MSE: Lift timestampOffset and appendWindow[Start,End] storage to WebSourceBufferImpl

content/renderer/media/websourcebuffer_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/websourcebuffer_impl.h"
 
 #include "base/float_util.h"
 #include "media/filters/chunk_demuxer.h"
 
 namespace content {
@@ skipping 12 matching lines @@
   if (time >= max_time_in_seconds)
     return max_time;
 
   return base::TimeDelta::FromMicroseconds(
       time * base::Time::kMicrosecondsPerSecond);
 }
 
 WebSourceBufferImpl::WebSourceBufferImpl(
     const std::string& id, media::ChunkDemuxer* demuxer)
     : id_(id),
-      demuxer_(demuxer) {
+      demuxer_(demuxer),
+      append_window_end_(media::kInfiniteDuration()) {
   DCHECK(demuxer_);
 }
 
 WebSourceBufferImpl::~WebSourceBufferImpl() {
   DCHECK(!demuxer_) << "Object destroyed w/o removedFromMediaSource() call";
 }
 
 bool WebSourceBufferImpl::setMode(WebSourceBuffer::AppendMode mode) {
-  bool sequence_mode = false;
+  if (demuxer_->IsParsingMediaSegment(id_))
+    return false;
+
   switch (mode) {
     case WebSourceBuffer::AppendModeSegments:
-      break;
+      demuxer_->SetSequenceMode(id_, false);
+      return true;
     case WebSourceBuffer::AppendModeSequence:
-      sequence_mode = true;
-      break;
+      demuxer_->SetSequenceMode(id_, true);
+      return true;
   }
 
-  return demuxer_->SetSequenceMode(id_, sequence_mode);
+  NOTREACHED();
+  return false;
 }
 
 blink::WebTimeRanges WebSourceBufferImpl::buffered() {
   media::Ranges<base::TimeDelta> ranges = demuxer_->GetBufferedRanges(id_);
   blink::WebTimeRanges result(ranges.size());
   for (size_t i = 0; i < ranges.size(); i++) {
     result[i].start = ranges.start(i).InSecondsF();
     result[i].end = ranges.end(i).InSecondsF();
   }
   return result;
 }
 
 void WebSourceBufferImpl::append(
     const unsigned char* data,
     unsigned length,
     double* timestamp_offset) {
-  demuxer_->AppendData(id_, data, length, timestamp_offset);
+  base::TimeDelta old_offset = timestamp_offset_;
+  demuxer_->AppendData(id_, data, length,
+                       append_window_start_, append_window_end_,
+                       &timestamp_offset_);
+
+  // Coded frame processing may update the timestamp offset. If the caller
+  // provides a non-NULL |timestamp_offset| and frame processing changes the
+  // timestamp offset, report the new offset to the caller. Do not update the
+  // caller's offset otherwise, to preserve any pre-existing value that may have
+  // more than microsecond precision.
+  if (timestamp_offset && old_offset != timestamp_offset_)
+    *timestamp_offset = timestamp_offset_.InSecondsF();
 }
 
 void WebSourceBufferImpl::abort() {
   demuxer_->Abort(id_);
 }
 
 void WebSourceBufferImpl::remove(double start, double end) {
   demuxer_->Remove(id_, DoubleToTimeDelta(start), DoubleToTimeDelta(end));
 }
 
 bool WebSourceBufferImpl::setTimestampOffset(double offset) {
-  base::TimeDelta time_offset = base::TimeDelta::FromMicroseconds(
-      offset * base::Time::kMicrosecondsPerSecond);
-  return demuxer_->SetTimestampOffset(id_, time_offset);
+  if (demuxer_->IsParsingMediaSegment(id_))
+    return false;
+
+  timestamp_offset_ = DoubleToTimeDelta(offset);
+  return true;
 }
 
 void WebSourceBufferImpl::setAppendWindowStart(double start) {
-  demuxer_->SetAppendWindowStart(id_, DoubleToTimeDelta(start));
+  append_window_start_ = DoubleToTimeDelta(start);
 }
 
 void WebSourceBufferImpl::setAppendWindowEnd(double end) {
-  demuxer_->SetAppendWindowEnd(id_, DoubleToTimeDelta(end));
+  append_window_end_ = DoubleToTimeDelta(end);
 }
 
 void WebSourceBufferImpl::removedFromMediaSource() {
   demuxer_->RemoveId(id_);
   demuxer_ = NULL;
 }
 
 }  // namespace content