test/fake_encoder.cc

/*
 *  Copyright (c) 2013 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/test/fake_encoder.h"

#include "testing/gtest/include/gtest/gtest.h"

namespace webrtc {
namespace test {

FakeEncoder::FakeEncoder(Clock* clock)
    : clock_(clock),
      callback_(NULL),
      target_bitrate_kbps_(0),
      last_encode_time_ms_(0) {
  // Generate some arbitrary not-all-zero data
  for (size_t i = 0; i < sizeof(encoded_buffer_); ++i) {
    encoded_buffer_[i] = static_cast<uint8_t>(i);
  }
}

FakeEncoder::~FakeEncoder() {}

void FakeEncoder::SetCodecSettings(VideoCodec* codec,
                                   size_t num_streams) {
  assert(num_streams > 0);
  assert(num_streams <= kMaxSimulcastStreams);

  static const SimulcastStream stream_settings[] = {
      {320, 180, 0, 150, 150, 50, codec->qpMax},
      {640, 360, 0, 500, 500, 150, codec->qpMax},
      {1280, 720, 0, 1200, 1200, 600, codec->qpMax}};
  // Add more streams to the settings above with reasonable values if required.
  assert(num_streams <= sizeof(stream_settings) / sizeof(stream_settings[0]));

  codec->numberOfSimulcastStreams = static_cast<unsigned char>(num_streams);

  unsigned int sum_of_max_bitrates = 0;
  for (size_t i = 0; i < num_streams; ++i) {
    codec->simulcastStream[i] = stream_settings[i];
    sum_of_max_bitrates += stream_settings[i].maxBitrate;
  }

  size_t last_stream = num_streams - 1;
  codec->width = stream_settings[last_stream].width;
  codec->height = stream_settings[last_stream].height;
  // Start with the average for the middle stream's max/min settings.
  codec->startBitrate = (stream_settings[last_stream / 2].maxBitrate +
                         stream_settings[last_stream / 2].minBitrate) /
                        2;
  codec->minBitrate = stream_settings[0].minBitrate;
  codec->maxBitrate = sum_of_max_bitrates;

  codec->codecType = kVideoCodecGeneric;
  strcpy(codec->plName, "FAKE");
}

int32_t FakeEncoder::InitEncode(const VideoCodec* config,
                                int32_t number_of_cores,
                                uint32_t max_payload_size) {
  config_ = *config;
  target_bitrate_kbps_ = config_.startBitrate;
  return 0;
}

int32_t FakeEncoder::Encode(
    const I420VideoFrame& input_image,
    const CodecSpecificInfo* codec_specific_info,
    const std::vector<VideoFrameType>* frame_types) {
  assert(config_.maxFramerate > 0);
  int delta_since_last_encode = 1000 / config_.maxFramerate;
  int64_t time_now_ms = clock_->TimeInMilliseconds();
  if (last_encode_time_ms_ > 0) {
    // For all frames but the first we can estimate the display time by looking
    // at the display time of the previous frame.
    delta_since_last_encode = time_now_ms - last_encode_time_ms_;
  }

  int bits_available = target_bitrate_kbps_ * delta_since_last_encode;
  int min_bits =
      config_.simulcastStream[0].minBitrate * delta_since_last_encode;
  if (bits_available < min_bits)
    bits_available = min_bits;
  last_encode_time_ms_ = time_now_ms;

  for (int i = 0; i < config_.numberOfSimulcastStreams; ++i) {
    CodecSpecificInfo specifics;
    memset(&specifics, 0, sizeof(specifics));
    specifics.codecType = kVideoCodecGeneric;
    specifics.codecSpecific.generic.simulcast_idx = i;
    int min_stream_bits = config_.simulcastStream[i].minBitrate *
        delta_since_last_encode;
    int max_stream_bits = config_.simulcastStream[i].maxBitrate *
        delta_since_last_encode;
    int stream_bits = (bits_available > max_stream_bits) ? max_stream_bits :
        bits_available;
    int stream_bytes = (stream_bits + 7) / 8;
    if (static_cast<size_t>(stream_bytes) > sizeof(encoded_buffer_))
      stream_bytes = sizeof(encoded_buffer_);

    EncodedImage encoded(
        encoded_buffer_, stream_bytes, sizeof(encoded_buffer_));
    encoded._timeStamp = input_image.timestamp();
    encoded.capture_time_ms_ = input_image.render_time_ms();
    encoded._frameType = (*frame_types)[i];
    if (min_stream_bits > bits_available) {
      encoded._length = 0;
      encoded._frameType = kSkipFrame;
    }
    if (callback_->Encoded(encoded, &specifics, NULL) != 0)
      return -1;

    bits_available -= encoded._length * 8;
  }
  return 0;
}

int32_t FakeEncoder::RegisterEncodeCompleteCallback(
    EncodedImageCallback* callback) {
  callback_ = callback;
  return 0;
}

int32_t FakeEncoder::Release() { return 0; }

int32_t FakeEncoder::SetChannelParameters(uint32_t packet_loss, int rtt) {
  return 0;
}

int32_t FakeEncoder::SetRates(uint32_t new_target_bitrate, uint32_t framerate) {
  target_bitrate_kbps_ = new_target_bitrate;
  return 0;
}
}  // namespace test
}  // namespace webrtc