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 "base/time.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,
+  };
+
+  enum BufferFlag {
+    BUFFER_FLAG_END_OF_STREAM = 4,
+    BUFFER_FLAG_CODEC_CONFIG = 2,
+    BUFFER_FLAG_FLAG_SYNC_FRAME = 1,

[Ami GONE FROM CHROMIUM, 2013/02/05 20:24:33]

Neither of the latter two flags is used.  Are you sure they're worth including
at this point?

[dwkang1, 2013/02/07 14:01:36]

Removed.

+  };
+
+  enum DequeueBufferInfo {
+    INFO_OUTPUT_BUFFERS_CHANGED = -3,
+    INFO_OUTPUT_FORMAT_CHANGED = -2,
+    INFO_TRY_AGAIN_LATER = -1,
+  };
+
+  static const base::TimeDelta kTimeOutInfinity;
+
+  explicit MediaCodecBridge(const Codec codec);
+
+  ~MediaCodecBridge();
+
+  // Starts decoding with the given codec params.
+  void StartAudio(
+      const Codec codec, int sample_rate, int channel_count);
+  void StartVideo(
+      const Codec codec, const gfx::Size& size, jobject surface);

[Ami GONE FROM CHROMIUM, 2013/02/05 20:24:33]

Actually, instead of feeding in a dummy size, how about dropping the param here
and using the dummy value (16x16 or somesuch only in bridge.cc)?

+
+  // 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.
+  void Flush();

[Ami GONE FROM CHROMIUM, 2013/02/05 20:24:33]

My point was that this would be better named Reset() to match other media::
code.

[dwkang1, 2013/02/07 14:01:36]

Ah, I am poor at getting the real meaning of the sentence. Will fix.

+
+  // Finishes the decode/encode session. The instance remains active
+  // and ready to be StartAudio/Video()ed again. HOWEVER, due to the buggy
+  // vendor's implementation, Stop() -> StartAudio/Video() may not work on some
+  // devices. For reliability, Stop() -> delete and recreate new instance ->
+  // StartAudio/Video() is recommended.
+  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);
+
+  // Submits 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,
+                        base::TimeDelta presentation_time, int flags);
+
+  // 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.
+  // Use kTimeOutInfinity for infinite timeout.
+  int DequeueInputBuffer(base::TimeDelta timeout);
+
+  // 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.
+  // Use kTimeOutInfinity for infinite timeout.
+  int DequeueOutputBuffer(
+      base::TimeDelta timeout, int* offset, int* size,
+      base::TimeDelta& presentation_time, int* flags);

[Ami GONE FROM CHROMIUM, 2013/02/05 20:24:33]

style: no non-const refs in chromium. 
s/base::TimeDelta&/base::TimeDelta*/

[dwkang1, 2013/02/07 14:01:36]

Done.

+
+  // 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);
+
+  // Puts a byte array to the given input buffer. Returns the number of bytes
+  // put to the input buffer.
+  size_t PutToInputBuffer(int index, const uint8* data, int size);

[Ami GONE FROM CHROMIUM, 2013/02/05 20:24:33]

Why does GIB() still make sense as an API?  Wouldn't it make sense to combine
that and this into a single method?
(and, in fact, since the only flag you use is EOS, could drop the magical value
of 0-size buffers and replace with a
bool EnqueueEOS();

[dwkang1, 2013/02/07 14:01:36]

I don't think so. we can just call GIB() once after Start(). We don't need to
call GIB() every time we feed input data.
Maybe, are you talking about combining PTIB() and QIB()?

+
+  // 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();
+
+ private:
+
+  // Calls start() against the media codec instance. Used in StartXXX() after
+  // configuring media codec.
+  void Start();
+
+  // 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_
+