This commit removes the badly duplicated code between the encoder and
the muxer. That may sound surprising, but the encoder is now responsible
from the encoding of the picture when muxing to a .gif file. It also
does not require anymore a manual user intervention such as a -pix_fmt
rgb24 to work properly. To summarize, output gif are now easier to
generate, code is saner and simpler, and files are smaller (thanks to
the lzw encoding which was unused so far with the default .gif output).
We can certainly make things even better, but this is the first step.

FATE is updated because of the output being produced by the encoder and
not the muxer (no lzw in the muxer), and in the seek test only the size
mismatches.

Fixes Ticket #2262

Solution based on rational.c, which uses isinf() too

This should fix compilation with msvc
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Simplify.

Avoid implicit int->unsigned conversion, causing invalid access in case
of negative linesize.

Fix crash with:
ffplay -f lavfi testsrc,vflip

Allow to set a ratio as "a:b" (with proper escaping), and correctly
honour the max parameter.

Set select->select internally to the function, avoid lossy double->int
conversion causing spurious frame drop (e.g. in case the evaluation
result is positive and less than 1).

* cigaes/master:
  lavfi/buffersrc: fix failed requests count.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

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

Should fix pgc warning
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

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

Linesizes that did not match output width produced several artifacts.
Signed-off-by: Paul B Mahol <onemda@gmail.com>

* qatar/master:
  indeo3: check motion vectors.

Conflicts:
	libavcodec/indeo3.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

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

* commit '34e6af9e':
  indeo3: fix data size check
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '66531d63':
  indeo3: switch parsing the header to bytestream2

Conflicts:
	libavcodec/indeo3.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '01d376f5':
  rv10: check that extradata is large enough
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'bac8d38c':
  rv10: return meaningful error codes.

Conflicts:
	libavcodec/rv10.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit '69f6f03c':
  rv10: cosmetics, reformat
  qdm2: check that the FFT size is a power of 2

Conflicts:
	libavcodec/rv10.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'ecff5acb':
  svq1dec: clip motion vectors to the frame size.

Conflicts:
	libavcodec/svq1dec.c
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'b1bb8fb8':
  svq1dec: check that the reference frame has the same dimensions as the current one

Conflicts:
	libavcodec/svq1dec.c

See: 3b57bb47Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'c0771a1a':
  af_channelmap: cosmetics, use an extra local variable to shorten the code
Merged-by: Michael Niedermayer <michaelni@gmx.at>

* commit 'aafed117':
  af_channelmap: sanity check input channel indices in all cases.
Merged-by: Michael Niedermayer <michaelni@gmx.at>

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

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

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

The data offsets are relative to the bistream header, which is 16 bytes
after the start of the data.
Fixes invalid reads with corrupted files.

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

Also add an additional sanity check to the alt_quant table.
Fixes invalid reads with corrupted files.

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