png: check bit depth for PAL8/Y400A pixel formats.

Wrong bit depth can lead to invalid rowsize values, which crashes the
decoder further down.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
This commit is contained in:
Ronald S. Bultje 2012-05-02 10:58:55 -07:00
parent 273e6af47b
commit d2205d6543
1 changed files with 4 additions and 2 deletions

View File

@ -479,9 +479,11 @@ static int decode_frame(AVCodecContext *avctx,
} else if (s->bit_depth == 1 &&
s->color_type == PNG_COLOR_TYPE_GRAY) {
avctx->pix_fmt = PIX_FMT_MONOBLACK;
} else if (s->color_type == PNG_COLOR_TYPE_PALETTE) {
} else if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_PALETTE) {
avctx->pix_fmt = PIX_FMT_PAL8;
} else if (s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
} else if (s->bit_depth == 8 &&
s->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) {
avctx->pix_fmt = PIX_FMT_Y400A;
} else {
goto fail;