Merge remote-tracking branch 'qatar/master'

* qatar/master:
  vsrc_buffer: allow buffering arbitrary number of frames.
  vf_scale: avoid a pointless memcpy in no-op conversion.
  avfiltergraph: try to reduce format conversions in filters.
  avfiltergraph: add an AVClass to AVFilterGraph on next major bump.
  id3v2: fix skipping extended header in id3v2.4

Conflicts:
	libavfilter/vf_scale.c
	libavfilter/vsrc_buffer.c
	libavformat/id3v2.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 29 insertions, 14 deletions

diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
index 692e2c5a14..deb7009fa1 100644
--- a/libavfilter/vf_scale.c
+++ b/libavfilter/vf_scale.c
@@ -214,21 +214,26 @@ static int config_props(AVFilterLink *outlink)
 
     if (scale->sws)
         sws_freeContext(scale->sws);
-    scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
-                                outlink->w, outlink->h, outfmt,
-                                scale->flags, NULL, NULL, NULL);
-    if (scale->isws[0])
-        sws_freeContext(scale->isws[0]);
-    scale->isws[0] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
-                                    outlink->w, outlink->h/2, outfmt,
+    if (inlink->w == outlink->w && inlink->h == outlink->h &&
+        inlink->format == outlink->format)
+        scale->sws = NULL;
+    else {
+        scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
+                                    outlink->w, outlink->h, outfmt,
                                     scale->flags, NULL, NULL, NULL);
-    if (scale->isws[1])
-        sws_freeContext(scale->isws[1]);
-    scale->isws[1] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
-                                    outlink->w, outlink->h/2, outfmt,
-                                    scale->flags, NULL, NULL, NULL);
-    if (!scale->sws || !scale->isws[0] || !scale->isws[1])
-        return AVERROR(EINVAL);
+        if (scale->isws[0])
+            sws_freeContext(scale->isws[0]);
+        scale->isws[0] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
+                                        outlink->w, outlink->h/2, outfmt,
+                                        scale->flags, NULL, NULL, NULL);
+        if (scale->isws[1])
+            sws_freeContext(scale->isws[1]);
+        scale->isws[1] = sws_getContext(inlink ->w, inlink ->h/2, inlink ->format,
+                                        outlink->w, outlink->h/2, outfmt,
+                                        scale->flags, NULL, NULL, NULL);
+        if (!scale->sws || !scale->isws[0] || !scale->isws[1])
+            return AVERROR(EINVAL);
+    }
 
     if (inlink->sample_aspect_ratio.num){
         outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
@@ -257,6 +262,11 @@ static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
     AVFilterLink *outlink = link->dst->outputs[0];
     AVFilterBufferRef *outpicref;
 
+    if (!scale->sws) {
+        avfilter_start_frame(outlink, avfilter_ref_buffer(picref, ~0));
+        return;
+    }
+
     scale->hsub = av_pix_fmt_descriptors[link->format].log2_chroma_w;
     scale->vsub = av_pix_fmt_descriptors[link->format].log2_chroma_h;
 
@@ -307,6 +317,11 @@ static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
     ScaleContext *scale = link->dst->priv;
     int out_h;
 
+    if (!scale->sws) {
+        avfilter_draw_slice(link->dst->outputs[0], y, h, slice_dir);
+        return;
+    }
+
     if (scale->slice_y == 0 && slice_dir == -1)
         scale->slice_y = link->dst->outputs[0]->h;