Add support for dynamic x, y expressions evaluation.

Also add support for an evaluation mode which allows to disable per-frame
evaluation, so that there is no speedloss in case the expression does not
depend on frame variables.

The new name is more semantically and stilistically consistent.

* commit 'b439c992':
  lavfi: switch to an AVOptions-based system.
  dfa: implement missing TDLT coding method

Conflicts:
	libavcodec/dfa.c
	libavfilter/avfilter.c
Merged-by: NMichael Niedermayer <michaelni@gmx.at>

Signed-off-by: NJames Almer <jamrial@gmail.com>

From 253 to 51 cycles on Arrandale and Win64.
44 cycles on SandyBridge.
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

Since the PTS need double accuracy, the timebase denominator is doubled
as well, and this new time base is used for the timestamp unit.

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

Fixes ticket #2412.
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

Signed-off-by: NPaul B Mahol <onemda@gmail.com>

* cigaes/master:
  ffmpeg: use a rational for -aspect option.
Merged-by: NMichael Niedermayer <michaelni@gmx.at>

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

Fixes Ticket2405
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

The EC code does not support fields currently thus it makes no
sense to wait for these cases (which also the check doesnt handle
correctly)

Fixes Ticket 2454
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

Fixes second half of Ticket2414
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

Fixes first half of Ticket2414
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

* qatar/master:
  srtp: Include rtpdec.h for RTP_MAX_PACKET_LENGTH
  rtpdec: Increase max rtp packet size to 8192
  lavf: Use RTP_MAX_PACKET_LENGTH instead of 1500
  h264pred: Add a few missing const declarations for ff_cropTbl derived pointers
Merged-by: NMichael Niedermayer <michaelni@gmx.at>

This was missed from 350ad50b - this fixes building the fate-srtp
test.
Signed-off-by: NMartin Storsjö <martin@martin.st>

This fixes connecting to "Ceton InfiniTV4 PCIe & USB".
Signed-off-by: NMartin Storsjö <martin@martin.st>

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

* cus/stable:
  ffplay: simplify video pts calculation
  ffplay: fix indentation
  ffplay: handle audio buffersink output properly with buffering filters
  ffplay: set time_base of audio filter buffer src
Merged-by: NMichael Niedermayer <michaelni@gmx.at>

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

Native filter have reached similar performance.
Signed-off-by: NPaul B Mahol <onemda@gmail.com>

Signed-off-by: NPaul B Mahol <onemda@gmail.com>

Also use frame->pts instead of a standalone variable
Signed-off-by: NMarton Balint <cus@passwd.hu>

Signed-off-by: NMarton Balint <cus@passwd.hu>

Fixes cases when the audio filter generates less or more frames than the input.
Signed-off-by: NMarton Balint <cus@passwd.hu>

Fixes ticket #2408.
Signed-off-by: NMarton Balint <cus@passwd.hu>

Signed-off-by: NPaul B Mahol <onemda@gmail.com>

The pointers that get assigned ff_cropTbl were made const in
9e0f14f1, but other variables that transitively are assigned
based on these variables were missed.
Signed-off-by: NMartin Storsjö <martin@martin.st>

Morphing was introduced in 0d6e5a17 and forced cos/sin computations
with some mult all the time. This commit makes sure these are computed
only when morphing is enabled.

WAV chunks must be even aligned. This patch skip the extra padding byte
if chunk size is odd.

Fixes ticket #2417.
Reviewed-by: NDerek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

Fixes Ticket2294
Signed-off-by: NMichael Niedermayer <michaelni@gmx.at>

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

Signed-off-by: NPaul B Mahol <onemda@gmail.com>