libx264: Define X264_API_IMPORTS on MSVC/ICL

libx264 has a few data exports which require X264_API_IMPORTS
to be defined if we link to libx264 dynamically on Windows.

In a similar fashion to how we handle our compat snprintf
implementation, if we define it all the time, the compiler
will first try and link to __imp_x264_symbol_name, and failing
that, as in the case of a static libx264, will attempt to link
to the non-prefixed symbol, which has already been pulled in by
other x264 functions' object files.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
configure: generate full msvc debug symbols when linking in debug mode

Signed-off-by: Martin Storsjö <martin@martin.st>
libspeexdec: fix detection of final terminator code
arm: Add VFP-accelerated version of synth_filter_float

               Before           After
               Mean    StdDev   Mean    StdDev  Change
This function   9295.0 114.9     4853.2 83.5    +91.5%
Overall        23699.8 397.6    19285.5 292.0   +22.9%

Signed-off-by: Martin Storsjö <martin@martin.st>
arm: Add VFP-accelerated version of int32_to_float_fmul_scalar

               Before           After
               Mean    StdDev   Mean    StdDev  Change
This function   1175.0   4.4      366.2  18.3   +220.8%
Overall        19285.5 292.0    18420.5 489.1     +4.7%

Signed-off-by: Martin Storsjö <martin@martin.st>
fmtconvert: Add a new method, int32_to_float_fmul_array8

This is similar to int32_to_float_fmul_scalar, but
loads a new scalar multiplier every 8 input samples.
This enables the use of much larger input arrays, which
is important for pipelining on some CPUs (such as
ARMv6).

Signed-off-by: Martin Storsjö <martin@martin.st>
dcadec: Use int32_to_float_fmul_array8

Signed-off-by: Martin Storsjö <martin@martin.st>
arm: Add VFP-accelerated version of int32_to_float_fmul_array8

               Before           After
               Mean    StdDev   Mean    StdDev  Change
This function    366.2  18.3      277.8  13.7   +31.9%
Overall        18420.5 489.1    17049.5 408.2    +8.0%

Signed-off-by: Martin Storsjö <martin@martin.st>
arm: Add VFP-accelerated version of imdct_half

               Before           After
               Mean    StdDev   Mean    StdDev  Change
This function   2653.0  28.5     1108.8  51.4   +139.3%
Overall        17049.5 408.2    15973.0 223.2     +6.7%

Signed-off-by: Martin Storsjö <martin@martin.st>
arm: Add VFP-accelerated version of dca_lfe_fir

               Before           After
               Mean    StdDev   Mean    StdDev  Change
This function    868.2  33.5      436.0  27.0   +99.1%
Overall        15973.0 223.2    15577.5  83.2    +2.5%

Signed-off-by: Martin Storsjö <martin@martin.st>
arm: Add VFP-accelerated version of fft16

               Before           After
               Mean    StdDev   Mean    StdDev  Change
This function   1389.3  4.2       967.8  35.1   +43.6%
Overall        15577.5 83.2     15400.0 336.4    +1.2%

Signed-off-by: Martin Storsjö <martin@martin.st>
dcadsp: Add a new method, qmf_32_subbands

This does most of the work formerly carried out by
the static function qmf_32_subbands() in dcadec.c.

Signed-off-by: Martin Storsjö <martin@martin.st>
arm: Add VFP-accelerated version of qmf_32_subbands

               Before           After
               Mean    StdDev   Mean    StdDev  Change
This function   1323.0  98.0      746.2  60.6   +77.3%
Overall        15400.0 336.4    14147.5 288.4    +8.9%

Signed-off-by: Martin Storsjö <martin@martin.st>
Merge commit '4719040cd1b54381796b22056a9ae37bd2b4668d'

* commit '4719040cd1b54381796b22056a9ae37bd2b4668d':
  libx264: Define X264_API_IMPORTS on MSVC/ICL

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '7ef760d95c73dfee021b8fdee04f65126eb7edd1'

* commit '7ef760d95c73dfee021b8fdee04f65126eb7edd1':
  configure: generate full msvc debug symbols when linking in debug mode

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '8000206abcc82491c2a8c71e494c5477ede7264c'

* commit '8000206abcc82491c2a8c71e494c5477ede7264c':
  libspeexdec: fix detection of final terminator code

See: f3c9d66bafde9b8586bd63dd3307daa87352af75
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '41ef1d360bac65032aa32f6b43ae137666507ae5'

* commit '41ef1d360bac65032aa32f6b43ae137666507ae5':
  arm: Add VFP-accelerated version of synth_filter_float

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'ce9ed10ac27b9cf32a6257e083ea2f052692d971'

* commit 'ce9ed10ac27b9cf32a6257e083ea2f052692d971':
  arm: Add VFP-accelerated version of int32_to_float_fmul_scalar

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '31c6f6f65c0ed5a894e26ce44ab0c3e89c82b9a2'

* commit '31c6f6f65c0ed5a894e26ce44ab0c3e89c82b9a2':
  fmtconvert: Add a new method, int32_to_float_fmul_array8

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '26ffcc7de1d98f77400a2ebe4e75055515c54587'

* commit '26ffcc7de1d98f77400a2ebe4e75055515c54587':
  dcadec: Use int32_to_float_fmul_array8

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