Refactor FFmpegVideoDecoder to try and generalize code common to all video decoders.

This changes the DecoderBase API to be fully asynchronous when invoking its subclass's actions.

Review URL: http://codereview.chromium.org/465044

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@34208 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 36 insertions, 0 deletions

diff --git a/media/ffmpeg/ffmpeg_util.cc b/media/ffmpeg/ffmpeg_util.cc
new file mode 100644
index 0000000..1be3b12
--- /dev/null
+++ b/media/ffmpeg/ffmpeg_util.cc
@@ -0,0 +1,18 @@
+// Copyright (c) 2009 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/ffmpeg/ffmpeg_util.h"
+
+#include "media/filters/ffmpeg_common.h"
+
+namespace media {
+
+static const AVRational kMicrosBase = { 1, base::Time::kMicrosecondsPerSecond };
+
+base::TimeDelta ConvertTimestamp(const AVRational& time_base, int64 timestamp) {
+  int64 microseconds = av_rescale_q(timestamp, time_base, kMicrosBase);
+  return base::TimeDelta::FromMicroseconds(microseconds);
+}
+
+}  // namespace media
diff --git a/media/ffmpeg/ffmpeg_util.h b/media/ffmpeg/ffmpeg_util.h
new file mode 100644
index 0000000..6799cc4
--- /dev/null
+++ b/media/ffmpeg/ffmpeg_util.h
@@ -0,0 +1,18 @@
+// Copyright (c) 2009 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.
+
+#ifndef MEDIA_FFMPEG_FFMPEG_UTIL_H_
+#define MEDIA_FFMPEG_FFMPEG_UTIL_H_
+
+#include "base/time.h"
+
+struct AVRational;
+
+namespace media {
+
+base::TimeDelta ConvertTimestamp(const AVRational& time_base, int64 timestamp);
+
+}  // namespace media
+
+#endif  // MEDIA_FFMPEG_FFMPEG_UTIL_H_