Revert "rtc-svc: Set the multi-threading per spatial layer"

This reverts commit 8c7bc8035aaaaf5c28bff20be6ab92d888822b1b.
But keep the changes to the svc_datarate_test.c

Reason for revert:
With the recent fixes to MT for RTC, this change forcing 1 thread for lower resolutions is not needed. Performance is little better now with allowing MT for all spatial layers.

Change-Id: Ie2142f0d824abbfde440e9d99650a4b84ae142d8

av1/av1_cx_iface.c

diff --git a/av1/av1_cx_iface.c b/av1/av1_cx_iface.c
index ac85960..5b03354 100644
--- a/av1/av1_cx_iface.c
+++ b/av1/av1_cx_iface.c
@@ -2289,8 +2289,6 @@
       num_workers = av1_fp_compute_num_enc_workers(cpi);
 #endif
     } else {
-      if (cpi->use_svc && cpi->svc.number_spatial_layers > 1)
-        av1_svc_set_mt_per_spatial_layer(cpi);
       av1_compute_num_workers_for_mt(cpi);
       num_workers = av1_get_max_num_workers(cpi);
     }

av1/encoder/svc_layercontext.c

diff --git a/av1/encoder/svc_layercontext.c b/av1/encoder/svc_layercontext.c
index 650ec27..1710920 100644
--- a/av1/encoder/svc_layercontext.c
+++ b/av1/encoder/svc_layercontext.c
@@ -80,9 +80,6 @@
     }
     svc->downsample_filter_type[sl] = BILINEAR;
     svc->downsample_filter_phase[sl] = 8;
-    svc->max_threads[sl] = 1;
-    svc->tile_columns[sl] = 0;
-    svc->tile_rows[sl] = 0;
   }
   if (svc->number_spatial_layers == 3) {
     svc->downsample_filter_type[0] = EIGHTTAP_SMOOTH;
@@ -126,17 +123,6 @@
       lrc->worst_quality = av1_quantizer_to_qindex(lc->max_q);
       lrc->best_quality = av1_quantizer_to_qindex(lc->min_q);
     }
-    // The user settings of mult-threading are only applied to top
-    // spatial layer for now, keep lower spatial layers at 1 thread.
-    if (sl == svc->number_spatial_layers - 1) {
-      svc->max_threads[sl] = cpi->oxcf.max_threads;
-      svc->tile_columns[sl] = cpi->oxcf.tile_cfg.tile_columns;
-      svc->tile_rows[sl] = cpi->oxcf.tile_cfg.tile_rows;
-    } else {
-      svc->max_threads[sl] = 1;
-      svc->tile_columns[sl] = 0;
-      svc->tile_rows[sl] = 0;
-    }
   }
 }
 
@@ -356,10 +342,3 @@
   cpi->common.height = height;
   av1_update_frame_size(cpi);
 }
-
-void av1_svc_set_mt_per_spatial_layer(AV1_COMP *const cpi) {
-  int sl = cpi->svc.spatial_layer_id;
-  cpi->oxcf.max_threads = cpi->svc.max_threads[sl];
-  cpi->oxcf.tile_cfg.tile_columns = cpi->svc.tile_columns[sl];
-  cpi->oxcf.tile_cfg.tile_rows = cpi->svc.tile_rows[sl];
-}

av1/encoder/svc_layercontext.h

diff --git a/av1/encoder/svc_layercontext.h b/av1/encoder/svc_layercontext.h
index b28c301..1eeba5e 100644
--- a/av1/encoder/svc_layercontext.h
+++ b/av1/encoder/svc_layercontext.h
@@ -138,21 +138,6 @@
    * Force zero-mv in mode search for the spatial/inter-layer reference.
    */
   int force_zero_mode_spatial_ref;
-
-  /*!
-   *  max threads per spatial layer.
-   */
-  int max_threads[AOM_MAX_SS_LAYERS];
-
-  /*!
-   *  tile columns per spatial layer.
-   */
-  int tile_columns[AOM_MAX_SS_LAYERS];
-
-  /*!
-   *  tile rows per spatial layer.
-   */
-  int tile_rows[AOM_MAX_SS_LAYERS];
 } SVC;
 
 struct AV1_COMP;
@@ -286,17 +271,6 @@
 void av1_get_layer_resolution(const int width_org, const int height_org,
                               const int num, const int den, int *width_out,
                               int *height_out);
-
-/*!\brief Set multi-threading for the current spatial layer.
- *
- * \ingroup SVC
- * \param[in]       cpi  Top level encoder structure
- *
- * \return Nothing is returned. Instead the max_threads, tile_columns and
- tile_rows are set for the current spatial layer.
- */
-void av1_svc_set_mt_per_spatial_layer(struct AV1_COMP *const cpi);
-
 #ifdef __cplusplus
 }  // extern "C"
 #endif