hevc/sao: optimze sao implementation

- adding one extra pixel all around the frame
- do not copy when SAO is not applied

5% improvement

cherry picked from commit 10fc29fc19a12c4d8168fbe1a954b76386db12d0
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/hevc.c

@@ -276,6 +276,24 @@ static int decode_lt_rps(HEVCContext *s, LongTermRPS *rps, GetBitContext *gb)
     return 0;
 }
 
+static int get_buffer_sao(HEVCContext *s, AVFrame *frame)
+{
+    int ret, i;
+
+    frame->width  = s->avctx->width  + 2;
+    frame->height = s->avctx->height + 2;
+    if ((ret = ff_get_buffer(s->avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
+        return ret;
+    for (i = 0; frame->data[i]; i++) {
+        int offset = frame->linesize[i] + 1;
+        frame->data[i] += offset;
+    }
+    frame->width  = s->avctx->width;
+    frame->height = s->avctx->height;
+
+    return 0;
+}
+
 static int set_sps(HEVCContext *s, const HEVCSPS *sps)
 {
     int ret;
@@ -317,10 +335,8 @@ static int set_sps(HEVCContext *s, const HEVCSPS *sps)
 
     if (sps->sao_enabled) {
         av_frame_unref(s->tmp_frame);
-        ret = ff_get_buffer(s->avctx, s->tmp_frame, AV_GET_BUFFER_FLAG_REF);
-        if (ret < 0)
-            goto fail;
-        s->frame = s->tmp_frame;
+        ret = get_buffer_sao(s, s->tmp_frame);
+        s->sao_frame = s->tmp_frame;
     }
 
     s->sps = sps;
@@ -2582,8 +2598,7 @@ static int hevc_frame_start(HEVCContext *s)
     if (s->pps->tiles_enabled_flag)
         lc->end_of_tiles_x = s->pps->column_width[0] << s->sps->log2_ctb_size;
 
-    ret = ff_hevc_set_new_ref(s, s->sps->sao_enabled ? &s->sao_frame : &s->frame,
-                              s->poc);
+    ret = ff_hevc_set_new_ref(s, &s->frame, s->poc);
     if (ret < 0)
         goto fail;
 

libavcodec/hevc.h

@@ -260,6 +260,7 @@ enum SAOType {
     SAO_NOT_APPLIED = 0,
     SAO_BAND,
     SAO_EDGE,
+    SAO_APPLIED
 };
 
 enum SAOEOClass {

libavcodec/hevc_filter.c

@@ -142,14 +142,14 @@ static int get_qPy(HEVCContext *s, int xC, int yC)
 }
 
 static void copy_CTB(uint8_t *dst, uint8_t *src,
-                     int width, int height, int stride)
+                     int width, int height, int stride_dst, int stride_src)
 {
     int i;
 
     for (i = 0; i < height; i++) {
         memcpy(dst, src, width);
-        dst += stride;
-        src += stride;
+        dst += stride_dst;
+        src += stride_src;
     }
 }
 
@@ -174,7 +174,7 @@ static void restore_tqb_pixels(HEVCContext *s, int x0, int y0, int width, int he
                     uint8_t *src = &s->frame->data[c_idx][    ((y << s->sps->log2_min_pu_size) >> vshift) * stride + (((x << s->sps->log2_min_pu_size) >> hshift) << s->sps->pixel_shift)];
                     uint8_t *dst = &s->sao_frame->data[c_idx][((y << s->sps->log2_min_pu_size) >> vshift) * stride + (((x << s->sps->log2_min_pu_size) >> hshift) << s->sps->pixel_shift)];
                     for (n = 0; n < (min_pu_size >> vshift); n++) {
-                        memcpy(dst, src, len);
+                        memcpy(src, dst, len);
                         src += stride;
                         dst += stride;
                     }
@@ -247,29 +247,58 @@ static void sao_filter_CTB(HEVCContext *s, int x, int y)
     for (c_idx = 0; c_idx < 3; c_idx++) {
         int x0       = x >> s->sps->hshift[c_idx];
         int y0       = y >> s->sps->vshift[c_idx];
-        int stride   = s->frame->linesize[c_idx];
+        int stride_src = s->frame->linesize[c_idx];
+        int stride_dst = s->sao_frame->linesize[c_idx];
         int ctb_size_h = (1 << (s->sps->log2_ctb_size)) >> s->sps->hshift[c_idx];
         int ctb_size_v = (1 << (s->sps->log2_ctb_size)) >> s->sps->vshift[c_idx];
-        int width    = FFMIN(ctb_size_h,
-                             (s->sps->width  >> s->sps->hshift[c_idx]) - x0);
-        int height   = FFMIN(ctb_size_v,
-                             (s->sps->height >> s->sps->vshift[c_idx]) - y0);
-
-        uint8_t *src = &s->frame->data[c_idx][y0 * stride + (x0 << s->sps->pixel_shift)];
-        uint8_t *dst = &s->sao_frame->data[c_idx][y0 * stride + (x0 << s->sps->pixel_shift)];
+        int width    = FFMIN(ctb_size_h, (s->sps->width  >> s->sps->hshift[c_idx]) - x0);
+        int height   = FFMIN(ctb_size_v, (s->sps->height >> s->sps->vshift[c_idx]) - y0);
+        uint8_t *src = &s->frame->data[c_idx][y0 * stride_src + (x0 << s->sps->pixel_shift)];
+        uint8_t *dst = &s->sao_frame->data[c_idx][y0 * stride_dst + (x0 << s->sps->pixel_shift)];
 
         switch (sao->type_idx[c_idx]) {
         case SAO_BAND:
-            s->hevcdsp.sao_band_filter(dst, src,
-                                       stride,
+            copy_CTB(dst, src, width << s->sps->pixel_shift, height, stride_dst, stride_src);
+            s->hevcdsp.sao_band_filter(src, dst,
+                                       stride_src, stride_dst,
                                        sao,
                                        edges, width,
                                        height, c_idx);
             restore_tqb_pixels(s, x, y, width, height, c_idx);
+            sao->type_idx[c_idx] = SAO_APPLIED;
             break;
         case SAO_EDGE:
-            s->hevcdsp.sao_edge_filter[restore](dst, src,
-                                                stride,
+        {
+            uint8_t left_pixels = !edges[0] && (CTB(s->sao, x_ctb-1, y_ctb).type_idx[c_idx] != SAO_APPLIED);
+            if (!edges[1]) {
+                uint8_t top_left  = !edges[0] && (CTB(s->sao, x_ctb-1, y_ctb-1).type_idx[c_idx] != SAO_APPLIED);
+                uint8_t top_right = !edges[2] && (CTB(s->sao, x_ctb+1, y_ctb-1).type_idx[c_idx] != SAO_APPLIED);
+                if (CTB(s->sao, x_ctb  , y_ctb-1).type_idx[c_idx] == 0)
+                    memcpy( dst - stride_dst - (top_left << s->sps->pixel_shift),
+                            src - stride_src - (top_left << s->sps->pixel_shift),
+                            (top_left + width + top_right) << s->sps->pixel_shift);
+                else {
+                    if (top_left)
+                        memcpy( dst - stride_dst - (1 << s->sps->pixel_shift),
+                                src - stride_src - (1 << s->sps->pixel_shift),
+                                1 << s->sps->pixel_shift);
+                    if(top_right)
+                        memcpy( dst - stride_dst + (width << s->sps->pixel_shift),
+                                src - stride_src + (width << s->sps->pixel_shift),
+                                1 << s->sps->pixel_shift);
+                }
+            }
+            if (!edges[3]) {                                                                // bottom and bottom right
+                uint8_t bottom_left = !edges[0] && (CTB(s->sao, x_ctb-1, y_ctb+1).type_idx[c_idx] != SAO_APPLIED);
+                memcpy( dst + height * stride_dst - (bottom_left << s->sps->pixel_shift),
+                        src + height * stride_src - (bottom_left << s->sps->pixel_shift),
+                        (width + 1 + bottom_left) << s->sps->pixel_shift);
+            }
+            copy_CTB(dst - (left_pixels << s->sps->pixel_shift),
+                     src - (left_pixels << s->sps->pixel_shift),
+                     (width + 1 + left_pixels) << s->sps->pixel_shift, height, stride_dst, stride_src);
+            s->hevcdsp.sao_edge_filter[restore](src, dst,
+                                                stride_src, stride_dst,
                                                 sao,
                                                 edges, width,
                                                 height, c_idx,
@@ -277,10 +306,9 @@ static void sao_filter_CTB(HEVCContext *s, int x, int y)
                                                 horiz_edge,
                                                 diag_edge);
             restore_tqb_pixels(s, x, y, width, height, c_idx);
+            sao->type_idx[c_idx] = SAO_APPLIED;
             break;
-        default :
-            copy_CTB(dst, src, width << s->sps->pixel_shift, height, stride);
-            break;
+        }
         }
     }
 }

libavcodec/hevcdsp.h

@@ -58,11 +58,11 @@ typedef struct HEVCDSPContext {
 
     void (*transform_dc_add[4])(uint8_t *dst, int16_t *coeffs, ptrdiff_t stride);
 
-    void (*sao_band_filter)(uint8_t *_dst, uint8_t *_src, ptrdiff_t _stride,
+    void (*sao_band_filter)(uint8_t *_dst, uint8_t *_src, ptrdiff_t _stride_dst, ptrdiff_t _stride_src,
                             struct SAOParams *sao, int *borders,
                             int width, int height, int c_idx);
 
-    void (*sao_edge_filter[2])(uint8_t *_dst, uint8_t *_src, ptrdiff_t _stride,
+    void (*sao_edge_filter[2])(uint8_t *_dst, uint8_t *_src, ptrdiff_t _stride_dst, ptrdiff_t _stride_src,
                                struct SAOParams *sao, int *borders, int _width,
                                int _height, int c_idx, uint8_t *vert_edge,
                                uint8_t *horiz_edge, uint8_t *diag_edge);