The existing code attempts to clear the frame by painting in OVER mode with transparent black - which is 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.
Switch the code to paint using the CLEAR compositing operator, which fills every channel with 0 values (setting a source colour is not required). --- libavcodec/librsvgdec.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) Updated based on feedback - instead of setting a transparent paint colour, I'm just using the CLEAR operator which is hard-coded to transparent black, and might have an optimized fast path. diff --git a/libavcodec/librsvgdec.c b/libavcodec/librsvgdec.c index e57070f8e4..6697785026 100644 --- a/libavcodec/librsvgdec.c +++ b/libavcodec/librsvgdec.c @@ -82,8 +82,10 @@ 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_operator(crender, CAIRO_OPERATOR_CLEAR); + 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