[FFmpeg-cvslog] png: check bit depth for PAL8/Y400A pixel formats.

[Reinhard Tartler]

ffmpeg | branch: release/0.5 | Reinhard Tartler <siretart at tauware.de> | Sun Jun  3 19:35:50 2012 +0200| [5a9588b088423772ba567a71a3b0d4800c77d407] | committer: Reinhard Tartler

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 at libav.org
(cherry picked from commit d2205d6543881f2e6fa18c8a354bbcf91a1235f7)

Signed-off-by: Reinhard Tartler <siretart at tauware.de>
(cherry picked from commit b8d6ba9d50e80fdce2ed74cdaffd4960df8a21c5)

Signed-off-by: Reinhard Tartler <siretart at tauware.de>
(cherry picked from commit 33f93005f1a86c108302b4c5978aa1a3d8e092cc)

Signed-off-by: Reinhard Tartler <siretart at tauware.de>
(cherry picked from commit 4c8c2660bd9252775c9a1dc2e2f36cb34718595a)

Signed-off-by: Reinhard Tartler <siretart at tauware.de>

Conflicts:

	libavcodec/pngdec.c

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5a9588b088423772ba567a71a3b0d4800c77d407
---

 libavcodec/pngdec.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index a343152..d583a52 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -473,7 +473,8 @@ 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 {
                     goto fail;