| /* 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 <stdlib.h> |
| #include <algorithm> |
| |
| #include "vpx/vpx_encoder.h" |
| #include "vpx/vp8cx.h" |
| #include "webrtc/base/checks.h" |
| #include "webrtc/base/optional.h" |
| #include "webrtc/modules/video_coding/include/video_codec_interface.h" |
| #include "webrtc/modules/video_coding/codecs/vp8/include/vp8_common_types.h" |
| #include "webrtc/modules/video_coding/codecs/vp8/temporal_layers.h" |
| |
| // This file implements logic to adapt the number of temporal layers based on |
| // input frame rate in order to avoid having the base layer being relaying at |
| // a below acceptable framerate. |
| namespace webrtc { |
| namespace { |
| enum { |
| kTemporalUpdateLast = VP8_EFLAG_NO_UPD_GF | VP8_EFLAG_NO_UPD_ARF | |
| VP8_EFLAG_NO_REF_GF | |
| VP8_EFLAG_NO_REF_ARF, |
| |
| kTemporalUpdateGolden = |
| VP8_EFLAG_NO_REF_ARF | VP8_EFLAG_NO_UPD_ARF | VP8_EFLAG_NO_UPD_LAST, |
| |
| kTemporalUpdateGoldenWithoutDependency = |
| kTemporalUpdateGolden | VP8_EFLAG_NO_REF_GF, |
| |
| kTemporalUpdateAltref = VP8_EFLAG_NO_UPD_GF | VP8_EFLAG_NO_UPD_LAST, |
| |
| kTemporalUpdateAltrefWithoutDependency = |
| kTemporalUpdateAltref | VP8_EFLAG_NO_REF_ARF | VP8_EFLAG_NO_REF_GF, |
| |
| kTemporalUpdateNone = VP8_EFLAG_NO_UPD_GF | VP8_EFLAG_NO_UPD_ARF | |
| VP8_EFLAG_NO_UPD_LAST | |
| VP8_EFLAG_NO_UPD_ENTROPY, |
| |
| kTemporalUpdateNoneNoRefAltref = kTemporalUpdateNone | VP8_EFLAG_NO_REF_ARF, |
| |
| kTemporalUpdateNoneNoRefGoldenRefAltRef = |
| VP8_EFLAG_NO_REF_GF | VP8_EFLAG_NO_UPD_GF | VP8_EFLAG_NO_UPD_ARF | |
| VP8_EFLAG_NO_UPD_LAST | |
| VP8_EFLAG_NO_UPD_ENTROPY, |
| |
| kTemporalUpdateGoldenWithoutDependencyRefAltRef = |
| VP8_EFLAG_NO_REF_GF | VP8_EFLAG_NO_UPD_ARF | VP8_EFLAG_NO_UPD_LAST, |
| |
| kTemporalUpdateLastRefAltRef = |
| VP8_EFLAG_NO_UPD_GF | VP8_EFLAG_NO_UPD_ARF | VP8_EFLAG_NO_REF_GF, |
| |
| kTemporalUpdateGoldenRefAltRef = VP8_EFLAG_NO_UPD_ARF | VP8_EFLAG_NO_UPD_LAST, |
| |
| kTemporalUpdateLastAndGoldenRefAltRef = |
| VP8_EFLAG_NO_UPD_ARF | VP8_EFLAG_NO_REF_GF, |
| |
| kTemporalUpdateLastRefAll = VP8_EFLAG_NO_UPD_ARF | VP8_EFLAG_NO_UPD_GF, |
| }; |
| |
| int CalculateNumberOfTemporalLayers(int current_temporal_layers, |
| int input_fps) { |
| if (input_fps >= 24) { |
| return 3; |
| } |
| if (input_fps >= 20 && current_temporal_layers >= 3) { |
| // Keep doing 3 temporal layers until we go below 20fps. |
| return 3; |
| } |
| if (input_fps >= 10) { |
| return 2; |
| } |
| if (input_fps > 8 && current_temporal_layers >= 2) { |
| // keep doing 2 temporal layers until we go below 8fps |
| return 2; |
| } |
| return 1; |
| } |
| |
| class RealTimeTemporalLayers : public TemporalLayers { |
| public: |
| RealTimeTemporalLayers(int max_num_temporal_layers, |
| uint8_t initial_tl0_pic_idx) |
| : temporal_layers_(1), |
| max_temporal_layers_(max_num_temporal_layers), |
| tl0_pic_idx_(initial_tl0_pic_idx), |
| frame_counter_(static_cast<unsigned int>(-1)), |
| timestamp_(0), |
| last_base_layer_sync_(0), |
| layer_ids_length_(0), |
| layer_ids_(NULL), |
| encode_flags_length_(0), |
| encode_flags_(NULL) { |
| RTC_CHECK_GE(max_temporal_layers_, 1); |
| RTC_CHECK_GE(max_temporal_layers_, 3); |
| } |
| |
| virtual ~RealTimeTemporalLayers() {} |
| |
| std::vector<uint32_t> OnRatesUpdated(int bitrate_kbps, |
| int max_bitrate_kbps, |
| int framerate) override { |
| temporal_layers_ = |
| CalculateNumberOfTemporalLayers(temporal_layers_, framerate); |
| temporal_layers_ = std::min(temporal_layers_, max_temporal_layers_); |
| RTC_CHECK_GE(temporal_layers_, 1); |
| RTC_CHECK_LE(temporal_layers_, 3); |
| |
| switch (temporal_layers_) { |
| case 1: { |
| static const unsigned int layer_ids[] = {0u}; |
| layer_ids_ = layer_ids; |
| layer_ids_length_ = sizeof(layer_ids) / sizeof(*layer_ids); |
| |
| static const int encode_flags[] = {kTemporalUpdateLastRefAll}; |
| encode_flags_length_ = sizeof(encode_flags) / sizeof(*layer_ids); |
| encode_flags_ = encode_flags; |
| } break; |
| |
| case 2: { |
| static const unsigned int layer_ids[] = {0u, 1u}; |
| layer_ids_ = layer_ids; |
| layer_ids_length_ = sizeof(layer_ids) / sizeof(*layer_ids); |
| |
| static const int encode_flags[] = { |
| kTemporalUpdateLastAndGoldenRefAltRef, |
| kTemporalUpdateGoldenWithoutDependencyRefAltRef, |
| kTemporalUpdateLastRefAltRef, |
| kTemporalUpdateGoldenRefAltRef, |
| kTemporalUpdateLastRefAltRef, |
| kTemporalUpdateGoldenRefAltRef, |
| kTemporalUpdateLastRefAltRef, |
| kTemporalUpdateNone}; |
| encode_flags_length_ = sizeof(encode_flags) / sizeof(*layer_ids); |
| encode_flags_ = encode_flags; |
| } break; |
| |
| case 3: { |
| static const unsigned int layer_ids[] = {0u, 2u, 1u, 2u}; |
| layer_ids_ = layer_ids; |
| layer_ids_length_ = sizeof(layer_ids) / sizeof(*layer_ids); |
| |
| static const int encode_flags[] = { |
| kTemporalUpdateLastAndGoldenRefAltRef, |
| kTemporalUpdateNoneNoRefGoldenRefAltRef, |
| kTemporalUpdateGoldenWithoutDependencyRefAltRef, |
| kTemporalUpdateNone, |
| kTemporalUpdateLastRefAltRef, |
| kTemporalUpdateNone, |
| kTemporalUpdateGoldenRefAltRef, |
| kTemporalUpdateNone}; |
| encode_flags_length_ = sizeof(encode_flags) / sizeof(*layer_ids); |
| encode_flags_ = encode_flags; |
| } break; |
| |
| default: |
| RTC_NOTREACHED(); |
| return std::vector<uint32_t>(); |
| } |
| |
| std::vector<uint32_t> bitrates; |
| const int num_layers = std::max(1, temporal_layers_); |
| for (int i = 0; i < num_layers; ++i) { |
| float layer_bitrate = |
| bitrate_kbps * kVp8LayerRateAlloction[num_layers - 1][i]; |
| bitrates.push_back(static_cast<uint32_t>(layer_bitrate + 0.5)); |
| } |
| new_bitrates_kbps_ = rtc::Optional<std::vector<uint32_t>>(bitrates); |
| |
| // Allocation table is of aggregates, transform to individual rates. |
| uint32_t sum = 0; |
| for (int i = 0; i < num_layers; ++i) { |
| uint32_t layer_bitrate = bitrates[i]; |
| RTC_DCHECK_LE(sum, bitrates[i]); |
| bitrates[i] -= sum; |
| sum += layer_bitrate; |
| |
| if (sum == static_cast<uint32_t>(bitrate_kbps)) { |
| // Sum adds up; any subsequent layers will be 0. |
| bitrates.resize(i); |
| break; |
| } |
| } |
| |
| return bitrates; |
| } |
| |
| bool UpdateConfiguration(vpx_codec_enc_cfg_t* cfg) override { |
| if (!new_bitrates_kbps_) |
| return false; |
| |
| cfg->ts_number_layers = temporal_layers_; |
| for (int tl = 0; tl < temporal_layers_; ++tl) { |
| cfg->ts_target_bitrate[tl] = (*new_bitrates_kbps_)[tl]; |
| } |
| new_bitrates_kbps_ = rtc::Optional<std::vector<uint32_t>>(); |
| |
| cfg->ts_periodicity = layer_ids_length_; |
| int decimator = 1; |
| for (int i = temporal_layers_ - 1; i >= 0; --i, decimator *= 2) { |
| cfg->ts_rate_decimator[i] = decimator; |
| } |
| |
| memcpy(cfg->ts_layer_id, layer_ids_, |
| sizeof(unsigned int) * layer_ids_length_); |
| |
| return true; |
| } |
| |
| int EncodeFlags(uint32_t timestamp) override { |
| frame_counter_++; |
| return CurrentEncodeFlags(); |
| } |
| |
| int CurrentEncodeFlags() const { |
| assert(encode_flags_length_ > 0 && encode_flags_ != NULL); |
| int index = frame_counter_ % encode_flags_length_; |
| assert(index >= 0 && index < encode_flags_length_); |
| return encode_flags_[index]; |
| } |
| |
| int CurrentLayerId() const override { |
| assert(layer_ids_length_ > 0 && layer_ids_ != NULL); |
| int index = frame_counter_ % layer_ids_length_; |
| assert(index >= 0 && index < layer_ids_length_); |
| return layer_ids_[index]; |
| } |
| |
| void PopulateCodecSpecific(bool base_layer_sync, |
| CodecSpecificInfoVP8* vp8_info, |
| uint32_t timestamp) override { |
| assert(temporal_layers_ > 0); |
| |
| if (temporal_layers_ == 1) { |
| vp8_info->temporalIdx = kNoTemporalIdx; |
| vp8_info->layerSync = false; |
| vp8_info->tl0PicIdx = kNoTl0PicIdx; |
| } else { |
| if (base_layer_sync) { |
| vp8_info->temporalIdx = 0; |
| vp8_info->layerSync = true; |
| } else { |
| vp8_info->temporalIdx = CurrentLayerId(); |
| int temporal_reference = CurrentEncodeFlags(); |
| |
| if (temporal_reference == kTemporalUpdateAltrefWithoutDependency || |
| temporal_reference == kTemporalUpdateGoldenWithoutDependency || |
| temporal_reference == |
| kTemporalUpdateGoldenWithoutDependencyRefAltRef || |
| temporal_reference == kTemporalUpdateNoneNoRefGoldenRefAltRef || |
| (temporal_reference == kTemporalUpdateNone && |
| temporal_layers_ == 4)) { |
| vp8_info->layerSync = true; |
| } else { |
| vp8_info->layerSync = false; |
| } |
| } |
| if (last_base_layer_sync_ && vp8_info->temporalIdx != 0) { |
| // Regardless of pattern the frame after a base layer sync will always |
| // be a layer sync. |
| vp8_info->layerSync = true; |
| } |
| if (vp8_info->temporalIdx == 0 && timestamp != timestamp_) { |
| timestamp_ = timestamp; |
| tl0_pic_idx_++; |
| } |
| last_base_layer_sync_ = base_layer_sync; |
| vp8_info->tl0PicIdx = tl0_pic_idx_; |
| } |
| } |
| |
| void FrameEncoded(unsigned int size, uint32_t timestamp, int qp) override {} |
| |
| private: |
| int temporal_layers_; |
| int max_temporal_layers_; |
| |
| int tl0_pic_idx_; |
| unsigned int frame_counter_; |
| uint32_t timestamp_; |
| bool last_base_layer_sync_; |
| |
| // Pattern of temporal layer ids. |
| int layer_ids_length_; |
| const unsigned int* layer_ids_; |
| |
| // Pattern of encode flags. |
| int encode_flags_length_; |
| const int* encode_flags_; |
| |
| rtc::Optional<std::vector<uint32_t>> new_bitrates_kbps_; |
| }; |
| } // namespace |
| |
| TemporalLayers* RealTimeTemporalLayersFactory::Create( |
| int simulcast_id, |
| int max_temporal_layers, |
| uint8_t initial_tl0_pic_idx) const { |
| TemporalLayers* tl = |
| new RealTimeTemporalLayers(max_temporal_layers, initial_tl0_pic_idx); |
| if (listener_) |
| listener_->OnTemporalLayersCreated(simulcast_id, tl); |
| return tl; |
| } |
| } // namespace webrtc |