Use AV1E_SET_AUTO_TILES

Delegate control over number of times to encoder using AV1E_SET_AUTO_TILES that was added in https://aomedia-review.googlesource.com/c/aom/+/191102.

Bug: webrtc:351644568
Change-Id: I87ed11734e907c7f6c6508ac7389c84ececf5b21
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/361140
Commit-Queue: Sergey Silkin <ssilkin@webrtc.org>
Reviewed-by: Marco Paniconi <marpan@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42903}

modules/video_coding/codecs/av1/libaom_av1_encoder.cc

diff --git a/modules/video_coding/codecs/av1/libaom_av1_encoder.cc b/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
index db92384..c067922 100644
--- a/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
+++ b/modules/video_coding/codecs/av1/libaom_av1_encoder.cc
@@ -307,21 +307,7 @@
     SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_ENABLE_PALETTE, 0);
   }
 
-  if (cfg_.g_threads == 8) {
-    // Values passed to AV1E_SET_TILE_ROWS and AV1E_SET_TILE_COLUMNS are log2()
-    // based.
-    // Use 4 tile columns x 2 tile rows for 8 threads.
-    SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_TILE_ROWS, 1);
-    SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_TILE_COLUMNS, 2);
-  } else if (cfg_.g_threads == 4) {
-    // Use 2 tile columns x 2 tile rows for 4 threads.
-    SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_TILE_ROWS, 1);
-    SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_TILE_COLUMNS, 1);
-  } else {
-    SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_TILE_COLUMNS,
-                                      static_cast<int>(log2(cfg_.g_threads)));
-  }
-
+  SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_AUTO_TILES, 1);
   SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_ROW_MT, 1);
   SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_ENABLE_OBMC, 0);
   SET_ENCODER_PARAM_OR_RETURN_ERROR(AV1E_SET_NOISE_SENSITIVITY, 0);