modules/video_coding/generic_decoder.cc

/*
 *  Copyright (c) 2012 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 "modules/video_coding/generic_decoder.h"

#include <algorithm>

#include "modules/video_coding/include/video_coding.h"
#include "modules/video_coding/internal_defines.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#include "rtc_base/timeutils.h"
#include "rtc_base/trace_event.h"
#include "system_wrappers/include/clock.h"

namespace webrtc {

VCMDecodedFrameCallback::VCMDecodedFrameCallback(VCMTiming* timing,
                                                 Clock* clock)
    : _clock(clock),
      _timing(timing),
      _timestampMap(kDecoderFrameMemoryLength),
      _lastReceivedPictureID(0) {
  decoder_thread_.DetachFromThread();
  ntp_offset_ =
      _clock->CurrentNtpInMilliseconds() - _clock->TimeInMilliseconds();
}

VCMDecodedFrameCallback::~VCMDecodedFrameCallback() {
  // TODO(tommi): Re-enable this DCHECK once downstream issues have been fixed.
  // RTC_DCHECK(construction_thread_.CalledOnValidThread());
}

void VCMDecodedFrameCallback::SetUserReceiveCallback(
    VCMReceiveCallback* receiveCallback) {
  RTC_DCHECK(construction_thread_.CalledOnValidThread());
  RTC_DCHECK((!_receiveCallback && receiveCallback) ||
             (_receiveCallback && !receiveCallback));
  _receiveCallback = receiveCallback;
  // When the callback is cleared, it signals to us that the decoder thread
  // is no longer running. Another decoder thread might be started, so it's
  // important to reset the thread checker first.
  if (!receiveCallback)
    decoder_thread_.DetachFromThread();
}

VCMReceiveCallback* VCMDecodedFrameCallback::UserReceiveCallback() {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  // Called on the decode thread via VCMCodecDataBase::GetDecoder.
  // The callback must always have been set before this happens.
  RTC_DCHECK(_receiveCallback);
  return _receiveCallback;
}

int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage) {
  return Decoded(decodedImage, -1);
}

int32_t VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
                                         int64_t decode_time_ms) {
  Decoded(decodedImage,
          decode_time_ms >= 0 ? rtc::Optional<int32_t>(decode_time_ms)
                              : rtc::nullopt,
          rtc::nullopt);
  return WEBRTC_VIDEO_CODEC_OK;
}

void VCMDecodedFrameCallback::Decoded(VideoFrame& decodedImage,
                                      rtc::Optional<int32_t> decode_time_ms,
                                      rtc::Optional<uint8_t> qp) {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  RTC_DCHECK(_receiveCallback) << "Callback must not be null at this point";

  TRACE_EVENT_INSTANT1("webrtc", "VCMDecodedFrameCallback::Decoded",
                       "timestamp", decodedImage.timestamp());
  // TODO(holmer): We should improve this so that we can handle multiple
  // callbacks from one call to Decode().
  VCMFrameInformation* frameInfo = _timestampMap.Pop(decodedImage.timestamp());

  if (frameInfo == NULL) {
    RTC_LOG(LS_WARNING) << "Too many frames backed up in the decoder, dropping "
                           "this one.";
    return;
  }

  const int64_t now_ms = _clock->TimeInMilliseconds();
  if (!decode_time_ms) {
    decode_time_ms = now_ms - frameInfo->decodeStartTimeMs;
  }
  _timing->StopDecodeTimer(decodedImage.timestamp(), *decode_time_ms, now_ms,
                           frameInfo->renderTimeMs);

  // Report timing information.
  if (frameInfo->timing.flags != TimingFrameFlags::kInvalid) {
    int64_t capture_time_ms = decodedImage.ntp_time_ms() - ntp_offset_;
    // Convert remote timestamps to local time from ntp timestamps.
    frameInfo->timing.encode_start_ms -= ntp_offset_;
    frameInfo->timing.encode_finish_ms -= ntp_offset_;
    frameInfo->timing.packetization_finish_ms -= ntp_offset_;
    frameInfo->timing.pacer_exit_ms -= ntp_offset_;
    frameInfo->timing.network_timestamp_ms -= ntp_offset_;
    frameInfo->timing.network2_timestamp_ms -= ntp_offset_;

    int64_t sender_delta_ms = 0;
    if (decodedImage.ntp_time_ms() < 0) {
      // Sender clock is not estimated yet. Make sure that sender times are all
      // negative to indicate that. Yet they still should be relatively correct.
      sender_delta_ms =
          std::max({capture_time_ms, frameInfo->timing.encode_start_ms,
                    frameInfo->timing.encode_finish_ms,
                    frameInfo->timing.packetization_finish_ms,
                    frameInfo->timing.pacer_exit_ms,
                    frameInfo->timing.network_timestamp_ms,
                    frameInfo->timing.network2_timestamp_ms}) +
          1;
    }

    TimingFrameInfo timing_frame_info;

    timing_frame_info.capture_time_ms = capture_time_ms - sender_delta_ms;
    timing_frame_info.encode_start_ms =
        frameInfo->timing.encode_start_ms - sender_delta_ms;
    timing_frame_info.encode_finish_ms =
        frameInfo->timing.encode_finish_ms - sender_delta_ms;
    timing_frame_info.packetization_finish_ms =
        frameInfo->timing.packetization_finish_ms - sender_delta_ms;
    timing_frame_info.pacer_exit_ms =
        frameInfo->timing.pacer_exit_ms - sender_delta_ms;
    timing_frame_info.network_timestamp_ms =
        frameInfo->timing.network_timestamp_ms - sender_delta_ms;
    timing_frame_info.network2_timestamp_ms =
        frameInfo->timing.network2_timestamp_ms - sender_delta_ms;
    timing_frame_info.receive_start_ms = frameInfo->timing.receive_start_ms;
    timing_frame_info.receive_finish_ms = frameInfo->timing.receive_finish_ms;
    timing_frame_info.decode_start_ms = frameInfo->decodeStartTimeMs;
    timing_frame_info.decode_finish_ms = now_ms;
    timing_frame_info.render_time_ms = frameInfo->renderTimeMs;
    timing_frame_info.rtp_timestamp = decodedImage.timestamp();
    timing_frame_info.flags = frameInfo->timing.flags;

    _timing->SetTimingFrameInfo(timing_frame_info);
  }

  decodedImage.set_timestamp_us(
      frameInfo->renderTimeMs * rtc::kNumMicrosecsPerMillisec);
  decodedImage.set_rotation(frameInfo->rotation);
  _receiveCallback->FrameToRender(decodedImage, qp, frameInfo->content_type);
}

int32_t VCMDecodedFrameCallback::ReceivedDecodedReferenceFrame(
    const uint64_t pictureId) {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  return _receiveCallback->ReceivedDecodedReferenceFrame(pictureId);
}

int32_t VCMDecodedFrameCallback::ReceivedDecodedFrame(
    const uint64_t pictureId) {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  _lastReceivedPictureID = pictureId;
  return 0;
}

uint64_t VCMDecodedFrameCallback::LastReceivedPictureID() const {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  return _lastReceivedPictureID;
}

void VCMDecodedFrameCallback::OnDecoderImplementationName(
    const char* implementation_name) {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  _receiveCallback->OnDecoderImplementationName(implementation_name);
}

void VCMDecodedFrameCallback::Map(uint32_t timestamp,
                                  VCMFrameInformation* frameInfo) {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  _timestampMap.Add(timestamp, frameInfo);
}

int32_t VCMDecodedFrameCallback::Pop(uint32_t timestamp) {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  return _timestampMap.Pop(timestamp) == nullptr ? VCM_GENERAL_ERROR : VCM_OK;
}

VCMGenericDecoder::VCMGenericDecoder(std::unique_ptr<VideoDecoder> decoder)
    : VCMGenericDecoder(decoder.release(), false /* isExternal */) {}

VCMGenericDecoder::VCMGenericDecoder(VideoDecoder* decoder, bool isExternal)
    : _callback(NULL),
      _frameInfos(),
      _nextFrameInfoIdx(0),
      decoder_(decoder),
      _codecType(kVideoCodecUnknown),
      _isExternal(isExternal),
      _last_keyframe_content_type(VideoContentType::UNSPECIFIED) {
  RTC_DCHECK(decoder_);
}

VCMGenericDecoder::~VCMGenericDecoder() {
  decoder_->Release();
  if (_isExternal)
    decoder_.release();
  RTC_DCHECK(_isExternal || decoder_);
}

int32_t VCMGenericDecoder::InitDecode(const VideoCodec* settings,
                                      int32_t numberOfCores) {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  TRACE_EVENT0("webrtc", "VCMGenericDecoder::InitDecode");
  _codecType = settings->codecType;

  return decoder_->InitDecode(settings, numberOfCores);
}

int32_t VCMGenericDecoder::Decode(const VCMEncodedFrame& frame, int64_t nowMs) {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  TRACE_EVENT2("webrtc", "VCMGenericDecoder::Decode", "timestamp",
               frame.EncodedImage()._timeStamp, "decoder",
               decoder_->ImplementationName());
  _frameInfos[_nextFrameInfoIdx].decodeStartTimeMs = nowMs;
  _frameInfos[_nextFrameInfoIdx].renderTimeMs = frame.RenderTimeMs();
  _frameInfos[_nextFrameInfoIdx].rotation = frame.rotation();
  _frameInfos[_nextFrameInfoIdx].timing = frame.video_timing();
  // Set correctly only for key frames. Thus, use latest key frame
  // content type. If the corresponding key frame was lost, decode will fail
  // and content type will be ignored.
  if (frame.FrameType() == kVideoFrameKey) {
    _frameInfos[_nextFrameInfoIdx].content_type = frame.contentType();
    _last_keyframe_content_type = frame.contentType();
  } else {
    _frameInfos[_nextFrameInfoIdx].content_type = _last_keyframe_content_type;
  }
  _callback->Map(frame.TimeStamp(), &_frameInfos[_nextFrameInfoIdx]);

  _nextFrameInfoIdx = (_nextFrameInfoIdx + 1) % kDecoderFrameMemoryLength;
  const RTPFragmentationHeader dummy_header;
  int32_t ret = decoder_->Decode(frame.EncodedImage(), frame.MissingFrame(),
                                 &dummy_header, frame.CodecSpecific(),
                                 frame.RenderTimeMs());

  // TODO(tommi): Necessary every time?
  // Maybe this should be the first thing the function does, and only the first
  // time around?
  _callback->OnDecoderImplementationName(decoder_->ImplementationName());

  if (ret != WEBRTC_VIDEO_CODEC_OK) {
    if (ret < WEBRTC_VIDEO_CODEC_OK) {
      RTC_LOG(LS_WARNING) << "Failed to decode frame with timestamp "
                          << frame.TimeStamp() << ", error code: " << ret;
    }
    // We pop the frame for all non-'OK', failure or success codes such as
    // WEBRTC_VIDEO_CODEC_NO_OUTPUT and WEBRTC_VIDEO_CODEC_REQUEST_SLI.
    _callback->Pop(frame.TimeStamp());
  }

  return ret;
}

int32_t VCMGenericDecoder::RegisterDecodeCompleteCallback(
    VCMDecodedFrameCallback* callback) {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  _callback = callback;
  return decoder_->RegisterDecodeCompleteCallback(callback);
}

bool VCMGenericDecoder::PrefersLateDecoding() const {
  RTC_DCHECK_RUN_ON(&decoder_thread_);
  return decoder_->PrefersLateDecoding();
}

}  // namespace webrtc