float_dsp: add vector_dmul_scalar() to multiply a vector of doubles

Include x86-optimized versions for SSE2 and AVX.
eval: treat dB as decibels instead of decibytes
lavu/opt: do not filter out the initial sign character except for flags

This allows parsing of special-case negative numbers like decibels.
x86: af_volume: add SSE2-optimized s16 volume scaling
x86: af_volume: add SSE2/SSSE3/AVX-optimized s32 volume scaling
avconv: deprecate the -vol option

Remove the code for volume scaling in avconv.c and instead auto-insert a
volume filter into the beginning of the filter chain.
lavfi: add volume filter

Based on the volume filter in FFmpeg written by Stefano Sabatini
<stefasab@gmail.com>.
pixdesc: fix yuva 10bit bit depth

It was wrongly set as the yuva 16bit one.

Signed-off-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
alacenc: add support for multi-channel encoding
h264: slice-mt: get last_pic_dropable from master context

Fixes fate-h264-conformance-cvnlfi2_sony_h and smllwebdl.mkv from
https://github.com/OpenELEC/OpenELEC.tv/issues/1557 .

CC: libav-stable@libav.org
h264: slice-mt: check master context for valid current_picture_ptr

Fixes errors in slice based multithreading introduced in 0b300daad2f5.

CC: libav-stable@libav.org
lavf: add a concat demuxer.
Merge commit '9d5c62ba5b586c80af508b5914934b1c439f6652'

* commit '9d5c62ba5b586c80af508b5914934b1c439f6652':
  lavu/opt: do not filter out the initial sign character except for flags
  eval: treat dB as decibels instead of decibytes
  float_dsp: add vector_dmul_scalar() to multiply a vector of doubles

Conflicts:
	libavutil/eval.c
	tests/ref/fate/eval

Merged-by: Michael Niedermayer <michaelni@gmx.at>
lavfi/silencedetect: use eval builtin to parse dB.

Also update FATE test to use the dB form.
lavd/lavfi: fix float.h include.

float.h is a system header.
Merge commit 'b384e031daeb1ac612620985e3e5377bc587559c'

* commit 'b384e031daeb1ac612620985e3e5377bc587559c':
  lavfi: add volume filter

Conflicts:
	Changelog
	libavfilter/Makefile
	libavfilter/af_volume.c
	libavfilter/version.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
lavfi: rename af_volume to af_volume_stefano

This matches the naming style of the new af_volume_justin filter.

Note, Yes i would too prefer having one filter instead of 2.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'b519298a1578e0c895d53d4b4ed8867b1c031a56'

* commit 'b519298a1578e0c895d53d4b4ed8867b1c031a56':
  pixdesc: fix yuva 10bit bit depth
  avconv: deprecate the -vol option
  x86: af_volume: add SSE2/SSSE3/AVX-optimized s32 volume scaling
  x86: af_volume: add SSE2-optimized s16 volume scaling

Conflicts:
	ffmpeg.c
	tests/ref/lavfi/pixdesc
	tests/ref/lavfi/pixfmts_copy
	tests/ref/lavfi/pixfmts_null
	tests/ref/lavfi/pixfmts_scale
	tests/ref/lavfi/pixfmts_vflip

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  h264: slice-mt: check master context for valid current_picture_ptr
  h264: slice-mt: get last_pic_dropable from master context
  alacenc: add support for multi-channel encoding

Conflicts:
	Changelog
	libavcodec/alac.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
lavfi/deshake: switch to filter_frame.