NEW_MULTISYMBOL: adapt remaining bits in the magnitude.

Reduce the number of contexts from 10 to 6.

BUG=aomedia:830

Change-Id: If0ec302816975293b7dbd164c867feb66fa76847

av1/common/entropy.c

@@ -2255,6 +2255,7 @@ void av1_average_tile_mv_cdfs(FRAME_CONTEXT *fc, FRAME_CONTEXT *ec_ctxs[],
       AVERAGE_TILE_CDFS(nmvc[j].comps[k].hp_cdf)
       AVERAGE_TILE_CDFS(nmvc[j].comps[k].class0_hp_cdf)
       AVERAGE_TILE_CDFS(nmvc[j].comps[k].class0_cdf)
+      AVERAGE_TILE_CDFS(nmvc[j].comps[k].bits_cdf)
 #endif
     }
   }

av1/common/entropymv.c

@@ -68,6 +68,12 @@ static const nmv_context default_nmv_context = {
         { AOM_ICDF(160 * 128), AOM_ICDF(32768), 0 },
         { AOM_ICDF(128 * 128), AOM_ICDF(32768), 0 },
         { AOM_ICDF(216 * 128), AOM_ICDF(32768), 0 },
+        { { AOM_ICDF(128 * 196), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 198), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 208), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 224), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 245), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 240), AOM_ICDF(32768), 0 } },  // bits_cdf
 #endif
     },
     {
@@ -93,6 +99,12 @@ static const nmv_context default_nmv_context = {
         { AOM_ICDF(160 * 128), AOM_ICDF(32768), 0 },
         { AOM_ICDF(128 * 128), AOM_ICDF(32768), 0 },
         { AOM_ICDF(216 * 128), AOM_ICDF(32768), 0 },
+        { { AOM_ICDF(128 * 196), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 198), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 208), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 224), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 245), AOM_ICDF(32768), 0 },
+          { AOM_ICDF(128 * 240), AOM_ICDF(32768), 0 } },  // bits_cdf
 #endif
     } },
 };

av1/common/entropymv.h

@@ -66,6 +66,9 @@ typedef enum {
 #define CLASS0_BITS 1 /* bits at integer precision for class 0 */
 #define CLASS0_SIZE (1 << CLASS0_BITS)
 #define MV_OFFSET_BITS (MV_CLASSES + CLASS0_BITS - 2)
+#if CONFIG_NEW_MULTISYMBOL
+#define MV_BITS_CONTEXTS 6
+#endif
 #define MV_FP_SIZE 4
 
 #define MV_MAX_BITS (MV_CLASSES + CLASS0_BITS + 2)
@@ -97,6 +100,7 @@ typedef struct {
   aom_cdf_prob class0_hp_cdf[CDF_SIZE(2)];
   aom_cdf_prob hp_cdf[CDF_SIZE(2)];
   aom_cdf_prob class0_cdf[CDF_SIZE(CLASS0_SIZE)];
+  aom_cdf_prob bits_cdf[MV_BITS_CONTEXTS][CDF_SIZE(2)];
 #endif
 } nmv_component;
 

av1/decoder/decodeframe.c

@@ -5723,7 +5723,9 @@ void av1_decode_tg_tiles_and_wrapup(AV1Decoder *pbi, const uint8_t *data,
 
       if (!frame_is_intra_only(cm)) {
         av1_adapt_inter_frame_probs(cm);
+#if !CONFIG_NEW_MULTISYMBOL
         av1_adapt_mv_probs(cm, cm->allow_high_precision_mv);
+#endif
         av1_average_tile_inter_cdfs(&pbi->common, pbi->common.fc, tile_ctxs,
                                     cdf_ptrs, cm->tile_rows * cm->tile_cols);
         av1_average_tile_mv_cdfs(pbi->common.fc, tile_ctxs, cdf_ptrs,

av1/decoder/decodemv.c

@@ -1274,9 +1274,13 @@ static int read_mv_component(aom_reader *r, nmv_component *mvcomp,
   } else {
     int i;
     const int n = mv_class + CLASS0_BITS - 1;  // number of bits
-
     d = 0;
+#if CONFIG_NEW_MULTISYMBOL
+    for (i = 0; i < n; ++i)
+      d |= aom_read_symbol(r, mvcomp->bits_cdf[(i + 1) / 2], 2, ACCT_STR) << i;
+#else
     for (i = 0; i < n; ++i) d |= aom_read(r, mvcomp->bits[i], ACCT_STR) << i;
+#endif
     mag = CLASS0_SIZE << (mv_class + 2);
   }
 

av1/encoder/encodemv.c

@@ -62,9 +62,13 @@ static void encode_mv_component(aom_writer *w, int comp, nmv_component *mvcomp,
   } else {
     int i;
     const int n = mv_class + CLASS0_BITS - 1;  // number of bits
+#if CONFIG_NEW_MULTISYMBOL
+    for (i = 0; i < n; ++i)
+      aom_write_symbol(w, (d >> i) & 1, mvcomp->bits_cdf[(i + 1) / 2], 2);
+#else
     for (i = 0; i < n; ++i) aom_write(w, (d >> i) & 1, mvcomp->bits[i]);
+#endif
   }
-
 // Fractional bits
 #if CONFIG_INTRABC || CONFIG_AMVR
   if (precision > MV_SUBPEL_NONE)