Store Stream Data and Not CueEvent

In the cue aligner, instead of storing the cue event, store a
stream data so that we don't need to know the stream index when
sending the cue event downstream.

Change-Id: Ice27da021fad2872e2a23975b959630a9d43b736

packager/media/chunking/cue_alignment_handler.cc

@@ -102,7 +102,7 @@ Status CueAlignmentHandler::OnFlushRequest(size_t stream_index) {
     if (stream.info->stream_type() == kStreamVideo) {
       DCHECK_EQ(stream.samples.size(), 0u)
           << "Video streams should not store samples";
-      DCHECK_EQ(stream.cue, nullptr) << "Video streams should not store cues";
+      DCHECK(!stream.cue) << "Video streams should not store cues";
     }
 
     if (!stream.samples.empty()) {
@@ -151,7 +151,8 @@ Status CueAlignmentHandler::OnVideoSample(std::unique_ptr<StreamData> sample) {
     }
 
     RETURN_IF_ERROR(UseNewSyncPoint(std::move(next_sync)));
-    RETURN_IF_ERROR(DispatchCueEvent(stream_index, std::move(stream.cue)));
+    DCHECK(stream.cue);
+    RETURN_IF_ERROR(Dispatch(std::move(stream.cue)));
   }
 
   return Dispatch(std::move(sample));
@@ -212,40 +213,31 @@ Status CueAlignmentHandler::UseNewSyncPoint(
   hint_ = sync_points_->GetHint(new_sync->time_in_seconds);
   DCHECK_GT(hint_, new_sync->time_in_seconds);
 
-  Status status;
+  // No stream should be so out of sync with the others that they would
-  for (StreamState& stream_state : stream_states_) {
+  // still be working on an old cue.
-    // No stream should be so out of sync with the others that they would
+  for (auto& stream : stream_states_) {
-    // still be working on an old cue.
+    if (!stream.cue) {
-    if (stream_state.cue) {
+      continue;
-      // TODO(kqyang): Could this happen for text when there are no text samples
-      // between the two cues?
-      LOG(ERROR) << "Found two cue events that are too close together. One at "
-                 << stream_state.cue->time_in_seconds << " and the other at "
-                 << new_sync->time_in_seconds;
-      return Status(error::INVALID_ARGUMENT, "Cue events too close together");
     }
 
-    stream_state.cue = new_sync;
+    // TODO(kqyang): Could this happen for text when there are no text samples
-
+    // between the two cues?
-    while (status.ok() && !stream_state.samples.empty()) {
+    LOG(ERROR) << "Found two cue events that are too close together. One at "
-      std::unique_ptr<StreamData>& sample = stream_state.samples.front();
+               << stream.cue->cue_event->time_in_seconds << " and the other at "
-      const double sample_time_in_seconds =
+               << new_sync->time_in_seconds;
-          TimeInSeconds(*stream_state.info, *sample);
+    return Status(error::INVALID_ARGUMENT, "Cue events too close together");
-      if (sample_time_in_seconds >= hint_) {
-        DCHECK(!stream_state.cue);
-        break;
-      }
-
-      const size_t stream_index = sample->stream_index;
-      if (stream_state.cue) {
-        status.Update(DispatchCueIfNeeded(stream_index, sample_time_in_seconds,
-                                          &stream_state));
-      }
-      status.Update(Dispatch(std::move(sample)));
-      stream_state.samples.pop_front();
-    }
   }
-  return status;
+
+  // Add the cue to each stream and give them each a chance to run through their
+  // samples.
+  for (size_t index = 0; index < stream_states_.size(); index++) {
+    StreamState& stream = stream_states_[index];
+    stream.cue = StreamData::FromCueEvent(index, new_sync);
+
+    RETURN_IF_ERROR(RunThroughSamples(&stream));
+  }
+
+  return Status::OK;
 }
 
 bool CueAlignmentHandler::EveryoneWaitingAtHint() const {
@@ -263,25 +255,16 @@ bool CueAlignmentHandler::EveryoneWaitingAtHint() const {
 //  2. Save the sample in the buffer as it comes after the next sync point.
 Status CueAlignmentHandler::AcceptSample(std::unique_ptr<StreamData> sample,
                                          StreamState* stream_state) {
+  DCHECK(sample);
+  DCHECK(sample->media_sample || sample->text_sample);
   DCHECK(stream_state);
 
+  // Need to cache the stream index as we will lose the pointer when we add
+  // the sample to the queue.
   const size_t stream_index = sample->stream_index;
-  if (stream_state->samples.empty()) {
-    const double sample_time_in_seconds =
-        TimeInSeconds(*stream_state->info, *sample);
-    if (sample_time_in_seconds < hint_) {
-      Status status;
-      if (stream_state->cue) {
-        status.Update(DispatchCueIfNeeded(stream_index, sample_time_in_seconds,
-                                          stream_state));
-      }
-      status.Update(Dispatch(std::move(sample)));
-      return status;
-    }
-    DCHECK(!stream_state->cue);
-  }
 
   stream_state->samples.push_back(std::move(sample));
+
   if (stream_state->samples.size() > kMaxBufferSize) {
     LOG(ERROR) << "Stream " << stream_index << " has buffered "
                << stream_state->samples.size() << " when the max is "
@@ -290,19 +273,37 @@ Status CueAlignmentHandler::AcceptSample(std::unique_ptr<StreamData> sample,
                   "Streams are not properly multiplexed.");
   }
 
+  return RunThroughSamples(stream_state);
+}
+
+Status CueAlignmentHandler::RunThroughSamples(StreamState* stream) {
+  // Step through all our samples until we find where we can insert the cue.
+  // Think of this as a merge sort.
+  while (stream->cue && stream->samples.size()) {
+    const double sample_time_in_seconds =
+        TimeInSeconds(*stream->info, *stream->samples.front());
+    const double cue_time_in_seconds = stream->cue->cue_event->time_in_seconds;
+
+    // The cue can go out now. So let it, but we can't let the sample out yet
+    // because we need to check it with the hint.
+    if (cue_time_in_seconds <= sample_time_in_seconds) {
+      RETURN_IF_ERROR(Dispatch(std::move(stream->cue)));
+    } else {
+      RETURN_IF_ERROR(Dispatch(std::move(stream->samples.front())));
+      stream->samples.pop_front();
+    }
+  }
+
+  // If we still have samples, then it means that we sent out the cue and can
+  // now work up to the hint. So now send all samples that come before the hint
+  // downstream.
+  while (stream->samples.size() &&
+         TimeInSeconds(*stream->info, *stream->samples.front()) < hint_) {
+    RETURN_IF_ERROR(Dispatch(std::move(stream->samples.front())));
+    stream->samples.pop_front();
+  }
+
   return Status::OK;
 }
-
-Status CueAlignmentHandler::DispatchCueIfNeeded(
-    size_t stream_index,
-    double next_sample_time_in_seconds,
-    StreamState* stream_state) {
-  DCHECK(stream_state->cue);
-  if (next_sample_time_in_seconds < stream_state->cue->time_in_seconds)
-    return Status::OK;
-  DCHECK_LT(stream_state->cue->time_in_seconds, hint_);
-  return DispatchCueEvent(stream_index, std::move(stream_state->cue));
-}
-
 }  // namespace media
 }  // namespace shaka

packager/media/chunking/cue_alignment_handler.h

@@ -41,9 +41,9 @@ class CueAlignmentHandler : public MediaHandler {
     bool to_be_flushed = false;
 
     // If set, it points to the next cue it has to send downstream. Note that if
-    // it is not set, the next cue is not determined.
+    // it is not set, the next cue is not determined. We store the stream data
-    // This is set but not really used by video stream.
+    // so that we don't need a stream index to send it out.
-    std::shared_ptr<const CueEvent> cue;
+    std::unique_ptr<StreamData> cue;
   };
 
   // MediaHandler overrides.
@@ -68,10 +68,8 @@ class CueAlignmentHandler : public MediaHandler {
   Status AcceptSample(std::unique_ptr<StreamData> sample,
                       StreamState* stream_state);
 
-  // Dispatch the cue if the new sample comes at or after it.
+  // Dispatch all samples and cues (in the correct order) for the given stream.
-  Status DispatchCueIfNeeded(size_t stream_index,
+  Status RunThroughSamples(StreamState* stream);
-                             double next_sample_time_in_seconds,
-                             StreamState* stream_state);
 
   SyncPointQueue* const sync_points_ = nullptr;
   std::vector<StreamState> stream_states_;