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/callback.h"
+//#include "base/memory/ref_counted.h"

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

remove prev 2 lines

[dwkang1, 2013/01/28 14:54:30]

Done.

+
+// This class serves as a bridge for native code to call java functions inside

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

Move down to immediately precede class declaration

[dwkang1, 2013/01/28 14:54:30]

Done.

+// Android MediaCodec class. For more information on Android MediaCodec, check
+// http://developer.android.com/reference/android/media/MediaCodec.html
+
+namespace media {
+
+class MediaCodecBridge {
+ public:
+  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,
+  };
+
+  explicit MediaCodecBridge(const std::string& type);

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

s/type/mime_type/

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

It seems wrong to me for this to be a ctor and not a static factory method or an
Init method, because the type param is free-form.  What happens if I pass this
"foobar" as the type?  Will the DCHECK in the .cc trigger?  Or do I get back a
non-functioning MediaCodec? 
(the javadoc isn't particularly helpful on this count :( )

[dwkang1, 2013/01/28 14:54:30]

Done.

+
+  ~MediaCodecBridge();
+
+  void ConfigureAudio(const std::string& mime, int sample_rate,

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

s/mime/mime_type/

[dwkang1, 2013/01/28 14:54:30]

Done.

+      int channel_count, const uint8* csd0, int csd0_size, const uint8* csd1,

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

What's up with these csd0/1 params?
(why exactly 2 of them, why not use a vector<uint8> or a std::string to avoid
having to specify ptr/length  separately, etc)

[dwkang1, 2013/01/28 14:54:30]

Actually, they are optional params for codec specific data. 
I think It's better to make this clean and extend the function when it is
needed.

+      int csd1_size, int encoder_delay, int encoder_padding,
+      int max_input_size);
+  void ConfigureVideo(const std::string& mime, int width, int height,
+      const uint8* csd0, int csd0_size, const uint8* csd1, int csd1_size,

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

Ditto csd questions, and in fact I think you should just drop them entirely, as
the VDA should pump them in as part of the bitstream, anyway.

[dwkang1, 2013/01/28 14:54:30]

Ditto.

+      jobject surface);
+
+  void Start();
+  void Flush();

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

I think MediaCodec.flush() is something media:: code refers to as Reset().
Please document what this does (drops all queued inputs on the floor, ready to
start decoding at a new seek point?)

[dwkang1, 2013/01/28 14:54:30]

Actually, mediacodec's flush is somewhat different from omx's flush. Please see
the comment I added.

+  void Stop();

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

Stop() is irreversible in most media:: code.  Please document.

[dwkang1, 2013/01/28 14:54:30]

Done.

+  void Release();

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

Again, please document what this does.  Why would someone call this instead of
simply deleting the object?  Can a Release()'d MediaCodecBridge object ever be
used again for any purpose?

[dwkang1, 2013/01/28 14:54:30]

Agreed that this is not necessary in C++.

+
+  void GetOutputFormat(int* format, int* width, int* height);
+
+  void QueueInputBuffer(int index, int offset, int size,
+                        int64 presentation_time_us, int flags);
+  int DequeueInputBuffer(int64 timeout_us);

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

document API
(I'll stop commenting on this explicitly; please do all the rest, too)

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

I question the value of providing a "waiting" API at this layer (in other words,
I think you want to omit this param and instead always pass 0 to the Java
layer).

Does the 10us value you use in AVDA behave any differently from a value of 0?

[dwkang1, 2013/01/28 14:54:30]

I made AVDA use 0us for  timeout, but I think having timeout argument has value.
For example, the timeout would be useful if someone needs to get the output
index right after it is ready.

+  int DequeueOutputBuffer(
+      int64 timeout_us, int* offset, int* size, int64* presentation_time_us,
+      int* flags);
+  void ReleaseOutputBuffer(int index, bool render);
+
+  int GetInputBuffers();
+  int GetOutputBuffers();
+
+  void PutToInputBuffer(int index, const uint8* data, int size);
+  void GetFromOutputBuffer(int index, int offset, uint8* data, int size);
+  void GetFromOutputBuffer(int index,

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

Neither of the GetFromOutputBuffer methods is called; drop or annotate as
not-to-be-used for decode (where we use Surfaces)?

[dwkang1, 2013/01/28 14:54:30]

Done. Surface is passed when we call configure().

+                           uint8* data0, int size0,
+                           uint8* data1, int size1,
+                           uint8* data2, int size2);
+
+ private:
+  // Java MediaCodec instance.
+  base::android::ScopedJavaGlobalRef<jobject> j_media_codec_;
+
+  base::android::ScopedJavaGlobalRef<jobjectArray> j_input_buffers_;
+  base::android::ScopedJavaGlobalRef<jobjectArray> j_output_buffers_;
+
+  int j_byte_array_size_;
+  base::android::ScopedJavaGlobalRef<jbyteArray> j_byte_array_;

[Ami GONE FROM CHROMIUM, 2013/01/23 01:32:32]

Unused (both prev lines)?

[dwkang1, 2013/01/28 14:54:30]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(MediaCodecBridge);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_ANDROID_MEDIA_CODEC_BRIDGE_H_
+