/* -*- 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/. */

#include "H264Converter.h"

#include "DecoderDoctorDiagnostics.h"
#include "ImageContainer.h"
#include "MediaInfo.h"
#include "MediaPrefs.h"
#include "PDMFactory.h"
#include "mozilla/TaskQueue.h"
#include "AnnexB.h"
#include "H264.h"

namespace mozilla
{

H264Converter::H264Converter(PlatformDecoderModule* aPDM,
                             const CreateDecoderParams& aParams)
  : mPDM(aPDM)
  , mOriginalConfig(aParams.VideoConfig())
  , mCurrentConfig(aParams.VideoConfig())
  , mKnowsCompositor(aParams.mKnowsCompositor)
  , mImageContainer(aParams.mImageContainer)
  , mTaskQueue(aParams.mTaskQueue)
  , mDecoder(nullptr)
  , mGMPCrashHelper(aParams.mCrashHelper)
  , mLastError(NS_OK)
  , mType(aParams.mType)
  , mOnWaitingForKeyEvent(aParams.mOnWaitingForKeyEvent)
  , mDecoderOptions(aParams.mOptions)
  , mRate(aParams.mRate)
{
  mLastError = CreateDecoder(mOriginalConfig, aParams.mDiagnostics);
  if (mDecoder) {
    MOZ_ASSERT(H264::HasSPS(mOriginalConfig.mExtraData));
    // The video metadata contains out of band SPS/PPS (AVC1) store it.
    mOriginalExtraData = mOriginalConfig.mExtraData;
  }
}

H264Converter::~H264Converter()
{
}

RefPtr<MediaDataDecoder::InitPromise>
H264Converter::Init()
{
  if (mDecoder) {
    return mDecoder->Init();
  }

  // We haven't been able to initialize a decoder due to a missing SPS/PPS.
  return MediaDataDecoder::InitPromise::CreateAndResolve(
           TrackType::kVideoTrack, __func__);
}

RefPtr<MediaDataDecoder::DecodePromise>
H264Converter::Decode(MediaRawData* aSample)
{
  MOZ_RELEASE_ASSERT(mFlushPromise.IsEmpty(), "Flush operatin didn't complete");

  MOZ_RELEASE_ASSERT(!mDecodePromiseRequest.Exists() &&
                       !mInitPromiseRequest.Exists(),
                     "Can't request a new decode until previous one completed");

  if (!AnnexB::ConvertSampleToAVCC(aSample)) {
    // We need AVCC content to be able to later parse the SPS.
    // This is a no-op if the data is already AVCC.
    return DecodePromise::CreateAndReject(
      MediaResult(NS_ERROR_OUT_OF_MEMORY, RESULT_DETAIL("ConvertSampleToAVCC")),
      __func__);
  }

  if (!AnnexB::IsAVCC(aSample)) {
    return DecodePromise::CreateAndReject(
      MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
                  RESULT_DETAIL("Invalid H264 content")),
      __func__);
  }

  MediaResult rv(NS_OK);
  if (!mDecoder) {
    // It is not possible to create an AVCC H264 decoder without SPS.
    // As such, creation will fail if the extra_data just extracted doesn't
    // contain a SPS.
    rv = CreateDecoderAndInit(aSample);
    if (rv == NS_ERROR_NOT_INITIALIZED) {
      // We are missing the required SPS to create the decoder.
      // Ignore for the time being, the MediaRawData will be dropped.
      return DecodePromise::CreateAndResolve(DecodedData(), __func__);
    }
  } else {
    // Initialize the members that we couldn't if the extradata was given during
    // H264Converter's construction.
    if (!mNeedAVCC) {
      mNeedAVCC =
        Some(mDecoder->NeedsConversion() == ConversionRequired::kNeedAVCC);
    }
    if (!mCanRecycleDecoder) {
      mCanRecycleDecoder = Some(CanRecycleDecoder());
    }
    rv = CheckForSPSChange(aSample);
  }

  if (rv == NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER) {
    // The decoder is pending initialization.
    RefPtr<DecodePromise> p = mDecodePromise.Ensure(__func__);
    return p;
  }

  if (NS_FAILED(rv)) {
    return DecodePromise::CreateAndReject(rv, __func__);
  }

  if (mNeedKeyframe && !aSample->mKeyframe) {
    return DecodePromise::CreateAndResolve(DecodedData(), __func__);
  }

  auto res = !*mNeedAVCC
             ? AnnexB::ConvertSampleToAnnexB(aSample, mNeedKeyframe)
             : Ok();
  if (res.isErr()) {
    return DecodePromise::CreateAndReject(
      MediaResult(res.unwrapErr(), RESULT_DETAIL("ConvertSampleToAnnexB")),
      __func__);
  }

  mNeedKeyframe = false;

  aSample->mExtraData = mCurrentConfig.mExtraData;

  return mDecoder->Decode(aSample);
}

RefPtr<MediaDataDecoder::FlushPromise>
H264Converter::Flush()
{
  mDecodePromiseRequest.DisconnectIfExists();
  mDecodePromise.RejectIfExists(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
  mNeedKeyframe = true;
  mPendingFrames.Clear();

  MOZ_RELEASE_ASSERT(mFlushPromise.IsEmpty(), "Previous flush didn't complete");

  /*
    When we detect a change of content in the H264 stream, we first drain the
    current decoder (1), flush (2), shut it down (3) create a new decoder and
    initialize it (4). It is possible for H264Converter::Flush to be called
    during any of those times.
    If during (1):
      - mDrainRequest will not be empty.
      - The old decoder can still be used, with the current extradata as stored
        in mCurrentConfig.mExtraData.

    If during (2):
      - mFlushRequest will not be empty.
      - The old decoder can still be used, with the current extradata as stored
        in mCurrentConfig.mExtraData.

    If during (3):
      - mShutdownRequest won't be empty.
      - mDecoder is empty.
      - The old decoder is no longer referenced by the H264Converter.

    If during (4):
      - mInitPromiseRequest won't be empty.
      - mDecoder is set but not usable yet.
  */

  if (mDrainRequest.Exists() || mFlushRequest.Exists() ||
      mShutdownRequest.Exists() || mInitPromiseRequest.Exists()) {
    // We let the current decoder complete and will resume after.
    return mFlushPromise.Ensure(__func__);
  }
  if (mDecoder) {
    return mDecoder->Flush();
  }
  return FlushPromise::CreateAndResolve(true, __func__);
}

RefPtr<MediaDataDecoder::DecodePromise>
H264Converter::Drain()
{
  MOZ_RELEASE_ASSERT(!mDrainRequest.Exists());
  mNeedKeyframe = true;
  if (mDecoder) {
    return mDecoder->Drain();
  }
  return DecodePromise::CreateAndResolve(DecodedData(), __func__);
}

RefPtr<ShutdownPromise>
H264Converter::Shutdown()
{
  mInitPromiseRequest.DisconnectIfExists();
  mDecodePromiseRequest.DisconnectIfExists();
  mDecodePromise.RejectIfExists(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
  mDrainRequest.DisconnectIfExists();
  mFlushRequest.DisconnectIfExists();
  mFlushPromise.RejectIfExists(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
  mShutdownRequest.DisconnectIfExists();

  if (mShutdownPromise) {
    // We have a shutdown in progress, return that promise instead as we can't
    // shutdown a decoder twice.
    return mShutdownPromise.forget();
  }
  return ShutdownDecoder();
}

RefPtr<ShutdownPromise>
H264Converter::ShutdownDecoder()
{
  mNeedAVCC.reset();
  if (mDecoder) {
    RefPtr<MediaDataDecoder> decoder = mDecoder.forget();
    return decoder->Shutdown();
  }
  return ShutdownPromise::CreateAndResolve(true, __func__);
}

bool
H264Converter::IsHardwareAccelerated(nsACString& aFailureReason) const
{
  if (mDecoder) {
    return mDecoder->IsHardwareAccelerated(aFailureReason);
  }
  return MediaDataDecoder::IsHardwareAccelerated(aFailureReason);
}

void
H264Converter::SetSeekThreshold(const media::TimeUnit& aTime)
{
  if (mDecoder) {
    mDecoder->SetSeekThreshold(aTime);
  } else {
    MediaDataDecoder::SetSeekThreshold(aTime);
  }
}

MediaResult
H264Converter::CreateDecoder(const VideoInfo& aConfig,
                             DecoderDoctorDiagnostics* aDiagnostics)
{
  if (!H264::HasSPS(aConfig.mExtraData)) {
    // nothing found yet, will try again later
    return NS_ERROR_NOT_INITIALIZED;
  }
  UpdateConfigFromExtraData(aConfig.mExtraData);

  SPSData spsdata;
  if (H264::DecodeSPSFromExtraData(aConfig.mExtraData, spsdata)) {
    // Do some format check here.
    // WMF H.264 Video Decoder and Apple ATDecoder do not support YUV444 format.
    if (spsdata.profile_idc == 244 /* Hi444PP */ ||
        spsdata.chroma_format_idc == PDMFactory::kYUV444) {
      if (aDiagnostics) {
        aDiagnostics->SetVideoNotSupported();
      }
      return MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
                         RESULT_DETAIL("No support for YUV444 format."));
    }
  } else {
    return MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
                       RESULT_DETAIL("Invalid SPS NAL."));
  }

  MediaResult error = NS_OK;
  mDecoder = mPDM->CreateVideoDecoder({
    aConfig,
    mTaskQueue,
    aDiagnostics,
    mImageContainer,
    mKnowsCompositor,
    mGMPCrashHelper,
    mType,
    mOnWaitingForKeyEvent,
    mDecoderOptions,
    mRate,
    &error
  });

  if (!mDecoder) {
    if (NS_FAILED(error)) {
      // The decoder supports CreateDecoderParam::mError, returns the value.
      return error;
    } else {
      return MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
                         RESULT_DETAIL("Unable to create H264 decoder"));
    }
  }

  DDLINKCHILD("decoder", mDecoder.get());

  mNeedKeyframe = true;

  return NS_OK;
}

MediaResult
H264Converter::CreateDecoderAndInit(MediaRawData* aSample)
{
  RefPtr<MediaByteBuffer> extra_data =
    H264::ExtractExtraData(aSample);
  bool inbandExtradata = H264::HasSPS(extra_data);
  if (!inbandExtradata &&
      !H264::HasSPS(mCurrentConfig.mExtraData)) {
    return NS_ERROR_NOT_INITIALIZED;
  }

  if (inbandExtradata) {
    UpdateConfigFromExtraData(extra_data);
  }

  MediaResult rv =
    CreateDecoder(mCurrentConfig, /* DecoderDoctorDiagnostics* */ nullptr);

  if (NS_SUCCEEDED(rv)) {
    RefPtr<H264Converter> self = this;
    RefPtr<MediaRawData> sample = aSample;
    mDecoder->Init()
      ->Then(
        AbstractThread::GetCurrent()->AsTaskQueue(),
        __func__,
        [self, sample, this](const TrackType aTrackType) {
          mInitPromiseRequest.Complete();
          mNeedAVCC =
            Some(mDecoder->NeedsConversion() == ConversionRequired::kNeedAVCC);
          mCanRecycleDecoder = Some(CanRecycleDecoder());

          if (!mFlushPromise.IsEmpty()) {
            // A Flush is pending, abort the current operation.
            mFlushPromise.Resolve(true, __func__);
            return;
          }

          DecodeFirstSample(sample);
        },
        [self, this](const MediaResult& aError) {
          mInitPromiseRequest.Complete();

          if (!mFlushPromise.IsEmpty()) {
            // A Flush is pending, abort the current operation.
            mFlushPromise.Reject(aError, __func__);
            return;
          }

          mDecodePromise.Reject(
            MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
                        RESULT_DETAIL("Unable to initialize H264 decoder")),
            __func__);
        })
      ->Track(mInitPromiseRequest);
    return NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER;
  }
  return rv;
}

bool
H264Converter::CanRecycleDecoder() const
{
  MOZ_ASSERT(mDecoder);
  return MediaPrefs::MediaDecoderCheckRecycling() &&
         mDecoder->SupportDecoderRecycling();
}

void
H264Converter::DecodeFirstSample(MediaRawData* aSample)
{
  if (mNeedKeyframe && !aSample->mKeyframe) {
    mDecodePromise.Resolve(mPendingFrames, __func__);
    mPendingFrames.Clear();
    return;
  }

  auto res = !*mNeedAVCC
             ? AnnexB::ConvertSampleToAnnexB(aSample, mNeedKeyframe)
             : Ok();
  if (res.isErr()) {
    mDecodePromise.Reject(
      MediaResult(res.unwrapErr(), RESULT_DETAIL("ConvertSampleToAnnexB")),
      __func__);
    return;
  }

  mNeedKeyframe = false;

  RefPtr<H264Converter> self = this;
  mDecoder->Decode(aSample)
    ->Then(AbstractThread::GetCurrent()->AsTaskQueue(), __func__,
           [self, this](const MediaDataDecoder::DecodedData& aResults) {
             mDecodePromiseRequest.Complete();
             mPendingFrames.AppendElements(aResults);
             mDecodePromise.Resolve(mPendingFrames, __func__);
             mPendingFrames.Clear();
           },
           [self, this](const MediaResult& aError) {
             mDecodePromiseRequest.Complete();
             mDecodePromise.Reject(aError, __func__);
           })
    ->Track(mDecodePromiseRequest);
}

MediaResult
H264Converter::CheckForSPSChange(MediaRawData* aSample)
{
  RefPtr<MediaByteBuffer> extra_data =
    H264::ExtractExtraData(aSample);
  if (!H264::HasSPS(extra_data)) {
    MOZ_ASSERT(mCanRecycleDecoder.isSome());
    if (!*mCanRecycleDecoder) {
      // If the decoder can't be recycled, the out of band extradata will never
      // change as the H264Converter will be recreated by the MediaFormatReader
      // instead. So there's no point in testing for changes.
      return NS_OK;
    }
    // This sample doesn't contain inband SPS/PPS
    // We now check if the out of band one has changed.
    // This scenario can only occur on Android with devices that can recycle a
    // decoder.
    if (!H264::HasSPS(aSample->mExtraData) ||
        H264::CompareExtraData(aSample->mExtraData,
                                            mOriginalExtraData)) {
      return NS_OK;
    }
    extra_data = mOriginalExtraData = aSample->mExtraData;
  }
  if (H264::CompareExtraData(extra_data,
                                          mCurrentConfig.mExtraData)) {
    return NS_OK;
  }

  MOZ_ASSERT(mCanRecycleDecoder.isSome());
  if (*mCanRecycleDecoder) {
    // Do not recreate the decoder, reuse it.
    UpdateConfigFromExtraData(extra_data);
    if (!aSample->mTrackInfo) {
      aSample->mTrackInfo = new TrackInfoSharedPtr(mCurrentConfig, 0);
    }
    mNeedKeyframe = true;
    return NS_OK;
  }

  // The SPS has changed, signal to drain the current decoder and once done
  // create a new one.
  DrainThenFlushDecoder(aSample);
  return NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER;
}

void
H264Converter::DrainThenFlushDecoder(MediaRawData* aPendingSample)
{
  RefPtr<MediaRawData> sample = aPendingSample;
  RefPtr<H264Converter> self = this;
  mDecoder->Drain()
    ->Then(AbstractThread::GetCurrent()->AsTaskQueue(),
           __func__,
           [self, sample, this](const MediaDataDecoder::DecodedData& aResults) {
             mDrainRequest.Complete();
             if (!mFlushPromise.IsEmpty()) {
               // A Flush is pending, abort the current operation.
               mFlushPromise.Resolve(true, __func__);
               return;
             }
             if (aResults.Length() > 0) {
               mPendingFrames.AppendElements(aResults);
               DrainThenFlushDecoder(sample);
               return;
             }
             // We've completed the draining operation, we can now flush the
             // decoder.
             FlushThenShutdownDecoder(sample);
           },
           [self, this](const MediaResult& aError) {
             mDrainRequest.Complete();
             if (!mFlushPromise.IsEmpty()) {
               // A Flush is pending, abort the current operation.
               mFlushPromise.Reject(aError, __func__);
               return;
             }
             mDecodePromise.Reject(aError, __func__);
           })
    ->Track(mDrainRequest);
}

void H264Converter::FlushThenShutdownDecoder(MediaRawData* aPendingSample)
{
  RefPtr<MediaRawData> sample = aPendingSample;
  RefPtr<H264Converter> self = this;
  mDecoder->Flush()
    ->Then(AbstractThread::GetCurrent()->AsTaskQueue(),
           __func__,
           [self, sample, this]() {
             mFlushRequest.Complete();

             if (!mFlushPromise.IsEmpty()) {
               // A Flush is pending, abort the current operation.
               mFlushPromise.Resolve(true, __func__);
               return;
             }

             mShutdownPromise = ShutdownDecoder();
             mShutdownPromise
               ->Then(AbstractThread::GetCurrent()->AsTaskQueue(),
                      __func__,
                      [self, sample, this]() {
                        mShutdownRequest.Complete();
                        mShutdownPromise = nullptr;

                        if (!mFlushPromise.IsEmpty()) {
                          // A Flush is pending, abort the current operation.
                          mFlushPromise.Resolve(true, __func__);
                          return;
                        }

                        MediaResult rv = CreateDecoderAndInit(sample);
                        if (rv == NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER) {
                          // All good so far, will continue later.
                          return;
                        }
                        MOZ_ASSERT(NS_FAILED(rv));
                        mDecodePromise.Reject(rv, __func__);
                        return;
                      },
                      [] { MOZ_CRASH("Can't reach here'"); })
               ->Track(mShutdownRequest);
           },
           [self, this](const MediaResult& aError) {
             mFlushRequest.Complete();
             if (!mFlushPromise.IsEmpty()) {
               // A Flush is pending, abort the current operation.
               mFlushPromise.Reject(aError, __func__);
               return;
             }
             mDecodePromise.Reject(aError, __func__);
           })
    ->Track(mFlushRequest);
}

void
H264Converter::UpdateConfigFromExtraData(MediaByteBuffer* aExtraData)
{
  SPSData spsdata;
  if (H264::DecodeSPSFromExtraData(aExtraData, spsdata) &&
      spsdata.pic_width > 0 && spsdata.pic_height > 0) {
    H264::EnsureSPSIsSane(spsdata);
    mCurrentConfig.mImage.width = spsdata.pic_width;
    mCurrentConfig.mImage.height = spsdata.pic_height;
    mCurrentConfig.mDisplay.width = spsdata.display_width;
    mCurrentConfig.mDisplay.height = spsdata.display_height;
  }
  mCurrentConfig.mExtraData = aExtraData;
}

} // namespace mozilla