Implementation of MediaCodecPlayer stage 1

media/base/android/access_unit_queue.cc

+// Copyright 2015 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 "media/base/android/access_unit_queue.h"
+
+#include "base/logging.h"
+#include "media/base/demuxer_stream.h"
+
+namespace media {
+
+AccessUnitQueue::AccessUnitQueue()
+    : index_in_chunk_(0),
+      has_eos_(false) {
+  current_chunk_ = chunks_.end();
+}
+
+AccessUnitQueue::~AccessUnitQueue() {}
+
+void AccessUnitQueue::PushBack(const DemuxerData& data) {
+  // Media thread
+  DCHECK(!data.access_units.empty());
+
+#if DCHECK_IS_ON()
+  // Verify the rule "one DemuxerConfigs for one AU with |kConfigChanged|".
+  size_t num_config_placeholders = 0;
+#endif
+
+  // Determine whether the chunk contains EOS.
+  bool has_eos = false;
+  for (const AccessUnit& unit : data.access_units) {
+#if DCHECK_IS_ON()
+    if (unit.status == DemuxerStream::kConfigChanged)
+      ++num_config_placeholders;
+#endif
+    if (unit.is_end_of_stream) {
+      DVLOG(1) << "AccessUnitQueue::" << __FUNCTION__ << ": EOS detected";
+      has_eos = true;
+    }
+  }
+
+  DCHECK(data.demuxer_configs.size() == num_config_placeholders);
+
+  // Also verify that there is no more than one |kConfigChanged| per chunk.
+  DCHECK(num_config_placeholders <= 1);
+
+  // Create the next chunk and copy data to it.
+  scoped_ptr<DemuxerData> chunk(new DemuxerData(data));
+
+  // Append this chunk to the queue.
+  base::AutoLock lock(lock_);
+
+  bool was_empty = (current_chunk_ == chunks_.end());
+
+  chunks_.push_back(chunk.Pass());
+
+  // Position the current chunk.
+  if (was_empty) {
+    current_chunk_ = chunks_.end();
+    --current_chunk_;
+    index_in_chunk_ = 0;
+  }
+
+  // We expect that the chunk containing EOS is the last chunk.
+  DCHECK(!has_eos_);
+  has_eos_ = has_eos;
+}
+
+void AccessUnitQueue::Advance() {
+  // Decoder thread
+  base::AutoLock lock(lock_);
+
+  if (current_chunk_ == chunks_.end())
+    return;
+
+  ++index_in_chunk_;
+  if ((*current_chunk_)->access_units.size() <= index_in_chunk_) {
+    index_in_chunk_ = 0;
+    ++current_chunk_;
+  }
+
+  // Remove all chunks before the current
+  DataChunkQueue::iterator first_to_keep = current_chunk_;
+  chunks_.erase(chunks_.begin(), first_to_keep);
+}
+
+void AccessUnitQueue::Flush() {
+  // Media thread
+  base::AutoLock lock(lock_);
+
+  chunks_.clear();
+
+  current_chunk_ = chunks_.end();
+  index_in_chunk_ = 0;
+  has_eos_ = false;
+}
+
+bool AccessUnitQueue::SkipToKeyFrame() {
+  // Media thread
+  base::AutoLock lock(lock_);
+
+  // Search backwards in the current chunk only.
+
+  if (current_chunk_ == chunks_.end())
+    return false;
+
+  for (int i = index_in_chunk_; i >= 0; --i) {
+    if ((*current_chunk_)->access_units[i].is_key_frame)
+      return true;
+  }
+
+  return false;
+}
+
+void AccessUnitQueue::GetInfo(Info* info) const {
+  // Media thread, Decoder thread
+  base::AutoLock lock(lock_);
+
+  info->length = GetLength();
+  info->has_eos = has_eos_;
+  info->front_unit = nullptr;
+  info->configs = nullptr;
+
+  if (info->length > 0) {
+    DCHECK(current_chunk_ != chunks_.end());
+    DCHECK(index_in_chunk_ < (*current_chunk_)->access_units.size());
+    info->front_unit = &(*current_chunk_)->access_units[index_in_chunk_];
+
+    if (info->front_unit->status == DemuxerStream::kConfigChanged) {
+      DCHECK(!(*current_chunk_)->demuxer_configs.empty());

[qinmin, 2015/05/31 20:19:12]

This DCHECK is useless, the next DCHECK covers this one.

[Tima Vaisburd, 2015/06/01 18:56:52]

Done.

+      DCHECK((*current_chunk_)->demuxer_configs.size() == 1);
+      info->configs = &(*current_chunk_)->demuxer_configs[0];
+    }
+  }
+}
+
+int AccessUnitQueue::GetLength() const {
+  int result = 0;
+  DataChunkQueue::const_iterator chunk;
+  for (chunk = current_chunk_; chunk != chunks_.end(); ++chunk) {
+    result += (*chunk)->access_units.size();
+    if (chunk == current_chunk_)
+      result -= index_in_chunk_;
+  }
+  return result;
+}
+
+}  // namespace media