diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index a90d8a02b1..12819cbb06 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -22,6 +22,7 @@ OBJS = allfilters.o                                                     \
        formats.o                                                        \
        graphparser.o                                                    \
        vf_scale.o                                                       \
+       video.o                                                          \
 
 OBJS-$(CONFIG_AFORMAT_FILTER)                += af_aformat.o
 OBJS-$(CONFIG_ANULL_FILTER)                  += af_anull.o
diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
index 57108b13ce..9dacf70e22 100644
--- a/libavfilter/avfilter.c
+++ b/libavfilter/avfilter.c
@@ -248,35 +248,6 @@ static char *ff_get_ref_perms_string(char *buf, size_t buf_size, int perms)
 }
 #endif
 
-static void ff_dlog_ref(void *ctx, AVFilterBufferRef *ref, int end)
-{
-    av_unused char buf[16];
-    av_dlog(ctx,
-            "ref[%p buf:%p refcount:%d perms:%s data:%p linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64,
-            ref, ref->buf, ref->buf->refcount, ff_get_ref_perms_string(buf, sizeof(buf), ref->perms), ref->data[0],
-            ref->linesize[0], ref->linesize[1], ref->linesize[2], ref->linesize[3],
-            ref->pts, ref->pos);
-
-    if (ref->video) {
-        av_dlog(ctx, " a:%d/%d s:%dx%d i:%c iskey:%d type:%c",
-                ref->video->pixel_aspect.num, ref->video->pixel_aspect.den,
-                ref->video->w, ref->video->h,
-                !ref->video->interlaced     ? 'P' :         /* Progressive  */
-                ref->video->top_field_first ? 'T' : 'B',    /* Top / Bottom */
-                ref->video->key_frame,
-                av_get_picture_type_char(ref->video->pict_type));
-    }
-    if (ref->audio) {
-        av_dlog(ctx, " cl:%"PRId64"d n:%d r:%d p:%d",
-                ref->audio->channel_layout,
-                ref->audio->nb_samples,
-                ref->audio->sample_rate,
-                ref->audio->planar);
-    }
-
-    av_dlog(ctx, "]%s", end ? "\n" : "");
-}
-
 void ff_dlog_link(void *ctx, AVFilterLink *link, int end)
 {
     if (link->type == AVMEDIA_TYPE_VIDEO) {
@@ -301,71 +272,6 @@ void ff_dlog_link(void *ctx, AVFilterLink *link, int end)
     }
 }
 
-AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
-{
-    AVFilterBufferRef *ret = NULL;
-
-    av_unused char buf[16];
-    FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0);
-    av_dlog(NULL, " perms:%s w:%d h:%d\n", ff_get_ref_perms_string(buf, sizeof(buf), perms), w, h);
-
-    if (link->dstpad->get_video_buffer)
-        ret = link->dstpad->get_video_buffer(link, perms, w, h);
-
-    if (!ret)
-        ret = avfilter_default_get_video_buffer(link, perms, w, h);
-
-    if (ret)
-        ret->type = AVMEDIA_TYPE_VIDEO;
-
-    FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " returning "); ff_dlog_ref(NULL, ret, 1);
-
-    return ret;
-}
-
-AVFilterBufferRef *
-avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
-                                          int w, int h, enum PixelFormat format)
-{
-    AVFilterBuffer *pic = av_mallocz(sizeof(AVFilterBuffer));
-    AVFilterBufferRef *picref = av_mallocz(sizeof(AVFilterBufferRef));
-
-    if (!pic || !picref)
-        goto fail;
-
-    picref->buf = pic;
-    picref->buf->free = ff_avfilter_default_free_buffer;
-    if (!(picref->video = av_mallocz(sizeof(AVFilterBufferRefVideoProps))))
-        goto fail;
-
-    pic->w = picref->video->w = w;
-    pic->h = picref->video->h = h;
-
-    /* make sure the buffer gets read permission or it's useless for output */
-    picref->perms = perms | AV_PERM_READ;
-
-    pic->refcount = 1;
-    picref->type = AVMEDIA_TYPE_VIDEO;
-    pic->format = picref->format = format;
-
-    memcpy(pic->data,        data,          4*sizeof(data[0]));
-    memcpy(pic->linesize,    linesize,      4*sizeof(linesize[0]));
-    memcpy(picref->data,     pic->data,     sizeof(picref->data));
-    memcpy(picref->linesize, pic->linesize, sizeof(picref->linesize));
-
-    pic->   extended_data = pic->data;
-    picref->extended_data = picref->data;
-
-    return picref;
-
-fail:
-    if (picref && picref->video)
-        av_free(picref->video);
-    av_free(picref);
-    av_free(pic);
-    return NULL;
-}
-
 int avfilter_request_frame(AVFilterLink *link)
 {
     FF_DPRINTF_START(NULL, request_frame); ff_dlog_link(NULL, link, 1);
@@ -395,96 +301,6 @@ int avfilter_poll_frame(AVFilterLink *link)
     return min;
 }
 
-/* XXX: should we do the duplicating of the picture ref here, instead of
- * forcing the source filter to do it? */
-void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
-{
-    void (*start_frame)(AVFilterLink *, AVFilterBufferRef *);
-    AVFilterPad *dst = link->dstpad;
-    int perms = picref->perms;
-
-    FF_DPRINTF_START(NULL, start_frame); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " "); ff_dlog_ref(NULL, picref, 1);
-
-    if (!(start_frame = dst->start_frame))
-        start_frame = avfilter_default_start_frame;
-
-    if (picref->linesize[0] < 0)
-        perms |= AV_PERM_NEG_LINESIZES;
-    /* prepare to copy the picture if it has insufficient permissions */
-    if ((dst->min_perms & perms) != dst->min_perms || dst->rej_perms & perms) {
-        av_log(link->dst, AV_LOG_DEBUG,
-                "frame copy needed (have perms %x, need %x, reject %x)\n",
-                picref->perms,
-                link->dstpad->min_perms, link->dstpad->rej_perms);
-
-        link->cur_buf = avfilter_get_video_buffer(link, dst->min_perms, link->w, link->h);
-        link->src_buf = picref;
-        avfilter_copy_buffer_ref_props(link->cur_buf, link->src_buf);
-    }
-    else
-        link->cur_buf = picref;
-
-    start_frame(link, link->cur_buf);
-}
-
-void avfilter_end_frame(AVFilterLink *link)
-{
-    void (*end_frame)(AVFilterLink *);
-
-    if (!(end_frame = link->dstpad->end_frame))
-        end_frame = avfilter_default_end_frame;
-
-    end_frame(link);
-
-    /* unreference the source picture if we're feeding the destination filter
-     * a copied version dues to permission issues */
-    if (link->src_buf) {
-        avfilter_unref_buffer(link->src_buf);
-        link->src_buf = NULL;
-    }
-}
-
-void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
-{
-    uint8_t *src[4], *dst[4];
-    int i, j, vsub;
-    void (*draw_slice)(AVFilterLink *, int, int, int);
-
-    FF_DPRINTF_START(NULL, draw_slice); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " y:%d h:%d dir:%d\n", y, h, slice_dir);
-
-    /* copy the slice if needed for permission reasons */
-    if (link->src_buf) {
-        vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
-
-        for (i = 0; i < 4; i++) {
-            if (link->src_buf->data[i]) {
-                src[i] = link->src_buf-> data[i] +
-                    (y >> (i==1 || i==2 ? vsub : 0)) * link->src_buf-> linesize[i];
-                dst[i] = link->cur_buf->data[i] +
-                    (y >> (i==1 || i==2 ? vsub : 0)) * link->cur_buf->linesize[i];
-            } else
-                src[i] = dst[i] = NULL;
-        }
-
-        for (i = 0; i < 4; i++) {
-            int planew =
-                av_image_get_linesize(link->format, link->cur_buf->video->w, i);
-
-            if (!src[i]) continue;
-
-            for (j = 0; j < h >> (i==1 || i==2 ? vsub : 0); j++) {
-                memcpy(dst[i], src[i], planew);
-                src[i] += link->src_buf->linesize[i];
-                dst[i] += link->cur_buf->linesize[i];
-            }
-        }
-    }
-
-    if (!(draw_slice = link->dstpad->draw_slice))
-        draw_slice = avfilter_default_draw_slice;
-    draw_slice(link, y, h, slice_dir);
-}
-
 #define MAX_REGISTERED_AVFILTERS_NB 64
 
 static AVFilter *registered_avfilters[MAX_REGISTERED_AVFILTERS_NB + 1];
diff --git a/libavfilter/defaults.c b/libavfilter/defaults.c
index cb7bf1c4ef..9829cdcff4 100644
--- a/libavfilter/defaults.c
+++ b/libavfilter/defaults.c
@@ -36,73 +36,6 @@ void ff_avfilter_default_free_buffer(AVFilterBuffer *ptr)
     av_free(ptr);
 }
 
-/* TODO: set the buffer's priv member to a context structure for the whole
- * filter chain.  This will allow for a buffer pool instead of the constant
- * alloc & free cycle currently implemented. */
-AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
-{
-    int linesize[4];
-    uint8_t *data[4];
-    AVFilterBufferRef *picref = NULL;
-
-    // +2 is needed for swscaler, +16 to be SIMD-friendly
-    if (av_image_alloc(data, linesize, w, h, link->format, 16) < 0)
-        return NULL;
-
-    picref = avfilter_get_video_buffer_ref_from_arrays(data, linesize,
-                                                       perms, w, h, link->format);
-    if (!picref) {
-        av_free(data[0]);
-        return NULL;
-    }
-
-    return picref;
-}
-
-void avfilter_default_start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
-{
-    AVFilterLink *outlink = NULL;
-
-    if (inlink->dst->output_count)
-        outlink = inlink->dst->outputs[0];
-
-    if (outlink) {
-        outlink->out_buf = avfilter_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
-        avfilter_copy_buffer_ref_props(outlink->out_buf, picref);
-        avfilter_start_frame(outlink, avfilter_ref_buffer(outlink->out_buf, ~0));
-    }
-}
-
-void avfilter_default_draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
-{
-    AVFilterLink *outlink = NULL;
-
-    if (inlink->dst->output_count)
-        outlink = inlink->dst->outputs[0];
-
-    if (outlink)
-        avfilter_draw_slice(outlink, y, h, slice_dir);
-}
-
-void avfilter_default_end_frame(AVFilterLink *inlink)
-{
-    AVFilterLink *outlink = NULL;
-
-    if (inlink->dst->output_count)
-        outlink = inlink->dst->outputs[0];
-
-    avfilter_unref_buffer(inlink->cur_buf);
-    inlink->cur_buf = NULL;
-
-    if (outlink) {
-        if (outlink->out_buf) {
-            avfilter_unref_buffer(outlink->out_buf);
-            outlink->out_buf = NULL;
-        }
-        avfilter_end_frame(outlink);
-    }
-}
-
 /**
  * default config_link() implementation for output video links to simplify
  * the implementation of one input one output video filters */
@@ -186,23 +119,3 @@ int avfilter_default_query_formats(AVFilterContext *ctx)
 
     return 0;
 }
-
-void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
-{
-    avfilter_start_frame(link->dst->outputs[0], picref);
-}
-
-void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
-{
-    avfilter_draw_slice(link->dst->outputs[0], y, h, slice_dir);
-}
-
-void avfilter_null_end_frame(AVFilterLink *link)
-{
-    avfilter_end_frame(link->dst->outputs[0]);
-}
-
-AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
-{
-    return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
-}
diff --git a/libavfilter/video.c b/libavfilter/video.c
new file mode 100644
index 0000000000..26805feba0
--- /dev/null
+++ b/libavfilter/video.c
@@ -0,0 +1,294 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/imgutils.h"
+
+#include "avfilter.h"
+#include "internal.h"
+
+static void ff_dlog_ref(void *ctx, AVFilterBufferRef *ref, int end)
+{
+    av_unused char buf[16];
+    av_dlog(ctx,
+            "ref[%p buf:%p refcount:%d perms:%s data:%p linesize[%d, %d, %d, %d] pts:%"PRId64" pos:%"PRId64,
+            ref, ref->buf, ref->buf->refcount, ff_get_ref_perms_string(buf, sizeof(buf), ref->perms), ref->data[0],
+            ref->linesize[0], ref->linesize[1], ref->linesize[2], ref->linesize[3],
+            ref->pts, ref->pos);
+
+    if (ref->video) {
+        av_dlog(ctx, " a:%d/%d s:%dx%d i:%c iskey:%d type:%c",
+                ref->video->pixel_aspect.num, ref->video->pixel_aspect.den,
+                ref->video->w, ref->video->h,
+                !ref->video->interlaced     ? 'P' :         /* Progressive  */
+                ref->video->top_field_first ? 'T' : 'B',    /* Top / Bottom */
+                ref->video->key_frame,
+                av_get_picture_type_char(ref->video->pict_type));
+    }
+    if (ref->audio) {
+        av_dlog(ctx, " cl:%"PRId64"d n:%d r:%d p:%d",
+                ref->audio->channel_layout,
+                ref->audio->nb_samples,
+                ref->audio->sample_rate,
+                ref->audio->planar);
+    }
+
+    av_dlog(ctx, "]%s", end ? "\n" : "");
+}
+
+AVFilterBufferRef *avfilter_null_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
+{
+    return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
+}
+
+/* TODO: set the buffer's priv member to a context structure for the whole
+ * filter chain.  This will allow for a buffer pool instead of the constant
+ * alloc & free cycle currently implemented. */
+AVFilterBufferRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
+{
+    int linesize[4];
+    uint8_t *data[4];
+    AVFilterBufferRef *picref = NULL;
+
+    // +2 is needed for swscaler, +16 to be SIMD-friendly
+    if (av_image_alloc(data, linesize, w, h, link->format, 16) < 0)
+        return NULL;
+
+    picref = avfilter_get_video_buffer_ref_from_arrays(data, linesize,
+                                                       perms, w, h, link->format);
+    if (!picref) {
+        av_free(data[0]);
+        return NULL;
+    }
+
+    return picref;
+}
+
+AVFilterBufferRef *
+avfilter_get_video_buffer_ref_from_arrays(uint8_t *data[4], int linesize[4], int perms,
+                                          int w, int h, enum PixelFormat format)
+{
+    AVFilterBuffer *pic = av_mallocz(sizeof(AVFilterBuffer));
+    AVFilterBufferRef *picref = av_mallocz(sizeof(AVFilterBufferRef));
+
+    if (!pic || !picref)
+        goto fail;
+
+    picref->buf = pic;
+    picref->buf->free = ff_avfilter_default_free_buffer;
+    if (!(picref->video = av_mallocz(sizeof(AVFilterBufferRefVideoProps))))
+        goto fail;
+
+    pic->w = picref->video->w = w;
+    pic->h = picref->video->h = h;
+
+    /* make sure the buffer gets read permission or it's useless for output */
+    picref->perms = perms | AV_PERM_READ;
+
+    pic->refcount = 1;
+    picref->type = AVMEDIA_TYPE_VIDEO;
+    pic->format = picref->format = format;
+
+    memcpy(pic->data,        data,          4*sizeof(data[0]));
+    memcpy(pic->linesize,    linesize,      4*sizeof(linesize[0]));
+    memcpy(picref->data,     pic->data,     sizeof(picref->data));
+    memcpy(picref->linesize, pic->linesize, sizeof(picref->linesize));
+
+    pic->   extended_data = pic->data;
+    picref->extended_data = picref->data;
+
+    return picref;
+
+fail:
+    if (picref && picref->video)
+        av_free(picref->video);
+    av_free(picref);
+    av_free(pic);
+    return NULL;
+}
+
+AVFilterBufferRef *avfilter_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
+{
+    AVFilterBufferRef *ret = NULL;
+
+    av_unused char buf[16];
+    FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0);
+    av_dlog(NULL, " perms:%s w:%d h:%d\n", ff_get_ref_perms_string(buf, sizeof(buf), perms), w, h);
+
+    if (link->dstpad->get_video_buffer)
+        ret = link->dstpad->get_video_buffer(link, perms, w, h);
+
+    if (!ret)
+        ret = avfilter_default_get_video_buffer(link, perms, w, h);
+
+    if (ret)
+        ret->type = AVMEDIA_TYPE_VIDEO;
+
+    FF_DPRINTF_START(NULL, get_video_buffer); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " returning "); ff_dlog_ref(NULL, ret, 1);
+
+    return ret;
+}
+
+void avfilter_null_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
+{
+    avfilter_start_frame(link->dst->outputs[0], picref);
+}
+
+void avfilter_default_start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
+{
+    AVFilterLink *outlink = NULL;
+
+    if (inlink->dst->output_count)
+        outlink = inlink->dst->outputs[0];
+
+    if (outlink) {
+        outlink->out_buf = avfilter_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
+        avfilter_copy_buffer_ref_props(outlink->out_buf, picref);
+        avfilter_start_frame(outlink, avfilter_ref_buffer(outlink->out_buf, ~0));
+    }
+}
+
+/* XXX: should we do the duplicating of the picture ref here, instead of
+ * forcing the source filter to do it? */
+void avfilter_start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
+{
+    void (*start_frame)(AVFilterLink *, AVFilterBufferRef *);
+    AVFilterPad *dst = link->dstpad;
+    int perms = picref->perms;
+
+    FF_DPRINTF_START(NULL, start_frame); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " "); ff_dlog_ref(NULL, picref, 1);
+
+    if (!(start_frame = dst->start_frame))
+        start_frame = avfilter_default_start_frame;
+
+    if (picref->linesize[0] < 0)
+        perms |= AV_PERM_NEG_LINESIZES;
+    /* prepare to copy the picture if it has insufficient permissions */
+    if ((dst->min_perms & perms) != dst->min_perms || dst->rej_perms & perms) {
+        av_log(link->dst, AV_LOG_DEBUG,
+                "frame copy needed (have perms %x, need %x, reject %x)\n",
+                picref->perms,
+                link->dstpad->min_perms, link->dstpad->rej_perms);
+
+        link->cur_buf = avfilter_get_video_buffer(link, dst->min_perms, link->w, link->h);
+        link->src_buf = picref;
+        avfilter_copy_buffer_ref_props(link->cur_buf, link->src_buf);
+    }
+    else
+        link->cur_buf = picref;
+
+    start_frame(link, link->cur_buf);
+}
+
+void avfilter_null_end_frame(AVFilterLink *link)
+{
+    avfilter_end_frame(link->dst->outputs[0]);
+}
+
+void avfilter_default_end_frame(AVFilterLink *inlink)
+{
+    AVFilterLink *outlink = NULL;
+
+    if (inlink->dst->output_count)
+        outlink = inlink->dst->outputs[0];
+
+    avfilter_unref_buffer(inlink->cur_buf);
+    inlink->cur_buf = NULL;
+
+    if (outlink) {
+        if (outlink->out_buf) {
+            avfilter_unref_buffer(outlink->out_buf);
+            outlink->out_buf = NULL;
+        }
+        avfilter_end_frame(outlink);
+    }
+}
+
+void avfilter_end_frame(AVFilterLink *link)
+{
+    void (*end_frame)(AVFilterLink *);
+
+    if (!(end_frame = link->dstpad->end_frame))
+        end_frame = avfilter_default_end_frame;
+
+    end_frame(link);
+
+    /* unreference the source picture if we're feeding the destination filter
+     * a copied version dues to permission issues */
+    if (link->src_buf) {
+        avfilter_unref_buffer(link->src_buf);
+        link->src_buf = NULL;
+    }
+}
+
+void avfilter_null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
+{
+    avfilter_draw_slice(link->dst->outputs[0], y, h, slice_dir);
+}
+
+void avfilter_default_draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
+{
+    AVFilterLink *outlink = NULL;
+
+    if (inlink->dst->output_count)
+        outlink = inlink->dst->outputs[0];
+
+    if (outlink)
+        avfilter_draw_slice(outlink, y, h, slice_dir);
+}
+
+void avfilter_draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
+{
+    uint8_t *src[4], *dst[4];
+    int i, j, vsub;
+    void (*draw_slice)(AVFilterLink *, int, int, int);
+
+    FF_DPRINTF_START(NULL, draw_slice); ff_dlog_link(NULL, link, 0); av_dlog(NULL, " y:%d h:%d dir:%d\n", y, h, slice_dir);
+
+    /* copy the slice if needed for permission reasons */
+    if (link->src_buf) {
+        vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
+
+        for (i = 0; i < 4; i++) {
+            if (link->src_buf->data[i]) {
+                src[i] = link->src_buf-> data[i] +
+                    (y >> (i==1 || i==2 ? vsub : 0)) * link->src_buf-> linesize[i];
+                dst[i] = link->cur_buf->data[i] +
+                    (y >> (i==1 || i==2 ? vsub : 0)) * link->cur_buf->linesize[i];
+            } else
+                src[i] = dst[i] = NULL;
+        }
+
+        for (i = 0; i < 4; i++) {
+            int planew =
+                av_image_get_linesize(link->format, link->cur_buf->video->w, i);
+
+            if (!src[i]) continue;
+
+            for (j = 0; j < h >> (i==1 || i==2 ? vsub : 0); j++) {
+                memcpy(dst[i], src[i], planew);
+                src[i] += link->src_buf->linesize[i];
+                dst[i] += link->cur_buf->linesize[i];
+            }
+        }
+    }
+
+    if (!(draw_slice = link->dstpad->draw_slice))
+        draw_slice = avfilter_default_draw_slice;
+    draw_slice(link, y, h, slice_dir);
+}
+