Scaling experimentation

[melted] / src / modules / core / filter_resize.c

diff --git a/src/modules/core/filter_resize.c b/src/modules/core/filter_resize.c
index 537ce50..4122d8f 100644 (file)
--- a/src/modules/core/filter_resize.c
+++ b/src/modules/core/filter_resize.c
@@ -31,17 +31,99 @@
 
 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
 {
+       int error = 0;
+
+       // Get the properties from the frame
+       mlt_properties properties = mlt_frame_properties( this );
+
+       // Pop the top of stack now
+       mlt_filter filter = mlt_frame_pop_service( this );
+
+       // Assign requested width/height from our subordinate
        int owidth = *width;
        int oheight = *height;
-       mlt_frame_get_image( this, image, format, &owidth, &oheight, 0 );
-       if ( *width == 0 )
-               *width = 720;
-       if ( *height == 0 )
-               *height = 576;
-       if ( !strcmp( mlt_properties_get( mlt_frame_properties( this ), "resize.scale" ), "affine" ) )
-               *image = mlt_frame_rescale_yuv422( this, *width, *height );
-       else
-               *image = mlt_frame_resize_yuv422( this, *width, *height );
+
+       // Hmmm...
+       char *rescale = mlt_properties_get( properties, "rescale.interp" );
+       if ( rescale != NULL && !strcmp( rescale, "none" ) )
+               return mlt_frame_get_image( this, image, format, width, height, writable );
+
+       if ( mlt_properties_get( properties, "distort" ) == NULL )
+       {
+               // Normalise the input and out display aspect
+               int normalised_width = mlt_properties_get_int( properties, "normalised_width" );
+               int normalised_height = mlt_properties_get_int( properties, "normalised_height" );
+               double input_ar = mlt_frame_get_aspect_ratio( this );
+               double output_ar = mlt_properties_get_double( properties, "consumer_aspect_ratio" );
+               
+               // Optimised for the input_ar > output_ar case (e.g. widescreen on standard)
+               int scaled_width = normalised_width;
+               int scaled_height = output_ar / input_ar * normalised_height;
+
+               // Now ensure that our images fit in the normalised frame
+               if ( scaled_height > normalised_height )
+               {
+                       scaled_width = input_ar / output_ar * normalised_width;
+                       scaled_height = normalised_height;
+               }
+       
+               // Now calculate the actual image size that we want
+               owidth = scaled_width * owidth / normalised_width;
+               oheight = scaled_height * oheight / normalised_height;
+
+               // Tell frame we have conformed the aspect to the consumer
+               mlt_frame_set_aspect_ratio( this, output_ar );
+       }
+
+       // Now pass on the calculations down the line
+       mlt_properties_set_int( properties, "resize_width", *width );
+       mlt_properties_set_int( properties, "resize_height", *height );
+
+       // Now get the image
+       error = mlt_frame_get_image( this, image, format, &owidth, &oheight, writable );
+
+       // We only know how to process yuv422 at the moment
+       if ( error == 0 && *format == mlt_image_yuv422 )
+       {
+               // Get the requested scale operation
+               char *op = mlt_properties_get( mlt_filter_properties( filter ), "scale" );
+
+               // Correct field order if needed
+               if ( mlt_properties_get_int( properties, "top_field_first" ) == 1 )
+               {
+                       // Get the input image, width and height
+                       int size;
+                       uint8_t *image = mlt_properties_get_data( properties, "image", &size );
+
+                       // Keep the original image around to be destroyed on frame close
+                       mlt_properties_rename( properties, "image", "original_image" );
+
+                       // Offset the image pointer by one line
+                       image += owidth * 2;
+                       size -= owidth * 2;
+
+                       // Set the new image pointer with no destructor
+                       mlt_properties_set_data( properties, "image", image, size, NULL, NULL );
+
+                       // Set the normalised field order
+                       mlt_properties_set_int( properties, "top_field_first", 0 );
+               }
+
+               if ( !strcmp( op, "affine" ) )
+               {
+                       *image = mlt_frame_rescale_yuv422( this, *width, *height );
+               }
+               else if ( strcmp( op, "none" ) != 0 )
+               {
+                       *image = mlt_frame_resize_yuv422( this, *width, *height );
+               }
+               else
+               {
+                       *width = owidth;
+                       *height = oheight;
+               }
+       }
+
        return 0;
 }
 
@@ -50,8 +132,12 @@ static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *
 
 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
 {
+       // Push this on to the service stack
+       mlt_frame_push_service( frame, this );
+
+       // Push the get_image method on to the stack
        mlt_frame_push_get_image( frame, filter_get_image );
-       mlt_properties_set( mlt_frame_properties( frame ), "resize.scale", mlt_properties_get( mlt_filter_properties( this ), "scale" ) );
+
        return frame;
 }
 
@@ -64,10 +150,7 @@ mlt_filter filter_resize_init( char *arg )
        if ( mlt_filter_init( this, this ) == 0 )
        {
                this->process = filter_process;
-               if ( arg != NULL )
-                       mlt_properties_set( mlt_filter_properties( this ), "scale", arg );
-               else
-                       mlt_properties_set( mlt_filter_properties( this ), "scale", "off" );
+               mlt_properties_set( mlt_filter_properties( this ), "scale", arg == NULL ? "off" : arg );
        }
        return this;
 }