avfilter/vf_drawbox: add alpha pixel formats support

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavfilter/vf_drawbox.c

@@ -79,6 +79,7 @@ typedef struct DrawBoxContext {
     char *x_expr, *y_expr; ///< expression for x and y
     char *w_expr, *h_expr; ///< expression for width and height
     char *t_expr;          ///< expression for thickness
+    int have_alpha;
 } DrawBoxContext;
 
 static const int NUM_EXPR_EVALS = 5;
@@ -110,6 +111,7 @@ static int query_formats(AVFilterContext *ctx)
         AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUV410P,
         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
         AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUVJ440P,
+        AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
         AV_PIX_FMT_NONE
     };
     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
@@ -130,6 +132,7 @@ static int config_input(AVFilterLink *inlink)
 
     s->hsub = desc->log2_chroma_w;
     s->vsub = desc->log2_chroma_h;
+    s->have_alpha = desc->flags & AV_PIX_FMT_FLAG_ALPHA;
 
     var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
     var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
@@ -210,6 +213,33 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
     int plane, x, y, xb = s->x, yb = s->y;
     unsigned char *row[4];
 
+    if (s->have_alpha) {
+        for (y = FFMAX(yb, 0); y < frame->height && y < (yb + s->h); y++) {
+            row[0] = frame->data[0] + y * frame->linesize[0];
+            row[3] = frame->data[3] + y * frame->linesize[3];
+
+            for (plane = 1; plane < 3; plane++)
+                row[plane] = frame->data[plane] +
+                     frame->linesize[plane] * (y >> s->vsub);
+
+            if (s->invert_color) {
+                for (x = FFMAX(xb, 0); x < xb + s->w && x < frame->width; x++)
+                    if ((y - yb < s->thickness) || (yb + s->h - 1 - y < s->thickness) ||
+                        (x - xb < s->thickness) || (xb + s->w - 1 - x < s->thickness))
+                        row[0][x] = 0xff - row[0][x];
+            } else {
+                for (x = FFMAX(xb, 0); x < xb + s->w && x < frame->width; x++) {
+                    if ((y - yb < s->thickness) || (yb + s->h - 1 - y < s->thickness) ||
+                        (x - xb < s->thickness) || (xb + s->w - 1 - x < s->thickness)) {
+                        row[0][x           ] = s->yuv_color[Y];
+                        row[1][x >> s->hsub] = s->yuv_color[U];
+                        row[2][x >> s->hsub] = s->yuv_color[V];
+                        row[3][x           ] = s->yuv_color[A];
+                    }
+                }
+            }
+        }
+    } else {
     for (y = FFMAX(yb, 0); y < frame->height && y < (yb + s->h); y++) {
         row[0] = frame->data[0] + y * frame->linesize[0];
 
@@ -235,6 +265,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
             }
         }
     }
+    }
 
     return ff_filter_frame(inlink->dst->outputs[0], frame);
 }
@@ -323,6 +354,31 @@ static int drawgrid_filter_frame(AVFilterLink *inlink, AVFrame *frame)
     int plane, x, y;
     uint8_t *row[4];
 
+    if (drawgrid->have_alpha) {
+        for (y = 0; y < frame->height; y++) {
+            row[0] = frame->data[0] + y * frame->linesize[0];
+            row[3] = frame->data[3] + y * frame->linesize[3];
+
+            for (plane = 1; plane < 3; plane++)
+                row[plane] = frame->data[plane] +
+                     frame->linesize[plane] * (y >> drawgrid->vsub);
+
+            if (drawgrid->invert_color) {
+                for (x = 0; x < frame->width; x++)
+                    if (pixel_belongs_to_grid(drawgrid, x, y))
+                        row[0][x] = 0xff - row[0][x];
+            } else {
+                for (x = 0; x < frame->width; x++) {
+                    if (pixel_belongs_to_grid(drawgrid, x, y)) {
+                        row[0][x                  ] = drawgrid->yuv_color[Y];
+                        row[1][x >> drawgrid->hsub] = drawgrid->yuv_color[U];
+                        row[2][x >> drawgrid->hsub] = drawgrid->yuv_color[V];
+                        row[3][x                  ] = drawgrid->yuv_color[A];
+                    }
+                }
+            }
+        }
+    } else {
     for (y = 0; y < frame->height; y++) {
         row[0] = frame->data[0] + y * frame->linesize[0];
 
@@ -346,6 +402,7 @@ static int drawgrid_filter_frame(AVFilterLink *inlink, AVFrame *frame)
             }
         }
     }
+    }
 
     return ff_filter_frame(inlink->dst->outputs[0], frame);
 }