This commit introduces a new AVPacket side data type:
AV_PKT_DATA_STRINGS_METADATA. Its main goal is to provide a way to
transmit the metadata from the AVFilterBufferRef up to the AVFrame. This
is at the moment "only" useful for lavfi input from libavdevice:
lavd/lavfi only outputs packets, and the metadata from the buffer ref
kept in its context needs to be transmitted from the packet to the frame
by the decoders. The buffer ref can be destroyed at any time (along with
the metadata), and a duplication of the AVPacket needs to duplicate the
metadata as well, so the choice of using the side data to store them was
selected.

Making sure lavd/lavfi raises the metadata is useful to allow tools like
ffprobe to access the filters metadata (it is at the moment the only
way); ffprobe will now automatically show the AVFrame metadata in any
customizable output format for users. API users will also be able to
access the AVFrame->metadata pointer the same way ffprobe does
(av_frame_get_metadata).

All the changes are done in this single commit to avoid some memory
leaks: for instances, the changes in lavfi/avcodec.c are meant to
duplicate the metadata from the buffer ref into the AVFrame. Unless we
have an internal way of freeing the AVFrame->metadata automatically, it
will leak in most of the user apps. To fix this problem, we introduce
AVCodecContext->metadata and link avctx->metadata to the current
frame->metadata and free it at each decode frame call (and in the codec
closing callback for the last one). But doing this also means to update
the way the tiff decoder already handles the AVFrame->metadata (it's the
only one decoder with frame metadata at the moment), by making sure it
is not trying to free a pointer already freed by the lavc internals.

The lavfi/avcodec.c buffer ref code is based on an old Thomas Kühnel
work, the rest of the code belongs to the commit author.
Signed-off-by: Thomas Kühnel <kuehnelth@googlemail.com>
Signed-off-by: Clément Bœsch <ubitux@gmail.com>

* qatar/master:
  fate: adpcm: cosmetics: Sort test entries
  fate: adpcm: Add dependencies
  svq3: cosmetics: Drop useless parentheses

Conflicts:
	libavcodec/svq3.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'a7d2861d':
  svq3: K&R formatting cosmetics
  fate: Introduce ENCMUX macro for tests that require encoders and a muxer
  ffv1: Add missing #includes to header file

Conflicts:
	libavcodec/ffv1.h
	libavcodec/svq3.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '2d09b36c':
  doc/platform: Add info on shared builds with MSVC
  doc/platform: Move a caveat down to the notes section
  ARM: reinstate optimised intmath.h
  ffv1: update to ffv1 version 3

Conflicts:
	doc/platform.texi
	libavcodec/ffv1.c
	libavcodec/ffv1.h
	libavcodec/ffv1dec.c
	libavcodec/ffv1enc.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '4a2a4524':
  ffv1: propagate errors

Conflicts:
	libavcodec/ffv1dec.c
	libavcodec/ffv1enc.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '71f7b22d':
  ffv1: split decoder and encoder

Conflicts:
	libavcodec/Makefile
	libavcodec/ffv1.c
	libavcodec/ffv1.h
	libavcodec/ffv1dec.c
	libavcodec/ffv1enc.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

This is not based on lucas work due to code divergence (its less work this way
than trying to merge from a split based on 2 years outdated code)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'd15c21e5':
  avutil: Add a copy of ff_sqrt_tab back into avutil to restore ABI compatibility
  avutil: make some tables visible again
  avutil: remove inline av_log2 from public API
  celp_math: rename ff_log2 to ff_log2_q15

Conflicts:
	libavutil/libavutil.v
Merged-by: Michael Niedermayer <michaelni@gmx.at>

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

The libav code depends on mp3 startcodes only occuring at the start of
frames. But there is nothing in mp3 that prevents them occuring elsewhere
by chance. Thus the code would fail randomly, the new code searches for 3
consecutive valid frames. If this turns out to be still insufficient the
number can be raised further, or additional checks added.
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

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

This should also fix CID717889.

Should fix CID733781 and CID733782.

Should fix CID733779 and CID733780.

Fixes CID703688
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes CID733715
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes CID732199
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes CID739471
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This also places tests of related formats together.

Fixes CID700575
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes CID717749
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes CID703682
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes CID703745
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Decrease confusion.

Fixes CID700562-7
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Fixes CID703629
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Use of the ARM optimised intmath.h was accidentally dropped in 9734b8ba.
Signed-off-by: Mans Rullgard <mans@mansr.com>

Based on code from Carl Eugen Hoyos, Michael Niedermayer and Paul B Mahol.

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