/*
 *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#include <algorithm>
#include <deque>
#include <memory>
#include <vector>

#include "api/video_codecs/sdp_video_format.h"
#include "common_video/h264/h264_bitstream_parser.h"
#include "common_video/include/i420_buffer_pool.h"
#include "media/base/mediaconstants.h"
#include "modules/video_coding/include/video_codec_interface.h"
#include "modules/video_coding/utility/vp8_header_parser.h"
#include "rtc_base/bind.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/numerics/safe_conversions.h"
#include "rtc_base/scoped_ref_ptr.h"
#include "rtc_base/thread.h"
#include "rtc_base/timeutils.h"
#include "sdk/android/generated_video_jni/jni/MediaCodecVideoDecoder_jni.h"
#include "sdk/android/native_api/jni/java_types.h"
#include "sdk/android/src/jni/androidmediacodeccommon.h"
#include "sdk/android/src/jni/videoframe.h"
#include "third_party/libyuv/include/libyuv/convert.h"
#include "third_party/libyuv/include/libyuv/planar_functions.h"
#include "third_party/libyuv/include/libyuv/video_common.h"

using rtc::Bind;
using rtc::Thread;
using rtc::ThreadManager;
namespace webrtc {
namespace jni {

// Logging macros.
#define TAG_DECODER "MediaCodecVideoDecoder"
#ifdef TRACK_BUFFER_TIMING
#define ALOGV(...) \
  __android_log_print(ANDROID_LOG_VERBOSE, TAG_DECODER, __VA_ARGS__)
#else
#define ALOGV(...)
#endif
#define ALOGD RTC_LOG_TAG(rtc::LS_INFO, TAG_DECODER)
#define ALOGW RTC_LOG_TAG(rtc::LS_WARNING, TAG_DECODER)
#define ALOGE RTC_LOG_TAG(rtc::LS_ERROR, TAG_DECODER)

enum { kMaxWarningLogFrames = 2 };

class MediaCodecVideoDecoder : public VideoDecoder, public rtc::MessageHandler {
 public:
  explicit MediaCodecVideoDecoder(JNIEnv* jni,
                                  VideoCodecType codecType,
                                  bool use_surface);
  ~MediaCodecVideoDecoder() override;

  int32_t InitDecode(const VideoCodec* codecSettings,
                     int32_t numberOfCores) override;

  int32_t Decode(const EncodedImage& inputImage,
                 bool missingFrames,
                 const CodecSpecificInfo* codecSpecificInfo = NULL,
                 int64_t renderTimeMs = -1) override;

  int32_t RegisterDecodeCompleteCallback(
      DecodedImageCallback* callback) override;

  int32_t Release() override;

  bool PrefersLateDecoding() const override { return true; }

  // rtc::MessageHandler implementation.
  void OnMessage(rtc::Message* msg) override;

  const char* ImplementationName() const override;

 private:
  // CHECK-fail if not running on |codec_thread_|.
  void CheckOnCodecThread();

  int32_t InitDecodeOnCodecThread();
  int32_t ResetDecodeOnCodecThread();
  int32_t ReleaseOnCodecThread();
  int32_t DecodeOnCodecThread(const EncodedImage& inputImage);
  // Deliver any outputs pending in the MediaCodec to our |callback_| and return
  // true on success.
  bool DeliverPendingOutputs(JNIEnv* jni, int dequeue_timeout_us);
  int32_t ProcessHWErrorOnCodecThread();
  void EnableFrameLogOnWarning();
  void ResetVariables();

  // Type of video codec.
  VideoCodecType codecType_;

  bool key_frame_required_;
  bool inited_;
  bool sw_fallback_required_;
  const bool use_surface_;
  VideoCodec codec_;
  I420BufferPool decoded_frame_pool_;
  DecodedImageCallback* callback_;
  int frames_received_;  // Number of frames received by decoder.
  int frames_decoded_;   // Number of frames decoded by decoder.
  // Number of decoded frames for which log information is displayed.
  int frames_decoded_logged_;
  int64_t start_time_ms_;  // Start time for statistics.
  int current_frames_;  // Number of frames in the current statistics interval.
  int current_bytes_;   // Encoded bytes in the current statistics interval.
  int current_decoding_time_ms_;  // Overall decoding time in the current second
  int current_delay_time_ms_;     // Overall delay time in the current second.
  int32_t max_pending_frames_;    // Maximum number of pending input frames.
  H264BitstreamParser h264_bitstream_parser_;
  std::deque<absl::optional<uint8_t>> pending_frame_qps_;

  // State that is constant for the lifetime of this object once the ctor
  // returns.
  std::unique_ptr<Thread>
      codec_thread_;  // Thread on which to operate MediaCodec.
  ScopedJavaGlobalRef<jobject> j_media_codec_video_decoder_;

  // Global references; must be deleted in Release().
  std::vector<ScopedJavaGlobalRef<jobject>> input_buffers_;
};

MediaCodecVideoDecoder::MediaCodecVideoDecoder(JNIEnv* jni,
                                               VideoCodecType codecType,
                                               bool use_surface)
    : codecType_(codecType),
      key_frame_required_(true),
      inited_(false),
      sw_fallback_required_(false),
      use_surface_(use_surface),
      codec_thread_(Thread::Create()),
      j_media_codec_video_decoder_(
          jni,
          Java_MediaCodecVideoDecoder_Constructor(jni)) {
  codec_thread_->SetName("MediaCodecVideoDecoder", NULL);
  RTC_CHECK(codec_thread_->Start()) << "Failed to start MediaCodecVideoDecoder";

  ALOGD << "MediaCodecVideoDecoder ctor. Use surface: " << use_surface_;
  memset(&codec_, 0, sizeof(codec_));
  AllowBlockingCalls();
}

MediaCodecVideoDecoder::~MediaCodecVideoDecoder() {
  // Call Release() to ensure no more callbacks to us after we are deleted.
  Release();
}

int32_t MediaCodecVideoDecoder::InitDecode(const VideoCodec* inst,
                                           int32_t numberOfCores) {
  ALOGD << "InitDecode.";
  if (inst == NULL) {
    ALOGE << "NULL VideoCodec instance";
    return WEBRTC_VIDEO_CODEC_ERR_PARAMETER;
  }
  // Factory should guard against other codecs being used with us.
  RTC_CHECK(inst->codecType == codecType_)
      << "Unsupported codec " << inst->codecType << " for " << codecType_;

  if (sw_fallback_required_) {
    ALOGE << "InitDecode() - fallback to SW decoder";
    return WEBRTC_VIDEO_CODEC_OK;
  }
  // Save VideoCodec instance for later.
  if (&codec_ != inst) {
    codec_ = *inst;
  }
  // If maxFramerate is not set then assume 30 fps.
  codec_.maxFramerate = (codec_.maxFramerate >= 1) ? codec_.maxFramerate : 30;

  // Call Java init.
  return codec_thread_->Invoke<int32_t>(
      RTC_FROM_HERE,
      Bind(&MediaCodecVideoDecoder::InitDecodeOnCodecThread, this));
}

void MediaCodecVideoDecoder::ResetVariables() {
  CheckOnCodecThread();

  key_frame_required_ = true;
  frames_received_ = 0;
  frames_decoded_ = 0;
  frames_decoded_logged_ = kMaxDecodedLogFrames;
  start_time_ms_ = rtc::TimeMillis();
  current_frames_ = 0;
  current_bytes_ = 0;
  current_decoding_time_ms_ = 0;
  current_delay_time_ms_ = 0;
  pending_frame_qps_.clear();
}

int32_t MediaCodecVideoDecoder::InitDecodeOnCodecThread() {
  CheckOnCodecThread();
  JNIEnv* jni = AttachCurrentThreadIfNeeded();
  ScopedLocalRefFrame local_ref_frame(jni);
  ALOGD << "InitDecodeOnCodecThread Type: " << static_cast<int>(codecType_)
        << ". " << codec_.width << " x " << codec_.height
        << ". Fps: " << static_cast<int>(codec_.maxFramerate);

  // Release previous codec first if it was allocated before.
  int ret_val = ReleaseOnCodecThread();
  if (ret_val < 0) {
    ALOGE << "Release failure: " << ret_val << " - fallback to SW codec";
    sw_fallback_required_ = true;
    return WEBRTC_VIDEO_CODEC_ERROR;
  }

  ResetVariables();

  ScopedJavaLocalRef<jobject> j_video_codec_enum =
      Java_VideoCodecType_fromNativeIndex(jni, codecType_);
  bool success = Java_MediaCodecVideoDecoder_initDecode(
      jni, j_media_codec_video_decoder_, j_video_codec_enum, codec_.width,
      codec_.height);

  if (CheckException(jni) || !success) {
    ALOGE << "Codec initialization error - fallback to SW codec.";
    sw_fallback_required_ = true;
    return WEBRTC_VIDEO_CODEC_ERROR;
  }
  inited_ = true;

  switch (codecType_) {
    case kVideoCodecVP8:
      max_pending_frames_ = kMaxPendingFramesVp8;
      break;
    case kVideoCodecVP9:
      max_pending_frames_ = kMaxPendingFramesVp9;
      break;
    case kVideoCodecH264:
      max_pending_frames_ = kMaxPendingFramesH264;
      break;
    default:
      max_pending_frames_ = 0;
  }
  ALOGD << "Maximum amount of pending frames: " << max_pending_frames_;

  ScopedJavaLocalRef<jobjectArray> input_buffers =
      Java_MediaCodecVideoDecoder_getInputBuffers(jni,
                                                  j_media_codec_video_decoder_);
  input_buffers_ = JavaToNativeVector<ScopedJavaGlobalRef<jobject>>(
      jni, input_buffers, [](JNIEnv* env, const JavaRef<jobject>& o) {
        return ScopedJavaGlobalRef<jobject>(env, o);
      });

  codec_thread_->PostDelayed(RTC_FROM_HERE, kMediaCodecPollMs, this);

  return WEBRTC_VIDEO_CODEC_OK;
}

int32_t MediaCodecVideoDecoder::ResetDecodeOnCodecThread() {
  CheckOnCodecThread();
  JNIEnv* jni = AttachCurrentThreadIfNeeded();
  ScopedLocalRefFrame local_ref_frame(jni);
  ALOGD << "ResetDecodeOnCodecThread Type: " << static_cast<int>(codecType_)
        << ". " << codec_.width << " x " << codec_.height;
  ALOGD << "  Frames received: " << frames_received_
        << ". Frames decoded: " << frames_decoded_;

  inited_ = false;
  rtc::MessageQueueManager::Clear(this);
  ResetVariables();

  Java_MediaCodecVideoDecoder_reset(jni, j_media_codec_video_decoder_,
                                    codec_.width, codec_.height);

  if (CheckException(jni)) {
    ALOGE << "Soft reset error - fallback to SW codec.";
    sw_fallback_required_ = true;
    return WEBRTC_VIDEO_CODEC_ERROR;
  }
  inited_ = true;

  codec_thread_->PostDelayed(RTC_FROM_HERE, kMediaCodecPollMs, this);

  return WEBRTC_VIDEO_CODEC_OK;
}

int32_t MediaCodecVideoDecoder::Release() {
  ALOGD << "DecoderRelease request";
  return codec_thread_->Invoke<int32_t>(
      RTC_FROM_HERE, Bind(&MediaCodecVideoDecoder::ReleaseOnCodecThread, this));
}

int32_t MediaCodecVideoDecoder::ReleaseOnCodecThread() {
  if (!inited_) {
    return WEBRTC_VIDEO_CODEC_OK;
  }
  CheckOnCodecThread();
  JNIEnv* jni = AttachCurrentThreadIfNeeded();
  ALOGD << "DecoderReleaseOnCodecThread: Frames received: " << frames_received_
        << ". Frames decoded: " << frames_decoded_;
  ScopedLocalRefFrame local_ref_frame(jni);
  input_buffers_.clear();
  Java_MediaCodecVideoDecoder_release(jni, j_media_codec_video_decoder_);
  inited_ = false;
  rtc::MessageQueueManager::Clear(this);
  if (CheckException(jni)) {
    ALOGE << "Decoder release exception";
    return WEBRTC_VIDEO_CODEC_ERROR;
  }
  ALOGD << "DecoderReleaseOnCodecThread done";
  return WEBRTC_VIDEO_CODEC_OK;
}

void MediaCodecVideoDecoder::CheckOnCodecThread() {
  RTC_CHECK(codec_thread_.get() == ThreadManager::Instance()->CurrentThread())
      << "Running on wrong thread!";
}

void MediaCodecVideoDecoder::EnableFrameLogOnWarning() {
  // Log next 2 output frames.
  frames_decoded_logged_ =
      std::max(frames_decoded_logged_, frames_decoded_ + kMaxWarningLogFrames);
}

int32_t MediaCodecVideoDecoder::ProcessHWErrorOnCodecThread() {
  CheckOnCodecThread();
  int ret_val = ReleaseOnCodecThread();
  if (ret_val < 0) {
    ALOGE << "ProcessHWError: Release failure";
  }
  if (codecType_ == kVideoCodecH264) {
    // For now there is no SW H.264 which can be used as fallback codec.
    // So try to restart hw codec for now.
    ret_val = InitDecodeOnCodecThread();
    ALOGE << "Reset H.264 codec done. Status: " << ret_val;
    if (ret_val == WEBRTC_VIDEO_CODEC_OK) {
      // H.264 codec was succesfully reset - return regular error code.
      return WEBRTC_VIDEO_CODEC_ERROR;
    } else {
      // Fail to restart H.264 codec - return error code which should stop the
      // call.
      return WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE;
    }
  } else {
    sw_fallback_required_ = true;
    ALOGE << "Return WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE";
    return WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE;
  }
}

int32_t MediaCodecVideoDecoder::Decode(
    const EncodedImage& inputImage,
    bool missingFrames,
    const CodecSpecificInfo* codecSpecificInfo,
    int64_t renderTimeMs) {
  if (sw_fallback_required_) {
    ALOGE << "Decode() - fallback to SW codec";
    return WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE;
  }
  if (callback_ == NULL) {
    ALOGE << "Decode() - callback_ is NULL";
    return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
  }
  if (inputImage._buffer == NULL && inputImage._length > 0) {
    ALOGE << "Decode() - inputImage is incorrect";
    return WEBRTC_VIDEO_CODEC_ERR_PARAMETER;
  }
  if (!inited_) {
    ALOGE << "Decode() - decoder is not initialized";
    return WEBRTC_VIDEO_CODEC_UNINITIALIZED;
  }

  // Check if encoded frame dimension has changed.
  if ((inputImage._encodedWidth * inputImage._encodedHeight > 0) &&
      (inputImage._encodedWidth != codec_.width ||
       inputImage._encodedHeight != codec_.height)) {
    ALOGW << "Input resolution changed from " << codec_.width << " x "
          << codec_.height << " to " << inputImage._encodedWidth << " x "
          << inputImage._encodedHeight;
    codec_.width = inputImage._encodedWidth;
    codec_.height = inputImage._encodedHeight;
    int32_t ret;
    if (use_surface_ &&
        (codecType_ == kVideoCodecVP8 || codecType_ == kVideoCodecH264)) {
      // Soft codec reset - only for surface decoding.
      ret = codec_thread_->Invoke<int32_t>(
          RTC_FROM_HERE,
          Bind(&MediaCodecVideoDecoder::ResetDecodeOnCodecThread, this));
    } else {
      // Hard codec reset.
      ret = InitDecode(&codec_, 1);
    }
    if (ret < 0) {
      ALOGE << "InitDecode failure: " << ret << " - fallback to SW codec";
      sw_fallback_required_ = true;
      return WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE;
    }
  }

  // Always start with a complete key frame.
  if (key_frame_required_) {
    if (inputImage._frameType != kVideoFrameKey) {
      ALOGE << "Decode() - key frame is required";
      return WEBRTC_VIDEO_CODEC_ERROR;
    }
    if (!inputImage._completeFrame) {
      ALOGE << "Decode() - complete frame is required";
      return WEBRTC_VIDEO_CODEC_ERROR;
    }
    key_frame_required_ = false;
  }
  if (inputImage._length == 0) {
    return WEBRTC_VIDEO_CODEC_ERROR;
  }

  return codec_thread_->Invoke<int32_t>(
      RTC_FROM_HERE,
      Bind(&MediaCodecVideoDecoder::DecodeOnCodecThread, this, inputImage));
}

int32_t MediaCodecVideoDecoder::DecodeOnCodecThread(
    const EncodedImage& inputImage) {
  CheckOnCodecThread();
  JNIEnv* jni = AttachCurrentThreadIfNeeded();
  ScopedLocalRefFrame local_ref_frame(jni);

  // Try to drain the decoder and wait until output is not too
  // much behind the input.
  if (codecType_ == kVideoCodecH264 &&
      frames_received_ > frames_decoded_ + max_pending_frames_) {
    // Print warning for H.264 only - for VP8/VP9 one frame delay is ok.
    ALOGW << "Decoder is too far behind. Try to drain. Received: "
          << frames_received_ << ". Decoded: " << frames_decoded_;
    EnableFrameLogOnWarning();
  }
  const int64_t drain_start = rtc::TimeMillis();
  while ((frames_received_ > frames_decoded_ + max_pending_frames_) &&
         (rtc::TimeMillis() - drain_start) < kMediaCodecTimeoutMs) {
    if (!DeliverPendingOutputs(jni, kMediaCodecPollMs)) {
      ALOGE << "DeliverPendingOutputs error. Frames received: "
            << frames_received_ << ". Frames decoded: " << frames_decoded_;
      return ProcessHWErrorOnCodecThread();
    }
  }
  if (frames_received_ > frames_decoded_ + max_pending_frames_) {
    ALOGE << "Output buffer dequeue timeout. Frames received: "
          << frames_received_ << ". Frames decoded: " << frames_decoded_;
    return ProcessHWErrorOnCodecThread();
  }

  // Get input buffer.
  int j_input_buffer_index = Java_MediaCodecVideoDecoder_dequeueInputBuffer(
      jni, j_media_codec_video_decoder_);
  if (CheckException(jni) || j_input_buffer_index < 0) {
    ALOGE << "dequeueInputBuffer error: " << j_input_buffer_index
          << ". Retry DeliverPendingOutputs.";
    EnableFrameLogOnWarning();
    // Try to drain the decoder.
    if (!DeliverPendingOutputs(jni, kMediaCodecPollMs)) {
      ALOGE << "DeliverPendingOutputs error. Frames received: "
            << frames_received_ << ". Frames decoded: " << frames_decoded_;
      return ProcessHWErrorOnCodecThread();
    }
    // Try dequeue input buffer one last time.
    j_input_buffer_index = Java_MediaCodecVideoDecoder_dequeueInputBuffer(
        jni, j_media_codec_video_decoder_);
    if (CheckException(jni) || j_input_buffer_index < 0) {
      ALOGE << "dequeueInputBuffer critical error: " << j_input_buffer_index;
      return ProcessHWErrorOnCodecThread();
    }
  }

  // Copy encoded data to Java ByteBuffer.
  jobject j_input_buffer = input_buffers_[j_input_buffer_index].obj();
  uint8_t* buffer =
      reinterpret_cast<uint8_t*>(jni->GetDirectBufferAddress(j_input_buffer));
  RTC_CHECK(buffer) << "Indirect buffer??";
  size_t buffer_capacity =
      rtc::dchecked_cast<size_t>(jni->GetDirectBufferCapacity(j_input_buffer));
  if (CheckException(jni) || buffer_capacity < inputImage._length) {
    ALOGE << "Input frame size " << inputImage._length
          << " is bigger than buffer size " << buffer_capacity;
    return ProcessHWErrorOnCodecThread();
  }
  jlong presentation_timestamp_us = static_cast<jlong>(
      static_cast<int64_t>(frames_received_) * 1000000 / codec_.maxFramerate);
  memcpy(buffer, inputImage._buffer, inputImage._length);

  if (frames_decoded_ < frames_decoded_logged_) {
    ALOGD << "Decoder frame in # " << frames_received_
          << ". Type: " << inputImage._frameType << ". Buffer # "
          << j_input_buffer_index
          << ". TS: " << presentation_timestamp_us / 1000
          << ". Size: " << inputImage._length;
  }

  // Save input image timestamps for later output.
  frames_received_++;
  current_bytes_ += inputImage._length;
  absl::optional<uint8_t> qp;
  if (codecType_ == kVideoCodecVP8) {
    int qp_int;
    if (vp8::GetQp(inputImage._buffer, inputImage._length, &qp_int)) {
      qp = qp_int;
    }
  } else if (codecType_ == kVideoCodecH264) {
    h264_bitstream_parser_.ParseBitstream(inputImage._buffer,
                                          inputImage._length);
    int qp_int;
    if (h264_bitstream_parser_.GetLastSliceQp(&qp_int)) {
      qp = qp_int;
    }
  }
  pending_frame_qps_.push_back(qp);

  // Feed input to decoder.
  bool success = Java_MediaCodecVideoDecoder_queueInputBuffer(
      jni, j_media_codec_video_decoder_, j_input_buffer_index,
      static_cast<int>(inputImage._length), presentation_timestamp_us,
      static_cast<int64_t>(inputImage.Timestamp()), inputImage.ntp_time_ms_);
  if (CheckException(jni) || !success) {
    ALOGE << "queueInputBuffer error";
    return ProcessHWErrorOnCodecThread();
  }

  // Try to drain the decoder
  if (!DeliverPendingOutputs(jni, 0)) {
    ALOGE << "DeliverPendingOutputs error";
    return ProcessHWErrorOnCodecThread();
  }

  return WEBRTC_VIDEO_CODEC_OK;
}

bool MediaCodecVideoDecoder::DeliverPendingOutputs(JNIEnv* jni,
                                                   int dequeue_timeout_ms) {
  CheckOnCodecThread();
  if (frames_received_ <= frames_decoded_) {
    // No need to query for output buffers - decoder is drained.
    return true;
  }
  // Get decoder output.
  ScopedJavaLocalRef<jobject> j_decoder_output_buffer =
      (use_surface_ ? &Java_MediaCodecVideoDecoder_dequeueTextureBuffer
                    : &Java_MediaCodecVideoDecoder_dequeueOutputBuffer)(
          jni, j_media_codec_video_decoder_, dequeue_timeout_ms);
  if (CheckException(jni)) {
    ALOGE << "dequeueOutputBuffer() error";
    return false;
  }
  if (IsNull(jni, j_decoder_output_buffer)) {
    // No decoded frame ready.
    return true;
  }

  // Get decoded video frame properties.
  int color_format = Java_MediaCodecVideoDecoder_getColorFormat(
      jni, j_media_codec_video_decoder_);
  int width =
      Java_MediaCodecVideoDecoder_getWidth(jni, j_media_codec_video_decoder_);
  int height =
      Java_MediaCodecVideoDecoder_getHeight(jni, j_media_codec_video_decoder_);

  rtc::scoped_refptr<VideoFrameBuffer> frame_buffer;
  int64_t presentation_timestamps_ms = 0;
  int64_t output_timestamps_ms = 0;
  int64_t output_ntp_timestamps_ms = 0;
  int decode_time_ms = 0;
  int64_t frame_delayed_ms = 0;
  if (use_surface_) {
    // Extract data from Java DecodedTextureBuffer.
    presentation_timestamps_ms =
        Java_DecodedTextureBuffer_getPresentationTimestampMs(
            jni, j_decoder_output_buffer);
    output_timestamps_ms =
        Java_DecodedTextureBuffer_getTimeStampMs(jni, j_decoder_output_buffer);
    output_ntp_timestamps_ms = Java_DecodedTextureBuffer_getNtpTimestampMs(
        jni, j_decoder_output_buffer);
    decode_time_ms =
        Java_DecodedTextureBuffer_getDecodeTimeMs(jni, j_decoder_output_buffer);

    ScopedJavaLocalRef<jobject> j_video_frame_buffer =
        Java_DecodedTextureBuffer_getVideoFrameBuffer(jni,
                                                      j_decoder_output_buffer);
    // |video_frame_buffer| == null represents a dropped frame.
    if (!j_video_frame_buffer.is_null()) {
      frame_delayed_ms = Java_DecodedTextureBuffer_getFrameDelayMs(
          jni, j_decoder_output_buffer);
      frame_buffer = AndroidVideoBuffer::Adopt(jni, j_video_frame_buffer);
    } else {
      EnableFrameLogOnWarning();
    }
  } else {
    // Extract data from Java ByteBuffer and create output yuv420 frame -
    // for non surface decoding only.
    int stride = Java_MediaCodecVideoDecoder_getStride(
        jni, j_media_codec_video_decoder_);
    const int slice_height = Java_MediaCodecVideoDecoder_getSliceHeight(
        jni, j_media_codec_video_decoder_);
    const int output_buffer_index =
        Java_DecodedOutputBuffer_getIndex(jni, j_decoder_output_buffer);
    const int output_buffer_offset =
        Java_DecodedOutputBuffer_getOffset(jni, j_decoder_output_buffer);
    const int output_buffer_size =
        Java_DecodedOutputBuffer_getSize(jni, j_decoder_output_buffer);
    presentation_timestamps_ms =
        Java_DecodedOutputBuffer_getPresentationTimestampMs(
            jni, j_decoder_output_buffer);
    output_timestamps_ms =
        Java_DecodedOutputBuffer_getTimestampMs(jni, j_decoder_output_buffer);
    output_ntp_timestamps_ms = Java_DecodedOutputBuffer_getNtpTimestampMs(
        jni, j_decoder_output_buffer);

    decode_time_ms =
        Java_DecodedOutputBuffer_getDecodeTimeMs(jni, j_decoder_output_buffer);
    RTC_CHECK_GE(slice_height, height);

    if (output_buffer_size < width * height * 3 / 2) {
      ALOGE << "Insufficient output buffer size: " << output_buffer_size;
      return false;
    }
    if (output_buffer_size < stride * height * 3 / 2 &&
        slice_height == height && stride > width) {
      // Some codecs (Exynos) incorrectly report stride information for
      // output byte buffer, so actual stride value need to be corrected.
      stride = output_buffer_size * 2 / (height * 3);
    }
    ScopedJavaLocalRef<jobjectArray> output_buffers =
        Java_MediaCodecVideoDecoder_getOutputBuffers(
            jni, j_media_codec_video_decoder_);
    jobject output_buffer =
        jni->GetObjectArrayElement(output_buffers.obj(), output_buffer_index);
    uint8_t* payload =
        reinterpret_cast<uint8_t*>(jni->GetDirectBufferAddress(output_buffer));
    if (CheckException(jni)) {
      return false;
    }
    payload += output_buffer_offset;

    // Create yuv420 frame.
    rtc::scoped_refptr<I420Buffer> i420_buffer =
        decoded_frame_pool_.CreateBuffer(width, height);
    if (color_format == COLOR_FormatYUV420Planar) {
      RTC_CHECK_EQ(0, stride % 2);
      const int uv_stride = stride / 2;
      const uint8_t* y_ptr = payload;
      const uint8_t* u_ptr = y_ptr + stride * slice_height;

      // Note that the case with odd |slice_height| is handled in a special way.
      // The chroma height contained in the payload is rounded down instead of
      // up, making it one row less than what we expect in WebRTC. Therefore, we
      // have to duplicate the last chroma rows for this case. Also, the offset
      // between the Y plane and the U plane is unintuitive for this case. See
      // http://bugs.webrtc.org/6651 for more info.
      const int chroma_width = (width + 1) / 2;
      const int chroma_height =
          (slice_height % 2 == 0) ? (height + 1) / 2 : height / 2;
      const int u_offset = uv_stride * slice_height / 2;
      const uint8_t* v_ptr = u_ptr + u_offset;
      libyuv::CopyPlane(y_ptr, stride, i420_buffer->MutableDataY(),
                        i420_buffer->StrideY(), width, height);
      libyuv::CopyPlane(u_ptr, uv_stride, i420_buffer->MutableDataU(),
                        i420_buffer->StrideU(), chroma_width, chroma_height);
      libyuv::CopyPlane(v_ptr, uv_stride, i420_buffer->MutableDataV(),
                        i420_buffer->StrideV(), chroma_width, chroma_height);
      if (slice_height % 2 == 1) {
        RTC_CHECK_EQ(height, slice_height);
        // Duplicate the last chroma rows.
        uint8_t* u_last_row_ptr = i420_buffer->MutableDataU() +
                                  chroma_height * i420_buffer->StrideU();
        memcpy(u_last_row_ptr, u_last_row_ptr - i420_buffer->StrideU(),
               i420_buffer->StrideU());
        uint8_t* v_last_row_ptr = i420_buffer->MutableDataV() +
                                  chroma_height * i420_buffer->StrideV();
        memcpy(v_last_row_ptr, v_last_row_ptr - i420_buffer->StrideV(),
               i420_buffer->StrideV());
      }
    } else {
      // All other supported formats are nv12.
      const uint8_t* y_ptr = payload;
      const uint8_t* uv_ptr = y_ptr + stride * slice_height;
      libyuv::NV12ToI420(y_ptr, stride, uv_ptr, stride,
                         i420_buffer->MutableDataY(), i420_buffer->StrideY(),
                         i420_buffer->MutableDataU(), i420_buffer->StrideU(),
                         i420_buffer->MutableDataV(), i420_buffer->StrideV(),
                         width, height);
    }
    frame_buffer = i420_buffer;

    // Return output byte buffer back to codec.
    Java_MediaCodecVideoDecoder_returnDecodedOutputBuffer(
        jni, j_media_codec_video_decoder_, output_buffer_index);
    if (CheckException(jni)) {
      ALOGE << "returnDecodedOutputBuffer error";
      return false;
    }
  }
  if (frames_decoded_ < frames_decoded_logged_) {
    ALOGD << "Decoder frame out # " << frames_decoded_ << ". " << width << " x "
          << height << ". Color: " << color_format
          << ". TS: " << presentation_timestamps_ms
          << ". DecTime: " << static_cast<int>(decode_time_ms)
          << ". DelayTime: " << static_cast<int>(frame_delayed_ms);
  }

  // Calculate and print decoding statistics - every 3 seconds.
  frames_decoded_++;
  current_frames_++;
  current_decoding_time_ms_ += decode_time_ms;
  current_delay_time_ms_ += frame_delayed_ms;
  int statistic_time_ms = rtc::TimeMillis() - start_time_ms_;
  if (statistic_time_ms >= kMediaCodecStatisticsIntervalMs &&
      current_frames_ > 0) {
    int current_bitrate = current_bytes_ * 8 / statistic_time_ms;
    int current_fps =
        (current_frames_ * 1000 + statistic_time_ms / 2) / statistic_time_ms;
    ALOGD << "Frames decoded: " << frames_decoded_
          << ". Received: " << frames_received_
          << ". Bitrate: " << current_bitrate << " kbps"
          << ". Fps: " << current_fps
          << ". DecTime: " << (current_decoding_time_ms_ / current_frames_)
          << ". DelayTime: " << (current_delay_time_ms_ / current_frames_)
          << " for last " << statistic_time_ms << " ms.";
    start_time_ms_ = rtc::TimeMillis();
    current_frames_ = 0;
    current_bytes_ = 0;
    current_decoding_time_ms_ = 0;
    current_delay_time_ms_ = 0;
  }

  // If the frame was dropped, frame_buffer is left as nullptr.
  if (frame_buffer) {
    VideoFrame decoded_frame(frame_buffer, 0, 0, kVideoRotation_0);
    decoded_frame.set_timestamp(output_timestamps_ms);
    decoded_frame.set_ntp_time_ms(output_ntp_timestamps_ms);

    absl::optional<uint8_t> qp = pending_frame_qps_.front();
    pending_frame_qps_.pop_front();
    callback_->Decoded(decoded_frame, decode_time_ms, qp);
  }
  return true;
}

int32_t MediaCodecVideoDecoder::RegisterDecodeCompleteCallback(
    DecodedImageCallback* callback) {
  callback_ = callback;
  return WEBRTC_VIDEO_CODEC_OK;
}

void MediaCodecVideoDecoder::OnMessage(rtc::Message* msg) {
  JNIEnv* jni = AttachCurrentThreadIfNeeded();
  ScopedLocalRefFrame local_ref_frame(jni);
  if (!inited_) {
    return;
  }
  // We only ever send one message to |this| directly (not through a Bind()'d
  // functor), so expect no ID/data.
  RTC_CHECK(!msg->message_id) << "Unexpected message!";
  RTC_CHECK(!msg->pdata) << "Unexpected message!";
  CheckOnCodecThread();

  if (!DeliverPendingOutputs(jni, 0)) {
    ALOGE << "OnMessage: DeliverPendingOutputs error";
    ProcessHWErrorOnCodecThread();
    return;
  }
  codec_thread_->PostDelayed(RTC_FROM_HERE, kMediaCodecPollMs, this);
}

const char* MediaCodecVideoDecoder::ImplementationName() const {
  return "MediaCodec";
}

static jlong JNI_MediaCodecVideoDecoder_CreateDecoder(
    JNIEnv* env,
    const JavaParamRef<jclass>&,
    const JavaParamRef<jstring>& codec,
    jboolean use_surface) {
  ScopedLocalRefFrame local_ref_frame(env);
  return jlongFromPointer(new MediaCodecVideoDecoder(
      env, PayloadStringToCodecType(JavaToNativeString(env, codec)),
      use_surface));
}

}  // namespace jni
}  // namespace webrtc