1 files changed, 342 insertions, 0 deletions
diff --git a/dom/media/NextFrameSeekTask.cpp b/dom/media/NextFrameSeekTask.cpp
new file mode 100644
index 000000000..2a7e90bf1
--- /dev/null
+++ b/dom/media/NextFrameSeekTask.cpp
@@ -0,0 +1,342 @@
+/* -*- 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 "NextFrameSeekTask.h"
+#include "MediaDecoderReaderWrapper.h"
+#include "mozilla/AbstractThread.h"
+#include "mozilla/Assertions.h"
+#include "nsPrintfCString.h"
+
+namespace mozilla {
+
+extern LazyLogModule gMediaSampleLog;
+
+#define SAMPLE_LOG(x, ...) MOZ_LOG(gMediaSampleLog, LogLevel::Debug, \
+  ("[NextFrameSeekTask] Decoder=%p " x, mDecoderID, ##__VA_ARGS__))
+
+namespace media {
+
+NextFrameSeekTask::NextFrameSeekTask(const void* aDecoderID,
+                                     AbstractThread* aThread,
+                                     MediaDecoderReaderWrapper* aReader,
+                                     const SeekTarget& aTarget,
+                                     const MediaInfo& aInfo,
+                                     const media::TimeUnit& aDuration,
+                                     int64_t aCurrentTime,
+                                     MediaQueue<MediaData>& aAudioQueue,
+                                     MediaQueue<MediaData>& aVideoQueue)
+  : SeekTask(aDecoderID, aThread, aReader, aTarget)
+  , mAudioQueue(aAudioQueue)
+  , mVideoQueue(aVideoQueue)
+  , mCurrentTime(aCurrentTime)
+  , mDuration(aDuration)
+{
+  AssertOwnerThread();
+  MOZ_ASSERT(aInfo.HasVideo());
+
+  // Configure MediaDecoderReaderWrapper.
+  SetCallbacks();
+}
+
+NextFrameSeekTask::~NextFrameSeekTask()
+{
+  AssertOwnerThread();
+  MOZ_ASSERT(mIsDiscarded);
+}
+
+void
+NextFrameSeekTask::Discard()
+{
+  AssertOwnerThread();
+
+  // Disconnect MDSM.
+  RejectIfExist(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
+
+  // Disconnect MediaDecoderReader.
+  CancelCallbacks();
+
+  mIsDiscarded = true;
+}
+
+bool
+NextFrameSeekTask::NeedToResetMDSM() const
+{
+  AssertOwnerThread();
+  return false;
+}
+
+/*
+ * Remove samples from the queue until aCompare() returns false.
+ * aCompare A function object with the signature bool(int64_t) which returns
+ *          true for samples that should be removed.
+ */
+template <typename Function> static void
+DiscardFrames(MediaQueue<MediaData>& aQueue, const Function& aCompare)
+{
+  while(aQueue.GetSize() > 0) {
+    if (aCompare(aQueue.PeekFront()->mTime)) {
+      RefPtr<MediaData> releaseMe = aQueue.PopFront();
+      continue;
+    }
+    break;
+  }
+}
+
+RefPtr<NextFrameSeekTask::SeekTaskPromise>
+NextFrameSeekTask::Seek(const media::TimeUnit&)
+{
+  AssertOwnerThread();
+
+  auto currentTime = mCurrentTime;
+  DiscardFrames(mVideoQueue, [currentTime] (int64_t aSampleTime) {
+    return aSampleTime <= currentTime;
+  });
+
+  RefPtr<SeekTaskPromise> promise = mSeekTaskPromise.Ensure(__func__);
+  if (!IsVideoRequestPending() && NeedMoreVideo()) {
+    RequestVideoData();
+  }
+  MaybeFinishSeek(); // Might resolve mSeekTaskPromise and modify audio queue.
+  return promise;
+}
+
+void
+NextFrameSeekTask::RequestVideoData()
+{
+  AssertOwnerThread();
+  mReader->RequestVideoData(false, media::TimeUnit());
+}
+
+bool
+NextFrameSeekTask::NeedMoreVideo() const
+{
+  AssertOwnerThread();
+  // Need to request video when we have none and video queue is not finished.
+  return mVideoQueue.GetSize() == 0 &&
+         !mSeekedVideoData &&
+         !mVideoQueue.IsFinished() &&
+         !mIsVideoQueueFinished;
+}
+
+bool
+NextFrameSeekTask::IsVideoRequestPending() const
+{
+  AssertOwnerThread();
+  return mReader->IsRequestingVideoData() || mReader->IsWaitingVideoData();
+}
+
+bool
+NextFrameSeekTask::IsAudioSeekComplete() const
+{
+  AssertOwnerThread();
+  // Don't finish seek until there are no pending requests. Otherwise, we might
+  // lose audio samples for the promise is resolved asynchronously.
+  return !mReader->IsRequestingAudioData() && !mReader->IsWaitingAudioData();
+}
+
+bool
+NextFrameSeekTask::IsVideoSeekComplete() const
+{
+  AssertOwnerThread();
+  // Don't finish seek until there are no pending requests. Otherwise, we might
+  // lose video samples for the promise is resolved asynchronously.
+  return !IsVideoRequestPending() && !NeedMoreVideo();
+}
+
+void
+NextFrameSeekTask::MaybeFinishSeek()
+{
+  AssertOwnerThread();
+  if (IsAudioSeekComplete() && IsVideoSeekComplete()) {
+    UpdateSeekTargetTime();
+
+    auto time = mTarget.GetTime().ToMicroseconds();
+    DiscardFrames(mAudioQueue, [time] (int64_t aSampleTime) {
+      return aSampleTime < time;
+    });
+
+    Resolve(__func__); // Call to MDSM::SeekCompleted();
+  }
+}
+
+void
+NextFrameSeekTask::OnAudioDecoded(MediaData* aAudioSample)
+{
+  AssertOwnerThread();
+  MOZ_ASSERT(aAudioSample);
+  MOZ_ASSERT(!mSeekTaskPromise.IsEmpty(), "Seek shouldn't be finished");
+
+  // The MDSM::mDecodedAudioEndTime will be updated once the whole SeekTask is
+  // resolved.
+
+  SAMPLE_LOG("OnAudioDecoded [%lld,%lld]",
+             aAudioSample->mTime,
+             aAudioSample->GetEndTime());
+
+  // We accept any audio data here.
+  mSeekedAudioData = aAudioSample;
+
+  MaybeFinishSeek();
+}
+
+void
+NextFrameSeekTask::OnAudioNotDecoded(const MediaResult& aError)
+{
+  AssertOwnerThread();
+  MOZ_ASSERT(!mSeekTaskPromise.IsEmpty(), "Seek shouldn't be finished");
+
+  SAMPLE_LOG("OnAudioNotDecoded (aError=%u)", aError.Code());
+
+  // We don't really handle audio deocde error here. Let MDSM to trigger further
+  // audio decoding tasks if it needs to play audio, and MDSM will then receive
+  // the decoding state from MediaDecoderReader.
+
+  MaybeFinishSeek();
+}
+
+void
+NextFrameSeekTask::OnVideoDecoded(MediaData* aVideoSample)
+{
+  AssertOwnerThread();
+  MOZ_ASSERT(aVideoSample);
+  MOZ_ASSERT(!mSeekTaskPromise.IsEmpty(), "Seek shouldn't be finished");
+
+  // The MDSM::mDecodedVideoEndTime will be updated once the whole SeekTask is
+  // resolved.
+
+  SAMPLE_LOG("OnVideoDecoded [%lld,%lld]",
+             aVideoSample->mTime,
+             aVideoSample->GetEndTime());
+
+  if (aVideoSample->mTime > mCurrentTime) {
+    mSeekedVideoData = aVideoSample;
+  }
+
+  if (NeedMoreVideo()) {
+    RequestVideoData();
+    return;
+  }
+
+  MaybeFinishSeek();
+}
+
+void
+NextFrameSeekTask::OnVideoNotDecoded(const MediaResult& aError)
+{
+  AssertOwnerThread();
+  MOZ_ASSERT(!mSeekTaskPromise.IsEmpty(), "Seek shouldn't be finished");
+
+  SAMPLE_LOG("OnVideoNotDecoded (aError=%u)", aError.Code());
+
+  if (aError == NS_ERROR_DOM_MEDIA_END_OF_STREAM) {
+    mIsVideoQueueFinished = true;
+  }
+
+  // Video seek not finished.
+  if (NeedMoreVideo()) {
+    switch (aError.Code()) {
+      case NS_ERROR_DOM_MEDIA_WAITING_FOR_DATA:
+        mReader->WaitForData(MediaData::VIDEO_DATA);
+        break;
+      case NS_ERROR_DOM_MEDIA_CANCELED:
+        RequestVideoData();
+        break;
+      case NS_ERROR_DOM_MEDIA_END_OF_STREAM:
+        MOZ_ASSERT(false, "Shouldn't want more data for ended video.");
+        break;
+      default:
+        // We might lose the audio sample after canceling the callbacks.
+        // However it doesn't really matter because MDSM is gonna shut down
+        // when seek fails.
+        CancelCallbacks();
+        // Reject the promise since we can't finish video seek anyway.
+        RejectIfExist(aError, __func__);
+        break;
+    }
+    return;
+  }
+
+  MaybeFinishSeek();
+}
+
+void
+NextFrameSeekTask::SetCallbacks()
+{
+  AssertOwnerThread();
+
+  // Register dummy callbcak for audio decoding since we don't need to handle
+  // the decoded audio samples.
+  RefPtr<NextFrameSeekTask> self = this;
+  mAudioCallback = mReader->AudioCallback().Connect(
+    OwnerThread(), [self] (AudioCallbackData aData) {
+    if (aData.is<MediaData*>()) {
+      self->OnAudioDecoded(aData.as<MediaData*>());
+    } else {
+      self->OnAudioNotDecoded(aData.as<MediaResult>());
+    }
+  });
+
+  mVideoCallback = mReader->VideoCallback().Connect(
+    OwnerThread(), [self] (VideoCallbackData aData) {
+    typedef Tuple<MediaData*, TimeStamp> Type;
+    if (aData.is<Type>()) {
+      self->OnVideoDecoded(Get<0>(aData.as<Type>()));
+    } else {
+      self->OnVideoNotDecoded(aData.as<MediaResult>());
+    }
+  });
+
+  mAudioWaitCallback = mReader->AudioWaitCallback().Connect(
+    OwnerThread(), [self] (WaitCallbackData aData) {
+    // We don't make an audio decode request here, instead, let MDSM to
+    // trigger further audio decode tasks if MDSM itself needs to play audio.
+    self->MaybeFinishSeek();
+  });
+
+  mVideoWaitCallback = mReader->VideoWaitCallback().Connect(
+    OwnerThread(), [self] (WaitCallbackData aData) {
+    if (self->NeedMoreVideo()) {
+      if (aData.is<MediaData::Type>()) {
+        self->RequestVideoData();
+      } else {
+        // Reject if we can't finish video seeking.
+        self->CancelCallbacks();
+        self->RejectIfExist(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
+      }
+      return;
+    }
+    self->MaybeFinishSeek();
+  });
+}
+
+void
+NextFrameSeekTask::CancelCallbacks()
+{
+  AssertOwnerThread();
+  mAudioCallback.DisconnectIfExists();
+  mVideoCallback.DisconnectIfExists();
+  mAudioWaitCallback.DisconnectIfExists();
+  mVideoWaitCallback.DisconnectIfExists();
+}
+
+void
+NextFrameSeekTask::UpdateSeekTargetTime()
+{
+  AssertOwnerThread();
+
+  RefPtr<MediaData> data = mVideoQueue.PeekFront();
+  if (data) {
+    mTarget.SetTime(TimeUnit::FromMicroseconds(data->mTime));
+  } else if (mSeekedVideoData) {
+    mTarget.SetTime(TimeUnit::FromMicroseconds(mSeekedVideoData->mTime));
+  } else if (mIsVideoQueueFinished || mVideoQueue.AtEndOfStream()) {
+    mTarget.SetTime(mDuration);
+  } else {
+    MOZ_ASSERT(false, "No data!");
+  }
+}
+} // namespace media
+} // namespace mozilla