Prevent buffer overread.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

Directly return from code 1, 2 and 6 codepaths and simplify the
remaining one to have a single overflow check and a single call to
mcdc.

Check for out of picture macroblocks before calling mcdc.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

Make sure the value of wlog2 is always between 0 and 3.

Partially mitigate out of memory writes.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

Split sound and video tag parsing in separate functions.

Signed-off-by: Martin Storsjö <martin@martin.st>

This also simplifies the code.

This allows handling matroska files with errors.
Fixes test4.mkv and test7.mkv from the official Matroska test suite,
and by extension Bugzilla #62.

Based on a patch by Reimar Doffinger <Reimar.Doeffinger@gmx.de>
Signed-off-by: Anton Khirnov <anton@khirnov.net>

This avoids warnings about this option not having any effect on
this platform.

We still want to enable the pic configure item for these platforms
(if detected via the compiler builtin define __PIC__) to get proper
inline assembly workarounds.
Signed-off-by: Martin Storsjö <martin@martin.st>

This reverts e08c946c and 05165c2f. The actual intention of
e08c946c was to fix shared library builds for arm/win32, which
can also be accomplished in other ways.

Disabling pic on those platforms broke inline assembly on cygwin/64
(since some inline assembly requires knowing whether we are building
as PIC or not), and might also break inline assembly on other
compilers on windows.

As a side-effect, this unfortunately brings back all the warnings
about PIC not having any effect on that platform.
Signed-off-by: Martin Storsjö <martin@martin.st>

The object file format doesn't support PIC loads in ARM assembly,
there are no relocation types in PE/COFF that correspond to
BFD_RELOC_32_PCREL (R_ARM_REL32 in ELF).
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>

Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>

Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>

And optionally forward them to the caller instead of concealing them.

Unify err and ret in a single variable.

At least 2 bytes from the source are read every loop.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org

Return the proper error values and optionally report them.

Report when zlib support is missing.

Signed-off-by: Martin Storsjö <martin@martin.st>

The missing object file was added to the matroska muxer already, but
not to the webm muxer.
Signed-off-by: Martin Storsjö <martin@martin.st>

CC: libav-stable@libav.org

Fixes a segfault in exit_program() if opening an output file fails.