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;
+
+  for (size_t i = 0; i < data.access_units.size(); ++i) {
+    const AccessUnit& unit = data.access_units[i];
+    if (unit.status == DemuxerStream::kConfigChanged)
+      ++num_config_placeholders;
+
+    // EOS must be the last unit in the chunk
+    if (unit.is_end_of_stream) {
+      DCHECK(i == data.access_units.size() - 1);
+    }
+  }
+#endif
+
+  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));
+
+  // EOS flag can only be in the last access unit.
+  bool has_eos = chunk->access_units.back().is_end_of_stream;
+
+  // 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();
+    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) {
+      index_in_chunk_ = i;
+      return true;
+    }
+  }
+
+  return false;
+}
+
+AccessUnitQueue::Info AccessUnitQueue::GetInfo() const {
+  // Media thread, Decoder thread
+
+  Info info;
+  base::AutoLock lock(lock_);
+
+  info.length = GetUndecodedAccessUnitLength();
+  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.size() == 1);
+      info.configs = &(*current_chunk_)->demuxer_configs[0];
+    }
+  }
+  return info;
+}
+
+int AccessUnitQueue::GetUndecodedAccessUnitLength() const {
+  int result = 0;
+  DataChunkQueue::const_iterator chunk;
+  for (chunk = current_chunk_; chunk != chunks_.end(); ++chunk)
+    result += (*chunk)->access_units.size();
+
+  result -= index_in_chunk_;
+  return result;
+}
+
+}  // namespace media