vf_colorspace: Forbid odd dimensions

This prevents writing past bounds.
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>

doc/filters.texi

@@ -5278,6 +5278,7 @@ colormatrix=bt601:smpte240m
 @section colorspace
 
 Convert colorspace, transfer characteristics or color primaries.
+Input video needs to have an even size.
 
 The filter accepts the following options:
 

libavfilter/vf_colorspace.c

@@ -168,7 +168,7 @@ typedef struct ColorSpaceContext {
     int did_warn_range;
 } ColorSpaceContext;
 
-// FIXME deal with odd width/heights (or just forbid it)
+// FIXME deal with odd width/heights
 // FIXME faster linearize/delinearize implementation (integer pow)
 // FIXME bt2020cl support (linearization between yuv/rgb step instead of between rgb/xyz)
 // FIXME test that the values in (de)lin_lut don't exceed their container storage
@@ -1031,8 +1031,15 @@ static int query_formats(AVFilterContext *ctx)
 
 static int config_props(AVFilterLink *outlink)
 {
+    AVFilterContext *ctx = outlink->dst;
     AVFilterLink *inlink = outlink->src->inputs[0];
 
+    if (inlink->w % 2 || inlink->h % 2) {
+        av_log(ctx, AV_LOG_ERROR, "Invalid odd size (%dx%d)\n",
+               inlink->w, inlink->h);
+        return AVERROR_PATCHWELCOME;
+    }
+
     outlink->w = inlink->w;
     outlink->h = inlink->h;
     outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;