Since we can't know which stride a custom get_buffer() implementation is
going to use we have to allocate this scratch buffers after the linesize
is known. It was pretty safe for 8 bit per pixel pixel formats since we
always allocated memory for up to 16 bits per pixel. It broke hoever
with cmdutis.c's alloc_buffer() and high pixel bit depth since it
allocated larger edges than mpegvideo expected.

Fixes fuzzed sample nasa-8s2.ts_s244342.

Fixes null pointer dereference.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind

Compute dist_scale_factor_field only for MBAFF since that is the only
case in which it is used.

Prevents writing beyond array bounds.
Signed-off-by: Janne Grunau <janne-libav@jannau.net>

It is not posible to call get_buffer during frame-mt codec
initialization. Libavformat might pass huge amounts of data as
extradata after parsing broken files. The 'extradata' for the fuzzed
sample sample_varPAR_s5374_r001-02.avi is 2.8M large and contains
multiple slices.

The "pts for a given stream" was nonsensical.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

This reduces code size when either piece has been disabled.

Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>

It adds unnecessary complication for insignificant usability improvement.
The user really should know if they'll need resampling compensation before
opening the context.

Note that only the documentation has changed. The current functionality will
still work until the next major bump.

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

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

This makes it easier for receivers to decide what to do if data
is lost.

Refactor calculating the max payload size, to avoid hardcoding the
header size in too many places, reducing the number of lines that
have to be touched if the header is adjusted further.
Signed-off-by: Martin Storsjö <martin@martin.st>

Introduced in d7d6efe4.

Since a NAL_DPA can start a new frame it has to be handled before
ff_thread_finish_setup is called.

Fixes CVE-2012-2783

CC: libav-stable@libav.org

Returning 0 for failure is misleading.

CC: libav-stable@libav.org

Fixes CVE-2012-2791.

CC: libav-stable@libav.org

Fixes build errors with nasm introduced in 6f40e9f0 for stack
memory alignment. Noticed by BugMaster.

This requires to move the avcodec_default_free_buffers() call to
ff_MPV_common_end() since otherwise delayed pictures would get freed
during a size change.

Direct rendering capable decoders call get_buffer() which will set the
frame parameters.

Prevents frames with wrong parameters when a decoder outputs delayed
frames after a resolution or pixel format change.

Fixes a crash in the fuzzed sample sample_varPAR.avi_s26638 with
alternating bit depths.

Note the time base for the option. Add an additional example description.

Currently it will do padding, but it does not properly handle
start-of-stream trimming as documented.

The max_comp option is supposed to limit maximum compensation, but
currently the clipped value is not actually used.

Interlacing is not supported at all and mismanaged down the normal
codepaths causing possible buffer management issues.

CC: libav-stable@libav.org

Found-by: pawlkt
CC: libav-stable@libav.org

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