@@ -25,10 +25,12 @@

 #include "avfilter.h"

 #include "libavutil/pixdesc.h"

+#include "libavutil/avassert.h"

 #include "libswscale/swscale.h"

 typedef struct {

     struct SwsContext *sws;     ///< software scaler context

+    struct SwsContext *isws[2]; ///< software scaler context for interlaced material

     /**

      * New dimensions. Special values are:

@@ -41,6 +43,7 @@ typedef struct {

     int hsub, vsub;             ///< chroma subsampling

     int slice_y;                ///< top of current output slice

     int input_is_pal;           ///< set to 1 if the input format is paletted

+    int interlaced;

 } ScaleContext;

 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)

@@ -53,6 +56,10 @@ static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)

         sscanf(args, "%d:%d", &scale->w, &scale->h);

         p = strstr(args,"flags=");

         if (p) scale->flags = strtoul(p+6, NULL, 0);

+        if(strstr(args,"interl=1")){

+            scale->interlaced=1;

+        }else if(strstr(args,"interl=-1"))

+            scale->interlaced=-1;

     }

     /* sanity check params */

@@ -70,6 +77,8 @@ static av_cold void uninit(AVFilterContext *ctx)

 {

     ScaleContext *scale = ctx->priv;

     sws_freeContext(scale->sws);

+    sws_freeContext(scale->isws[0]);

+    sws_freeContext(scale->isws[1]);

     scale->sws = NULL;

 }

@@ -138,6 +147,12 @@ static int config_props(AVFilterLink *outlink)

     scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,

                                 outlink->w, outlink->h, outlink->format,

                                 scale->flags, NULL, NULL, NULL);

+    scale->isws[0] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,

+                                    outlink->w, outlink->h/2, outlink->format,

+                                    scale->flags, NULL, NULL, NULL);

+    scale->isws[1] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,

+                                    outlink->w, outlink->h/2, outlink->format,

+                                    scale->flags, NULL, NULL, NULL);

     if (!scale->sws)

         return AVERROR(EINVAL);

@@ -169,26 +184,46 @@ static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)

     avfilter_start_frame(outlink, avfilter_ref_buffer(outpicref, ~0));

 }

+static int scale_slice(AVFilterLink *link, struct SwsContext *sws, int y, int h, int mul, int field)

+{

+    ScaleContext *scale = link->dst->priv;

+    AVFilterBufferRef *cur_pic = link->cur_buf;

+    AVFilterBufferRef *out_buf = link->dst->outputs[0]->out_buf;

+    const uint8_t *in[4], *out[4];

+    int in_stride[4],out_stride[4];

+    int i;

+

+    for(i=0; i<4; i++){

+        int vsub= ((i+1)&2) ? scale->vsub : 0;

+         in_stride[i] = cur_pic->linesize[i] * mul;

+        out_stride[i] = out_buf->linesize[i] * mul;

+         in[i] = cur_pic->data[i] + ((y>>vsub)+field) * cur_pic->linesize[i];

+        out[i] = out_buf->data[i] +            field  * out_buf->linesize[i];

+    }

+    if(scale->input_is_pal){

+         in[1] = cur_pic->data[1];

+        out[1] = out_buf->data[1];

+    }

+

+    return sws_scale(sws, in, in_stride, y/mul, h,

+                         out,out_stride);

+}

+

 static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)

 {

     ScaleContext *scale = link->dst->priv;

     int out_h;

-    AVFilterBufferRef *cur_pic = link->cur_buf;

-    const uint8_t *data[4];

     if (scale->slice_y == 0 && slice_dir == -1)

         scale->slice_y = link->dst->outputs[0]->h;

-    data[0] = cur_pic->data[0] +  y               * cur_pic->linesize[0];

-    data[1] = scale->input_is_pal ?

-              cur_pic->data[1] :

-              cur_pic->data[1] + (y>>scale->vsub) * cur_pic->linesize[1];

-    data[2] = cur_pic->data[2] + (y>>scale->vsub) * cur_pic->linesize[2];

-    data[3] = cur_pic->data[3] +  y               * cur_pic->linesize[3];

-

-    out_h = sws_scale(scale->sws, data, cur_pic->linesize, y, h,

-                      link->dst->outputs[0]->out_buf->data,

-                      link->dst->outputs[0]->out_buf->linesize);

+    if(scale->interlaced>0 || (scale->interlaced<0 && link->cur_buf->video->interlaced)){

+        av_assert0(y%4 == 0);

+        out_h = scale_slice(link, scale->isws[0], y, (h+1)/2, 2, 0);

+        out_h+= scale_slice(link, scale->isws[1], y,  h   /2, 2, 1);

+    }else{

+        out_h = scale_slice(link, scale->sws, y, h, 1, 0);

+    }

     if (slice_dir == -1)

         scale->slice_y -= out_h;