libwebp: update snapshot to v0.3.0-rc6

third_party/libwebp/dec/frame.c

 // Copyright 2010 Google Inc. All Rights Reserved.
 //
 // This code is licensed under the same terms as WebM:
 //  Software License Agreement:  http://www.webmproject.org/license/software/
 //  Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
 // -----------------------------------------------------------------------------
 //
 // Frame-reconstruction function. Memory allocation.
 //
 // Author: Skal (pascal.massimino@gmail.com)
@@ skipping 79 matching lines @@
 static void FilterRow(const VP8Decoder* const dec) {
   int mb_x;
   const int mb_y = dec->thread_ctx_.mb_y_;
   assert(dec->thread_ctx_.filter_row_);
   for (mb_x = dec->tl_mb_x_; mb_x < dec->br_mb_x_; ++mb_x) {
     DoFilter(dec, mb_x, mb_y);
   }
 }
 
 //------------------------------------------------------------------------------
+// Precompute the filtering strength for each segment and each i4x4/i16x16 mode.
 
-void VP8StoreBlock(VP8Decoder* const dec) {
+static void PrecomputeFilterStrengths(VP8Decoder* const dec) {
   if (dec->filter_type_ > 0) {
-    VP8FInfo* const info = dec->f_info_ + dec->mb_x_;
-    const int skip = dec->mb_info_[dec->mb_x_].skip_;
-    int level = dec->filter_levels_[dec->segment_];
-    if (dec->filter_hdr_.use_lf_delta_) {
-      // TODO(skal): only CURRENT is handled for now.
-      level += dec->filter_hdr_.ref_lf_delta_[0];
-      if (dec->is_i4x4_) {
-        level += dec->filter_hdr_.mode_lf_delta_[0];
+    int s;
+    const VP8FilterHeader* const hdr = &dec->filter_hdr_;
+    for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
+      int i4x4;
+      // First, compute the initial level
+      int base_level;
+      if (dec->segment_hdr_.use_segment_) {
+        base_level = dec->segment_hdr_.filter_strength_[s];
+        if (!dec->segment_hdr_.absolute_delta_) {
+          base_level += hdr->level_;
+        }
+      } else {
+        base_level = hdr->level_;
       }
-    }
-    level = (level < 0) ? 0 : (level > 63) ? 63 : level;
-    info->f_level_ = level;
+      for (i4x4 = 0; i4x4 <= 1; ++i4x4) {
+        VP8FInfo* const info = &dec->fstrengths_[s][i4x4];
+        int level = base_level;
+        if (hdr->use_lf_delta_) {
+          // TODO(skal): only CURRENT is handled for now.
+          level += hdr->ref_lf_delta_[0];
+          if (i4x4) {
+            level += hdr->mode_lf_delta_[0];
+          }
+        }
+        level = (level < 0) ? 0 : (level > 63) ? 63 : level;
+        info->f_level_ = level;
 
-    if (dec->filter_hdr_.sharpness_ > 0) {
-      if (dec->filter_hdr_.sharpness_ > 4) {
-        level >>= 2;
-      } else {
-        level >>= 1;
+        if (hdr->sharpness_ > 0) {
+          if (hdr->sharpness_ > 4) {
+            level >>= 2;
+          } else {
+            level >>= 1;
+          }
+          if (level > 9 - hdr->sharpness_) {
+            level = 9 - hdr->sharpness_;
+          }
+        }
+        info->f_ilevel_ = (level < 1) ? 1 : level;
+        info->f_inner_ = 0;
       }
-      if (level > 9 - dec->filter_hdr_.sharpness_) {
-        level = 9 - dec->filter_hdr_.sharpness_;
-      }
-    }
-
-    info->f_ilevel_ = (level < 1) ? 1 : level;
-    info->f_inner_ = (!skip || dec->is_i4x4_);
-  }
-  {
-    // Transfer samples to row cache
-    int y;
-    const int y_offset = dec->cache_id_ * 16 * dec->cache_y_stride_;
-    const int uv_offset = dec->cache_id_ * 8 * dec->cache_uv_stride_;
-    uint8_t* const ydst = dec->cache_y_ + dec->mb_x_ * 16 + y_offset;
-    uint8_t* const udst = dec->cache_u_ + dec->mb_x_ * 8 + uv_offset;
-    uint8_t* const vdst = dec->cache_v_ + dec->mb_x_ * 8 + uv_offset;
-    for (y = 0; y < 16; ++y) {
-      memcpy(ydst + y * dec->cache_y_stride_,
-             dec->yuv_b_ + Y_OFF + y * BPS, 16);
-    }
-    for (y = 0; y < 8; ++y) {
-      memcpy(udst + y * dec->cache_uv_stride_,
-           dec->yuv_b_ + U_OFF + y * BPS, 8);
-      memcpy(vdst + y * dec->cache_uv_stride_,
-           dec->yuv_b_ + V_OFF + y * BPS, 8);
     }
   }
 }
 
 //------------------------------------------------------------------------------
 // This function is called after a row of macroblocks is finished decoding.
 // It also takes into account the following restrictions:
 //  * In case of in-loop filtering, we must hold off sending some of the bottom
 //    pixels as they are yet unfiltered. They will be when the next macroblock
 //    row is decoded. Meanwhile, we must preserve them by rotating them in the
@@ skipping 175 matching lines @@
     // We need some 'extra' pixels on the right/bottom.
     dec->br_mb_y_ = (io->crop_bottom + 15 + extra_pixels) >> 4;
     dec->br_mb_x_ = (io->crop_right + 15 + extra_pixels) >> 4;
     if (dec->br_mb_x_ > dec->mb_w_) {
       dec->br_mb_x_ = dec->mb_w_;
     }
     if (dec->br_mb_y_ > dec->mb_h_) {
       dec->br_mb_y_ = dec->mb_h_;
     }
   }
+  PrecomputeFilterStrengths(dec);
   return VP8_STATUS_OK;
 }
 
 int VP8ExitCritical(VP8Decoder* const dec, VP8Io* const io) {
   int ok = 1;
   if (dec->use_threads_) {
     ok = WebPWorkerSync(&dec->worker_);
   }
 
   if (io->teardown) {
@@ skipping 137 matching lines @@
                   + 16 * num_caches * dec->cache_y_stride_ + extra_uv;
     dec->cache_v_ = dec->cache_u_
                   + 8 * num_caches * dec->cache_uv_stride_ + extra_uv;
     dec->cache_id_ = 0;
   }
   mem += cache_size;
 
   // alpha plane
   dec->alpha_plane_ = alpha_size ? (uint8_t*)mem : NULL;
   mem += alpha_size;
+  assert(mem <= (uint8_t*)dec->mem_ + dec->mem_size_);
 
   // note: left-info is initialized once for all.
   memset(dec->mb_info_ - 1, 0, mb_info_size);
 
   // initialize top
   memset(dec->intra_t_, B_DC_PRED, intra_pred_mode_size);
 
   return 1;
 }
 
@@ skipping 35 matching lines @@
     }
   }
   return mode;
 }
 
 static WEBP_INLINE void Copy32b(uint8_t* dst, uint8_t* src) {
   *(uint32_t*)dst = *(uint32_t*)src;
 }
 
 void VP8ReconstructBlock(VP8Decoder* const dec) {
+  int j;
   uint8_t* const y_dst = dec->yuv_b_ + Y_OFF;
   uint8_t* const u_dst = dec->yuv_b_ + U_OFF;
   uint8_t* const v_dst = dec->yuv_b_ + V_OFF;
 
   // Rotate in the left samples from previously decoded block. We move four
   // pixels at a time for alignment reason, and because of in-loop filter.
   if (dec->mb_x_ > 0) {
-    int j;
     for (j = -1; j < 16; ++j) {
       Copy32b(&y_dst[j * BPS - 4], &y_dst[j * BPS + 12]);
     }
     for (j = -1; j < 8; ++j) {
       Copy32b(&u_dst[j * BPS - 4], &u_dst[j * BPS + 4]);
       Copy32b(&v_dst[j * BPS - 4], &v_dst[j * BPS + 4]);
     }
   } else {
-    int j;
     for (j = 0; j < 16; ++j) {
       y_dst[j * BPS - 1] = 129;
     }
     for (j = 0; j < 8; ++j) {
       u_dst[j * BPS - 1] = 129;
       v_dst[j * BPS - 1] = 129;
     }
     // Init top-left sample on left column too
     if (dec->mb_y_ > 0) {
       y_dst[-1 - BPS] = u_dst[-1 - BPS] = v_dst[-1 - BPS] = 129;
@@ skipping 82 matching lines @@
       }
 
       // stash away top samples for next block
       if (dec->mb_y_ < dec->mb_h_ - 1) {
         memcpy(top_y, y_dst + 15 * BPS, 16);
         memcpy(top_u, u_dst +  7 * BPS,  8);
         memcpy(top_v, v_dst +  7 * BPS,  8);
       }
     }
   }
+  // Transfer reconstructed samples from yuv_b_ cache to final destination.
+  {
+    const int y_offset = dec->cache_id_ * 16 * dec->cache_y_stride_;
+    const int uv_offset = dec->cache_id_ * 8 * dec->cache_uv_stride_;
+    uint8_t* const y_out = dec->cache_y_ + dec->mb_x_ * 16 + y_offset;
+    uint8_t* const u_out = dec->cache_u_ + dec->mb_x_ * 8 + uv_offset;
+    uint8_t* const v_out = dec->cache_v_ + dec->mb_x_ * 8 + uv_offset;
+    for (j = 0; j < 16; ++j) {
+      memcpy(y_out + j * dec->cache_y_stride_, y_dst + j * BPS, 16);
+    }
+    for (j = 0; j < 8; ++j) {
+      memcpy(u_out + j * dec->cache_uv_stride_, u_dst + j * BPS, 8);
+      memcpy(v_out + j * dec->cache_uv_stride_, v_dst + j * BPS, 8);
+    }
+  }
 }
 
 //------------------------------------------------------------------------------
 
 #if defined(__cplusplus) || defined(c_plusplus)
 }    // extern "C"
 #endif