#!/usr/bin/perl -w

use warnings;

use strict;

my @audiotypes = qw(

U8

S8

U16LSB

S16LSB

U16MSB

S16MSB

S32LSB

S32MSB

F32LSB

F32MSB

);

my %funcs;

my $custom_converters = 0;

sub getTypeConvertHashId {

my ($from, $to) = @_;

return "TYPECONVERTER $from/$to";

}

sub getResamplerHashId {

my ($from, $channels, $upsample, $multiple) = @_;

return "RESAMPLER $from/$channels/$upsample/$multiple";

}

sub outputHeader {

print <<EOF;

/*

SDL - Simple DirectMedia Layer

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

Sam Lantinga

slouken\@libsdl.org

*/

#include "SDL_config.h"

#include "SDL_audio.h"

#include "SDL_audio_c.h"

#ifndef DEBUG_CONVERT

#define DEBUG_CONVERT 0

#endif

/* If you can guarantee your data and need space, you can eliminate code... */

/* Just build the arbitrary resamplers if you're saving code space. */

#ifndef LESS_RESAMPLERS

#define LESS_RESAMPLERS 0

#endif

/* Don't build any resamplers if you're REALLY saving code space. */

#ifndef NO_RESAMPLERS

#define NO_RESAMPLERS 0

#endif

/* Don't build any type converters if you're saving code space. */

#ifndef NO_CONVERTERS

#define NO_CONVERTERS 0

#endif

EOF

foreach (@vals) {

my $val = $_;

my $fval = 1.0 / $val;

print("#define DIVBY${val} ${fval}f\n");

}

print("\n");

}

sub outputFooter {

print <<EOF;

/* $custom_converters converters generated. */

/* *INDENT-ON* */

/* vi: set ts=4 sw=4 expandtab: */

EOF

}

sub splittype {

my $t = shift;

my ($signed, $size, $endian) = $t =~ /([USF])(\d+)([LM]SB|)/;

my $float = ($signed eq 'F') ? 1 : 0;

$signed = (($float) or ($signed eq 'S')) ? 1 : 0;

$endian = 'NONE' if ($endian eq '');

my $ctype = '';

if ($float) {

$ctype = (($size == 32) ? 'float' : 'double');

} else {

$ctype = (($signed) ? 'S' : 'U') . "int${size}";

}

return ($signed, $float, $size, $endian, $ctype);

}

sub getSwapFunc {

my ($size, $signed, $float, $endian, $val) = @_;

my $BEorLE = (($endian eq 'MSB') ? 'BE' : 'LE');

my $code = '';

if ($float) {

$code = "SDL_SwapFloat${BEorLE}($val)";

} else {

if ($size > 8) {

$code = "SDL_Swap${BEorLE}${size}($val)";

} else {

$code = $val;

}

if (($signed) and (!$float)) {

$code = "((Sint${size}) $code)";

}

}

return "${code}";

}

sub maxIntVal {

my $size = shift;

if ($size == 8) {

return 0x7F;

} elsif ($size == 16) {

return 0x7FFF;

} elsif ($size == 32) {

return 0x7FFFFFFF;

}

die("bug in script.\n");

}

sub getFloatToIntMult {

my $size = shift;

my $val = maxIntVal($size) . '.0';

$val .= 'f' if ($size < 32);

return $val;

}

sub getIntToFloatDivBy {

my $size = shift;

return 'DIVBY' . maxIntVal($size);

}

sub getSignFlipVal {

my $size = shift;

if ($size == 8) {

return '0x80';

} elsif ($size == 16) {

return '0x8000';

} elsif ($size == 32) {

return '0x80000000';

}

die("bug in script.\n");

}

sub buildCvtFunc {

my ($from, $to) = @_;

my ($fsigned, $ffloat, $fsize, $fendian, $fctype) = splittype($from);

my ($tsigned, $tfloat, $tsize, $tendian, $tctype) = splittype($to);

my $diffs = 0;

$diffs++ if ($fsize != $tsize);

$diffs++ if ($fsigned != $tsigned);

$diffs++ if ($ffloat != $tfloat);

$diffs++ if ($fendian ne $tendian);

return if ($diffs == 0);

if (1) { # !!! FIXME: if ($diffs > 1) {

my $sym = "SDL_Convert_${from}_to_${to}";

$funcs{$hashid} = $sym;

$custom_converters++;

# Always unsigned for ints, for possible byteswaps.

my $srctype = (($ffloat) ? 'float' : "Uint${fsize}");

print <<EOF;

static void SDLCALL

${sym}(SDL_AudioCVT * cvt, SDL_AudioFormat format)

{

int i;

const $srctype *src;

$tctype *dst;

fprintf(stderr, "Converting AUDIO_${from} to AUDIO_${to}.\\n");

#endif

EOF

if ($fsize < $tsize) {

my $mult = $tsize / $fsize;

print <<EOF;

src = ((const $srctype *) (cvt->buf + cvt->len_cvt)) - 1;

dst = (($tctype *) (cvt->buf + cvt->len_cvt * $mult)) - 1;

for (i = cvt->len_cvt / sizeof ($srctype); i; --i, --src, --dst) {

EOF

} else {

print <<EOF;

src = (const $srctype *) cvt->buf;

dst = ($tctype *) cvt->buf;

for (i = cvt->len_cvt / sizeof ($srctype); i; --i, ++src, ++dst) {

EOF

}

# Have to convert to/from float/int.

# !!! FIXME: cast through double for int32<->float?

my $code = getSwapFunc($fsize, $fsigned, $ffloat, $fendian, '*src');

if ($ffloat != $tfloat) {

if ($ffloat) {

my $mult = getFloatToIntMult($tsize);

if (!$tsigned) { # bump from -1.0f/1.0f to 0.0f/2.0f

$code = "($code + 1.0f)";

}

$code = "(($tctype) ($code * $mult))";

} else {

# $divby will be the reciprocal, to avoid pipeline stalls

# from floating point division...so multiply it.

if (!$fsigned) { # bump from 0.0f/2.0f to -1.0f/1.0f.

$code = "($code - 1.0f)";

}

}

} else {

# All integer conversions here.

if ($fsigned != $tsigned) {

my $signflipval = getSignFlipVal($fsize);

$code = "(($code) ^ $signflipval)";

}

my $shiftval = abs($fsize - $tsize);

if ($fsize < $tsize) {

$code = "((($tctype) $code) << $shiftval)";

} elsif ($fsize > $tsize) {

$code = "(($tctype) ($code >> $shiftval))";

}

}

my $swap = getSwapFunc($tsize, $tsigned, $tfloat, $tendian, 'val');

print <<EOF;

const $tctype val = $code;

*dst = ${swap};

}

EOF

if ($fsize > $tsize) {

my $divby = $fsize / $tsize;

print(" cvt->len_cvt /= $divby;\n");

} elsif ($fsize < $tsize) {

my $mult = $tsize / $fsize;

print(" cvt->len_cvt *= $mult;\n");

}

print <<EOF;

if (cvt->filters[++cvt->filter_index]) {

}

}

EOF

} else {

if ($fsigned != $tsigned) {

$funcs{$hashid} = 'SDL_ConvertSigned';

} elsif ($ffloat != $tfloat) {

$funcs{$hashid} = 'SDL_ConvertFloat';

} elsif ($fsize != $tsize) {

$funcs{$hashid} = 'SDL_ConvertSize';

} elsif ($fendian ne $tendian) {

$funcs{$hashid} = 'SDL_ConvertEndian';

} else {

die("error in script.\n");

}

}

}

foreach (@audiotypes) {

my $from = $_;

foreach (@audiotypes) {

my $to = $_;

buildCvtFunc($from, $to);

}

}

print "const SDL_AudioTypeFilters sdl_audio_type_filters[] =\n{\n";

my $from = $_;

foreach (@audiotypes) {

my $to = $_;

if ($from ne $to) {

my $hashid = getTypeConvertHashId($from, $to);

my $sym = $funcs{$hashid};

print(" { AUDIO_$from, AUDIO_$to, $sym },\n");

}

}

}

print "};\n\n\n";

}

sub getBiggerCtype {

my ($isfloat, $size) = @_;

if ($isfloat) {

if ($size == 32) {

return 'double';

}

die("bug in script.\n");

}

if ($size == 8) {

return 'Sint16';

} elsif ($size == 16) {

return 'Sint32'

} elsif ($size == 32) {

return 'Sint64'

die("bug in script.\n");

}

# These handle arbitrary resamples...44100Hz to 48000Hz, for example.

# Man, this code is skanky.

sub buildArbitraryResampleFunc {

# !!! FIXME: we do a lot of unnecessary and ugly casting in here, due to getSwapFunc().

my ($from, $channels, $upsample) = @_;

my ($fsigned, $ffloat, $fsize, $fendian, $fctype) = splittype($from);

my $bigger = getBiggerCtype($ffloat, $fsize);

my $interp = ($ffloat) ? '* 0.5' : '>> 1';

my $resample = ($upsample) ? 'Upsample' : 'Downsample';

my $hashid = getResamplerHashId($from, $channels, $upsample, 0);

my $sym = "SDL_${resample}_${from}_${channels}c";

$funcs{$hashid} = $sym;

$custom_converters++;

my $fudge = $fsize * $channels * 2; # !!! FIXME

my $eps_adjust = ($upsample) ? 'dstsize' : 'srcsize';

my $incr = '';

my $incr2 = '';

# !!! FIXME: DEBUG_CONVERT should report frequencies.

print <<EOF;

static void SDLCALL

${sym}(SDL_AudioCVT * cvt, SDL_AudioFormat format)

fprintf(stderr, "$resample arbitrary (x%f) AUDIO_${from}, ${channels} channels.\\n", cvt->rate_incr);

#endif

const int srcsize = cvt->len_cvt - $fudge;

const int dstsize = (int) (((double)cvt->len_cvt) * cvt->rate_incr);

register int eps = 0;

EOF

# Upsampling (growing the buffer) needs to work backwards, since we

# overwrite the buffer as we go.

if ($upsample) {

print <<EOF;

$fctype *dst = (($fctype *) (cvt->buf + dstsize)) - $channels;

const $fctype *src = (($fctype *) (cvt->buf + cvt->len_cvt)) - $channels;

const $fctype *target = ((const $fctype *) cvt->buf) - $channels;

EOF

} else {

print <<EOF;

$fctype *dst = ($fctype *) cvt->buf;

const $fctype *src = ($fctype *) cvt->buf;

const $fctype *target = (const $fctype *) (cvt->buf + dstsize);

EOF

}

for (my $i = 0; $i < $channels; $i++) {

my $idx = ($upsample) ? (($channels - $i) - 1) : $i;

my $val = getSwapFunc($fsize, $fsigned, $ffloat, $fendian, "src[$idx]");

print <<EOF;

$fctype sample${idx} = $val;

EOF

}

for (my $i = 0; $i < $channels; $i++) {

my $idx = ($upsample) ? (($channels - $i) - 1) : $i;

print <<EOF;

$fctype last_sample${idx} = sample${idx};

EOF

}

print <<EOF;

while (dst != target) {

EOF

if ($upsample) {

for (my $i = 0; $i < $channels; $i++) {

# !!! FIXME: don't do this swap every write, just when the samples change.

my $idx = (($channels - $i) - 1);

my $val = getSwapFunc($fsize, $fsigned, $ffloat, $fendian, "sample${idx}");

print <<EOF;

dst[$idx] = $val;

EOF

}

$incr = ($channels == 1) ? 'dst--' : "dst -= $channels";

$incr2 = ($channels == 1) ? 'src--' : "src -= $channels";

print <<EOF;

$incr;

eps += srcsize;

if ((eps << 1) >= dstsize) {

$incr2;

EOF

} else { # downsample.

$incr = ($channels == 1) ? 'src++' : "src += $channels";

print <<EOF;

$incr;

eps += dstsize;

if ((eps << 1) >= srcsize) {

EOF

for (my $i = 0; $i < $channels; $i++) {

my $val = getSwapFunc($fsize, $fsigned, $ffloat, $fendian, "sample${i}");

print <<EOF;

dst[$i] = $val;

EOF

$incr = ($channels == 1) ? 'dst++' : "dst += $channels";

print <<EOF;

$incr;

EOF

}

for (my $i = 0; $i < $channels; $i++) {

my $idx = ($upsample) ? (($channels - $i) - 1) : $i;

my $swapped = getSwapFunc($fsize, $fsigned, $ffloat, $fendian, "src[$idx]");

print <<EOF;

sample${idx} = ($fctype) (((($bigger) $swapped) + (($bigger) last_sample${idx})) $interp);

EOF

}

for (my $i = 0; $i < $channels; $i++) {

my $idx = ($upsample) ? (($channels - $i) - 1) : $i;

print <<EOF;

last_sample${idx} = sample${idx};

EOF

}

print <<EOF;

eps -= $eps_adjust;

}

}

EOF

print <<EOF;

cvt->len_cvt = dstsize;

if (cvt->filters[++cvt->filter_index]) {

cvt->filters[cvt->filter_index] (cvt, format);

}

}

# These handle clean resamples...doubling and quadrupling the sample rate, etc.

sub buildMultipleResampleFunc {

# !!! FIXME: we do a lot of unnecessary and ugly casting in here, due to getSwapFunc().

my ($from, $channels, $upsample, $multiple) = @_;

my ($fsigned, $ffloat, $fsize, $fendian, $fctype) = splittype($from);

my $bigger = getBiggerCtype($ffloat, $fsize);

my $interp = ($ffloat) ? '* 0.5' : '>> 1';

my $interp2 = ($ffloat) ? '* 0.25' : '>> 2';

my $mult3 = ($ffloat) ? '3.0' : '3';

my $lencvtop = ($upsample) ? '*' : '/';

my $resample = ($upsample) ? 'Upsample' : 'Downsample';

my $hashid = getResamplerHashId($from, $channels, $upsample, $multiple);

my $sym = "SDL_${resample}_${from}_${channels}c_x${multiple}";

$funcs{$hashid} = $sym;

$custom_converters++;

# !!! FIXME: DEBUG_CONVERT should report frequencies.

print <<EOF;

static void SDLCALL

${sym}(SDL_AudioCVT * cvt, SDL_AudioFormat format)

{

fprintf(stderr, "$resample (x${multiple}) AUDIO_${from}, ${channels} channels.\\n");

#endif

const int srcsize = cvt->len_cvt;

const int dstsize = cvt->len_cvt $lencvtop $multiple;

EOF

my $endcomparison = '!=';

# Upsampling (growing the buffer) needs to work backwards, since we

# overwrite the buffer as we go.

if ($upsample) {

print <<EOF;

$fctype *dst = (($fctype *) (cvt->buf + dstsize)) - $channels;

const $fctype *src = (($fctype *) (cvt->buf + cvt->len_cvt)) - $channels;

const $fctype *target = ((const $fctype *) cvt->buf) - $channels;

EOF

} else {

print <<EOF;

$fctype *dst = ($fctype *) cvt->buf;

const $fctype *src = ($fctype *) cvt->buf;

const $fctype *target = (const $fctype *) (cvt->buf + dstsize);

EOF

}

for (my $i = 0; $i < $channels; $i++) {

my $idx = ($upsample) ? (($channels - $i) - 1) : $i;

my $val = getSwapFunc($fsize, $fsigned, $ffloat, $fendian, "src[$idx]");

print <<EOF;

$bigger last_sample${idx} = ($bigger) $val;

EOF

}

print <<EOF;

EOF

for (my $i = 0; $i < $channels; $i++) {

my $idx = ($upsample) ? (($channels - $i) - 1) : $i;

my $val = getSwapFunc($fsize, $fsigned, $ffloat, $fendian, "src[$idx]");

print <<EOF;

const $bigger sample${idx} = ($bigger) $val;

EOF

}

my $incr = '';

if ($upsample) {

$incr = ($channels == 1) ? 'src--' : "src -= $channels";

} else {

my $amount = $channels * $multiple;

$incr = "src += $amount"; # can't ever be 1, so no "++" version.

}

print <<EOF;

$incr;

EOF

# !!! FIXME: This really begs for some Altivec or SSE, etc.

if ($upsample) {

if ($multiple == 2) {

for (my $i = $channels-1; $i >= 0; $i--) {

my $dsti = $i + $channels;

print <<EOF;

dst[$dsti] = ($fctype) ((sample${i} + last_sample${i}) $interp);

EOF

}

for (my $i = $channels-1; $i >= 0; $i--) {

my $dsti = $i;

print <<EOF;

dst[$dsti] = ($fctype) sample${i};

EOF

}

} elsif ($multiple == 4) {

for (my $i = $channels-1; $i >= 0; $i--) {

my $dsti = $i + ($channels * 3);

print <<EOF;

dst[$dsti] = ($fctype) sample${i};

EOF

}

for (my $i = $channels-1; $i >= 0; $i--) {

my $dsti = $i + ($channels * 2);

print <<EOF;

dst[$dsti] = ($fctype) ((($mult3 * sample${i}) + last_sample${i}) $interp2);

EOF

}

for (my $i = $channels-1; $i >= 0; $i--) {

my $dsti = $i + ($channels * 1);

print <<EOF;

dst[$dsti] = ($fctype) ((sample${i} + last_sample${i}) $interp);

}

for (my $i = $channels-1; $i >= 0; $i--) {

my $dsti = $i + ($channels * 0);

print <<EOF;

dst[$dsti] = ($fctype) ((sample${i} + ($mult3 * last_sample${i})) $interp2);

EOF

}

} else {

die('bug in program.'); # we only handle x2 and x4.

}

} else { # downsample.

if ($multiple == 2) {

for (my $i = 0; $i < $channels; $i++) {

print <<EOF;

dst[$i] = ($fctype) ((sample${i} + last_sample${i}) $interp);

EOF

}

} elsif ($multiple == 4) {

# !!! FIXME: interpolate all 4 samples?

for (my $i = 0; $i < $channels; $i++) {

print <<EOF;

dst[$i] = ($fctype) ((sample${i} + last_sample${i}) $interp);

EOF

}

} else {

die('bug in program.'); # we only handle x2 and x4.

}

}

for (my $i = 0; $i < $channels; $i++) {

my $idx = ($upsample) ? (($channels - $i) - 1) : $i;

print <<EOF;

last_sample${idx} = sample${idx};

EOF

}

if ($upsample) {

my $amount = $channels * $multiple;

$incr = "dst -= $amount"; # can't ever be 1, so no "--" version.

} else {

$incr = ($channels == 1) ? 'dst++' : "dst += $channels";

}

print <<EOF;

$incr;

}

cvt->len_cvt = dstsize;

if (cvt->filters[++cvt->filter_index]) {

cvt->filters[cvt->filter_index] (cvt, format);

}

}

EOF

}

sub buildResamplers {

print "#if !NO_RESAMPLERS\n\n";

foreach (@audiotypes) {

my $from = $_;

foreach (@channels) {

my $channel = $_;

buildArbitraryResampleFunc($from, $channel, 1);

buildArbitraryResampleFunc($from, $channel, 0);

}

}

print "\n#if !LESS_RESAMPLERS\n\n";

foreach (@audiotypes) {

my $from = $_;

foreach (@channels) {

my $channel = $_;

for (my $multiple = 2; $multiple <= 4; $multiple += 2) {

buildMultipleResampleFunc($from, $channel, 1, $multiple);

buildMultipleResampleFunc($from, $channel, 0, $multiple);

}

}

}

print "#endif /* !LESS_RESAMPLERS */\n";

print "#endif /* !NO_RESAMPLERS */\n\n\n";

print "#if !NO_RESAMPLERS\n";

foreach (@audiotypes) {

my $from = $_;

foreach (@channels) {

my $channel = $_;

for (my $upsample = 0; $upsample <= 1; $upsample++) {

my $hashid = getResamplerHashId($from, $channel, $upsample, 0);

my $sym = $funcs{$hashid};

print(" { AUDIO_$from, $channel, $upsample, 0, $sym },\n");

}

}

}

print "#if !LESS_RESAMPLERS\n";

foreach (@audiotypes) {

my $from = $_;

foreach (@channels) {

my $channel = $_;

for (my $upsample = 0; $upsample <= 1; $upsample++) {

my $hashid = getResamplerHashId($from, $channel, $upsample, $multiple);

my $sym = $funcs{$hashid};

print(" { AUDIO_$from, $channel, $upsample, $multiple, $sym },\n");

}

}

}

}

print "#endif /* !LESS_RESAMPLERS */\n";

print "#endif /* !NO_RESAMPLERS */\n";

print "};\n\n";

}

# mainline ...

outputHeader();

buildTypeConverters();

buildResamplers();

outputFooter();

exit 0;