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>

5 files changed, 117 insertions, 72 deletions

diff --git a/libavcodec/hevc.c b/libavcodec/hevc.c
index afb2baaf65..d466aa6253 100644
--- a/libavcodec/hevc.c
+++ b/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;
 
diff --git a/libavcodec/hevc.h b/libavcodec/hevc.h
index 2a5ce2523c..c38de1a2ea 100644
--- a/libavcodec/hevc.h
+++ b/libavcodec/hevc.h
@@ -260,6 +260,7 @@ enum SAOType {
     SAO_NOT_APPLIED = 0,
     SAO_BAND,
     SAO_EDGE,
+    SAO_APPLIED
 };
 
 enum SAOEOClass {
diff --git a/libavcodec/hevc_filter.c b/libavcodec/hevc_filter.c
index 0d3e238d69..b0b197cc66 100644
--- a/libavcodec/hevc_filter.c
+++ b/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;
+        }
         }
     }
 }
diff --git a/libavcodec/hevcdsp.h b/libavcodec/hevcdsp.h
index 3b82fabff1..dfff7801f7 100644
--- a/libavcodec/hevcdsp.h
+++ b/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);
diff --git a/libavcodec/hevcdsp_template.c b/libavcodec/hevcdsp_template.c
index f0bb256b4b..7840ec7472 100644
--- a/libavcodec/hevcdsp_template.c
+++ b/libavcodec/hevcdsp_template.c
@@ -329,7 +329,7 @@ IDCT_DC(32)
 #undef ADD_AND_SCALE
 
 static void FUNC(sao_band_filter_0)(uint8_t *_dst, uint8_t *_src,
-                                  ptrdiff_t stride, SAOParams *sao,
+                                  ptrdiff_t stride_dst, ptrdiff_t stride_src, SAOParams *sao,
                                   int *borders, int width, int height,
                                   int c_idx)
 {
@@ -341,22 +341,23 @@ static void FUNC(sao_band_filter_0)(uint8_t *_dst, uint8_t *_src,
     int *sao_offset_val = sao->offset_val[c_idx];
     int sao_left_class  = sao->band_position[c_idx];
 
-    stride /= sizeof(pixel);
+    stride_dst /= sizeof(pixel);
+    stride_src /= sizeof(pixel);
 
     for (k = 0; k < 4; k++)
         offset_table[(k + sao_left_class) & 31] = sao_offset_val[k + 1];
     for (y = 0; y < height; y++) {
         for (x = 0; x < width; x++)
-            dst[x] = av_clip_pixel(src[x] + offset_table[av_clip_pixel(src[x] >> shift)]);
-        dst += stride;
-        src += stride;
+            dst[x] = av_clip_pixel(src[x] + offset_table[src[x] >> shift]);
+        dst += stride_dst;
+        src += stride_src;
     }
 }
 
 #define CMP(a, b) ((a) > (b) ? 1 : ((a) == (b) ? 0 : -1))
 
 static void FUNC(sao_edge_filter)(uint8_t *_dst, uint8_t *_src,
-                                  ptrdiff_t stride, SAOParams *sao,
+                                  ptrdiff_t stride_dst, ptrdiff_t stride_src, SAOParams *sao,
                                   int width, int height,
                                   int c_idx, int init_x, int init_y) {
 
@@ -372,30 +373,32 @@ static void FUNC(sao_edge_filter)(uint8_t *_dst, uint8_t *_src,
     pixel *dst = (pixel *)_dst;
     pixel *src = (pixel *)_src;
 
-    int y_stride = init_y * stride;
+    int y_stride_src = init_y * stride_src;
+    int y_stride_dst = init_y * stride_dst;
     int pos_0_0  = pos[sao_eo_class][0][0];
     int pos_0_1  = pos[sao_eo_class][0][1];
     int pos_1_0  = pos[sao_eo_class][1][0];
     int pos_1_1  = pos[sao_eo_class][1][1];
     int x, y;
 
-    int y_stride_0_1 = (init_y + pos_0_1) * stride;
-    int y_stride_1_1 = (init_y + pos_1_1) * stride;
+    int y_stride_0_1 = (init_y + pos_0_1) * stride_src;
+    int y_stride_1_1 = (init_y + pos_1_1) * stride_src;
     for (y = init_y; y < height; y++) {
         for (x = init_x; x < width; x++) {
-            int diff0         = CMP(src[x + y_stride], src[x + pos_0_0 + y_stride_0_1]);
-            int diff1         = CMP(src[x + y_stride], src[x + pos_1_0 + y_stride_1_1]);
-            int offset_val    = edge_idx[2 + diff0 + diff1];
-            dst[x + y_stride] = av_clip_pixel(src[x + y_stride] + sao_offset_val[offset_val]);
+            int diff0             = CMP(src[x + y_stride_src], src[x + pos_0_0 + y_stride_0_1]);
+            int diff1             = CMP(src[x + y_stride_src], src[x + pos_1_0 + y_stride_1_1]);
+            int offset_val        = edge_idx[2 + diff0 + diff1];
+            dst[x + y_stride_dst] = av_clip_pixel(src[x + y_stride_src] + sao_offset_val[offset_val]);
         }
-        y_stride     += stride;
-        y_stride_0_1 += stride;
-        y_stride_1_1 += stride;
+        y_stride_src += stride_src;
+        y_stride_dst += stride_dst;
+        y_stride_0_1 += stride_src;
+        y_stride_1_1 += stride_src;
     }
 }
 
 static void FUNC(sao_edge_filter_0)(uint8_t *_dst, uint8_t *_src,
-                                    ptrdiff_t stride, SAOParams *sao,
+                                    ptrdiff_t stride_dst, ptrdiff_t stride_src, SAOParams *sao,
                                     int *borders, int _width, int _height,
                                     int c_idx, uint8_t *vert_edge,
                                     uint8_t *horiz_edge, uint8_t *diag_edge)
@@ -407,24 +410,22 @@ static void FUNC(sao_edge_filter_0)(uint8_t *_dst, uint8_t *_src,
     int sao_eo_class    = sao->eo_class[c_idx];
     int init_x = 0, init_y = 0, width = _width, height = _height;
 
-    stride /= sizeof(pixel);
+    stride_dst /= sizeof(pixel);
+    stride_src /= sizeof(pixel);
 
     if (sao_eo_class != SAO_EO_VERT) {
         if (borders[0]) {
             int offset_val = sao_offset_val[0];
-            int y_stride   = 0;
             for (y = 0; y < height; y++) {
-                dst[y_stride] = av_clip_pixel(src[y_stride] + offset_val);
-                y_stride     += stride;
+                dst[y * stride_dst] = av_clip_pixel(src[y * stride_src] + offset_val);
             }
             init_x = 1;
         }
         if (borders[2]) {
             int offset_val = sao_offset_val[0];
-            int x_stride   = width - 1;
+            int offset     = width - 1;
             for (x = 0; x < height; x++) {
-                dst[x_stride] = av_clip_pixel(src[x_stride] + offset_val);
-                x_stride     += stride;
+                dst[x * stride_dst + offset] = av_clip_pixel(src[x * stride_src + offset] + offset_val);
             }
             width--;
         }
@@ -437,19 +438,20 @@ static void FUNC(sao_edge_filter_0)(uint8_t *_dst, uint8_t *_src,
             init_y = 1;
         }
         if (borders[3]) {
-            int offset_val = sao_offset_val[0];
-            int y_stride   = stride * (height - 1);
+            int offset_val   = sao_offset_val[0];
+            int y_stride_dst = stride_dst * (height - 1);
+            int y_stride_src = stride_src * (height - 1);
             for (x = init_x; x < width; x++)
-                dst[x + y_stride] = av_clip_pixel(src[x + y_stride] + offset_val);
+                dst[x + y_stride_dst] = av_clip_pixel(src[x + y_stride_src] + offset_val);
             height--;
         }
     }
 
-    FUNC(sao_edge_filter)((uint8_t *)dst, (uint8_t *)src, stride, sao, width, height, c_idx, init_x, init_y);
+    FUNC(sao_edge_filter)((uint8_t *)dst, (uint8_t *)src, stride_dst, stride_src, sao, width, height, c_idx, init_x, init_y);
 }
 
 static void FUNC(sao_edge_filter_1)(uint8_t *_dst, uint8_t *_src,
-                                    ptrdiff_t stride, SAOParams *sao,
+                                    ptrdiff_t stride_dst, ptrdiff_t stride_src, SAOParams *sao,
                                     int *borders, int _width, int _height,
                                     int c_idx, uint8_t *vert_edge,
                                     uint8_t *horiz_edge, uint8_t *diag_edge)
@@ -461,24 +463,22 @@ static void FUNC(sao_edge_filter_1)(uint8_t *_dst, uint8_t *_src,
     int sao_eo_class    = sao->eo_class[c_idx];
     int init_x = 0, init_y = 0, width = _width, height = _height;
 
-    stride /= sizeof(pixel);
+    stride_dst /= sizeof(pixel);
+    stride_src /= sizeof(pixel);
 
     if (sao_eo_class != SAO_EO_VERT) {
         if (borders[0]) {
             int offset_val = sao_offset_val[0];
-            int y_stride   = 0;
             for (y = 0; y < height; y++) {
-                dst[y_stride] = av_clip_pixel(src[y_stride] + offset_val);
-                y_stride     += stride;
+                dst[y * stride_dst] = av_clip_pixel(src[y * stride_src] + offset_val);
             }
             init_x = 1;
         }
         if (borders[2]) {
             int offset_val = sao_offset_val[0];
-            int x_stride   = width - 1;
+            int offset     = width - 1;
             for (x = 0; x < height; x++) {
-                dst[x_stride] = av_clip_pixel(src[x_stride] + offset_val);
-                x_stride     += stride;
+                dst[x * stride_dst + offset] = av_clip_pixel(src[x * stride_src + offset] + offset_val);
             }
             width--;
         }
@@ -491,15 +491,16 @@ static void FUNC(sao_edge_filter_1)(uint8_t *_dst, uint8_t *_src,
             init_y = 1;
         }
         if (borders[3]) {
-            int offset_val = sao_offset_val[0];
-            int y_stride   = stride * (height - 1);
+            int offset_val   = sao_offset_val[0];
+            int y_stride_dst = stride_dst * (height - 1);
+            int y_stride_src = stride_src * (height - 1);
             for (x = init_x; x < width; x++)
-                dst[x + y_stride] = av_clip_pixel(src[x + y_stride] + offset_val);
+                dst[x + y_stride_dst] = av_clip_pixel(src[x + y_stride_src] + offset_val);
             height--;
         }
     }
 
-    FUNC(sao_edge_filter)((uint8_t *)dst, (uint8_t *)src, stride, sao, width, height, c_idx, init_x, init_y);
+    FUNC(sao_edge_filter)((uint8_t *)dst, (uint8_t *)src, stride_dst, stride_src, sao, width, height, c_idx, init_x, init_y);
 
     {
         int save_upper_left  = !diag_edge[0] && sao_eo_class == SAO_EO_135D && !borders[0] && !borders[1];
@@ -510,11 +511,11 @@ static void FUNC(sao_edge_filter_1)(uint8_t *_dst, uint8_t *_src,
         // Restore pixels that can't be modified
         if(vert_edge[0] && sao_eo_class != SAO_EO_VERT) {
             for(y = init_y+save_upper_left; y< height-save_lower_left; y++)
-                dst[y*stride] = src[y*stride];
+                dst[y*stride_dst] = src[y*stride_src];
         }
         if(vert_edge[1] && sao_eo_class != SAO_EO_VERT) {
             for(y = init_y+save_upper_right; y< height-save_lower_right; y++)
-                dst[y*stride+width-1] = src[y*stride+width-1];
+                dst[y*stride_dst+width-1] = src[y*stride_src+width-1];
         }
 
         if(horiz_edge[0] && sao_eo_class != SAO_EO_HORIZ) {
@@ -523,16 +524,16 @@ static void FUNC(sao_edge_filter_1)(uint8_t *_dst, uint8_t *_src,
         }
         if(horiz_edge[1] && sao_eo_class != SAO_EO_HORIZ) {
             for(x = init_x+save_lower_left; x < width-save_lower_right; x++)
-                dst[(height-1)*stride+x] = src[(height-1)*stride+x];
+                dst[(height-1)*stride_dst+x] = src[(height-1)*stride_src+x];
         }
         if(diag_edge[0] && sao_eo_class == SAO_EO_135D)
             dst[0] = src[0];
         if(diag_edge[1] && sao_eo_class == SAO_EO_45D)
             dst[width-1] = src[width-1];
         if(diag_edge[2] && sao_eo_class == SAO_EO_135D)
-            dst[stride*(height-1)+width-1] = src[stride*(height-1)+width-1];
+            dst[stride_dst*(height-1)+width-1] = src[stride_src*(height-1)+width-1];
         if(diag_edge[3] && sao_eo_class == SAO_EO_45D)
-            dst[stride*(height-1)] = src[stride*(height-1)];
+            dst[stride_dst*(height-1)] = src[stride_src*(height-1)];
 
     }
 }