avformat/filter_swscale.c: add support for scaling the alpha channel (needs further...

git-svn-id: https://mlt.svn.sourceforge.net/svnroot/mlt/trunk/mlt@1274 d19143bc-622f-0410-bfdd-b5b2a6649095

diff --git a/src/modules/avformat/filter_swscale.c b/src/modules/avformat/filter_swscale.c
index 4571acd66c693db953aafd0e579007f425ceffa4..1a31a8792bc4de476f2c0e4eeb561c6d5919511d 100644 (file)
--- a/src/modules/avformat/filter_swscale.c
+++ b/src/modules/avformat/filter_swscale.c
@@ -96,29 +96,71 @@ static int filter_scale( mlt_frame this, uint8_t **image, mlt_image_format iform
        else if ( strcmp( interps, "spline" ) == 0 )
                interp = SWS_SPLINE;
 
+       AVPicture input;
+       AVPicture output;
+       uint8_t *outbuf = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
+
        // Convert the pixel formats
        iformat = convert_mlt_to_av_cs( iformat );
        oformat = convert_mlt_to_av_cs( oformat );
 
-       // Create the context and output image
-       struct SwsContext *context = sws_getContext( iwidth, iheight, iformat, owidth, oheight, oformat, interp, NULL, NULL, NULL);
-       AVPicture input;
        avpicture_fill( &input, *image, iformat, iwidth, iheight );
-       AVPicture output;
-       uint8_t *outbuf = mlt_pool_alloc( owidth * ( oheight + 1 ) * 2 );
        avpicture_fill( &output, outbuf, oformat, owidth, oheight );
 
+       // Extract the alpha channel
+       if ( iformat == PIX_FMT_RGBA32 && oformat == PIX_FMT_YUV422 )
+       {
+               // Allocate the alpha mask
+               uint8_t *alpha = mlt_pool_alloc( iwidth * ( iheight + 1 ) );
+               if ( alpha )
+               {
+                       // Convert the image and extract alpha
+                       mlt_convert_rgb24a_to_yuv422( *image, iwidth, iheight, iwidth * 4, outbuf, alpha );
+                       mlt_properties_set_data( properties, "alpha", alpha, iwidth * ( iheight + 1 ), ( mlt_destructor )mlt_pool_release, NULL );
+                       iformat = PIX_FMT_YUV422;
+                       avpicture_fill( &input, outbuf, iformat, iwidth, iheight );
+                       avpicture_fill( &output, *image, oformat, owidth, oheight );
+               }
+       }
+
+       // Create the context and output image
+       struct SwsContext *context = sws_getContext( iwidth, iheight, iformat, owidth, oheight, oformat, interp, NULL, NULL, NULL);
+
        // Perform the scaling
        sws_scale( context, input.data, input.linesize, 0, iheight, output.data, output.linesize);
        sws_freeContext( context );
 
        // Now update the frame
-       mlt_properties_set_data( properties, "image", outbuf, owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
+       mlt_properties_set_data( properties, "image", output.data[0], owidth * ( oheight + 1 ) * 2, ( mlt_destructor )mlt_pool_release, NULL );
        mlt_properties_set_int( properties, "width", owidth );
        mlt_properties_set_int( properties, "height", oheight );
 
        // Return the output
-       *image = outbuf;
+       *image = output.data[0];
+
+       // Scale the alpha channel only if exists and not correct size
+       int alpha_size = 0;
+       mlt_properties_get_data( properties, "alpha", &alpha_size );
+       if ( alpha_size > 0 && alpha_size != ( owidth * oheight ) )
+       {
+               // Create the context and output image
+               uint8_t *alpha = mlt_frame_get_alpha_mask( this );
+               if ( alpha )
+               {
+                       iformat = oformat = PIX_FMT_GRAY8;
+                       struct SwsContext *context = sws_getContext( iwidth, iheight, iformat, owidth, oheight, oformat, interp, NULL, NULL, NULL);
+                       avpicture_fill( &input, alpha, iformat, iwidth, iheight );
+                       outbuf = mlt_pool_alloc( owidth * oheight );
+                       avpicture_fill( &output, outbuf, oformat, owidth, oheight );
+
+                       // Perform the scaling
+                       sws_scale( context, input.data, input.linesize, 0, iheight, output.data, output.linesize);
+                       sws_freeContext( context );
+
+                       // Set it back on the frame
+                       mlt_properties_set_data( MLT_FRAME_PROPERTIES( this ), "alpha", output.data[0], owidth * oheight, mlt_pool_release, NULL );
+               }
+       }
 
        return 0;
 }