libvpx: Pull from upstream

source/libvpx/examples/vp9_spatial_svc_encoder.c

 /*
  *  Copyright (c) 2012 The WebM 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.
  */
 
@@ skipping 612 matching lines @@
     }
   }
 #endif
 
   // skip initial frames
   for (i = 0; i < app_input.frames_to_skip; ++i)
     vpx_img_read(&raw, infile);
 
   if (svc_ctx.speed != -1)
     vpx_codec_control(&codec, VP8E_SET_CPUUSED, svc_ctx.speed);
-  vpx_codec_control(&codec, VP9E_SET_TILE_COLUMNS, 0);
+  if (svc_ctx.threads)
+    vpx_codec_control(&codec, VP9E_SET_TILE_COLUMNS, (svc_ctx.threads >> 1));
 
   // Encode frames
   while (!end_of_stream) {
     vpx_codec_iter_t iter = NULL;
     const vpx_codec_cx_pkt_t *cx_pkt;
     if (frame_cnt >= app_input.frames_to_code || !vpx_img_read(&raw, infile)) {
       // We need one extra vpx_svc_encode call at end of stream to flush
       // encoder and get remaining data
       end_of_stream = 1;
     }
@@ skipping 138 matching lines @@
       vpx_video_writer_close(outfile[tl]);
     }
   }
 #endif
   vpx_img_free(&raw);
   // display average size, psnr
   printf("%s", vpx_svc_dump_statistics(&svc_ctx));
   vpx_svc_release(&svc_ctx);
   return EXIT_SUCCESS;
 }