695 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			695 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // Copyright 2010 Google Inc. All Rights Reserved.
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| //
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| // Use of this source code is governed by a BSD-style license
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| // that can be found in the COPYING file in the root of the source
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| // tree. An additional intellectual property rights grant can be found
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| // in the file PATENTS. All contributing project authors may
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| // be found in the AUTHORS file in the root of the source tree.
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| // -----------------------------------------------------------------------------
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| //
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| // Frame-reconstruction function. Memory allocation.
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| //
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| // Author: Skal (pascal.massimino@gmail.com)
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| 
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| #include <stdlib.h>
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| #include "./vp8i.h"
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| #include "../utils/utils.h"
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| 
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| #if defined(__cplusplus) || defined(c_plusplus)
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| extern "C" {
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| #endif
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| 
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| #define ALIGN_MASK (32 - 1)
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| 
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| //------------------------------------------------------------------------------
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| // Filtering
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| 
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| // kFilterExtraRows[] = How many extra lines are needed on the MB boundary
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| // for caching, given a filtering level.
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| // Simple filter:  up to 2 luma samples are read and 1 is written.
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| // Complex filter: up to 4 luma samples are read and 3 are written. Same for
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| //                 U/V, so it's 8 samples total (because of the 2x upsampling).
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| static const uint8_t kFilterExtraRows[3] = { 0, 2, 8 };
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| 
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| static WEBP_INLINE int hev_thresh_from_level(int level, int keyframe) {
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|   if (keyframe) {
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|     return (level >= 40) ? 2 : (level >= 15) ? 1 : 0;
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|   } else {
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|     return (level >= 40) ? 3 : (level >= 20) ? 2 : (level >= 15) ? 1 : 0;
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|   }
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| }
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| 
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| static void DoFilter(const VP8Decoder* const dec, int mb_x, int mb_y) {
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|   const VP8ThreadContext* const ctx = &dec->thread_ctx_;
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|   const int y_bps = dec->cache_y_stride_;
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|   VP8FInfo* const f_info = ctx->f_info_ + mb_x;
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|   uint8_t* const y_dst = dec->cache_y_ + ctx->id_ * 16 * y_bps + mb_x * 16;
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|   const int level = f_info->f_level_;
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|   const int ilevel = f_info->f_ilevel_;
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|   const int limit = 2 * level + ilevel;
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|   if (level == 0) {
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|     return;
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|   }
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|   if (dec->filter_type_ == 1) {   // simple
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|     if (mb_x > 0) {
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|       VP8SimpleHFilter16(y_dst, y_bps, limit + 4);
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|     }
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|     if (f_info->f_inner_) {
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|       VP8SimpleHFilter16i(y_dst, y_bps, limit);
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|     }
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|     if (mb_y > 0) {
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|       VP8SimpleVFilter16(y_dst, y_bps, limit + 4);
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|     }
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|     if (f_info->f_inner_) {
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|       VP8SimpleVFilter16i(y_dst, y_bps, limit);
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|     }
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|   } else {    // complex
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|     const int uv_bps = dec->cache_uv_stride_;
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|     uint8_t* const u_dst = dec->cache_u_ + ctx->id_ * 8 * uv_bps + mb_x * 8;
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|     uint8_t* const v_dst = dec->cache_v_ + ctx->id_ * 8 * uv_bps + mb_x * 8;
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|     const int hev_thresh =
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|         hev_thresh_from_level(level, dec->frm_hdr_.key_frame_);
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|     if (mb_x > 0) {
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|       VP8HFilter16(y_dst, y_bps, limit + 4, ilevel, hev_thresh);
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|       VP8HFilter8(u_dst, v_dst, uv_bps, limit + 4, ilevel, hev_thresh);
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|     }
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|     if (f_info->f_inner_) {
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|       VP8HFilter16i(y_dst, y_bps, limit, ilevel, hev_thresh);
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|       VP8HFilter8i(u_dst, v_dst, uv_bps, limit, ilevel, hev_thresh);
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|     }
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|     if (mb_y > 0) {
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|       VP8VFilter16(y_dst, y_bps, limit + 4, ilevel, hev_thresh);
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|       VP8VFilter8(u_dst, v_dst, uv_bps, limit + 4, ilevel, hev_thresh);
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|     }
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|     if (f_info->f_inner_) {
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|       VP8VFilter16i(y_dst, y_bps, limit, ilevel, hev_thresh);
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|       VP8VFilter8i(u_dst, v_dst, uv_bps, limit, ilevel, hev_thresh);
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|     }
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|   }
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| }
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| 
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| // Filter the decoded macroblock row (if needed)
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| static void FilterRow(const VP8Decoder* const dec) {
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|   int mb_x;
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|   const int mb_y = dec->thread_ctx_.mb_y_;
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|   assert(dec->thread_ctx_.filter_row_);
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|   for (mb_x = dec->tl_mb_x_; mb_x < dec->br_mb_x_; ++mb_x) {
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|     DoFilter(dec, mb_x, mb_y);
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|   }
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| }
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| 
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| //------------------------------------------------------------------------------
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| // Precompute the filtering strength for each segment and each i4x4/i16x16 mode.
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| 
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| static void PrecomputeFilterStrengths(VP8Decoder* const dec) {
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|   if (dec->filter_type_ > 0) {
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|     int s;
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|     const VP8FilterHeader* const hdr = &dec->filter_hdr_;
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|     for (s = 0; s < NUM_MB_SEGMENTS; ++s) {
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|       int i4x4;
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|       // First, compute the initial level
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|       int base_level;
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|       if (dec->segment_hdr_.use_segment_) {
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|         base_level = dec->segment_hdr_.filter_strength_[s];
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|         if (!dec->segment_hdr_.absolute_delta_) {
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|           base_level += hdr->level_;
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|         }
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|       } else {
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|         base_level = hdr->level_;
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|       }
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|       for (i4x4 = 0; i4x4 <= 1; ++i4x4) {
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|         VP8FInfo* const info = &dec->fstrengths_[s][i4x4];
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|         int level = base_level;
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|         if (hdr->use_lf_delta_) {
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|           // TODO(skal): only CURRENT is handled for now.
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|           level += hdr->ref_lf_delta_[0];
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|           if (i4x4) {
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|             level += hdr->mode_lf_delta_[0];
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|           }
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|         }
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|         level = (level < 0) ? 0 : (level > 63) ? 63 : level;
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|         info->f_level_ = level;
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| 
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|         if (hdr->sharpness_ > 0) {
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|           if (hdr->sharpness_ > 4) {
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|             level >>= 2;
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|           } else {
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|             level >>= 1;
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|           }
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|           if (level > 9 - hdr->sharpness_) {
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|             level = 9 - hdr->sharpness_;
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|           }
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|         }
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|         info->f_ilevel_ = (level < 1) ? 1 : level;
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|         info->f_inner_ = 0;
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|       }
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|     }
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|   }
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| }
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| 
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| //------------------------------------------------------------------------------
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| // This function is called after a row of macroblocks is finished decoding.
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| // It also takes into account the following restrictions:
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| //  * In case of in-loop filtering, we must hold off sending some of the bottom
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| //    pixels as they are yet unfiltered. They will be when the next macroblock
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| //    row is decoded. Meanwhile, we must preserve them by rotating them in the
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| //    cache area. This doesn't hold for the very bottom row of the uncropped
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| //    picture of course.
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| //  * we must clip the remaining pixels against the cropping area. The VP8Io
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| //    struct must have the following fields set correctly before calling put():
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| 
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| #define MACROBLOCK_VPOS(mb_y)  ((mb_y) * 16)    // vertical position of a MB
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| 
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| // Finalize and transmit a complete row. Return false in case of user-abort.
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| static int FinishRow(VP8Decoder* const dec, VP8Io* const io) {
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|   int ok = 1;
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|   const VP8ThreadContext* const ctx = &dec->thread_ctx_;
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|   const int extra_y_rows = kFilterExtraRows[dec->filter_type_];
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|   const int ysize = extra_y_rows * dec->cache_y_stride_;
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|   const int uvsize = (extra_y_rows / 2) * dec->cache_uv_stride_;
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|   const int y_offset = ctx->id_ * 16 * dec->cache_y_stride_;
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|   const int uv_offset = ctx->id_ * 8 * dec->cache_uv_stride_;
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|   uint8_t* const ydst = dec->cache_y_ - ysize + y_offset;
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|   uint8_t* const udst = dec->cache_u_ - uvsize + uv_offset;
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|   uint8_t* const vdst = dec->cache_v_ - uvsize + uv_offset;
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|   const int first_row = (ctx->mb_y_ == 0);
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|   const int last_row = (ctx->mb_y_ >= dec->br_mb_y_ - 1);
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|   int y_start = MACROBLOCK_VPOS(ctx->mb_y_);
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|   int y_end = MACROBLOCK_VPOS(ctx->mb_y_ + 1);
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| 
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|   if (ctx->filter_row_) {
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|     FilterRow(dec);
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|   }
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| 
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|   if (io->put) {
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|     if (!first_row) {
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|       y_start -= extra_y_rows;
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|       io->y = ydst;
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|       io->u = udst;
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|       io->v = vdst;
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|     } else {
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|       io->y = dec->cache_y_ + y_offset;
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|       io->u = dec->cache_u_ + uv_offset;
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|       io->v = dec->cache_v_ + uv_offset;
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|     }
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| 
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|     if (!last_row) {
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|       y_end -= extra_y_rows;
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|     }
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|     if (y_end > io->crop_bottom) {
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|       y_end = io->crop_bottom;    // make sure we don't overflow on last row.
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|     }
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|     io->a = NULL;
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|     if (dec->alpha_data_ != NULL && y_start < y_end) {
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|       // TODO(skal): several things to correct here:
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|       // * testing presence of alpha with dec->alpha_data_ is not a good idea
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|       // * we're actually decompressing the full plane only once. It should be
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|       //   more obvious from signature.
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|       // * we could free alpha_data_ right after this call, but we don't own.
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|       io->a = VP8DecompressAlphaRows(dec, y_start, y_end - y_start);
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|       if (io->a == NULL) {
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|         return VP8SetError(dec, VP8_STATUS_BITSTREAM_ERROR,
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|                            "Could not decode alpha data.");
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|       }
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|     }
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|     if (y_start < io->crop_top) {
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|       const int delta_y = io->crop_top - y_start;
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|       y_start = io->crop_top;
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|       assert(!(delta_y & 1));
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|       io->y += dec->cache_y_stride_ * delta_y;
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|       io->u += dec->cache_uv_stride_ * (delta_y >> 1);
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|       io->v += dec->cache_uv_stride_ * (delta_y >> 1);
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|       if (io->a != NULL) {
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|         io->a += io->width * delta_y;
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|       }
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|     }
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|     if (y_start < y_end) {
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|       io->y += io->crop_left;
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|       io->u += io->crop_left >> 1;
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|       io->v += io->crop_left >> 1;
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|       if (io->a != NULL) {
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|         io->a += io->crop_left;
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|       }
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|       io->mb_y = y_start - io->crop_top;
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|       io->mb_w = io->crop_right - io->crop_left;
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|       io->mb_h = y_end - y_start;
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|       ok = io->put(io);
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|     }
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|   }
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|   // rotate top samples if needed
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|   if (ctx->id_ + 1 == dec->num_caches_) {
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|     if (!last_row) {
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|       memcpy(dec->cache_y_ - ysize, ydst + 16 * dec->cache_y_stride_, ysize);
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|       memcpy(dec->cache_u_ - uvsize, udst + 8 * dec->cache_uv_stride_, uvsize);
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|       memcpy(dec->cache_v_ - uvsize, vdst + 8 * dec->cache_uv_stride_, uvsize);
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|     }
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|   }
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| 
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|   return ok;
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| }
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| 
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| #undef MACROBLOCK_VPOS
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| 
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| //------------------------------------------------------------------------------
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| 
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| int VP8ProcessRow(VP8Decoder* const dec, VP8Io* const io) {
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|   int ok = 1;
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|   VP8ThreadContext* const ctx = &dec->thread_ctx_;
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|   if (!dec->use_threads_) {
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|     // ctx->id_ and ctx->f_info_ are already set
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|     ctx->mb_y_ = dec->mb_y_;
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|     ctx->filter_row_ = dec->filter_row_;
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|     ok = FinishRow(dec, io);
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|   } else {
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|     WebPWorker* const worker = &dec->worker_;
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|     // Finish previous job *before* updating context
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|     ok &= WebPWorkerSync(worker);
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|     assert(worker->status_ == OK);
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|     if (ok) {   // spawn a new deblocking/output job
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|       ctx->io_ = *io;
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|       ctx->id_ = dec->cache_id_;
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|       ctx->mb_y_ = dec->mb_y_;
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|       ctx->filter_row_ = dec->filter_row_;
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|       if (ctx->filter_row_) {    // just swap filter info
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|         VP8FInfo* const tmp = ctx->f_info_;
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|         ctx->f_info_ = dec->f_info_;
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|         dec->f_info_ = tmp;
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|       }
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|       WebPWorkerLaunch(worker);
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|       if (++dec->cache_id_ == dec->num_caches_) {
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|         dec->cache_id_ = 0;
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|       }
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|     }
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|   }
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|   return ok;
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| }
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| 
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| //------------------------------------------------------------------------------
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| // Finish setting up the decoding parameter once user's setup() is called.
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| 
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| VP8StatusCode VP8EnterCritical(VP8Decoder* const dec, VP8Io* const io) {
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|   // Call setup() first. This may trigger additional decoding features on 'io'.
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|   // Note: Afterward, we must call teardown() not matter what.
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|   if (io->setup && !io->setup(io)) {
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|     VP8SetError(dec, VP8_STATUS_USER_ABORT, "Frame setup failed");
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|     return dec->status_;
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|   }
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| 
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|   // Disable filtering per user request
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|   if (io->bypass_filtering) {
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|     dec->filter_type_ = 0;
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|   }
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|   // TODO(skal): filter type / strength / sharpness forcing
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| 
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|   // Define the area where we can skip in-loop filtering, in case of cropping.
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|   //
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|   // 'Simple' filter reads two luma samples outside of the macroblock and
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|   // and filters one. It doesn't filter the chroma samples. Hence, we can
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|   // avoid doing the in-loop filtering before crop_top/crop_left position.
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|   // For the 'Complex' filter, 3 samples are read and up to 3 are filtered.
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|   // Means: there's a dependency chain that goes all the way up to the
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|   // top-left corner of the picture (MB #0). We must filter all the previous
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|   // macroblocks.
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|   // TODO(skal): add an 'approximate_decoding' option, that won't produce
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|   // a 1:1 bit-exactness for complex filtering?
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|   {
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|     const int extra_pixels = kFilterExtraRows[dec->filter_type_];
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|     if (dec->filter_type_ == 2) {
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|       // For complex filter, we need to preserve the dependency chain.
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|       dec->tl_mb_x_ = 0;
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|       dec->tl_mb_y_ = 0;
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|     } else {
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|       // For simple filter, we can filter only the cropped region.
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|       // We include 'extra_pixels' on the other side of the boundary, since
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|       // vertical or horizontal filtering of the previous macroblock can
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|       // modify some abutting pixels.
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|       dec->tl_mb_x_ = (io->crop_left - extra_pixels) >> 4;
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|       dec->tl_mb_y_ = (io->crop_top - extra_pixels) >> 4;
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|       if (dec->tl_mb_x_ < 0) dec->tl_mb_x_ = 0;
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|       if (dec->tl_mb_y_ < 0) dec->tl_mb_y_ = 0;
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|     }
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|     // We need some 'extra' pixels on the right/bottom.
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|     dec->br_mb_y_ = (io->crop_bottom + 15 + extra_pixels) >> 4;
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|     dec->br_mb_x_ = (io->crop_right + 15 + extra_pixels) >> 4;
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|     if (dec->br_mb_x_ > dec->mb_w_) {
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|       dec->br_mb_x_ = dec->mb_w_;
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|     }
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|     if (dec->br_mb_y_ > dec->mb_h_) {
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|       dec->br_mb_y_ = dec->mb_h_;
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|     }
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|   }
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|   PrecomputeFilterStrengths(dec);
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|   return VP8_STATUS_OK;
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| }
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| 
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| int VP8ExitCritical(VP8Decoder* const dec, VP8Io* const io) {
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|   int ok = 1;
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|   if (dec->use_threads_) {
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|     ok = WebPWorkerSync(&dec->worker_);
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|   }
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| 
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|   if (io->teardown) {
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|     io->teardown(io);
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|   }
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|   return ok;
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| }
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| 
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| //------------------------------------------------------------------------------
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| // For multi-threaded decoding we need to use 3 rows of 16 pixels as delay line.
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| //
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| // Reason is: the deblocking filter cannot deblock the bottom horizontal edges
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| // immediately, and needs to wait for first few rows of the next macroblock to
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| // be decoded. Hence, deblocking is lagging behind by 4 or 8 pixels (depending
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| // on strength).
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| // With two threads, the vertical positions of the rows being decoded are:
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| // Decode:  [ 0..15][16..31][32..47][48..63][64..79][...
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| // Deblock:         [ 0..11][12..27][28..43][44..59][...
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| // If we use two threads and two caches of 16 pixels, the sequence would be:
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| // Decode:  [ 0..15][16..31][ 0..15!!][16..31][ 0..15][...
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| // Deblock:         [ 0..11][12..27!!][-4..11][12..27][...
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| // The problem occurs during row [12..15!!] that both the decoding and
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| // deblocking threads are writing simultaneously.
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| // With 3 cache lines, one get a safe write pattern:
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| // Decode:  [ 0..15][16..31][32..47][ 0..15][16..31][32..47][0..
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| // Deblock:         [ 0..11][12..27][28..43][-4..11][12..27][28...
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| // Note that multi-threaded output _without_ deblocking can make use of two
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| // cache lines of 16 pixels only, since there's no lagging behind. The decoding
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| // and output process have non-concurrent writing:
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| // Decode:  [ 0..15][16..31][ 0..15][16..31][...
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| // io->put:         [ 0..15][16..31][ 0..15][...
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| 
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| #define MT_CACHE_LINES 3
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| #define ST_CACHE_LINES 1   // 1 cache row only for single-threaded case
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| 
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| // Initialize multi/single-thread worker
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| static int InitThreadContext(VP8Decoder* const dec) {
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|   dec->cache_id_ = 0;
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|   if (dec->use_threads_) {
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|     WebPWorker* const worker = &dec->worker_;
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|     if (!WebPWorkerReset(worker)) {
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|       return VP8SetError(dec, VP8_STATUS_OUT_OF_MEMORY,
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|                          "thread initialization failed.");
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|     }
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|     worker->data1 = dec;
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|     worker->data2 = (void*)&dec->thread_ctx_.io_;
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|     worker->hook = (WebPWorkerHook)FinishRow;
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|     dec->num_caches_ =
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|       (dec->filter_type_ > 0) ? MT_CACHE_LINES : MT_CACHE_LINES - 1;
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|   } else {
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|     dec->num_caches_ = ST_CACHE_LINES;
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|   }
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|   return 1;
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| }
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| 
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| #undef MT_CACHE_LINES
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| #undef ST_CACHE_LINES
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| 
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| //------------------------------------------------------------------------------
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| // Memory setup
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| 
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| static int AllocateMemory(VP8Decoder* const dec) {
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|   const int num_caches = dec->num_caches_;
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|   const int mb_w = dec->mb_w_;
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|   // Note: we use 'size_t' when there's no overflow risk, uint64_t otherwise.
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|   const size_t intra_pred_mode_size = 4 * mb_w * sizeof(uint8_t);
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|   const size_t top_size = (16 + 8 + 8) * mb_w;
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|   const size_t mb_info_size = (mb_w + 1) * sizeof(VP8MB);
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|   const size_t f_info_size =
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|       (dec->filter_type_ > 0) ?
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|           mb_w * (dec->use_threads_ ? 2 : 1) * sizeof(VP8FInfo)
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|         : 0;
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|   const size_t yuv_size = YUV_SIZE * sizeof(*dec->yuv_b_);
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|   const size_t coeffs_size = 384 * sizeof(*dec->coeffs_);
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|   const size_t cache_height = (16 * num_caches
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|                             + kFilterExtraRows[dec->filter_type_]) * 3 / 2;
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|   const size_t cache_size = top_size * cache_height;
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|   // alpha_size is the only one that scales as width x height.
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|   const uint64_t alpha_size = (dec->alpha_data_ != NULL) ?
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|       (uint64_t)dec->pic_hdr_.width_ * dec->pic_hdr_.height_ : 0ULL;
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|   const uint64_t needed = (uint64_t)intra_pred_mode_size
 | |
|                         + top_size + mb_info_size + f_info_size
 | |
|                         + yuv_size + coeffs_size
 | |
|                         + cache_size + alpha_size + ALIGN_MASK;
 | |
|   uint8_t* mem;
 | |
| 
 | |
|   if (needed != (size_t)needed) return 0;  // check for overflow
 | |
|   if (needed > dec->mem_size_) {
 | |
|     free(dec->mem_);
 | |
|     dec->mem_size_ = 0;
 | |
|     dec->mem_ = WebPSafeMalloc(needed, sizeof(uint8_t));
 | |
|     if (dec->mem_ == NULL) {
 | |
|       return VP8SetError(dec, VP8_STATUS_OUT_OF_MEMORY,
 | |
|                          "no memory during frame initialization.");
 | |
|     }
 | |
|     // down-cast is ok, thanks to WebPSafeAlloc() above.
 | |
|     dec->mem_size_ = (size_t)needed;
 | |
|   }
 | |
| 
 | |
|   mem = (uint8_t*)dec->mem_;
 | |
|   dec->intra_t_ = (uint8_t*)mem;
 | |
|   mem += intra_pred_mode_size;
 | |
| 
 | |
|   dec->y_t_ = (uint8_t*)mem;
 | |
|   mem += 16 * mb_w;
 | |
|   dec->u_t_ = (uint8_t*)mem;
 | |
|   mem += 8 * mb_w;
 | |
|   dec->v_t_ = (uint8_t*)mem;
 | |
|   mem += 8 * mb_w;
 | |
| 
 | |
|   dec->mb_info_ = ((VP8MB*)mem) + 1;
 | |
|   mem += mb_info_size;
 | |
| 
 | |
|   dec->f_info_ = f_info_size ? (VP8FInfo*)mem : NULL;
 | |
|   mem += f_info_size;
 | |
|   dec->thread_ctx_.id_ = 0;
 | |
|   dec->thread_ctx_.f_info_ = dec->f_info_;
 | |
|   if (dec->use_threads_) {
 | |
|     // secondary cache line. The deblocking process need to make use of the
 | |
|     // filtering strength from previous macroblock row, while the new ones
 | |
|     // are being decoded in parallel. We'll just swap the pointers.
 | |
|     dec->thread_ctx_.f_info_ += mb_w;
 | |
|   }
 | |
| 
 | |
|   mem = (uint8_t*)((uintptr_t)(mem + ALIGN_MASK) & ~ALIGN_MASK);
 | |
|   assert((yuv_size & ALIGN_MASK) == 0);
 | |
|   dec->yuv_b_ = (uint8_t*)mem;
 | |
|   mem += yuv_size;
 | |
| 
 | |
|   dec->coeffs_ = (int16_t*)mem;
 | |
|   mem += coeffs_size;
 | |
| 
 | |
|   dec->cache_y_stride_ = 16 * mb_w;
 | |
|   dec->cache_uv_stride_ = 8 * mb_w;
 | |
|   {
 | |
|     const int extra_rows = kFilterExtraRows[dec->filter_type_];
 | |
|     const int extra_y = extra_rows * dec->cache_y_stride_;
 | |
|     const int extra_uv = (extra_rows / 2) * dec->cache_uv_stride_;
 | |
|     dec->cache_y_ = ((uint8_t*)mem) + extra_y;
 | |
|     dec->cache_u_ = dec->cache_y_
 | |
|                   + 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;
 | |
| }
 | |
| 
 | |
| static void InitIo(VP8Decoder* const dec, VP8Io* io) {
 | |
|   // prepare 'io'
 | |
|   io->mb_y = 0;
 | |
|   io->y = dec->cache_y_;
 | |
|   io->u = dec->cache_u_;
 | |
|   io->v = dec->cache_v_;
 | |
|   io->y_stride = dec->cache_y_stride_;
 | |
|   io->uv_stride = dec->cache_uv_stride_;
 | |
|   io->a = NULL;
 | |
| }
 | |
| 
 | |
| int VP8InitFrame(VP8Decoder* const dec, VP8Io* io) {
 | |
|   if (!InitThreadContext(dec)) return 0;  // call first. Sets dec->num_caches_.
 | |
|   if (!AllocateMemory(dec)) return 0;
 | |
|   InitIo(dec, io);
 | |
|   VP8DspInit();  // Init critical function pointers and look-up tables.
 | |
|   return 1;
 | |
| }
 | |
| 
 | |
| //------------------------------------------------------------------------------
 | |
| // Main reconstruction function.
 | |
| 
 | |
| static const int kScan[16] = {
 | |
|   0 +  0 * BPS,  4 +  0 * BPS, 8 +  0 * BPS, 12 +  0 * BPS,
 | |
|   0 +  4 * BPS,  4 +  4 * BPS, 8 +  4 * BPS, 12 +  4 * BPS,
 | |
|   0 +  8 * BPS,  4 +  8 * BPS, 8 +  8 * BPS, 12 +  8 * BPS,
 | |
|   0 + 12 * BPS,  4 + 12 * BPS, 8 + 12 * BPS, 12 + 12 * BPS
 | |
| };
 | |
| 
 | |
| static WEBP_INLINE int CheckMode(VP8Decoder* const dec, int mode) {
 | |
|   if (mode == B_DC_PRED) {
 | |
|     if (dec->mb_x_ == 0) {
 | |
|       return (dec->mb_y_ == 0) ? B_DC_PRED_NOTOPLEFT : B_DC_PRED_NOLEFT;
 | |
|     } else {
 | |
|       return (dec->mb_y_ == 0) ? B_DC_PRED_NOTOP : B_DC_PRED;
 | |
|     }
 | |
|   }
 | |
|   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) {
 | |
|     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 {
 | |
|     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;
 | |
|     }
 | |
|   }
 | |
|   {
 | |
|     // bring top samples into the cache
 | |
|     uint8_t* const top_y = dec->y_t_ + dec->mb_x_ * 16;
 | |
|     uint8_t* const top_u = dec->u_t_ + dec->mb_x_ * 8;
 | |
|     uint8_t* const top_v = dec->v_t_ + dec->mb_x_ * 8;
 | |
|     const int16_t* coeffs = dec->coeffs_;
 | |
|     int n;
 | |
| 
 | |
|     if (dec->mb_y_ > 0) {
 | |
|       memcpy(y_dst - BPS, top_y, 16);
 | |
|       memcpy(u_dst - BPS, top_u, 8);
 | |
|       memcpy(v_dst - BPS, top_v, 8);
 | |
|     } else if (dec->mb_x_ == 0) {
 | |
|       // we only need to do this init once at block (0,0).
 | |
|       // Afterward, it remains valid for the whole topmost row.
 | |
|       memset(y_dst - BPS - 1, 127, 16 + 4 + 1);
 | |
|       memset(u_dst - BPS - 1, 127, 8 + 1);
 | |
|       memset(v_dst - BPS - 1, 127, 8 + 1);
 | |
|     }
 | |
| 
 | |
|     // predict and add residuals
 | |
| 
 | |
|     if (dec->is_i4x4_) {   // 4x4
 | |
|       uint32_t* const top_right = (uint32_t*)(y_dst - BPS + 16);
 | |
| 
 | |
|       if (dec->mb_y_ > 0) {
 | |
|         if (dec->mb_x_ >= dec->mb_w_ - 1) {    // on rightmost border
 | |
|           top_right[0] = top_y[15] * 0x01010101u;
 | |
|         } else {
 | |
|           memcpy(top_right, top_y + 16, sizeof(*top_right));
 | |
|         }
 | |
|       }
 | |
|       // replicate the top-right pixels below
 | |
|       top_right[BPS] = top_right[2 * BPS] = top_right[3 * BPS] = top_right[0];
 | |
| 
 | |
|       // predict and add residues for all 4x4 blocks in turn.
 | |
|       for (n = 0; n < 16; n++) {
 | |
|         uint8_t* const dst = y_dst + kScan[n];
 | |
|         VP8PredLuma4[dec->imodes_[n]](dst);
 | |
|         if (dec->non_zero_ac_ & (1 << n)) {
 | |
|           VP8Transform(coeffs + n * 16, dst, 0);
 | |
|         } else if (dec->non_zero_ & (1 << n)) {  // only DC is present
 | |
|           VP8TransformDC(coeffs + n * 16, dst);
 | |
|         }
 | |
|       }
 | |
|     } else {    // 16x16
 | |
|       const int pred_func = CheckMode(dec, dec->imodes_[0]);
 | |
|       VP8PredLuma16[pred_func](y_dst);
 | |
|       if (dec->non_zero_) {
 | |
|         for (n = 0; n < 16; n++) {
 | |
|           uint8_t* const dst = y_dst + kScan[n];
 | |
|           if (dec->non_zero_ac_ & (1 << n)) {
 | |
|             VP8Transform(coeffs + n * 16, dst, 0);
 | |
|           } else if (dec->non_zero_ & (1 << n)) {  // only DC is present
 | |
|             VP8TransformDC(coeffs + n * 16, dst);
 | |
|           }
 | |
|         }
 | |
|       }
 | |
|     }
 | |
|     {
 | |
|       // Chroma
 | |
|       const int pred_func = CheckMode(dec, dec->uvmode_);
 | |
|       VP8PredChroma8[pred_func](u_dst);
 | |
|       VP8PredChroma8[pred_func](v_dst);
 | |
| 
 | |
|       if (dec->non_zero_ & 0x0f0000) {   // chroma-U
 | |
|         const int16_t* const u_coeffs = dec->coeffs_ + 16 * 16;
 | |
|         if (dec->non_zero_ac_ & 0x0f0000) {
 | |
|           VP8TransformUV(u_coeffs, u_dst);
 | |
|         } else {
 | |
|           VP8TransformDCUV(u_coeffs, u_dst);
 | |
|         }
 | |
|       }
 | |
|       if (dec->non_zero_ & 0xf00000) {   // chroma-V
 | |
|         const int16_t* const v_coeffs = dec->coeffs_ + 20 * 16;
 | |
|         if (dec->non_zero_ac_ & 0xf00000) {
 | |
|           VP8TransformUV(v_coeffs, v_dst);
 | |
|         } else {
 | |
|           VP8TransformDCUV(v_coeffs, v_dst);
 | |
|         }
 | |
|       }
 | |
| 
 | |
|       // 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
 | 
