Basic media tracks implementation for media stream parsers

media/base/media_tracks.cc

Index: media/base/media_tracks.cc
diff --git a/media/base/media_tracks.cc b/media/base/media_tracks.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3012f762e0dc3a10697f64fa66c9fb4656262863
--- /dev/null
+++ b/media/base/media_tracks.cc
@@ -0,0 +1,80 @@
+// Copyright (c) 2016 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/media_tracks.h"
+
+#include "base/bind.h"
+#include "media/base/audio_decoder_config.h"
+#include "media/base/media_track.h"

[wolenetz, 2016/02/26 00:06:20]

nit: this is already included by this class' header.

[servolk, 2016/02/26 01:56:31]

Done.

+#include "media/base/video_decoder_config.h"
+
+namespace media {
+
+MediaTracks::MediaTracks() {}
+
+MediaTracks::~MediaTracks() {}
+
+void MediaTracks::AddAudioTrack(const AudioDecoderConfig& config,
+                                const std::string& id,
+                                const std::string& kind,
+                                const std::string& label,
+                                const std::string& language) {
+  DCHECK(config.IsValidConfig());
+  scoped_ptr<MediaTrack> track = make_scoped_ptr(
+      new MediaTrack(MediaTrack::Audio, id, kind, label, language));
+  tracks_.push_back(std::move(track));

[wolenetz, 2016/02/26 00:06:20]

What if there is already an audio track with same |id| ?

+  audio_configs_[id] = config;
+}
+
+void MediaTracks::AddVideoTrack(const VideoDecoderConfig& config,
+                                const std::string& id,
+                                const std::string& kind,
+                                const std::string& label,
+                                const std::string& language) {
+  DCHECK(config.IsValidConfig());
+  scoped_ptr<MediaTrack> track = make_scoped_ptr(
+      new MediaTrack(MediaTrack::Video, id, kind, label, language));
+  tracks_.push_back(std::move(track));

[wolenetz, 2016/02/26 00:06:20]

Ditto (what if there is already a video track with same |id|?

+  video_configs_[id] = config;
+}
+
+const AudioDecoderConfig& MediaTracks::getAudioConfig(
+    const std::string& id) const {
+  auto it = audio_configs_.find(id);
+  if (it != audio_configs_.end())
+    return it->second;
+  static AudioDecoderConfig invalidConfig;
+  return invalidConfig;
+}
+
+const VideoDecoderConfig& MediaTracks::getVideoConfig(
+    const std::string& id) const {
+  auto it = video_configs_.find(id);
+  if (it != video_configs_.end())
+    return it->second;
+  static VideoDecoderConfig invalidConfig;
+  return invalidConfig;
+}
+
+const AudioDecoderConfig& MediaTracks::getFirstAudioConfig() const {
+  for (const auto& track : tracks()) {
+    if (track->type() == MediaTrack::Audio) {
+      return getAudioConfig(track->id());

[wolenetz, 2016/02/26 00:06:20]

for example, this would return probably an unexpected config if more than one
audio track had same id in |tracks_|.

+    }
+  }
+  static AudioDecoderConfig invalidConfig;
+  return invalidConfig;
+}
+
+const VideoDecoderConfig& MediaTracks::getFirstVideoConfig() const {
+  for (const auto& track : tracks()) {
+    if (track->type() == MediaTrack::Video) {
+      return getVideoConfig(track->id());

[wolenetz, 2016/02/26 00:06:20]

ditto example

+    }
+  }
+  static VideoDecoderConfig invalidConfig;
+  return invalidConfig;
+}
+
+}  // namespace media