From 20bede7cc7df7a0fea3f2ee060ad6cef1d1dc6f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Erik=20Spr=C3=A5ng?= <sprang@webrtc.org>
Date: Fri, 5 May 2023 16:18:10 +0200
Subject: [PATCH] Clean up dead code in vp9 encoder wrapper
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Bug: None
Change-Id: Ic99af40e95c5d82db9b4b5624eae3103d0a11c55
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/304286
Auto-Submit: Erik Språng <sprang@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40027}
---
 .../codecs/vp9/libvpx_vp9_encoder.cc          | 30 +++----------------
 .../codecs/vp9/libvpx_vp9_encoder.h           |  2 --
 2 files changed, 4 insertions(+), 28 deletions(-)

diff --git a/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc b/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc
index e05428964d..e460625aea 100644
--- a/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc
+++ b/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.cc
@@ -249,8 +249,6 @@ LibvpxVp9Encoder::LibvpxVp9Encoder(const cricket::VideoCodec& codec,
       trusted_rate_controller_(
           RateControlSettings::ParseFromKeyValueConfig(&trials)
               .LibvpxVp9TrustedRateController()),
-      layer_buffering_(false),
-      full_superframe_drop_(true),
       first_frame_in_picture_(true),
       ss_info_needed_(false),
       force_all_active_layers_(false),
@@ -920,18 +918,11 @@ int LibvpxVp9Encoder::InitAndSetControlSettings(const VideoCodec* inst) {
       for (size_t i = 0; i < num_spatial_layers_; ++i) {
         svc_drop_frame_.framedrop_thresh[i] = config_->rc_dropframe_thresh;
       }
-      // No buffering is needed because the highest layer is always present in
-      // all frames in CONSTRAINED_FROM_ABOVE drop mode.
-      layer_buffering_ = false;
     } else {
       // Configure encoder to drop entire superframe whenever it needs to drop
       // a layer. This mode is preferred over per-layer dropping which causes
       // quality flickering and is not compatible with RTP non-flexible mode.
-      svc_drop_frame_.framedrop_mode =
-          full_superframe_drop_ ? FULL_SUPERFRAME_DROP : CONSTRAINED_LAYER_DROP;
-      // Buffering is needed only for constrained layer drop, as it's not clear
-      // which frame is the last.
-      layer_buffering_ = !full_superframe_drop_;
+      svc_drop_frame_.framedrop_mode = FULL_SUPERFRAME_DROP;
       svc_drop_frame_.max_consec_drop = std::numeric_limits<int>::max();
       for (size_t i = 0; i < num_spatial_layers_; ++i) {
         svc_drop_frame_.framedrop_thresh[i] = config_->rc_dropframe_thresh;
@@ -1276,11 +1267,6 @@ int LibvpxVp9Encoder::Encode(const VideoFrame& input_image,
   }
   timestamp_ += duration;
 
-  if (layer_buffering_) {
-    const bool end_of_picture = true;
-    DeliverBufferedFrame(end_of_picture);
-  }
-
   return WEBRTC_VIDEO_CODEC_OK;
 }
 
@@ -1715,12 +1701,6 @@ void LibvpxVp9Encoder::GetEncodedLayerFrame(const vpx_codec_cx_pkt* pkt) {
   vpx_svc_layer_id_t layer_id = {0};
   libvpx_->codec_control(encoder_, VP9E_GET_SVC_LAYER_ID, &layer_id);
 
-  if (layer_buffering_) {
-    // Deliver buffered low spatial layer frame.
-    const bool end_of_picture = false;
-    DeliverBufferedFrame(end_of_picture);
-  }
-
   encoded_image_.SetEncodedData(EncodedImageBuffer::Create(
       static_cast<const uint8_t*>(pkt->data.frame.buf), pkt->data.frame.sz));
 
@@ -1765,11 +1745,9 @@ void LibvpxVp9Encoder::GetEncodedLayerFrame(const vpx_codec_cx_pkt* pkt) {
   libvpx_->codec_control(encoder_, VP8E_GET_LAST_QUANTIZER, &qp);
   encoded_image_.qp_ = qp;
 
-  if (!layer_buffering_) {
-    const bool end_of_picture = encoded_image_.SpatialIndex().value_or(0) + 1 ==
-                                num_active_spatial_layers_;
-    DeliverBufferedFrame(end_of_picture);
-  }
+  const bool end_of_picture = encoded_image_.SpatialIndex().value_or(0) + 1 ==
+                              num_active_spatial_layers_;
+  DeliverBufferedFrame(end_of_picture);
 }
 
 void LibvpxVp9Encoder::DeliverBufferedFrame(bool end_of_picture) {
diff --git a/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.h b/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.h
index 6b662ae8f9..0474e7bc17 100644
--- a/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.h
+++ b/modules/video_coding/codecs/vp9/libvpx_vp9_encoder.h
@@ -143,8 +143,6 @@ class LibvpxVp9Encoder : public VP9Encoder {
   InterLayerPredMode inter_layer_pred_;
   bool external_ref_control_;
   const bool trusted_rate_controller_;
-  bool layer_buffering_;
-  const bool full_superframe_drop_;
   vpx_svc_frame_drop_t svc_drop_frame_;
   bool first_frame_in_picture_;
   VideoBitrateAllocation current_bitrate_allocation_;