avfilter/vf_framerate: refine the filter_slice code for better readiablity

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
Signed-off-by: Marton Balint <cus@passwd.hu>

libavfilter/framerate.h

@@ -43,6 +43,7 @@ typedef struct FrameRateContext {
     int interp_end;                     ///< end of range to apply linear interpolation
 
     int line_size[4];                   ///< bytes of pixel data per line for each plane
+    int height[4];                      ///< height of each plane
     int vsub;
 
     AVRational srce_time_base;          ///< timebase of source

libavfilter/vf_framerate.c

@@ -95,29 +95,22 @@ static int filter_slice(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
 {
     FrameRateContext *s = ctx->priv;
     ThreadData *td = arg;
+    AVFrame *work = s->work;
+    AVFrame *src1 = td->copy_src1;
+    AVFrame *src2 = td->copy_src2;
     uint16_t src1_factor = td->src1_factor;
     uint16_t src2_factor = td->src2_factor;
     int plane;
 
-    for (plane = 0; plane < 4 && td->copy_src1->data[plane] && td->copy_src2->data[plane]; plane++) {
-        int cpy_line_width = s->line_size[plane];
-        uint8_t *cpy_src1_data = td->copy_src1->data[plane];
-        int cpy_src1_line_size = td->copy_src1->linesize[plane];
-        uint8_t *cpy_src2_data = td->copy_src2->data[plane];
-        int cpy_src2_line_size = td->copy_src2->linesize[plane];
-        int cpy_src_h = (plane > 0 && plane < 3) ? (td->copy_src1->height >> s->vsub) : (td->copy_src1->height);
-        uint8_t *cpy_dst_data = s->work->data[plane];
-        int cpy_dst_line_size = s->work->linesize[plane];
-        const int start = (cpy_src_h *  job   ) / nb_jobs;
-        const int end   = (cpy_src_h * (job+1)) / nb_jobs;
-        cpy_src1_data += start * cpy_src1_line_size;
-        cpy_src2_data += start * cpy_src2_line_size;
-        cpy_dst_data += start * cpy_dst_line_size;
-
-        s->blend(cpy_src1_data, cpy_src1_line_size,
-                 cpy_src2_data, cpy_src2_line_size,
-                 cpy_dst_data,  cpy_dst_line_size,
-                 cpy_line_width, end - start,
+    for (plane = 0; plane < 4 && src1->data[plane] && src2->data[plane]; plane++) {
+        const int start = (s->height[plane] *  job   ) / nb_jobs;
+        const int end   = (s->height[plane] * (job+1)) / nb_jobs;
+        uint8_t *src1_data = src1->data[plane] + start * src1->linesize[plane];
+        uint8_t *src2_data = src2->data[plane] + start * src2->linesize[plane];
+        uint8_t *dst_data  = work->data[plane] + start * work->linesize[plane];
+
+        s->blend(src1_data, src1->linesize[plane], src2_data, src2->linesize[plane],
+                 dst_data,  work->linesize[plane], s->line_size[plane], end - start,
                  src1_factor, src2_factor, s->blend_factor_max >> 1);
     }
 
@@ -293,13 +286,13 @@ static int config_input(AVFilterLink *inlink)
     const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
     int plane;
 
+    s->vsub = pix_desc->log2_chroma_h;
     for (plane = 0; plane < 4; plane++) {
-        s->line_size[plane] = av_image_get_linesize(inlink->format, inlink->w,
-                                                    plane);
+        s->line_size[plane] = av_image_get_linesize(inlink->format, inlink->w, plane);
+        s->height[plane] = inlink->h >> ((plane == 1 || plane == 2) ? s->vsub : 0);
     }
 
     s->bitdepth = pix_desc->comp[0].depth;
-    s->vsub = pix_desc->log2_chroma_h;
 
     s->sad = ff_scene_sad_get_fn(s->bitdepth == 8 ? 8 : 16);
     if (!s->sad)