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 DequeueBufferInfo {
+    INFO_OUTPUT_BUFFERS_CHANGED = -3,
+    INFO_OUTPUT_FORMAT_CHANGED = -2,
+    INFO_TRY_AGAIN_LATER = -1,
+  };
+
+  static const base::TimeDelta kTimeOutInfinity;
+  static const base::TimeDelta kTimeOutNoWait;
+
+  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);
+
+  // Resets 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 Reset();
+
+  // 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 , b/8125974, 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* width, int* height);
+
+  // Submits a byte array to the given input buffer. Call this after getting an
+  // available buffer from DequeueInputBuffer(). Returns the number of bytes
+  // put to the input buffer.
+  size_t QueueInputBuffer(int index, const uint8* data, int size,
+                          const base::TimeDelta& presentation_time);
+
+  // Submits an empty buffer with a EOS (END OF STREAM) flag.
+  void QueueEOS(int input_buffer_index);
+
+  // 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, bool* end_of_stream);
+
+  // 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 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();
+
+  // Gets input buffers from media codec and keeps them inside this class.
+  // To access them, use DequeueInputBuffer(), PutToInputBuffer() and
+  // QueueInputBuffer().
+  int GetInputBuffers();
+
+  // 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_
+