Cast: Use 2 threads for encoding on capable systems

media/cast/video_sender/codecs/vp8/vp8_encoder.cc

 // Copyright 2013 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.
 //
 // TODO (pwestin): add a link to the design document describing the generic
 // protocol and the VP8 specific details.
 #include "media/cast/video_sender/codecs/vp8/vp8_encoder.h"
 
 #include <vector>
 
@@ skipping 61 matching lines @@
   // Creating a wrapper to the image - setting image data to NULL. Actual
   // pointer will be set during encode. Setting align to 1, as it is
   // meaningless (actual memory is not allocated).
   raw_image_ = vpx_img_wrap(
       NULL, IMG_FMT_I420, cast_config_.width, cast_config_.height, 1, NULL);
 
   for (int i = 0; i < kNumberOfVp8VideoBuffers; ++i) {
     acked_frame_buffers_[i] = true;
     used_buffers_frame_id_[i] = kStartFrameId;
   }
-  InitEncode(cast_config_.number_of_cores);
+  InitEncode(cast_config_.number_of_encode_threads);
 }
 
-void Vp8Encoder::InitEncode(int number_of_cores) {
+void Vp8Encoder::InitEncode(int number_of_encode_threads) {
   DCHECK(thread_checker_.CalledOnValidThread());
   // Populate encoder configuration with default values.
   if (vpx_codec_enc_config_default(vpx_codec_vp8_cx(), config_.get(), 0)) {
     DCHECK(false) << "Invalid return value";
   }
   config_->g_w = cast_config_.width;
   config_->g_h = cast_config_.height;
   config_->rc_target_bitrate = cast_config_.start_bitrate / 1000;  // In kbit/s.
 
   // Setting the codec time base.
   config_->g_timebase.num = 1;
   config_->g_timebase.den = kVideoFrequency;
   config_->g_lag_in_frames = 0;
   config_->kf_mode = VPX_KF_DISABLED;
   if (use_multiple_video_buffers_) {
     // We must enable error resilience when we use multiple buffers, due to
     // codec requirements.
     config_->g_error_resilient = 1;
   }
-
-  if (cast_config_.width * cast_config_.height > 640 * 480 &&
-      number_of_cores >= 2) {
-    config_->g_threads = 2;  // 2 threads for qHD/HD.
-  } else {
-    config_->g_threads = 1;  // 1 thread for VGA or less.
-  }
+  config_->g_threads = number_of_encode_threads;
 
   // Rate control settings.
   // TODO(pwestin): revisit these constants. Currently identical to webrtc.
   config_->rc_dropframe_thresh = 30;
   config_->rc_end_usage = VPX_CBR;
   config_->g_pass = VPX_RC_ONE_PASS;
   config_->rc_resize_allowed = 0;
   config_->rc_min_quantizer = cast_config_.min_qp;
   config_->rc_max_quantizer = cast_config_.max_qp;
   config_->rc_undershoot_pct = 100;
@@ skipping 277 matching lines @@
   float scale_parameter = 0.5;
   uint32 target_pct = optimal_buffer_size_ms * scale_parameter *
                       cast_config_.max_frame_rate / 10;
 
   // Don't go below 3 times the per frame bandwidth.
   return std::max(target_pct, kMinIntra);
 }
 
 }  // namespace cast
 }  // namespace media