/*
 *  Copyright (c) 2017 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 "webrtc/modules/video_coding/codecs/test/videoprocessor_integrationtest.h"

#include <utility>

#if defined(WEBRTC_ANDROID)
#include "webrtc/modules/video_coding/codecs/test/android_test_initializer.h"
#include "webrtc/sdk/android/src/jni/androidmediadecoder_jni.h"
#include "webrtc/sdk/android/src/jni/androidmediaencoder_jni.h"
#elif defined(WEBRTC_IOS)
#include "webrtc/modules/video_coding/codecs/test/objc_codec_h264_test.h"
#endif

#include "webrtc/media/engine/internaldecoderfactory.h"
#include "webrtc/media/engine/internalencoderfactory.h"
#include "webrtc/media/engine/videoencodersoftwarefallbackwrapper.h"
#include "webrtc/modules/video_coding/codecs/vp8/include/vp8_common_types.h"
#include "webrtc/modules/video_coding/include/video_codec_interface.h"
#include "webrtc/modules/video_coding/include/video_coding.h"
#include "webrtc/rtc_base/checks.h"
#include "webrtc/rtc_base/event.h"
#include "webrtc/rtc_base/file.h"
#include "webrtc/rtc_base/logging.h"
#include "webrtc/rtc_base/ptr_util.h"
#include "webrtc/system_wrappers/include/sleep.h"
#include "webrtc/test/testsupport/fileutils.h"
#include "webrtc/test/testsupport/metrics/video_metrics.h"
#include "webrtc/test/video_codec_settings.h"

namespace webrtc {
namespace test {

namespace {

const int kPercTargetvsActualMismatch = 20;
const int kBaseKeyFrameInterval = 3000;

// Parameters from VP8 wrapper, which control target size of key frames.
const float kInitialBufferSize = 0.5f;
const float kOptimalBufferSize = 0.6f;
const float kScaleKeyFrameSize = 0.5f;

void VerifyQuality(const QualityMetricsResult& psnr_result,
                   const QualityMetricsResult& ssim_result,
                   const QualityThresholds& quality_thresholds) {
  EXPECT_GT(psnr_result.average, quality_thresholds.min_avg_psnr);
  EXPECT_GT(psnr_result.min, quality_thresholds.min_min_psnr);
  EXPECT_GT(ssim_result.average, quality_thresholds.min_avg_ssim);
  EXPECT_GT(ssim_result.min, quality_thresholds.min_min_ssim);
}

int NumberOfTemporalLayers(const VideoCodec& codec_settings) {
  if (codec_settings.codecType == kVideoCodecVP8) {
    return codec_settings.VP8().numberOfTemporalLayers;
  } else if (codec_settings.codecType == kVideoCodecVP9) {
    return codec_settings.VP9().numberOfTemporalLayers;
  } else {
    return 1;
  }
}

}  // namespace

VideoProcessorIntegrationTest::VideoProcessorIntegrationTest() {
#if defined(WEBRTC_VIDEOPROCESSOR_INTEGRATIONTEST_HW_CODECS_ENABLED) && \
    defined(WEBRTC_ANDROID)
  InitializeAndroidObjects();
#endif
}

VideoProcessorIntegrationTest::~VideoProcessorIntegrationTest() = default;

void VideoProcessorIntegrationTest::SetCodecSettings(TestConfig* config,
                                                     VideoCodecType codec_type,
                                                     int num_temporal_layers,
                                                     bool error_concealment_on,
                                                     bool denoising_on,
                                                     bool frame_dropper_on,
                                                     bool spatial_resize_on,
                                                     bool resilience_on,
                                                     int width,
                                                     int height) {
  webrtc::test::CodecSettings(codec_type, &config->codec_settings);

  // TODO(brandtr): Move the setting of |width| and |height| to the tests, and
  // DCHECK that they are set before initializing the codec instead.
  config->codec_settings.width = width;
  config->codec_settings.height = height;

  switch (config->codec_settings.codecType) {
    case kVideoCodecVP8:
      config->codec_settings.VP8()->resilience =
          resilience_on ? kResilientStream : kResilienceOff;
      config->codec_settings.VP8()->numberOfTemporalLayers =
          num_temporal_layers;
      config->codec_settings.VP8()->denoisingOn = denoising_on;
      config->codec_settings.VP8()->errorConcealmentOn = error_concealment_on;
      config->codec_settings.VP8()->automaticResizeOn = spatial_resize_on;
      config->codec_settings.VP8()->frameDroppingOn = frame_dropper_on;
      config->codec_settings.VP8()->keyFrameInterval = kBaseKeyFrameInterval;
      break;
    case kVideoCodecVP9:
      config->codec_settings.VP9()->resilienceOn = resilience_on;
      config->codec_settings.VP9()->numberOfTemporalLayers =
          num_temporal_layers;
      config->codec_settings.VP9()->denoisingOn = denoising_on;
      config->codec_settings.VP9()->frameDroppingOn = frame_dropper_on;
      config->codec_settings.VP9()->keyFrameInterval = kBaseKeyFrameInterval;
      config->codec_settings.VP9()->automaticResizeOn = spatial_resize_on;
      break;
    case kVideoCodecH264:
      config->codec_settings.H264()->frameDroppingOn = frame_dropper_on;
      config->codec_settings.H264()->keyFrameInterval = kBaseKeyFrameInterval;
      break;
    default:
      RTC_NOTREACHED();
      break;
  }
}

void VideoProcessorIntegrationTest::SetRateProfile(
    RateProfile* rate_profile,
    int rate_update_index,
    int bitrate_kbps,
    int framerate_fps,
    int frame_index_rate_update) {
  rate_profile->target_bit_rate[rate_update_index] = bitrate_kbps;
  rate_profile->input_frame_rate[rate_update_index] = framerate_fps;
  rate_profile->frame_index_rate_update[rate_update_index] =
      frame_index_rate_update;
}

void VideoProcessorIntegrationTest::AddRateControlThresholds(
    int max_num_dropped_frames,
    int max_key_frame_size_mismatch,
    int max_delta_frame_size_mismatch,
    int max_encoding_rate_mismatch,
    int max_time_hit_target,
    int num_spatial_resizes,
    int num_key_frames,
    std::vector<RateControlThresholds>* rc_thresholds) {
  RTC_DCHECK(rc_thresholds);

  rc_thresholds->emplace_back();
  RateControlThresholds* rc_threshold = &rc_thresholds->back();
  rc_threshold->max_num_dropped_frames = max_num_dropped_frames;
  rc_threshold->max_key_frame_size_mismatch = max_key_frame_size_mismatch;
  rc_threshold->max_delta_frame_size_mismatch = max_delta_frame_size_mismatch;
  rc_threshold->max_encoding_rate_mismatch = max_encoding_rate_mismatch;
  rc_threshold->max_time_hit_target = max_time_hit_target;
  rc_threshold->num_spatial_resizes = num_spatial_resizes;
  rc_threshold->num_key_frames = num_key_frames;
}

// Processes all frames in the clip and verifies the result.
void VideoProcessorIntegrationTest::ProcessFramesAndMaybeVerify(
    const RateProfile& rate_profile,
    const std::vector<RateControlThresholds>* rc_thresholds,
    const QualityThresholds* quality_thresholds,
    const VisualizationParams* visualization_params) {
  // The Android HW codec needs to be run on a task queue, so we simply always
  // run the test on a task queue.
  rtc::TaskQueue task_queue("VidProc TQ");
  rtc::Event sync_event(false, false);

  SetUpAndInitObjects(&task_queue, rate_profile.target_bit_rate[0],
                      rate_profile.input_frame_rate[0], visualization_params);

  // Set initial rates.
  int rate_update_index = 0;
  task_queue.PostTask([this, &rate_profile, rate_update_index] {
    processor_->SetRates(rate_profile.target_bit_rate[rate_update_index],
                         rate_profile.input_frame_rate[rate_update_index]);
  });

  // Process all frames.
  int frame_number = 0;
  const int num_frames = rate_profile.num_frames;
  RTC_DCHECK_GE(num_frames, 1);
  while (frame_number < num_frames) {
    // In order to not overwhelm the OpenMAX buffers in the Android
    // MediaCodec API, we roughly pace the frames here. The downside
    // of this is that the encode run will be done in real-time.
    // TODO(brandtr): Investigate if this is needed on iOS.
    if (config_.hw_encoder || config_.hw_decoder) {
      SleepMs(rtc::kNumMillisecsPerSec /
              rate_profile.input_frame_rate[rate_update_index]);
    }

    task_queue.PostTask([this] { processor_->ProcessFrame(); });
    ++frame_number;

    if (frame_number ==
        rate_profile.frame_index_rate_update[rate_update_index + 1]) {
      ++rate_update_index;

      task_queue.PostTask([this, &rate_profile, rate_update_index] {
        processor_->SetRates(rate_profile.target_bit_rate[rate_update_index],
                             rate_profile.input_frame_rate[rate_update_index]);
      });
    }
  }

  // Give the VideoProcessor pipeline some time to process the last frame,
  // and then release the codecs.
  if (config_.hw_encoder || config_.hw_decoder) {
    SleepMs(1 * rtc::kNumMillisecsPerSec);
  }
  ReleaseAndCloseObjects(&task_queue);

  // Calculate and print rate control statistics.
  rate_update_index = 0;
  frame_number = 0;
  ResetRateControlMetrics(rate_update_index, rate_profile);
  std::vector<int> num_dropped_frames;
  std::vector<int> num_resize_actions;
  sync_event.Reset();
  task_queue.PostTask(
      [this, &num_dropped_frames, &num_resize_actions, &sync_event]() {
        num_dropped_frames = processor_->NumberDroppedFramesPerRateUpdate();
        num_resize_actions = processor_->NumberSpatialResizesPerRateUpdate();
        sync_event.Set();
      });
  sync_event.Wait(rtc::Event::kForever);
  while (frame_number < num_frames) {
    UpdateRateControlMetrics(frame_number);

    ++frame_number;

    if (frame_number ==
        rate_profile.frame_index_rate_update[rate_update_index + 1]) {
      PrintAndMaybeVerifyRateControlMetrics(rate_update_index, rc_thresholds,
                                            num_dropped_frames,
                                            num_resize_actions);
      ++rate_update_index;
      ResetRateControlMetrics(rate_update_index, rate_profile);
    }
  }
  PrintAndMaybeVerifyRateControlMetrics(rate_update_index, rc_thresholds,
                                        num_dropped_frames, num_resize_actions);

  // Calculate and print other statistics.
  EXPECT_EQ(num_frames, static_cast<int>(stats_.size()));
  stats_.PrintSummary();

  // Calculate and print image quality statistics.
  // TODO(marpan): Should compute these quality metrics per SetRates update.
  QualityMetricsResult psnr_result, ssim_result;
  EXPECT_EQ(0, I420MetricsFromFiles(config_.input_filename.c_str(),
                                    config_.output_filename.c_str(),
                                    config_.codec_settings.width,
                                    config_.codec_settings.height, &psnr_result,
                                    &ssim_result));
  if (quality_thresholds) {
    VerifyQuality(psnr_result, ssim_result, *quality_thresholds);
  }
  printf("PSNR avg: %f, min: %f\nSSIM avg: %f, min: %f\n", psnr_result.average,
         psnr_result.min, ssim_result.average, ssim_result.min);
  printf("\n");

  // Remove analysis file.
  if (remove(config_.output_filename.c_str()) < 0) {
    fprintf(stderr, "Failed to remove temporary file!\n");
  }
}

void VideoProcessorIntegrationTest::CreateEncoderAndDecoder() {
  std::unique_ptr<cricket::WebRtcVideoEncoderFactory> encoder_factory;
  if (config_.hw_encoder) {
#if defined(WEBRTC_VIDEOPROCESSOR_INTEGRATIONTEST_HW_CODECS_ENABLED)
#if defined(WEBRTC_ANDROID)
    encoder_factory.reset(new jni::MediaCodecVideoEncoderFactory());
#elif defined(WEBRTC_IOS)
    EXPECT_EQ(kVideoCodecH264, config_.codec_settings.codecType)
        << "iOS HW codecs only support H264.";
    encoder_factory = CreateObjCEncoderFactory();
#else
    RTC_NOTREACHED() << "Only support HW encoder on Android and iOS.";
#endif
#endif  // WEBRTC_VIDEOPROCESSOR_INTEGRATIONTEST_HW_CODECS_ENABLED
  } else {
    encoder_factory.reset(new cricket::InternalEncoderFactory());
  }

  if (config_.hw_decoder) {
#if defined(WEBRTC_VIDEOPROCESSOR_INTEGRATIONTEST_HW_CODECS_ENABLED)
#if defined(WEBRTC_ANDROID)
    decoder_factory_.reset(new jni::MediaCodecVideoDecoderFactory());
#elif defined(WEBRTC_IOS)
    EXPECT_EQ(kVideoCodecH264, config_.codec_settings.codecType)
        << "iOS HW codecs only support H264.";
    decoder_factory_ = CreateObjCDecoderFactory();
#else
    RTC_NOTREACHED() << "Only support HW decoder on Android and iOS.";
#endif
#endif  // WEBRTC_VIDEOPROCESSOR_INTEGRATIONTEST_HW_CODECS_ENABLED
  } else {
    decoder_factory_.reset(new cricket::InternalDecoderFactory());
  }

  cricket::VideoCodec encoder_codec;
  switch (config_.codec_settings.codecType) {
    case kVideoCodecVP8:
      encoder_codec = cricket::VideoCodec(cricket::kVp8CodecName);
      encoder_.reset(encoder_factory->CreateVideoEncoder(encoder_codec));
      decoder_ = decoder_factory_->CreateVideoDecoder(kVideoCodecVP8);
      break;
    case kVideoCodecVP9:
      encoder_codec = cricket::VideoCodec(cricket::kVp9CodecName);
      encoder_.reset(encoder_factory->CreateVideoEncoder(encoder_codec));
      decoder_ = decoder_factory_->CreateVideoDecoder(kVideoCodecVP9);
      break;
    case kVideoCodecH264:
      // TODO(brandtr): Generalize so that we support multiple profiles here.
      encoder_codec = cricket::VideoCodec(cricket::kH264CodecName);
      encoder_.reset(encoder_factory->CreateVideoEncoder(encoder_codec));
      decoder_ = decoder_factory_->CreateVideoDecoder(kVideoCodecH264);
      break;
    default:
      RTC_NOTREACHED();
      break;
  }

  if (config_.sw_fallback_encoder) {
    encoder_ = rtc::MakeUnique<VideoEncoderSoftwareFallbackWrapper>(
        encoder_codec, std::move(encoder_));
  }

  EXPECT_TRUE(encoder_) << "Encoder not successfully created.";
  EXPECT_TRUE(decoder_) << "Decoder not successfully created.";
}

void VideoProcessorIntegrationTest::DestroyEncoderAndDecoder() {
  encoder_.reset();
  decoder_factory_->DestroyVideoDecoder(decoder_);
}

void VideoProcessorIntegrationTest::SetUpAndInitObjects(
    rtc::TaskQueue* task_queue,
    const int initial_bitrate_kbps,
    const int initial_framerate_fps,
    const VisualizationParams* visualization_params) {
  CreateEncoderAndDecoder();

  // Create file objects for quality analysis.
  analysis_frame_reader_.reset(new YuvFrameReaderImpl(
      config_.input_filename, config_.codec_settings.width,
      config_.codec_settings.height));
  analysis_frame_writer_.reset(new YuvFrameWriterImpl(
      config_.output_filename, config_.codec_settings.width,
      config_.codec_settings.height));
  EXPECT_TRUE(analysis_frame_reader_->Init());
  EXPECT_TRUE(analysis_frame_writer_->Init());

  if (visualization_params) {
    const std::string codec_name =
        CodecTypeToPayloadString(config_.codec_settings.codecType);
    const std::string implementation_type = config_.hw_encoder ? "hw" : "sw";
    // clang-format off
    const std::string output_filename_base =
        OutputPath() + config_.filename + "-" +
        codec_name + "-" + implementation_type + "-" +
        std::to_string(initial_bitrate_kbps);
    // clang-format on
    if (visualization_params->save_encoded_ivf) {
      rtc::File post_encode_file =
          rtc::File::Create(output_filename_base + ".ivf");
      encoded_frame_writer_ =
          IvfFileWriter::Wrap(std::move(post_encode_file), 0);
    }
    if (visualization_params->save_decoded_y4m) {
      decoded_frame_writer_.reset(new Y4mFrameWriterImpl(
          output_filename_base + ".y4m", config_.codec_settings.width,
          config_.codec_settings.height, initial_framerate_fps));
      EXPECT_TRUE(decoded_frame_writer_->Init());
    }
  }

  packet_manipulator_.reset(new PacketManipulatorImpl(
      &packet_reader_, config_.networking_config, config_.verbose));

  config_.codec_settings.minBitrate = 0;
  config_.codec_settings.startBitrate = initial_bitrate_kbps;
  config_.codec_settings.maxFramerate = initial_framerate_fps;

  rtc::Event sync_event(false, false);
  task_queue->PostTask([this, &sync_event]() {
    // TODO(brandtr): std::move |encoder_| and |decoder_| into the
    // VideoProcessor when we are able to store |decoder_| in a
    // std::unique_ptr. That is, when https://codereview.webrtc.org/3009973002
    // has been relanded.
    processor_ = rtc::MakeUnique<VideoProcessor>(
        encoder_.get(), decoder_, analysis_frame_reader_.get(),
        analysis_frame_writer_.get(), packet_manipulator_.get(), config_,
        &stats_, encoded_frame_writer_.get(), decoded_frame_writer_.get());
    processor_->Init();
    sync_event.Set();
  });
  sync_event.Wait(rtc::Event::kForever);
}

void VideoProcessorIntegrationTest::ReleaseAndCloseObjects(
    rtc::TaskQueue* task_queue) {
  rtc::Event sync_event(false, false);
  task_queue->PostTask([this, &sync_event]() {
    processor_->Release();
    sync_event.Set();
  });
  sync_event.Wait(rtc::Event::kForever);

  // The VideoProcessor must be ::Release()'d before we destroy the codecs.
  DestroyEncoderAndDecoder();

  // Close the analysis files before we use them for SSIM/PSNR calculations.
  analysis_frame_reader_->Close();
  analysis_frame_writer_->Close();

  // Close visualization files.
  if (encoded_frame_writer_) {
    EXPECT_TRUE(encoded_frame_writer_->Close());
  }
  if (decoded_frame_writer_) {
    decoded_frame_writer_->Close();
  }
}

// For every encoded frame, update the rate control metrics.
void VideoProcessorIntegrationTest::UpdateRateControlMetrics(int frame_number) {
  RTC_CHECK_GE(frame_number, 0);

  const int tl_idx = TemporalLayerIndexForFrame(frame_number);
  ++num_frames_per_update_[tl_idx];
  ++num_frames_total_;

  const FrameStatistic* frame_stat = stats_.GetFrame(frame_number);
  FrameType frame_type = frame_stat->frame_type;
  float encoded_size_kbits =
      frame_stat->encoded_frame_size_bytes * 8.0f / 1000.0f;

  // Update layer data.
  // Update rate mismatch relative to per-frame bandwidth for delta frames.
  if (frame_type == kVideoFrameDelta) {
    // TODO(marpan): Should we count dropped (zero size) frames in mismatch?
    sum_frame_size_mismatch_[tl_idx] +=
        fabs(encoded_size_kbits - per_frame_bandwidth_[tl_idx]) /
        per_frame_bandwidth_[tl_idx];
  } else {
    float target_size = (frame_number == 0) ? target_size_key_frame_initial_
                                            : target_size_key_frame_;
    sum_key_frame_size_mismatch_ +=
        fabs(encoded_size_kbits - target_size) / target_size;
    num_key_frames_ += 1;
  }
  sum_encoded_frame_size_[tl_idx] += encoded_size_kbits;
  // Encoding bit rate per temporal layer: from the start of the update/run
  // to the current frame.
  encoding_bitrate_[tl_idx] = sum_encoded_frame_size_[tl_idx] *
                              framerate_layer_[tl_idx] /
                              num_frames_per_update_[tl_idx];
  // Total encoding rate: from the start of the update/run to current frame.
  sum_encoded_frame_size_total_ += encoded_size_kbits;
  encoding_bitrate_total_ =
      sum_encoded_frame_size_total_ * framerate_ / num_frames_total_;
  perc_encoding_rate_mismatch_ =
      100 * fabs(encoding_bitrate_total_ - bitrate_kbps_) / bitrate_kbps_;
  if (perc_encoding_rate_mismatch_ < kPercTargetvsActualMismatch &&
      !encoding_rate_within_target_) {
    num_frames_to_hit_target_ = num_frames_total_;
    encoding_rate_within_target_ = true;
  }
}

// Verify expected behavior of rate control and print out data.
void VideoProcessorIntegrationTest::PrintAndMaybeVerifyRateControlMetrics(
    int rate_update_index,
    const std::vector<RateControlThresholds>* rc_thresholds,
    const std::vector<int>& num_dropped_frames,
    const std::vector<int>& num_resize_actions) {
  printf(
      "Rate update #%d:\n"
      " Target bitrate         : %d\n"
      " Encoded bitrate        : %f\n"
      " Frame rate             : %d\n",
      rate_update_index, bitrate_kbps_, encoding_bitrate_total_, framerate_);
  printf(
      " # processed frames     : %d\n"
      " # frames to convergence: %d\n"
      " # dropped frames       : %d\n"
      " # spatial resizes      : %d\n",
      num_frames_total_, num_frames_to_hit_target_,
      num_dropped_frames[rate_update_index],
      num_resize_actions[rate_update_index]);

  const RateControlThresholds* rc_threshold = nullptr;
  if (rc_thresholds) {
    rc_threshold = &(*rc_thresholds)[rate_update_index];

    EXPECT_LE(perc_encoding_rate_mismatch_,
              rc_threshold->max_encoding_rate_mismatch);
  }
  if (num_key_frames_ > 0) {
    int perc_key_frame_size_mismatch =
        100 * sum_key_frame_size_mismatch_ / num_key_frames_;
    printf(
        " # key frames           : %d\n"
        " Key frame rate mismatch: %d\n",
        num_key_frames_, perc_key_frame_size_mismatch);
    if (rc_threshold) {
      EXPECT_LE(perc_key_frame_size_mismatch,
                rc_threshold->max_key_frame_size_mismatch);
    }
  }

  const int num_temporal_layers =
      NumberOfTemporalLayers(config_.codec_settings);
  for (int i = 0; i < num_temporal_layers; i++) {
    int perc_frame_size_mismatch =
        100 * sum_frame_size_mismatch_[i] / num_frames_per_update_[i];
    int perc_encoding_rate_mismatch =
        100 * fabs(encoding_bitrate_[i] - bitrate_layer_[i]) /
        bitrate_layer_[i];
    printf(
        " Temporal layer #%d:\n"
        "  Target layer bitrate                : %f\n"
        "  Layer frame rate                    : %f\n"
        "  Layer per frame bandwidth           : %f\n"
        "  Layer encoding bitrate              : %f\n"
        "  Layer percent frame size mismatch   : %d\n"
        "  Layer percent encoding rate mismatch: %d\n"
        "  # frames processed per layer        : %d\n",
        i, bitrate_layer_[i], framerate_layer_[i], per_frame_bandwidth_[i],
        encoding_bitrate_[i], perc_frame_size_mismatch,
        perc_encoding_rate_mismatch, num_frames_per_update_[i]);
    if (rc_threshold) {
      EXPECT_LE(perc_frame_size_mismatch,
                rc_threshold->max_delta_frame_size_mismatch);
      EXPECT_LE(perc_encoding_rate_mismatch,
                rc_threshold->max_encoding_rate_mismatch);
    }
  }
  printf("\n");

  if (rc_threshold) {
    EXPECT_LE(num_frames_to_hit_target_, rc_threshold->max_time_hit_target);
    EXPECT_LE(num_dropped_frames[rate_update_index],
              rc_threshold->max_num_dropped_frames);
    EXPECT_EQ(rc_threshold->num_spatial_resizes,
              num_resize_actions[rate_update_index]);
    EXPECT_EQ(rc_threshold->num_key_frames, num_key_frames_);
  }
}

// Temporal layer index corresponding to frame number, for up to 3 layers.
int VideoProcessorIntegrationTest::TemporalLayerIndexForFrame(
    int frame_number) const {
  const int num_temporal_layers =
      NumberOfTemporalLayers(config_.codec_settings);
  int tl_idx = -1;
  switch (num_temporal_layers) {
    case 1:
      tl_idx = 0;
      break;
    case 2:
      // temporal layer 0:  0     2     4 ...
      // temporal layer 1:     1     3
      tl_idx = (frame_number % 2 == 0) ? 0 : 1;
      break;
    case 3:
      // temporal layer 0:  0            4            8 ...
      // temporal layer 1:        2            6
      // temporal layer 2:     1      3     5      7
      if (frame_number % 4 == 0) {
        tl_idx = 0;
      } else if ((frame_number + 2) % 4 == 0) {
        tl_idx = 1;
      } else if ((frame_number + 1) % 2 == 0) {
        tl_idx = 2;
      }
      break;
    default:
      RTC_NOTREACHED();
      break;
  }
  return tl_idx;
}

// Reset quantities before each encoder rate update.
void VideoProcessorIntegrationTest::ResetRateControlMetrics(
    int rate_update_index,
    const RateProfile& rate_profile) {
  // Set new rates.
  bitrate_kbps_ = rate_profile.target_bit_rate[rate_update_index];
  framerate_ = rate_profile.input_frame_rate[rate_update_index];
  const int num_temporal_layers =
      NumberOfTemporalLayers(config_.codec_settings);
  RTC_DCHECK_LE(num_temporal_layers, kMaxNumTemporalLayers);
  for (int i = 0; i < num_temporal_layers; i++) {
    float bit_rate_ratio = kVp8LayerRateAlloction[num_temporal_layers - 1][i];
    if (i > 0) {
      float bit_rate_delta_ratio =
          kVp8LayerRateAlloction[num_temporal_layers - 1][i] -
          kVp8LayerRateAlloction[num_temporal_layers - 1][i - 1];
      bitrate_layer_[i] = bitrate_kbps_ * bit_rate_delta_ratio;
    } else {
      bitrate_layer_[i] = bitrate_kbps_ * bit_rate_ratio;
    }
    framerate_layer_[i] =
        framerate_ / static_cast<float>(1 << (num_temporal_layers - 1));
  }
  if (num_temporal_layers == 3) {
    framerate_layer_[2] = framerate_ / 2.0f;
  }
  if (rate_update_index == 0) {
    target_size_key_frame_initial_ =
        0.5 * kInitialBufferSize * bitrate_layer_[0];
  }

  // Reset rate control metrics.
  for (int i = 0; i < num_temporal_layers; i++) {
    num_frames_per_update_[i] = 0;
    sum_frame_size_mismatch_[i] = 0.0f;
    sum_encoded_frame_size_[i] = 0.0f;
    encoding_bitrate_[i] = 0.0f;
    // Update layer per-frame-bandwidth.
    per_frame_bandwidth_[i] = static_cast<float>(bitrate_layer_[i]) /
                              static_cast<float>(framerate_layer_[i]);
  }
  // Set maximum size of key frames, following setting in the VP8 wrapper.
  float max_key_size = kScaleKeyFrameSize * kOptimalBufferSize * framerate_;
  // We don't know exact target size of the key frames (except for first one),
  // but the minimum in libvpx is ~|3 * per_frame_bandwidth| and maximum is
  // set by |max_key_size_ * per_frame_bandwidth|. Take middle point/average
  // as reference for mismatch. Note key frames always correspond to base
  // layer frame in this test.
  target_size_key_frame_ = 0.5 * (3 + max_key_size) * per_frame_bandwidth_[0];
  num_frames_total_ = 0;
  sum_encoded_frame_size_total_ = 0.0f;
  encoding_bitrate_total_ = 0.0f;
  perc_encoding_rate_mismatch_ = 0.0f;
  num_frames_to_hit_target_ =
      rate_profile.frame_index_rate_update[rate_update_index + 1];
  encoding_rate_within_target_ = false;
  sum_key_frame_size_mismatch_ = 0.0;
  num_key_frames_ = 0;
}

}  // namespace test
}  // namespace webrtc