hwcontext_vaapi: allow transfers to/from any size of sw frame

The hw frame used as reference has an attached size but it need not
match the actual size of the surface, so enforcing that the sw frame
used in copying matches its size exactly is not useful.

Signed-off-by: Anton Khirnov <anton@khirnov.net>

libavutil/hwcontext_vaapi.c

@@ -770,6 +770,9 @@ static int vaapi_transfer_data_from(AVHWFramesContext *hwfc,
     AVFrame *map;
     int err;
 
+    if (dst->width > hwfc->width || dst->height > hwfc->height)
+        return AVERROR(EINVAL);
+
     map = av_frame_alloc();
     if (!map)
         return AVERROR(ENOMEM);
@@ -779,6 +782,9 @@ static int vaapi_transfer_data_from(AVHWFramesContext *hwfc,
     if (err)
         goto fail;
 
+    map->width  = dst->width;
+    map->height = dst->height;
+
     err = av_frame_copy(dst, map);
     if (err)
         goto fail;
@@ -795,6 +801,9 @@ static int vaapi_transfer_data_to(AVHWFramesContext *hwfc,
     AVFrame *map;
     int err;
 
+    if (src->width > hwfc->width || src->height > hwfc->height)
+        return AVERROR(EINVAL);
+
     map = av_frame_alloc();
     if (!map)
         return AVERROR(ENOMEM);
@@ -804,6 +813,9 @@ static int vaapi_transfer_data_to(AVHWFramesContext *hwfc,
     if (err)
         goto fail;
 
+    map->width  = src->width;
+    map->height = src->height;
+
     err = av_frame_copy(map, src);
     if (err)
         goto fail;