Cast: Use 2 threads for encoding on capable systems

Cast: Use 2 threads for encoding on capable systems

We would like to use more than 1 thread for encoding to improve
performance. We do this only on a higher end system. The criteria is to
have at least 3 logical processors. This has worked well for WebRTC and
the same condition is applied here.

BUG=360966
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=262894

[miu, 2014-04-09 00:53:42]

lgtm, except:

https://codereview.chromium.org/228313002/diff/1/chrome/renderer/media/cast_r...
File chrome/renderer/media/cast_rtp_stream.cc (right):

https://codereview.chromium.org/228313002/diff/1/chrome/renderer/media/cast_r...
chrome/renderer/media/cast_rtp_stream.cc:130: return 2;
Unless I'm missing something, the change description should say "2" and not "3."

Also, something to consider: Should we attempt to use a number of encode threads
proportional to the number of pixels?  Meaning,

480p: 2 threads
720p: 3 threads
1080p: 4 threads

[Alpha Left Google, 2014-04-09 00:56:53]

The CQ bit was checked by hclam@chromium.org

[commit-bot: I haz the power, 2014-04-09 01:13:43]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hclam@chromium.org/228313002/1

[commit-bot: I haz the power, 2014-04-09 01:13:59]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-04-09 01:14:00]

Failed to apply patch for media/cast/cast_config.cc:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file media/cast/cast_config.cc
  Hunk #1 FAILED at 19.
  1 out of 1 hunk FAILED -- saving rejects to file media/cast/cast_config.cc.rej

Patch:       media/cast/cast_config.cc
Index: media/cast/cast_config.cc
diff --git a/media/cast/cast_config.cc b/media/cast/cast_config.cc
index
85231407ad4fa915b58e40c0206e85bcd9516acf..a0ea1635461b8051e76fa87aacaa7c7696c71543
100644
--- a/media/cast/cast_config.cc
+++ b/media/cast/cast_config.cc
@@ -19,7 +19,8 @@ VideoSenderConfig::VideoSenderConfig()
       max_qp(kDefaultMaxQp),
       min_qp(kDefaultMinQp),
       max_frame_rate(kDefaultMaxFrameRate),
-      max_number_of_video_buffers_used(kDefaultNumberOfVideoBuffers) {}
+      max_number_of_video_buffers_used(kDefaultNumberOfVideoBuffers),
+      number_of_encode_threads(1) {}
 
 AudioSenderConfig::AudioSenderConfig()
     : sender_ssrc(0),

[Alpha Left Google, 2014-04-09 22:43:42]

The CQ bit was checked by hclam@chromium.org

[commit-bot: I haz the power, 2014-04-09 22:44:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hclam@chromium.org/228313002/20001

[commit-bot: I haz the power, 2014-04-10 02:01:09]

Change committed as 262894