shithub: libvpx

Download patch

ref: 80812829c2d45d9f5597e619b8759e9562d6f1c0
parent: 5cac66078eb39ecf7328d58479bae6222853ab39
author: Sami Pietila <samipietila@google.com>
date: Mon May 27 06:14:53 EDT 2013 

Moving txfm_size bits before prediction mode bits.

Hardware implementation needs to load coeff probs based on the
transform size. For selectable transform size, moving these bits
earlier in the bitstream adds some delay giving time to preload
the probs and speeds up the decoding process.

Change-Id: I3bfc1f662ae6f219c9286fe9ae6310c7d8a63ea7


--- a/vp9/decoder/vp9_decodemv.c
+++ b/vp9/decoder/vp9_decodemv.c
@@ -118,6 +118,24 @@
   if (!m->mbmi.mb_skip_coeff)
     m->mbmi.mb_skip_coeff = vp9_read(r, vp9_get_pred_prob(cm, xd, PRED_MBSKIP));
 
+  if (cm->txfm_mode == TX_MODE_SELECT &&
+      m->mbmi.sb_type >= BLOCK_SIZE_SB8X8) {
+    const int allow_16x16 = m->mbmi.sb_type >= BLOCK_SIZE_MB16X16;
+    const int allow_32x32 = m->mbmi.sb_type >= BLOCK_SIZE_SB32X32;
+    m->mbmi.txfm_size = select_txfm_size(cm, r, allow_16x16, allow_32x32);
+  } else if (cm->txfm_mode >= ALLOW_32X32 &&
+             m->mbmi.sb_type >= BLOCK_SIZE_SB32X32) {
+    m->mbmi.txfm_size = TX_32X32;
+  } else if (cm->txfm_mode >= ALLOW_16X16 &&
+             m->mbmi.sb_type >= BLOCK_SIZE_MB16X16) {
+    m->mbmi.txfm_size = TX_16X16;
+  } else if (cm->txfm_mode >= ALLOW_8X8 &&
+             m->mbmi.sb_type >= BLOCK_SIZE_SB8X8) {
+    m->mbmi.txfm_size = TX_8X8;
+  } else {
+    m->mbmi.txfm_size = TX_4X4;
+  }
+
   // luma mode
   if (m->mbmi.sb_type >= BLOCK_SIZE_SB8X8) {
     const MB_PREDICTION_MODE A = above_block_mode(m, 0, mis);
@@ -153,25 +171,6 @@
   }
 
   m->mbmi.uv_mode = read_uv_mode(r, cm->kf_uv_mode_prob[m->mbmi.mode]);
-
-  if (cm->txfm_mode == TX_MODE_SELECT &&
-      m->mbmi.sb_type >= BLOCK_SIZE_SB8X8) {
-    const int allow_16x16 = m->mbmi.sb_type >= BLOCK_SIZE_MB16X16;
-    const int allow_32x32 = m->mbmi.sb_type >= BLOCK_SIZE_SB32X32;
-    m->mbmi.txfm_size = select_txfm_size(cm, r, allow_16x16, allow_32x32);
-  } else if (cm->txfm_mode >= ALLOW_32X32 &&
-             m->mbmi.sb_type >= BLOCK_SIZE_SB32X32) {
-    m->mbmi.txfm_size = TX_32X32;
-  } else if (cm->txfm_mode >= ALLOW_16X16 &&
-             m->mbmi.sb_type >= BLOCK_SIZE_MB16X16 &&
-             m->mbmi.mode <= TM_PRED) {
-    m->mbmi.txfm_size = TX_16X16;
-  } else if (cm->txfm_mode >= ALLOW_8X8 &&
-             m->mbmi.sb_type >= BLOCK_SIZE_SB8X8) {
-    m->mbmi.txfm_size = TX_8X8;
-  } else {
-    m->mbmi.txfm_size = TX_4X4;
-  }
 }
 
 static int read_mv_component(vp9_reader *r,
@@ -569,6 +568,24 @@
   // Read the reference frame
   mbmi->ref_frame = read_ref_frame(pbi, r, mbmi->segment_id);
 
+  if (cm->txfm_mode == TX_MODE_SELECT &&
+      (mbmi->mb_skip_coeff == 0 || mbmi->ref_frame == INTRA_FRAME) &&
+      bsize >= BLOCK_SIZE_SB8X8) {
+    const int allow_16x16 = bsize >= BLOCK_SIZE_MB16X16;
+    const int allow_32x32 = bsize >= BLOCK_SIZE_SB32X32;
+    mbmi->txfm_size = select_txfm_size(cm, r, allow_16x16, allow_32x32);
+  } else if (bsize >= BLOCK_SIZE_SB32X32 &&
+             cm->txfm_mode >= ALLOW_32X32) {
+    mbmi->txfm_size = TX_32X32;
+  } else if (cm->txfm_mode >= ALLOW_16X16 &&
+             bsize >= BLOCK_SIZE_MB16X16) {
+    mbmi->txfm_size = TX_16X16;
+  } else if (cm->txfm_mode >= ALLOW_8X8 && (bsize >= BLOCK_SIZE_SB8X8)) {
+    mbmi->txfm_size = TX_8X8;
+  } else {
+    mbmi->txfm_size = TX_4X4;
+  }
+
   // If reference frame is an Inter frame
   if (mbmi->ref_frame) {
     int_mv nearest, nearby, best_mv;
@@ -832,24 +849,6 @@
 
     mbmi->uv_mode = read_uv_mode(r, cm->fc.uv_mode_prob[mbmi->mode]);
     cm->fc.uv_mode_counts[mbmi->mode][mbmi->uv_mode]++;
-  }
-
-  if (cm->txfm_mode == TX_MODE_SELECT &&
-      (mbmi->mb_skip_coeff == 0 || mbmi->ref_frame == INTRA_FRAME) &&
-      bsize >= BLOCK_SIZE_SB8X8) {
-    const int allow_16x16 = bsize >= BLOCK_SIZE_MB16X16;
-    const int allow_32x32 = bsize >= BLOCK_SIZE_SB32X32;
-    mbmi->txfm_size = select_txfm_size(cm, r, allow_16x16, allow_32x32);
-  } else if (bsize >= BLOCK_SIZE_SB32X32 &&
-             cm->txfm_mode >= ALLOW_32X32) {
-    mbmi->txfm_size = TX_32X32;
-  } else if (cm->txfm_mode >= ALLOW_16X16 &&
-             bsize >= BLOCK_SIZE_MB16X16) {
-    mbmi->txfm_size = TX_16X16;
-  } else if (cm->txfm_mode >= ALLOW_8X8 && (bsize >= BLOCK_SIZE_SB8X8)) {
-    mbmi->txfm_size = TX_8X8;
-  } else {
-    mbmi->txfm_size = TX_4X4;
   }
 }
 
--- a/vp9/encoder/vp9_bitstream.c
+++ b/vp9/encoder/vp9_bitstream.c
@@ -700,6 +700,19 @@
   // Encode the reference frame.
   encode_ref_frame(bc, pc, xd, segment_id, rf);
 
+  if (mi->sb_type >= BLOCK_SIZE_SB8X8 && pc->txfm_mode == TX_MODE_SELECT &&
+      !(rf != INTRA_FRAME &&
+        (skip_coeff || vp9_segfeature_active(xd, segment_id, SEG_LVL_SKIP)))) {
+    TX_SIZE sz = mi->txfm_size;
+    // FIXME(rbultje) code ternary symbol once all experiments are merged
+    vp9_write(bc, sz != TX_4X4, pc->prob_tx[0]);
+    if (mi->sb_type >= BLOCK_SIZE_MB16X16 && sz != TX_4X4) {
+      vp9_write(bc, sz != TX_8X8, pc->prob_tx[1]);
+      if (mi->sb_type >= BLOCK_SIZE_SB32X32 && sz != TX_8X8)
+        vp9_write(bc, sz != TX_16X16, pc->prob_tx[2]);
+    }
+  }
+
   if (rf == INTRA_FRAME) {
 #ifdef ENTROPY_STATS
     active_section = 6;
@@ -807,19 +820,6 @@
         break;
     }
   }
-
-  if (mi->sb_type >= BLOCK_SIZE_SB8X8 && pc->txfm_mode == TX_MODE_SELECT &&
-      !(rf != INTRA_FRAME &&
-        (skip_coeff || vp9_segfeature_active(xd, segment_id, SEG_LVL_SKIP)))) {
-    TX_SIZE sz = mi->txfm_size;
-    // FIXME(rbultje) code ternary symbol once all experiments are merged
-    vp9_write(bc, sz != TX_4X4, pc->prob_tx[0]);
-    if (mi->sb_type >= BLOCK_SIZE_MB16X16 && sz != TX_4X4) {
-      vp9_write(bc, sz != TX_8X8, pc->prob_tx[1]);
-      if (mi->sb_type >= BLOCK_SIZE_SB32X32 && sz != TX_8X8)
-        vp9_write(bc, sz != TX_16X16, pc->prob_tx[2]);
-    }
-  }
 }
 
 static void write_mb_modes_kf(const VP9_COMP *cpi,
@@ -842,6 +842,17 @@
     vp9_write(bc, skip_coeff, vp9_get_pred_prob(c, xd, PRED_MBSKIP));
   }
 
+  if (m->mbmi.sb_type >= BLOCK_SIZE_SB8X8 && c->txfm_mode == TX_MODE_SELECT) {
+    TX_SIZE sz = m->mbmi.txfm_size;
+    // FIXME(rbultje) code ternary symbol once all experiments are merged
+    vp9_write(bc, sz != TX_4X4, c->prob_tx[0]);
+    if (m->mbmi.sb_type >= BLOCK_SIZE_MB16X16 && sz != TX_4X4) {
+      vp9_write(bc, sz != TX_8X8, c->prob_tx[1]);
+      if (m->mbmi.sb_type >= BLOCK_SIZE_SB32X32 && sz != TX_8X8)
+        vp9_write(bc, sz != TX_16X16, c->prob_tx[2]);
+    }
+  }
+
   if (m->mbmi.sb_type >= BLOCK_SIZE_SB8X8) {
     const B_PREDICTION_MODE A = above_block_mode(m, 0, mis);
     const B_PREDICTION_MODE L = xd->left_available ?
@@ -866,17 +877,6 @@
   }
 
   write_uv_mode(bc, m->mbmi.uv_mode, c->kf_uv_mode_prob[ym]);
-
-  if (m->mbmi.sb_type >= BLOCK_SIZE_SB8X8 && c->txfm_mode == TX_MODE_SELECT) {
-    TX_SIZE sz = m->mbmi.txfm_size;
-    // FIXME(rbultje) code ternary symbol once all experiments are merged
-    vp9_write(bc, sz != TX_4X4, c->prob_tx[0]);
-    if (m->mbmi.sb_type >= BLOCK_SIZE_MB16X16 && sz != TX_4X4) {
-      vp9_write(bc, sz != TX_8X8, c->prob_tx[1]);
-      if (m->mbmi.sb_type >= BLOCK_SIZE_SB32X32 && sz != TX_8X8)
-        vp9_write(bc, sz != TX_16X16, c->prob_tx[2]);
-    }
-  }
 }
 
 static void write_modes_b(VP9_COMP *cpi, MODE_INFO *m, vp9_writer *bc,
-- 
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