avcodec_decode_*() resets the frame itself.

This is a temporary workaround to allow deprecating
avcodec_get_frame_defaults(). The proper solution will be using a
properly allocated AVFrame in Picture.

ff_mpeg_unref_picture() already resets the frame.

avcodec_decode_audio4() will reset the frame itself.

avcodec_get_frame_defaults() will be deprecated.

Strictly speaking it is not correct to call it on refcounted frames, in
any case it is unnecessary, since filtered_frame is always unreferenced
after poll_filter() returns.

av_frame_free() should be used instead.

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

Signed-off-by: Anton Khirnov <anton@khirnov.net>

This enables a more POSIX-compliant printf implementation, that
allows using length modifiers like 'z'.

Fix writing over the end

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Addresses: CVE-2013-0845

It was incorrectly moved in c869fcde.

Simplifies host/target libc detection splitting.

Add preprocessor flags for API availability as necessary.
Signed-off-by: Diego Biurrun <diego@biurrun.de>

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

The a52 spec suggests that "partial compression" should scale the
drc value in this manner.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

Use only proper AVFrame API (no assigning of whole frames, since that
hardcodes sizeof(AVFrame) into lavc).

Make a copy of the side data, so the caller can use av_frame_unref/free
on non-refcounted frames, eliminating the need for
avcodec_get_frame_defaults()/avcodec_free_frame().

Flags can be considered metadata (at least those that are defined now).

Not just on failure. This is the same thing that is done in the audio
path and should prevent leaks in decoders that allocate a frame, but
then end up not writing into it.

av_frame_unref() works fine on unallocated frames.

data[0] may be NULL for valid frames with hwaccel pixel formats.

All decoders should now handle it properly.

Remove the extended_data workaround, all decoders should now handle this
properly.

Directly loads AviSynth through LoadLibrary instead of relying on
Video for Windows, and supports using AvxSynth (via dlopen) to
open scripts on Linux and OS X.

Error messages from AviSynth/AvxSynth are now reported through
av_log and exit, rather than the traditional behavior of generating
an error video that the user would need to watch to diagnose.

The main rewrite was authored by d s <avxsynth.testing@gmail.com>
from the AvxSynth team, with additional contributions by

Oka Motofumi <chikuzen.mo@gmail.com>
Stephen Hutchinson <qyot27@gmail.com>
Diego Biurrun <diego@biurrun.de>
Anton Khirnov <anton@khirnov.net>
Signed-off-by: Anton Khirnov <anton@khirnov.net>