Make sure inputs to sws_scale are aligned, as I think they must be.

[dcpomatic.git] / src / lib / image.cc

diff --git a/src/lib/image.cc b/src/lib/image.cc
index 3afb6205eb21f11245ac8e3f3e41e48f8b2738d6..0a51add002cf7787c919a9c29a03e36237a72200 100644 (file)
--- a/src/lib/image.cc
+++ b/src/lib/image.cc
@@ -96,11 +96,15 @@ Image::components () const
 }
 
 shared_ptr<Image>
-Image::scale (Size out_size, Scaler const * scaler, bool aligned) const
+Image::scale (Size out_size, Scaler const * scaler, bool result_aligned) const
 {
        assert (scaler);
+       /* Empirical testing suggests that sws_scale() will crash if
+          the input image is not aligned.
+       */
+       assert (aligned ());
 
-       shared_ptr<Image> scaled (new SimpleImage (pixel_format(), out_size, aligned));
+       shared_ptr<Image> scaled (new SimpleImage (pixel_format(), out_size, result_aligned));
 
        struct SwsContext* scale_context = sws_getContext (
                size().width, size().height, pixel_format(),
@@ -125,14 +129,18 @@ Image::scale (Size out_size, Scaler const * scaler, bool aligned) const
  *  @param scaler Scaler to use.
  */
 shared_ptr<Image>
-Image::scale_and_convert_to_rgb (Size out_size, int padding, Scaler const * scaler, bool aligned) const
+Image::scale_and_convert_to_rgb (Size out_size, int padding, Scaler const * scaler, bool result_aligned) const
 {
        assert (scaler);
+       /* Empirical testing suggests that sws_scale() will crash if
+          the input image is not aligned.
+       */
+       assert (aligned ());
 
        Size content_size = out_size;
        content_size.width -= (padding * 2);
 
-       shared_ptr<Image> rgb (new SimpleImage (PIX_FMT_RGB24, content_size, aligned));
+       shared_ptr<Image> rgb (new SimpleImage (PIX_FMT_RGB24, content_size, result_aligned));
 
        struct SwsContext* scale_context = sws_getContext (
                size().width, size().height, pixel_format(),
@@ -153,7 +161,7 @@ Image::scale_and_convert_to_rgb (Size out_size, int padding, Scaler const * scal
           scheme of things.
        */
        if (padding > 0) {
-               shared_ptr<Image> padded_rgb (new SimpleImage (PIX_FMT_RGB24, out_size, aligned));
+               shared_ptr<Image> padded_rgb (new SimpleImage (PIX_FMT_RGB24, out_size, result_aligned));
                padded_rgb->make_black ();
 
                /* XXX: we are cheating a bit here; we know the frame is RGB so we can
@@ -485,6 +493,12 @@ SimpleImage::size () const
        return _size;
 }
 
+bool
+SimpleImage::aligned () const
+{
+       return _aligned;
+}
+
 FilterBufferImage::FilterBufferImage (AVPixelFormat p, AVFilterBufferRef* b)
        : Image (p)
        , _buffer (b)
@@ -522,6 +536,13 @@ FilterBufferImage::size () const
        return Size (_buffer->video->w, _buffer->video->h);
 }
 
+bool
+FilterBufferImage::aligned () const
+{
+       /* XXX? */
+       return true;
+}
+
 RGBPlusAlphaImage::RGBPlusAlphaImage (shared_ptr<const Image> im)
        : SimpleImage (im->pixel_format(), im->size(), false)
 {