&ebml, 0x2, 0x0, "A_VORBIS", mSampleFreq,

                             mChannels, mCodecPrivateData.Elements(),

                             mCodecPrivateData.Length());

           }

         }

         Ebml_EndSubElement(&ebml, &trackLoc);

       }

     }

     // The Recording length is unknown and

     // ignore write the whole Segment element size

   }

   MOZ_ASSERT(ebml.offset <= DEFAULT_HEADER_SIZE + mCodecPrivateData.Length(),

              "write more data > EBML_BUFFER_SIZE");

   auto block = mClusterBuffs.AppendElement();

   block->SetLength(ebml.offset);

   memcpy(block->Elements(), ebml.buf, ebml.offset);

   mFlushState |= FLUSH_METADATA;

 }

 void EbmlComposer::FinishMetadata()

 {

   if (mFlushState & FLUSH_METADATA) {

     // We don't remove the first element of mClusterBuffs because the

     // |mClusterHeaderIndex| may have value.

     mClusterCanFlushBuffs.AppendElement()->SwapElements(mClusterBuffs[0]);

     mFlushState &= ~FLUSH_METADATA;

   }

 }

 void EbmlComposer::FinishCluster()

 {

   FinishMetadata();

   if (!(mFlushState & FLUSH_CLUSTER)) {

     // No completed cluster available.

     return;

   }

   MOZ_ASSERT(mClusterLengthLoc > 0);

   EbmlGlobal ebml;

   EbmlLoc ebmlLoc;

   ebmlLoc.offset = mClusterLengthLoc;

   ebml.offset = mClusterBuffs[mClusterHeaderIndex].Length();

   ebml.buf = mClusterBuffs[mClusterHeaderIndex].Elements();

   Ebml_EndSubElement(&ebml, &ebmlLoc);

   // Move the mClusterBuffs data from mClusterHeaderIndex that we can skip

   // the metadata and the rest P-frames after ContainerWriter::FLUSH_NEEDED.

   for (uint32_t i = mClusterHeaderIndex; i < mClusterBuffs.Length(); i++) {

     mClusterCanFlushBuffs.AppendElement()->SwapElements(mClusterBuffs[i]);

   }

   mClusterHeaderIndex = 0;

   mClusterLengthLoc = 0;

   mClusterBuffs.Clear();

   mFlushState &= ~FLUSH_CLUSTER;

 }

 void

 EbmlComposer::WriteSimpleBlock(EncodedFrame* aFrame)

 {

   EbmlGlobal ebml;

   ebml.offset = 0;

   if (aFrame->GetFrameType() == EncodedFrame::FrameType::VP8_I_FRAME) {

     FinishCluster();

   }

   auto block = mClusterBuffs.AppendElement();

   block->SetLength(aFrame->GetFrameData().Length() + DEFAULT_HEADER_SIZE);

   ebml.buf = block->Elements();

   if (aFrame->GetFrameType() == EncodedFrame::FrameType::VP8_I_FRAME) {

     EbmlLoc ebmlLoc;

     Ebml_StartSubElement(&ebml, &ebmlLoc, Cluster);

     MOZ_ASSERT(mClusterBuffs.Length() > 0);

     // current cluster header array index

     mClusterHeaderIndex = mClusterBuffs.Length() - 1;

     mClusterLengthLoc = ebmlLoc.offset;

     mClusterTimecode = aFrame->GetTimeStamp() / PR_USEC_PER_MSEC;

     Ebml_SerializeUnsigned(&ebml, Timecode, mClusterTimecode);

     mFlushState |= FLUSH_CLUSTER;

   }

   if (aFrame->GetFrameType() != EncodedFrame::FrameType::VORBIS_AUDIO_FRAME) {

     short timeCode = aFrame->GetTimeStamp() / PR_USEC_PER_MSEC

                      - mClusterTimecode;

     writeSimpleBlock(&ebml, 0x1, timeCode, aFrame->GetFrameType() ==

                      EncodedFrame::FrameType::VP8_I_FRAME,

                      0, 0, (unsigned char*)aFrame->GetFrameData().Elements(),

                      aFrame->GetFrameData().Length());

   } else {

     writeSimpleBlock(&ebml, 0x2, 0, false,

                      0, 0, (unsigned char*)aFrame->GetFrameData().Elements(),

                      aFrame->GetFrameData().Length());

   }

   MOZ_ASSERT(ebml.offset <= DEFAULT_HEADER_SIZE +

              aFrame->GetFrameData().Length(),

              "write more data > EBML_BUFFER_SIZE");

   block->SetLength(ebml.offset);

 }

 void

 EbmlComposer::SetVideoConfig(uint32_t aWidth, uint32_t aHeight,

                              uint32_t aDisplayWidth, uint32_t aDisplayHeight,

                              float aFrameRate)

 {

   MOZ_ASSERT(aWidth > 0, "Width should > 0");

   MOZ_ASSERT(aHeight > 0, "Height should > 0");

   MOZ_ASSERT(aDisplayWidth > 0, "DisplayWidth should > 0");

   MOZ_ASSERT(aDisplayHeight > 0, "DisplayHeight should > 0");

   MOZ_ASSERT(aFrameRate > 0, "FrameRate should > 0");

   mWidth = aWidth;

   mHeight = aHeight;

   mDisplayWidth = aDisplayWidth;

   mDisplayHeight = aDisplayHeight;

   mFrameRate = aFrameRate;

 }

 void

 EbmlComposer::SetAudioConfig(uint32_t aSampleFreq, uint32_t aChannels,

                              uint32_t aBitDepth)

 {

   MOZ_ASSERT(aSampleFreq > 0, "SampleFreq should > 0");

   MOZ_ASSERT(aBitDepth > 0, "BitDepth should > 0");

   MOZ_ASSERT(aChannels > 0, "Channels should > 0");

   mSampleFreq = aSampleFreq;

   mBitDepth = aBitDepth;

   mChannels = aChannels;

 }

 void

 EbmlComposer::ExtractBuffer(nsTArray<nsTArray<uint8_t> >* aDestBufs,

                             uint32_t aFlag)

 {

   if ((aFlag & ContainerWriter::FLUSH_NEEDED) ||

       (aFlag & ContainerWriter::GET_HEADER))

   {

     FinishMetadata();

   }

   if (aFlag & ContainerWriter::FLUSH_NEEDED)

   {

     FinishCluster();

   }

   // aDestBufs may have some element

   for (uint32_t i = 0; i < mClusterCanFlushBuffs.Length(); i++) {

     aDestBufs->AppendElement()->SwapElements(mClusterCanFlushBuffs[i]);

   }

   mClusterCanFlushBuffs.Clear();

 }

 EbmlComposer::EbmlComposer()

   : mFlushState(FLUSH_NONE)

   , mClusterHeaderIndex(0)

   , mClusterLengthLoc(0)

   , mClusterTimecode(0)

   , mWidth(0)

   , mHeight(0)

   , mFrameRate(0)

   , mSampleFreq(0)

   , mBitDepth(0)

   , mChannels(0)

 {}

 }