avcodec/pngdec: do not blend on transparent black
authorBenoit Fouet <benoit.fouet@free.fr>
Fri, 28 Nov 2014 09:43:01 +0000 (10:43 +0100)
committerMichael Niedermayer <michaelni@gmx.at>
Fri, 28 Nov 2014 14:51:23 +0000 (15:51 +0100)
commitaff50ae1d176edacf7ff3fb24db9d25ebe9a4b2e
tree884f7597b517b15480423e7111937c20dcd93b0d
parentbd67d0ead1451c8ea9b2ef40629360c4a9d9c99c
avcodec/pngdec: do not blend on transparent black

There is no need to memset the zlib output buffer, as there is no
blending happening there. Instead, do not blend when the dispose
operation is set to 'background' (tranparent black).

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
libavcodec/pngdec.c