| Message ID | 1517437057.19745.7.camel@kepstin.ca |
|---|---|
| State | Superseded |
| Headers | show |
On 31 January 2018 at 22:17, Calvin Walton <calvin.walton@kepstin.ca> wrote: > The existing code attempts to clear the frame by painting in OVER mode > with transparent black - which is, of course, a no-op. As a result if > you have many input frames (e.g. you're using a sequence of svg files), > you'll start to see new frames drawn over old frames as memory gets > re-used. > > Fix that by clearing the frame using the SOURCE blend mode, which > will replace whatever is in the buffer with transparent black. > > Referencing the cairo FAQ, > https://www.cairographics.org/FAQ/#clear_a_surface > --- > libavcodec/librsvgdec.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > It would probably be nice to get this into 3.4 branch as well? > > diff --git a/libavcodec/librsvgdec.c b/libavcodec/librsvgdec.c > index e57070f8e4..e16cb6247d 100644 > --- a/libavcodec/librsvgdec.c > +++ b/libavcodec/librsvgdec.c > @@ -82,8 +82,11 @@ static int librsvg_decode_frame(AVCodecContext *avctx, > void *data, int *got_fram > > crender = cairo_create(image); > > - cairo_set_source_rgba(crender, 0.0, 0.0, 0.0, 1.0f); > - cairo_paint_with_alpha(crender, 0.0f); > + cairo_save(crender); > + cairo_set_source_rgba(crender, 0.0, 0.0, 0.0, 0.0f); > + cairo_set_operator(crender, CAIRO_OPERATOR_SOURCE); > + cairo_paint(crender); > + cairo_restore(crender); > > cairo_scale(crender, dimensions.width / (double)unscaled_dimensions. > width, > dimensions.height / (double)unscaled_dimensions.height); > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > Could you resubmit the patch with CAIRO_OPERATOR_CLEAR and removing cairo_set_source_rgba() like the docs say? We don't need generic clearing to an arbitrary color and it might be faster if they optimize(d) it. Thanks
diff --git a/libavcodec/librsvgdec.c b/libavcodec/librsvgdec.c index e57070f8e4..e16cb6247d 100644 --- a/libavcodec/librsvgdec.c +++ b/libavcodec/librsvgdec.c @@ -82,8 +82,11 @@ static int librsvg_decode_frame(AVCodecContext *avctx, void *data, int *got_fram crender = cairo_create(image); - cairo_set_source_rgba(crender, 0.0, 0.0, 0.0, 1.0f); - cairo_paint_with_alpha(crender, 0.0f); + cairo_save(crender); + cairo_set_source_rgba(crender, 0.0, 0.0, 0.0, 0.0f); + cairo_set_operator(crender, CAIRO_OPERATOR_SOURCE); + cairo_paint(crender); + cairo_restore(crender); cairo_scale(crender, dimensions.width / (double)unscaled_dimensions.width, dimensions.height / (double)unscaled_dimensions.height);