avcodec/pngdsp: fix (un)signed type in end comparission

Fixes out of array accesses
Fixes Ticket2919

Found_by: ami_stuff
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 86736f59d6a527d8bc807d09b93f971c0fe0bb07)
avcodec/ffv1dec: check global header version

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 20b965a1a43ae88b7ae95635d5a3570e7dc2bbd4)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffv1dec: check that global parameters dont change in version 0/1

Such changes are not allowed nor supported

Fixes Ticket2906

Found-by: ami_stuff
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 547d690d676064069d44703a1917e0dab7e33445)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
ffv1dec: Check bits_per_raw_sample and colorspace for equality in ver 0/1 headers

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit b05cd1ea7e45a836f7f6071a716c38bb30326e0f)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/dsputil: fix signedness in sizeof() comparissions

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 454a11a1c9c686c78aa97954306fb63453299760)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>