@@ -142,6 +142,7 @@ typedef struct Stereo3DContext {

     int pixstep[4];

     AVFrame *prev;

     double ts_unit;

+    int in_off_left[4], in_off_right[4];

 } Stereo3DContext;

 #define OFFSET(x) offsetof(Stereo3DContext, x)

@@ -485,6 +486,42 @@ static inline uint8_t ana_convert(const int *coeff, const uint8_t *left, const u

     return av_clip_uint8(sum >> 16);

 }

+typedef struct ThreadData {

+    AVFrame *ileft, *iright;

+    AVFrame *out;

+} ThreadData;

+

+static int filter_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)

+{

+    Stereo3DContext *s = ctx->priv;

+    ThreadData *td = arg;

+    AVFrame *ileft = td->ileft;

+    AVFrame *iright = td->iright;

+    AVFrame *out = td->out;

+    int height = s->out.height;

+    int start = (height *  jobnr   ) / nb_jobs;

+    int end   = (height * (jobnr+1)) / nb_jobs;

+    uint8_t *dst = out->data[0];

+    const int **ana_matrix = s->ana_matrix;

+    int x, y, il, ir, o;

+    const uint8_t *lsrc = ileft->data[0];

+    const uint8_t *rsrc = iright->data[0];

+    int out_width = s->out.width;

+

+    for (y = start; y < end; y++) {

+        o   = out->linesize[0] * y;

+        il  = s->in_off_left[0]  + y * ileft->linesize[0];

+        ir  = s->in_off_right[0] + y * iright->linesize[0];

+        for (x = 0; x < out_width; x++, il += 3, ir += 3, o+= 3) {

+            dst[o    ] = ana_convert(ana_matrix[0], lsrc + il, rsrc + ir);

+            dst[o + 1] = ana_convert(ana_matrix[1], lsrc + il, rsrc + ir);

+            dst[o + 2] = ana_convert(ana_matrix[2], lsrc + il, rsrc + ir);

+        }

+    }

+

+    return 0;

+}

+

 static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)

 {

     AVFilterContext *ctx  = inlink->dst;

@@ -492,7 +529,6 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)

     AVFilterLink *outlink = ctx->outputs[0];

     AVFrame *out, *oleft, *oright, *ileft, *iright;

     int out_off_left[4], out_off_right[4];

-    int in_off_left[4], in_off_right[4];

     int i;

     switch (s->in.format) {

@@ -534,8 +570,8 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)

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

         int hsub = i == 1 || i == 2 ? s->hsub : 0;

         int vsub = i == 1 || i == 2 ? s->vsub : 0;

-        in_off_left[i]   = (FF_CEIL_RSHIFT(s->in.row_left,   vsub) + s->in.off_lstep)  * ileft->linesize[i]  + FF_CEIL_RSHIFT(s->in.off_left   * s->pixstep[i], hsub);

-        in_off_right[i]  = (FF_CEIL_RSHIFT(s->in.row_right,  vsub) + s->in.off_rstep)  * iright->linesize[i] + FF_CEIL_RSHIFT(s->in.off_right  * s->pixstep[i], hsub);

+        s->in_off_left[i]   = (FF_CEIL_RSHIFT(s->in.row_left,   vsub) + s->in.off_lstep)  * ileft->linesize[i]  + FF_CEIL_RSHIFT(s->in.off_left   * s->pixstep[i], hsub);

+        s->in_off_right[i]  = (FF_CEIL_RSHIFT(s->in.row_right,  vsub) + s->in.off_rstep)  * iright->linesize[i] + FF_CEIL_RSHIFT(s->in.off_right  * s->pixstep[i], hsub);

         out_off_left[i]  = (FF_CEIL_RSHIFT(s->out.row_left,  vsub) + s->out.off_lstep) * oleft->linesize[i]  + FF_CEIL_RSHIFT(s->out.off_left  * s->pixstep[i], hsub);

         out_off_right[i] = (FF_CEIL_RSHIFT(s->out.row_right, vsub) + s->out.off_rstep) * oright->linesize[i] + FF_CEIL_RSHIFT(s->out.off_right * s->pixstep[i], hsub);

     }

@@ -556,12 +592,12 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)

         for (i = 0; i < s->nb_planes; i++) {

             av_image_copy_plane(oleft->data[i] + out_off_left[i],

                                 oleft->linesize[i] * s->row_step,

-                                ileft->data[i] + in_off_left[i],

+                                ileft->data[i] + s->in_off_left[i],

                                 ileft->linesize[i] * s->row_step,

                                 s->linesize[i], s->pheight[i]);

             av_image_copy_plane(oright->data[i] + out_off_right[i],

                                 oright->linesize[i] * s->row_step,

-                                iright->data[i] + in_off_right[i],

+                                iright->data[i] + s->in_off_right[i],

                                 iright->linesize[i] * s->row_step,

                                 s->linesize[i], s->pheight[i]);

         }

@@ -571,7 +607,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)

     case MONO_R:

         for (i = 0; i < s->nb_planes; i++) {

             av_image_copy_plane(out->data[i], out->linesize[i],

-                                iright->data[i] + in_off_left[i],

+                                iright->data[i] + s->in_off_left[i],

                                 iright->linesize[i],

                                 s->linesize[i], s->pheight[i]);

         }

@@ -590,23 +626,11 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *inpicref)

     case ANAGLYPH_YB_HALF:

     case ANAGLYPH_YB_COLOR:

     case ANAGLYPH_YB_DUBOIS: {

-        int x, y, il, ir, o;

-        const uint8_t *lsrc = ileft->data[0];

-        const uint8_t *rsrc = iright->data[0];

-        uint8_t *dst = out->data[0];

-        int out_width = s->out.width;

-        const int **ana_matrix = s->ana_matrix;

-

-        for (y = 0; y < s->out.height; y++) {

-            o   = out->linesize[0] * y;

-            il  = in_off_left[0]  + y * ileft->linesize[0];

-            ir  = in_off_right[0] + y * iright->linesize[0];

-            for (x = 0; x < out_width; x++, il += 3, ir += 3, o+= 3) {

-                dst[o    ] = ana_convert(ana_matrix[0], lsrc + il, rsrc + ir);

-                dst[o + 1] = ana_convert(ana_matrix[1], lsrc + il, rsrc + ir);

-                dst[o + 2] = ana_convert(ana_matrix[2], lsrc + il, rsrc + ir);

-            }

-        }

+        ThreadData td;

+

+        td.ileft = ileft; td.iright = iright; td.out = out;

+        ctx->internal->execute(ctx, filter_slice, &td, NULL,

+                               FFMIN(s->out.height, ctx->graph->nb_threads));

         break;

     }

     default:

@@ -663,4 +687,5 @@ AVFilter ff_vf_stereo3d = {

     .inputs        = stereo3d_inputs,

     .outputs       = stereo3d_outputs,

     .priv_class    = &stereo3d_class,

+    .flags         = AVFILTER_FLAG_SLICE_THREADS,

 };