The Tor Browser: content/media/encoder/fmp4_muxer/ISOControl.cpp@44a2da4a2ab2 (annotated)

content/media/encoder/fmp4_muxer/ISOControl.cpp@44a2da4a2ab2 (annotated)

content/media/encoder/fmp4_muxer/ISOControl.cpp

Fri, 16 Jan 2015 04:50:19 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 04:50:19 +0100
branch: TOR_BUG_9701
changeset 13: 44a2da4a2ab2
permissions: -rw-r--r--

Replace accessor implementation with direct member state manipulation, by
request https://trac.torproject.org/projects/tor/ticket/9701#comment:32

 /* -*- 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 <time.h>
 #include "nsAutoPtr.h"
 #include "ISOControl.h"
 #include "ISOMediaBoxes.h"
 #include "EncodedFrameContainer.h"
 namespace mozilla {
 // For MP4 creation_time and modification_time offset from January 1, 1904 to
 // January 1, 1970.
 #define iso_time_offset 2082844800
 FragmentBuffer::FragmentBuffer(uint32_t aTrackType, uint32_t aFragDuration)
   : mTrackType(aTrackType)
   , mFragDuration(aFragDuration)
   , mMediaStartTime(0)
   , mFragmentNumber(0)
   , mLastFrameTimeOfLastFragment(0)
   , mEOS(false)
 {
   mFragArray.AppendElement();
   MOZ_COUNT_CTOR(FragmentBuffer);
 }
 FragmentBuffer::~FragmentBuffer()
 {
   MOZ_COUNT_DTOR(FragmentBuffer);
 }
 bool
 FragmentBuffer::HasEnoughData()
 {
   // Audio or video frame is enough to form a moof.
   return (mFragArray.Length() > 1);
 }
 nsresult
 FragmentBuffer::GetCSD(nsTArray<uint8_t>& aCSD)
 {
   if (!mCSDFrame) {
     return NS_ERROR_FAILURE;
   }
   aCSD.AppendElements(mCSDFrame->GetFrameData().Elements(),
                       mCSDFrame->GetFrameData().Length());
   return NS_OK;
 }
 nsresult
 FragmentBuffer::AddFrame(EncodedFrame* aFrame)
 {
   // already EOS, it rejects all new data.
   if (mEOS) {
     MOZ_ASSERT(0);
     return NS_OK;
   }
   EncodedFrame::FrameType type = aFrame->GetFrameType();
   if (type == EncodedFrame::AAC_CSD || type == EncodedFrame::AVC_CSD ||
       type == EncodedFrame::AMR_AUDIO_CSD) {
     mCSDFrame = aFrame;
     // Use CSD's timestamp as the start time. Encoder should send CSD frame first
     // and then data frames.
     mMediaStartTime = aFrame->GetTimeStamp();
     mFragmentNumber = 1;
     return NS_OK;
   }
   // if the timestamp is incorrect, abort it.
   if (aFrame->GetTimeStamp() < mMediaStartTime) {
     MOZ_ASSERT(false);
     return NS_ERROR_FAILURE;
   }
   mFragArray.LastElement().AppendElement(aFrame);
   // check if current fragment is reach the fragment duration.
   if ((aFrame->GetTimeStamp() - mMediaStartTime) >= (mFragDuration * mFragmentNumber)) {
     mFragArray.AppendElement();
     mFragmentNumber++;
   }
   return NS_OK;
 }
 nsresult
 FragmentBuffer::GetFirstFragment(nsTArray<nsRefPtr<EncodedFrame>>& aFragment,
                                  bool aFlush)
 {
   // It should be called only if there is a complete fragment in mFragArray.
   if (mFragArray.Length() <= 1 && !mEOS) {
     MOZ_ASSERT(false);
     return NS_ERROR_FAILURE;
   }
   if (aFlush) {
     aFragment.SwapElements(mFragArray.ElementAt(0));
     mFragArray.RemoveElementAt(0);
   } else {
     aFragment.AppendElements(mFragArray.ElementAt(0));
   }
   return NS_OK;
 }
 uint32_t
 FragmentBuffer::GetFirstFragmentSampleNumber()
 {
   return mFragArray.ElementAt(0).Length();
 }
 uint32_t
 FragmentBuffer::GetFirstFragmentSampleSize()
 {
   uint32_t size = 0;
   uint32_t len = mFragArray.ElementAt(0).Length();
   for (uint32_t i = 0; i < len; i++) {
     size += mFragArray.ElementAt(0).ElementAt(i)->GetFrameData().Length();
   }
   return size;
 }
 ISOControl::ISOControl(uint32_t aMuxingType)
   : mMuxingType(aMuxingType)
   , mAudioFragmentBuffer(nullptr)
   , mVideoFragmentBuffer(nullptr)
   , mFragNum(0)
   , mOutputSize(0)
   , mBitCount(0)
   , mBit(0)
 {
   // Create a data array for first mp4 Box, ftyp.
   mOutBuffers.SetLength(1);
   MOZ_COUNT_CTOR(ISOControl);
 }
 ISOControl::~ISOControl()
 {
   MOZ_COUNT_DTOR(ISOControl);
 }
 uint32_t
 ISOControl::GetNextTrackID()
 {
   return (mMetaArray.Length() + 1);
 }
 uint32_t
 ISOControl::GetTrackID(TrackMetadataBase::MetadataKind aKind)
 {
   for (uint32_t i = 0; i < mMetaArray.Length(); i++) {
     if (mMetaArray[i]->GetKind() == aKind) {
       return (i + 1);
     }
   }
   // Track ID shouldn't be 0. It must be something wrong here.
   MOZ_ASSERT(0);
   return 0;
 }
 nsresult
 ISOControl::SetMetadata(TrackMetadataBase* aTrackMeta)
 {
   if (aTrackMeta->GetKind() == TrackMetadataBase::METADATA_AAC ||
       aTrackMeta->GetKind() == TrackMetadataBase::METADATA_AMR ||
       aTrackMeta->GetKind() == TrackMetadataBase::METADATA_AVC) {
     mMetaArray.AppendElement(aTrackMeta);
     return NS_OK;
   }
   return NS_ERROR_FAILURE;
 }
 nsresult
 ISOControl::GetAudioMetadata(nsRefPtr<AudioTrackMetadata>& aAudMeta)
 {
   for (uint32_t i = 0; i < mMetaArray.Length() ; i++) {
     if (mMetaArray[i]->GetKind() == TrackMetadataBase::METADATA_AAC ||
         mMetaArray[i]->GetKind() == TrackMetadataBase::METADATA_AMR) {
       aAudMeta = static_cast<AudioTrackMetadata*>(mMetaArray[i].get());
       return NS_OK;
     }
   }
   return NS_ERROR_FAILURE;
 }
 nsresult
 ISOControl::GetVideoMetadata(nsRefPtr<VideoTrackMetadata>& aVidMeta)
 {
   for (uint32_t i = 0; i < mMetaArray.Length() ; i++) {
     if (mMetaArray[i]->GetKind() == TrackMetadataBase::METADATA_AVC) {
       aVidMeta = static_cast<VideoTrackMetadata*>(mMetaArray[i].get());
       return NS_OK;
     }
   }
   return NS_ERROR_FAILURE;
 }
 bool
 ISOControl::HasAudioTrack()
 {
   nsRefPtr<AudioTrackMetadata> audMeta;
   GetAudioMetadata(audMeta);
   return audMeta;
 }
 bool
 ISOControl::HasVideoTrack()
 {
   nsRefPtr<VideoTrackMetadata> vidMeta;
   GetVideoMetadata(vidMeta);
   return vidMeta;
 }
 nsresult
 ISOControl::SetFragment(FragmentBuffer* aFragment)
 {
   if (aFragment->GetType() == Audio_Track) {
     mAudioFragmentBuffer = aFragment;
   } else {
     mVideoFragmentBuffer = aFragment;
   }
   return NS_OK;
 }
 FragmentBuffer*
 ISOControl::GetFragment(uint32_t aType)
 {
   if (aType == Audio_Track) {
     return mAudioFragmentBuffer;
   } else if (aType == Video_Track){
     return mVideoFragmentBuffer;
   }
   MOZ_ASSERT(0);
   return nullptr;
 }
 nsresult
 ISOControl::GetBufs(nsTArray<nsTArray<uint8_t>>* aOutputBufs)
 {
   uint32_t len = mOutBuffers.Length();
   for (uint32_t i = 0; i < len; i++) {
     mOutBuffers[i].SwapElements(*aOutputBufs->AppendElement());
   }
   return FlushBuf();
 }
 nsresult
 ISOControl::FlushBuf()
 {
   mOutBuffers.SetLength(1);
   return NS_OK;
 }
 uint32_t
 ISOControl::WriteAVData(nsTArray<uint8_t>& aArray)
 {
   MOZ_ASSERT(!mBitCount);
   uint32_t len = aArray.Length();
   if (!len) {
     return 0;
   }
   mOutputSize += len;
   // The last element already has data, allocated a new element for pointer
   // swapping.
   if (mOutBuffers.LastElement().Length()) {
     mOutBuffers.AppendElement();
   }
   // Swap the video/audio data pointer.
   mOutBuffers.LastElement().SwapElements(aArray);
   // Following data could be boxes, so appending a new uint8_t array here.
   mOutBuffers.AppendElement();
   return len;
 }
 uint32_t
 ISOControl::WriteBits(uint64_t aBits, size_t aNumBits)
 {
   uint8_t output_byte = 0;
   MOZ_ASSERT(aNumBits <= 64);
   // TODO: rewritten following with bitset?
   for (size_t i = aNumBits; i > 0; i--) {
     mBit |= (((aBits >> (i - 1)) & 1) << (8 - ++mBitCount));
     if (mBitCount == 8) {
       Write(&mBit, sizeof(uint8_t));
       mBit = 0;
       mBitCount = 0;
       output_byte++;
     }
   }
   return output_byte;
 }
 uint32_t
 ISOControl::Write(uint8_t* aBuf, uint32_t aSize)
 {
   mOutBuffers.LastElement().AppendElements(aBuf, aSize);
   mOutputSize += aSize;
   return aSize;
 }
 uint32_t
 ISOControl::Write(uint8_t aData)
 {
   MOZ_ASSERT(!mBitCount);
   Write((uint8_t*)&aData, sizeof(uint8_t));
   return sizeof(uint8_t);
 }
 uint32_t
 ISOControl::GetBufPos()
 {
   uint32_t len = mOutBuffers.Length();
   uint32_t pos = 0;
   for (uint32_t i = 0; i < len; i++) {
     pos += mOutBuffers.ElementAt(i).Length();
   }
   return pos;
 }
 uint32_t
 ISOControl::WriteFourCC(const char* aType)
 {
   // Bit operation should be aligned to byte before writing any byte data.
   MOZ_ASSERT(!mBitCount);
   uint32_t size = strlen(aType);
   if (size == 4) {
     return Write((uint8_t*)aType, size);
   }
   return 0;
 }
 nsresult
 ISOControl::GenerateFtyp()
 {
   nsresult rv;
   uint32_t size;
   nsAutoPtr<FileTypeBox> type_box(new FileTypeBox(this));
   rv = type_box->Generate(&size);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = type_box->Write();
   NS_ENSURE_SUCCESS(rv, rv);
   return NS_OK;
 }
 nsresult
 ISOControl::GenerateMoov()
 {
   nsresult rv;
   uint32_t size;
   nsAutoPtr<MovieBox> moov_box(new MovieBox(this));
   rv = moov_box->Generate(&size);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = moov_box->Write();
   NS_ENSURE_SUCCESS(rv, rv);
   return NS_OK;
 }
 nsresult
 ISOControl::GenerateMoof(uint32_t aTrackType)
 {
   mFragNum++;
   nsresult rv;
   uint32_t size;
   uint64_t first_sample_offset = mOutputSize;
   nsAutoPtr<MovieFragmentBox> moof_box(new MovieFragmentBox(aTrackType, this));
   nsAutoPtr<MediaDataBox> mdat_box(new MediaDataBox(aTrackType, this));
   rv = moof_box->Generate(&size);
   NS_ENSURE_SUCCESS(rv, rv);
   first_sample_offset += size;
   rv = mdat_box->Generate(&size);
   NS_ENSURE_SUCCESS(rv, rv);
   first_sample_offset += mdat_box->FirstSampleOffsetInMediaDataBox();
   // correct offset info
   nsTArray<nsRefPtr<MuxerOperation>> tfhds;
   rv = moof_box->Find(NS_LITERAL_CSTRING("tfhd"), tfhds);
   NS_ENSURE_SUCCESS(rv, rv);
   uint32_t len = tfhds.Length();
   for (uint32_t i = 0; i < len; i++) {
     TrackFragmentHeaderBox* tfhd = (TrackFragmentHeaderBox*) tfhds.ElementAt(i).get();
     rv = tfhd->UpdateBaseDataOffset(first_sample_offset);
     NS_ENSURE_SUCCESS(rv, rv);
   }
   rv = moof_box->Write();
   NS_ENSURE_SUCCESS(rv, rv);
   rv = mdat_box->Write();
   NS_ENSURE_SUCCESS(rv, rv);
   return NS_OK;
 }
 uint32_t
 ISOControl::GetTime()
 {
   return (uint64_t)time(nullptr) + iso_time_offset;
 }
 }

The Tor Browser / annotate

content/media/encoder/fmp4_muxer/ISOControl.cpp@44a2da4a2ab2 (annotated)

content/media/encoder/fmp4_muxer/ISOControl.cpp