// 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/time.h"
#include "media/base/audio_decoder_config.h"
#include "media/base/video_decoder_config.h"
#include "ui/gfx/size.h"

namespace media {

struct SubsampleEntry;

// These must be in sync with MediaCodecBridge.MEDIA_CODEC_XXX constants in
// MediaCodecBridge.java.
enum MediaCodecStatus {
  MEDIA_CODEC_OK,
  MEDIA_CODEC_DEQUEUE_INPUT_AGAIN_LATER,
  MEDIA_CODEC_DEQUEUE_OUTPUT_AGAIN_LATER,
  MEDIA_CODEC_OUTPUT_BUFFERS_CHANGED,
  MEDIA_CODEC_OUTPUT_FORMAT_CHANGED,
  MEDIA_CODEC_INPUT_END_OF_STREAM,
  MEDIA_CODEC_OUTPUT_END_OF_STREAM,
  MEDIA_CODEC_NO_KEY,
  MEDIA_CODEC_STOPPED,
  MEDIA_CODEC_ERROR
};

// 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
// Note: MediaCodec is only available on JB and greater.
// Use AudioCodecBridge or VideoCodecBridge to create an instance of this
// object.
class MEDIA_EXPORT MediaCodecBridge {
 public:
  // Returns true if MediaCodec is available on the device.
  static bool IsAvailable();

  // Returns whether MediaCodecBridge has a decoder that |is_secure| and can
  // decode |codec| type.
  static bool CanDecode(const std::string& codec, bool is_secure);

  virtual ~MediaCodecBridge();

  // 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.
  // Returns MEDIA_CODEC_ERROR if an unexpected error happens, or Media_CODEC_OK
  // otherwise.
  MediaCodecStatus 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().
  MediaCodecStatus QueueInputBuffer(int index,
                                    const uint8* data,
                                    int size,
                                    const base::TimeDelta& presentation_time);

  // Similar to the above call, but submits a buffer that is encrypted.
  MediaCodecStatus QueueSecureInputBuffer(
      int index,
      const uint8* data, int data_size,
      const uint8* key_id, int key_id_size,
      const uint8* iv, int iv_size,
      const SubsampleEntry* subsamples, int subsamples_size,
      const base::TimeDelta& presentation_time);

  // Submits an empty buffer with a EOS (END OF STREAM) flag.
  void QueueEOS(int input_buffer_index);

  // Returns:
  // MEDIA_CODEC_OK if an input buffer is ready to be filled with valid data,
  // MEDIA_CODEC_ENQUEUE_INPUT_AGAIN_LATER if no such buffer is available, or
  // MEDIA_CODEC_ERROR if unexpected error happens.
  // Note: Never use infinite timeout as this would block the decoder thread and
  // prevent the decoder job from being released.
  MediaCodecStatus DequeueInputBuffer(const base::TimeDelta& timeout,
                                      int* index);

  // Dequeues an output buffer, block at most timeout_us microseconds.
  // Returns the status of this operation. If OK is returned, the output
  // parameters should be populated. Otherwise, the values of output parameters
  // should not be used.
  // Note: Never use infinite timeout as this would block the decoder thread and
  // prevent the decoder job from being released.
  // TODO(xhwang): Can we drop |end_of_stream| and return
  // MEDIA_CODEC_OUTPUT_END_OF_STREAM?
  MediaCodecStatus DequeueOutputBuffer(const base::TimeDelta& timeout,
                                       int* index,
                                       size_t* offset,
                                       size_t* 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 the java class.
  // To access them, use DequeueOutputBuffer().
  void GetOutputBuffers();

  static bool RegisterMediaCodecBridge(JNIEnv* env);

 protected:
  MediaCodecBridge(const std::string& mime, bool is_secure);

  // Calls start() against the media codec instance. Used in StartXXX() after
  // configuring media codec.
  void StartInternal();

  jobject media_codec() { return j_media_codec_.obj(); }

 private:
  // Fills a particular input buffer and returns the size of copied data.
  size_t FillInputBuffer(int index, const uint8* data, int data_size);

  // Java MediaCodec instance.
  base::android::ScopedJavaGlobalRef<jobject> j_media_codec_;

  DISALLOW_COPY_AND_ASSIGN(MediaCodecBridge);
};

class AudioCodecBridge : public MediaCodecBridge {
 public:
  // Returns an AudioCodecBridge instance if |codec| is supported, or a NULL
  // pointer otherwise.
  static AudioCodecBridge* Create(const AudioCodec codec);

  // Start the audio codec bridge.
  bool Start(const AudioCodec codec, int sample_rate, int channel_count,
             const uint8* extra_data, size_t extra_data_size,
             bool play_audio, jobject media_crypto);

  // Play the output buffer. This call must be called after
  // DequeueOutputBuffer() and before ReleaseOutputBuffer.
  void PlayOutputBuffer(int index, size_t size);

  // Set the volume of the audio output.
  void SetVolume(double volume);

 private:
  explicit AudioCodecBridge(const std::string& mime);

  // Configure the java MediaFormat object with the extra codec data passed in.
  bool ConfigureMediaFormat(jobject j_format, const AudioCodec codec,
                            const uint8* extra_data, size_t extra_data_size);
};

class MEDIA_EXPORT VideoCodecBridge : public MediaCodecBridge {
 public:
  // Returns an VideoCodecBridge instance if |codec| is supported, or a NULL
  // pointer otherwise.
  static VideoCodecBridge* Create(const VideoCodec codec, bool is_secure);

  // Start the video codec bridge.
  // TODO(qinmin): Pass codec specific data if available.
  bool Start(const VideoCodec codec, const gfx::Size& size, jobject surface,
             jobject media_crypto);

 private:
  VideoCodecBridge(const std::string& mime, bool is_secure);
};

}  // namespace media

#endif  // MEDIA_BASE_ANDROID_MEDIA_CODEC_BRIDGE_H_