VideoTrackRecorder: limit VP9 cpu usage and quality

content/renderer/media/video_track_recorder.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/video_track_recorder.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 242 matching lines @@
     // than-or-equal than the old size, in terms of area, the existing encoder
     // instance could be reused after changing |codec_config_.{g_w,g_h}|.
     DVLOG(1) << "Destroying/Re-Creating encoder for new frame size: "
              << gfx::Size(codec_config_.g_w, codec_config_.g_h).ToString()
              << " --> " << size.ToString() << (use_vp9_ ? " vp9" : " vp8");
     encoder_.reset();
   }
 
   const vpx_codec_iface_t* interface =
       use_vp9_ ? vpx_codec_vp9_cx() : vpx_codec_vp8_cx();
-  const vpx_codec_err_t result = vpx_codec_enc_config_default(interface,
-                                                              &codec_config_,
-                                                              0 /* reserved */);
+  vpx_codec_err_t result =
+      vpx_codec_enc_config_default(interface, &codec_config_, 0 /* reserved */);
   DCHECK_EQ(VPX_CODEC_OK, result);
 
   DCHECK_EQ(320u, codec_config_.g_w);
   DCHECK_EQ(240u, codec_config_.g_h);
   DCHECK_EQ(256u, codec_config_.rc_target_bitrate);
   // Use the selected bitrate or adjust default bit rate to account for the
   // actual size.
   if (bits_per_second_ > 0) {
     codec_config_.rc_target_bitrate = bits_per_second_;
   } else {
     codec_config_.rc_target_bitrate = size.GetArea() *
                                       codec_config_.rc_target_bitrate /
                                       codec_config_.g_w / codec_config_.g_h;
   }
   // Both VP8/VP9 configuration should be Variable BitRate by default.
   DCHECK_EQ(VPX_VBR, codec_config_.rc_end_usage);
   if (use_vp9_) {
     // Number of frames to consume before producing output.
     codec_config_.g_lag_in_frames = 0;
 
     // DCHECK that the profile selected by default is I420 (magic number 0).
     DCHECK_EQ(0u, codec_config_.g_profile);
+
+    // Values of VP8E_SET_CPUUSED greater than 0 will increase encoder speed at
+    // the expense of quality up to a maximum value of 16 for VP9, by tuning the
+    // target time spent encoding the frame. Go from 12 to 6 depending on the
+    // amount of cores available in the system.
+    const int kCpuUsed = std::max(6, 13 - base::SysInfo::NumberOfProcessors());
+    result = vpx_codec_control(encoder_.get(), VP8E_SET_CPUUSED, kCpuUsed);
+    DLOG_IF(WARNING, VPX_CODEC_OK != result) << "VP8E_SET_CPUUSED failed";
   } else {
     // VP8 always produces frames instantaneously.
     DCHECK_EQ(0u, codec_config_.g_lag_in_frames);
   }
 
   DCHECK(size.width());
   DCHECK(size.height());
   codec_config_.g_w = size.width();
   codec_config_.g_h = size.height();
   codec_config_.g_pass = VPX_RC_ONE_PASS;
@@ skipping 96 matching lines @@
   encoder_->set_paused(false);
 }
 
 void VideoTrackRecorder::OnVideoFrameForTesting(
     const scoped_refptr<media::VideoFrame>& frame,
     base::TimeTicks timestamp) {
   encoder_->StartFrameEncode(frame, timestamp);
 }
 
 }  // namespace content