avcodec/apng: Dispose previous frame properly
authorDonny Yang <work@kota.moe>
Sun, 7 Jun 2015 18:12:30 +0000 (18:12 +0000)
committerMichael Niedermayer <michaelni@gmx.at>
Mon, 8 Jun 2015 13:32:49 +0000 (15:32 +0200)
commited09bb3782e23c12a110469bf6e794f7ce8687e9
treec7a3d9bf5df61785fd6936e9f808d8e5585a0515
parent6dd5371e34c6602591766f73aa647b369d77853b
avcodec/apng: Dispose previous frame properly

The spec specifies the dispose operation as how the current (i.e., currently
being rendered) frame should be disposed when the next frame is blended onto it

This is contrary to ffmpeg's current behaviour of interpreting the dispose
operation as how the previous (i.e., already rendered) frame should be disposed

This patch fixes ffmpeg's behaviour to match those of the spec, which involved
a rewrite of the blending function

Signed-off-by: Donny Yang <work@kota.moe>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
libavcodec/pngdec.c