commit cb3a8ef5c5bac46e6f9cdfe9884d435175b8f460
author David Michael Barr <b@rr-dav.id.au> Sat Jan 06 15:48:49 2018 +0900
committer David Michael Barr <b@rr-dav.id.au> Tue Jan 16 21:51:22 2018 +0000
tree a33ec38ff5c184f4aa52a461179c00ca093160ad
parent a855cefc408e8de97a88fe01d79e14e59eda3287

[CFL] separate uv_mode CDFs, split on is_cfl_allowed

This is to exclude coding CFL for block sizes where it is normatively
not allowed.

Reuse the alternate CDFs from the --disable-cfl path.

This yields some improvement on subset1:
   PSNR | PSNR Cb | PSNR Cr | PSNR HVS |    SSIM | MS SSIM | CIEDE 2000
-0.0113 | -0.2630 | -0.2138 |   0.0021 | -0.0110 | -0.0157 |    -0.0511

BUG=aomedia:1182

Change-Id: I1e5f23ef7f2debcf8edce788bfa63ec95db4a679

av1/encoder/bitstream.c

diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index bd89081..e31f028 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -1101,11 +1101,18 @@
 
 static void write_intra_uv_mode(FRAME_CONTEXT *frame_ctx,
                                 UV_PREDICTION_MODE uv_mode,
-                                PREDICTION_MODE y_mode, aom_writer *w) {
-#if !CONFIG_CFL
-  uv_mode = get_uv_mode(uv_mode);
+                                PREDICTION_MODE y_mode,
+#if CONFIG_CFL
+                                CFL_ALLOWED_TYPE cfl_allowed,
 #endif
+                                aom_writer *w) {
+#if CONFIG_CFL
+  aom_write_symbol(w, uv_mode, frame_ctx->uv_mode_cdf[cfl_allowed][y_mode],
+                   UV_INTRA_MODES - !cfl_allowed);
+#else
+  uv_mode = get_uv_mode(uv_mode);
   aom_write_symbol(w, uv_mode, frame_ctx->uv_mode_cdf[y_mode], UV_INTRA_MODES);
+#endif
 }
 
 #if CONFIG_CFL
@@ -1334,18 +1341,12 @@
     write_intra_mode(ec_ctx, bsize, mode, w);
     if (is_chroma_reference(mi_row, mi_col, bsize, xd->plane[1].subsampling_x,
                             xd->plane[1].subsampling_y)) {
+#if !CONFIG_CFL
       write_intra_uv_mode(ec_ctx, mbmi->uv_mode, mode, w);
-
-#if CONFIG_CFL
-      if (mbmi->uv_mode == UV_CFL_PRED) {
-        if (!is_cfl_allowed(mbmi)) {
-          aom_internal_error(
-              &cm->error, AOM_CODEC_UNSUP_BITSTREAM,
-              "Chroma from Luma (CfL) cannot be signaled for a %dx%d block.",
-              block_size_wide[bsize], block_size_high[bsize]);
-        }
+#else
+      write_intra_uv_mode(ec_ctx, mbmi->uv_mode, mode, is_cfl_allowed(mbmi), w);
+      if (mbmi->uv_mode == UV_CFL_PRED)
         write_cfl_alphas(ec_ctx, mbmi->cfl_alpha_idx, mbmi->cfl_alpha_signs, w);
-      }
 #endif
     }
 
@@ -1645,18 +1646,13 @@
 
   if (is_chroma_reference(mi_row, mi_col, bsize, xd->plane[1].subsampling_x,
                           xd->plane[1].subsampling_y)) {
+#if !CONFIG_CFL
     write_intra_uv_mode(ec_ctx, mbmi->uv_mode, mbmi->mode, w);
-
-#if CONFIG_CFL
-    if (mbmi->uv_mode == UV_CFL_PRED) {
-      if (!is_cfl_allowed(mbmi)) {
-        aom_internal_error(
-            &cm->error, AOM_CODEC_UNSUP_BITSTREAM,
-            "Chroma from Luma (CfL) cannot be signaled for a %dx%d block.",
-            block_size_wide[bsize], block_size_high[bsize]);
-      }
+#else
+    write_intra_uv_mode(ec_ctx, mbmi->uv_mode, mbmi->mode, is_cfl_allowed(mbmi),
+                        w);
+    if (mbmi->uv_mode == UV_CFL_PRED)
       write_cfl_alphas(ec_ctx, mbmi->cfl_alpha_idx, mbmi->cfl_alpha_signs, w);
-    }
 #endif
   }