AndroidVDA by using Android's MediaCodec API.

media/base/android/media_codec_bridge.h

+// Copyright (c) 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.
+
+#ifndef MEDIA_BASE_ANDROID_MEDIA_CODEC_BRIDGE_H_
+#define MEDIA_BASE_ANDROID_MEDIA_CODEC_BRIDGE_H_
+
+#include <jni.h>
+#include <string>
+
+#include "base/android/scoped_java_ref.h"
+#include "ui/gfx/size.h"
+
+namespace media {
+
+// This class serves as a bridge for native code to call java functions inside
+// Android MediaCodec class. For more information on Android MediaCodec, check
+// http://developer.android.com/reference/android/media/MediaCodec.html
+class MediaCodecBridge {
+ public:
+  enum Codec {
+    AUDIO_MPEG,
+    VIDEO_H264,
+    VIDEO_VP8,
+    UNKNOWN

[Ami GONE FROM CHROMIUM, 2013/01/28 19:49:45]

This isn't buying you anything except for extra cases to test for in random
places.

[dwkang1, 2013/02/04 14:08:26]

Done.

+  };
+
+  enum BufferFlag {
+    BUFFER_FLAG_END_OF_STREAM = 4,
+    BUFFER_FLAG_CODEC_CONFIG = 2,
+    BUFFER_FLAG_FLAG_SYNC_FRAME = 1,
+  };
+
+  enum DequeueBufferInfo {
+    INFO_OUTPUT_BUFFERS_CHANGED = -3,
+    INFO_OUTPUT_FORMAT_CHANGED = -2,
+    INFO_TRY_AGAIN_LATER = -1,
+  };
+
+  enum TimeOut {
+    TIMEOUT_INFINITY = -1,
+  };
+
+  explicit MediaCodecBridge(const Codec codec);
+
+  ~MediaCodecBridge();
+
+  // Configures MediaCodec with the given codec params.

[Ami GONE FROM CHROMIUM, 2013/01/28 19:49:45]

These do more than configure; they also Start(). 
Since there's a public Stop() method below, I think this deserves saying (and
possibly renaming the methods to Start{Audio,Video})

[dwkang1, 2013/02/04 14:08:26]

Done.

+  // XXX: merge the following configure methods by introducing
+  //      MediaFormatBridge.
+  void ConfigureAudio(
+      const Codec codec, int sample_rate, int channel_count);
+  void ConfigureVideo(
+      const Codec codec, const gfx::Size& size, jobject surface);
+
+  // Flushes both input and output, all indices previously returned in calls to
+  // DequeueInputBuffer() and DequeueOutputBuffer() become invalid.
+  // Please note that this clears all the inputs in the media codec. In other
+  // words, there will be no outputs until new input is provided.

[Ami GONE FROM CHROMIUM, 2013/01/28 19:49:45]

How is this different from what media code calls Reset() (e.g. VDA::Reset())?

[dwkang1, 2013/02/04 14:08:26]

It should be the same. But, there is a difference between MediaCodec.flush() and
OpenMaxIL's flush. In OpenMax, when we call flush against ports, they return the
buffers passed to the component to the IL client.

+  void Flush();
+
+  // Finishes the decode session.

[Ami GONE FROM CHROMIUM, 2013/01/28 19:49:45]

This is not informative.
What happens to pending inputs & outputs?
What can be called after this is called?

[dwkang1, 2013/02/04 14:08:26]

More description is added, but when I tested stop() to check the pending inputs
& outputs, start() after stop() threw IllegalStateException. So, I could not
check the status after stop(). Will check this behavior with Android team.

+  void Stop();
+
+  // Used for getting output format. This is valid after DequeueInputBuffer()
+  // returns a format change by returning INFO_OUTPUT_FORMAT_CHANGED
+  void GetOutputFormat(int* format, int* width, int* height);
+
+  // Submit the given buffer to media codec. Call this after filling the input
+  // buffer at the specified index
+  void QueueInputBuffer(int index, int offset, int size,
+                        int64 presentation_time_us, int flags);

[Ami GONE FROM CHROMIUM, 2013/01/28 19:49:45]

Here & elsewhere, chromium code prefers base::TimeDelta to int64+unit suffix
(like _us).

[dwkang1, 2013/02/04 14:08:26]

Done.

+
+  // Returns the index of an input buffer to be filled with valid data or
+  // INFO_TRY_AGAIN_LATER if no such buffer is currently available.
+  // TIMEOUT_INFINITY for |timeout_us| indicates infinite.
+  int DequeueInputBuffer(int64 timeout_us);
+
+  // Dequeues an output buffer, block at most timeout_us microseconds.
+  // Returns the index of an output buffer that has been successfully decoded
+  // or one of DequeueBufferInfo above.
+  // TIMEOUT_INFINITY for |timeout_us| indicates infinite.
+  int DequeueOutputBuffer(
+      int64 timeout_us, int* offset, int* size, int64* presentation_time_us,
+      int* flags);
+
+  // Returns the buffer to the codec. If you previously specified a surface
+  // when configuring this video decoder you can optionally render the buffer.
+  void ReleaseOutputBuffer(int index, bool render);
+
+  // Gets input buffers from media codec and keeps them inside this class.
+  // To access them, use DequeueInputBuffer(), PutToInputBuffer() and
+  // QueueInputBuffer().
+  int GetInputBuffers();
+
+  // Gets output buffers from media codec and keeps them inside this class.
+  // To access them, use DequeueOutputBuffer() and GetFromOutputBuffer().
+  int GetOutputBuffers();
+
+  // Puts a byte array to the given input buffer.
+  void PutToInputBuffer(int index, const uint8* data, int size);
+
+  // Gets the data in the given output buffer.

[Ami GONE FROM CHROMIUM, 2013/01/28 19:49:45]

s/\.$/ (unnecessary when decoding video to a surface)./

[dwkang1, 2013/02/04 14:08:26]

Done.

+  void GetFromOutputBuffer(int index, int offset, uint8* data, int size);
+
+ private:
+
+  // Java MediaCodec instance.
+  base::android::ScopedJavaGlobalRef<jobject> j_media_codec_;
+
+  // Input buffers used for *InputBuffer() methods.
+  base::android::ScopedJavaGlobalRef<jobjectArray> j_input_buffers_;
+
+  // Output buffers used for *InputBuffer() methods.
+  base::android::ScopedJavaGlobalRef<jobjectArray> j_output_buffers_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaCodecBridge);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_ANDROID_MEDIA_CODEC_BRIDGE_H_
+